Volatile compounds were collected from apple branches (Malus domestica) at different developmenta... more Volatile compounds were collected from apple branches (Malus domestica) at different developmental stages, and the antennal response of codling moth females (Cydia pomonella) to these compounds was recorded by electroantennography coupled to gas chromatography. Presence of a range of terpenoid compounds, many of which had antennal activity, was characteristic for volatile collections from branches with leaves, and from small green apples. Nine compounds from branches with leaves and green fruit consistently elicited an antennal response: methyl salicylate, (E)--farnesene, -caryophyllene, 4,8-dimethyl-1,3(E),7-nonatriene, (Z)3-hexenol, (Z,E)-R-farnesene, linalool, germacrene D, and (E,E)-R-farnesene. The bouquet emitted from flowering branches contained in addition several benzenoid compounds which were not found after bloom. Small green apples, which are the main target of codling moth oviposition during the first seasonal flight period, released very few esters. In comparison, fully grown apples released a large number of esters, but fewer terpenoids. The study of apple volatiles eliciting an antennal response, together with a survey of the seasonal change in the release of these compounds, is the first step toward the identification of volatiles mediating host-finding and oviposition in codling moth females.
The adjustment of feeding behavior in response to hunger and satiety contributes to homeostatic r... more The adjustment of feeding behavior in response to hunger and satiety contributes to homeostatic regulation in animals. The fruit fly Drosophila melanogaster feeds on yeasts growing on overripe fruit, providing nutrients required for adult survival, reproduction and larval growth. Here, we present data on how the nutritional value of food affects subsequent yeast consumption in Drosophila adult males. After a period of starvation, flies showed intensive yeast consumption. In comparison, flies stopped feeding after having access to a nutritive cornmeal diet. Interestingly, dietary glucose was equally efficient as the complex cornmeal diet. In contrast, flies fed with sucralose, a non-metabolizable sweetener, behaved as if they were starved. The adipokinetic hormone and insulin-like peptides regulate metabolic processes in insects. We did not find any effect of the adipokinetic hormone pathway on this modulation. Instead, the insulin pathway was involved in these changes. Flies lacking...
In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtshi... more In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtship, through the odorant receptor Or67d. Long-lasting exposure to cVA suppresses male courtship, via a second channel, Or65a. In females, the role of Or65a has not been studied. We show that, shortly after mating, Drosophila females are no longer attracted to cVA and that activation of olfactory sensory neurons (OSNs) expressing Or65a generates this behavioral switch: when silencing Or65a, mated females remain responsive to cVA. Neurons expressing Or67d converge into the DA1 glomerulus in the antennal lobe, where they synapse onto projection neurons (PNs), that connect to higher neural circuits generating the attraction response to cVA. Functional imaging of these PNs shows that the DA1 glomerulus is inhibited by simultaneous activation of Or65a OSNs, which leads to a suppression of the attraction response to cVA. The behavioral role of postmating cVA exposure is substantiated by the observation that matings with starved males, which produce less cVA, do not alter the female response. Moreover, exposure to synthetic cVA abolishes attraction and decreases sexual receptivity in unmated females. Taken together, Or65a mediates an aversive effect of cVA and may accordingly regulate remating, through concurrent behavioral modulation in males and females. P olyandry, females mating multiply with different males, leads to a gender conflict over optimum mating rates and remating intervals. Polyandry is widespread in Drosophila and other insects. Females mate more than once, since a single mating does not yield sufficient sperm to match their egg production capacity, whereas high mating rates decrease female fitness and lifetime. This gives rise to a sexual conflict, which mediates pre-and postcopulatory selection on female traits that influence optimum mating rates and remating intervals 1-4 .
In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pherom... more In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases, and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of sensitivity and behavioural responsiveness to cVA in fed females is paralleled by a strong increase in receptivity to male courtship. Functional imaging of the antennal lobe (AL), the olfactory centre in the insect brain, shows that olfactory input to DA1 and VM2 glomeruli is also modulated by starvation. Knocking down insulin receptors in neurons converging onto the DA1 glomerulus suggests that insulin-signalling partly controls pheromone perception in the AL, and adjusts cVA attraction according to nutritional state and sexual receptivity in Drosophila females.
In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtshi... more In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtship, through the odorant receptor Or67d. Long-lasting exposure to cVA suppresses male courtship, via a second channel, Or65a. In females, the role of Or65a has not been studied. We show that, shortly after mating, Drosophila females are no longer attracted to cVA and that activation of olfactory sensory neurons (OSNs) expressing Or65a generates this behavioral switch: when silencing Or65a, mated females remain responsive to cVA. Neurons expressing Or67d converge into the DA1 glomerulus in the antennal lobe, where they synapse onto projection neurons (PNs), that connect to higher neural circuits generating the attraction response to cVA. Functional imaging of these PNs shows that the DA1 glomerulus is inhibited by simultaneous activation of Or65a OSNs, which leads to a suppression of the attraction response to cVA. The behavioral role of postmating cVA exposure is substantiated by the observation that matings with starved males, which produce less cVA, do not alter the female response. Moreover, exposure to synthetic cVA abolishes attraction and decreases sexual receptivity in unmated females. Taken together, Or65a mediates an aversive effect of cVA and may accordingly regulate remating, through concurrent behavioral modulation in males and females. P olyandry, females mating multiply with different males, leads to a gender conflict over optimum mating rates and remating intervals. Polyandry is widespread in Drosophila and other insects. Females mate more than once, since a single mating does not yield sufficient sperm to match their egg production capacity, whereas high mating rates decrease female fitness and lifetime. This gives rise to a sexual conflict, which mediates pre-and postcopulatory selection on female traits that influence optimum mating rates and remating intervals 1-4 .
ABSTRACT Mate recognition is crucial for reproductive isolation and for maintaining species integ... more ABSTRACT Mate recognition is crucial for reproductive isolation and for maintaining species integrity. Chemosensory-mediated sexual communication with pheromones is an essential component of mate recognition in moths. Confronted with sex pheromone stimuli released from conspecific and closely related heterospecific females, which partially overlap in chemical composition, male moths are under strong selection to recognize compatible mates. Here, we investigated the role of pheromone signals in premating communication in the sibling species Spodoptera littoralis and S. litura (Lepidoptera, Noctuidae). Further, we measured the reproductive consequence of conspecific vs. heterospecific matings. Both species use Z9,E11-14:Ac as the major pheromone compound, and the 11-component blend found in pheromone glands of S. littoralis comprises the compounds found in S. litura. Accordingly, S. littoralis and S. litura males readily responded to conspecific and heterospecific calling females in no-choice behavioural tests. In contrast, in a dual-choice test, S. littoralis males choose conspecific calling females, whereas S. litura males did not discriminate between conspecific and heterospecific females. In S. littoralis females, heterospecific matings had a negative fitness effect as compared to conspecific matings. Female longevity, egg-laying and hatching of larvae were significantly reduced by matings with heterospecific males. Reciprocal crossings, between S. litura females and S. littoralis males, were prevented by genital morphology, which is consistent with reduced heterospecific attraction of S. littoralis males in a dual-choice assay. On the other hand, matings between S. littoralis females and S. litura males, under a no-choice situation, show that interspecific matings occur in zones of geographical overlap and corroborate the idea that mate quality, in these closely related species, is a continuous and not a categorical trait.
Dispensers of E8,E 10-120H (codlemone), E8,E 10-12Ac (codlemone acetate), or both dispenser types... more Dispensers of E8,E 10-120H (codlemone), E8,E 10-12Ac (codlemone acetate), or both dispenser types were placed on the corners of 100 m' and 300 m' plots within apple orchards. Communication disruption of male codling moths, Cydia pomonella, was monitored with pheromone traps in the centres of these plots. In the 300 m2 plots, trap catch was reduced only by codlemone. In the 100 m' plots, trap catch was reduced in all three treatments, fewest males were caught in plots treated with both codlemone and codlemone acetate. Males were attracted to codlemone dispensers, they were also flying actively around the tree crowns, well above the dispensers. This behaviour was not observed in treatments with codlemone acetate, where male orientation flights were directed only towards the trap in the plot centre. The antagonistic effect of each of the four geometric isomers of codlemone acetate was shown by another trap test. Addition of 20% E,E-; E,Z-; Z,E-or Z8,ZIO-I2Ac decreased male attraction to traps baited with E8, E10-120H. pomonelfu: evidence for a behavioural role of dodecan-1
Discrimination of conspecific and heterospecific signals is a key element in the evolution of spe... more Discrimination of conspecific and heterospecific signals is a key element in the evolution of specific mate recognition systems. Lepidopteran pheromone signals are typically composed of several compounds that synergize attraction of conspecific and inhibit attraction of heterospecific males. Blends convey specificity, but not their single components, that are typically shared by several species. Many sex pheromones are blends of geometric or positional isomers of straight-chain acetates, while species-specific blends of analogous alcohols have not been described. We have, therefore, studied the attraction of tortricid moths to the geometric isomers (E,E)-, (E,Z)-, (Z,E)-and (Z,Z)-8,10-dodecadien-1-ol. Only one species responding to these alcohols seemed to be attracted to a blend of two isomers, while most species are attracted to only one alcohol isomer. Lack of a pronounced synergist or antagonist effect of the other geometric isomers explains the lack of specific attraction to isomer blends and reduces accordingly the number of specific communication signals composed of these alcohols. In comparison, many more species respond to the analogous (E,E)-, (E,Z)-, (Z,E)-and (Z,Z)-8,10dodecadienyl acetates and their binary blends. The acetate isomers all play a behavioural role, either as attractants, attraction synergists or antagonists, and thus promote specific communication with acetate blends. Male moths seem to discriminate the acetate isomers with greater precision than the analogous alcohols. It is proposed that discrimination is facilitated by steric differences between the four acetate isomers, as compared to the more uniform steric properties of the alcohols.
The behavioural response of Brazilian apple leafroller males, Bonagota cranaodes (Meyrick), to na... more The behavioural response of Brazilian apple leafroller males, Bonagota cranaodes (Meyrick), to natural and synthetic sex pheromone was studied in a wind tunnel. Calling females elicited upwind flights followed by landing and wingfanning at the source in 72% of the males tested. Female gland extracts, with the main compound (E, Z)3,5dodecadienyl acetate released at 100 pg/min, attracted 57% of the males to the source. Few males (1%) were attracted to the main compound alone, released at the same rate. Even a synthetic blend of all five gland compounds eliciting an antennal response, formulated according to their proportion in female gland extracts, was barely attractive (7%). Comparison of this synthetic blend and female gland extracts indicates a behavioural role of other gland compounds. Male attraction was significantly increased (34%) in response to a 100 : 5 : 5 : 5-blend of the main compound and three minor gland compounds, (Z)-5-dodecenyl acetate, (E, Z)-3,5-tetradecadienyl acetate, and (Z)-9-hexadecenyl acetate.
In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtshi... more In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtship, through the odorant receptor Or67d. Long-lasting exposure to cVA suppresses male courtship, via a second channel, Or65a. In females, the role of Or65a has not been studied. We show that, shortly after mating, Drosophila females are no longer attracted to cVA and that activation of olfactory sensory neurons (OSNs) expressing Or65a generates this behavioral switch: when silencing Or65a, mated females remain responsive to cVA. Neurons expressing Or67d converge into the DA1 glomerulus in the antennal lobe, where they synapse onto projection neurons (PNs), that connect to higher neural circuits generating the attraction response to cVA. Functional imaging of these PNs shows that the DA1 glomerulus is inhibited by simultaneous activation of Or65a OSNs, which leads to a suppression of the attraction response to cVA. The behavioral role of postmating cVA exposure is substantiated by the observation that matings with starved males, which produce less cVA, do not alter the female response. Moreover, exposure to synthetic cVA abolishes attraction and decreases sexual receptivity in unmated females. Taken together, Or65a mediates an aversive effect of cVA and may accordingly regulate remating, through concurrent behavioral modulation in males and females. P olyandry, females mating multiply with different males, leads to a gender conflict over optimum mating rates and remating intervals. Polyandry is widespread in Drosophila and other insects. Females mate more than once, since a single mating does not yield sufficient sperm to match their egg production capacity, whereas high mating rates decrease female fitness and lifetime. This gives rise to a sexual conflict, which mediates pre-and postcopulatory selection on female traits that influence optimum mating rates and remating intervals 1-4 .
The behavioral mechanisms of mating disruption in Guatemalan potato moth Tecia solanivora were st... more The behavioral mechanisms of mating disruption in Guatemalan potato moth Tecia solanivora were studied using the sex pheromone components, (E)-3-dodecenyl acetate, (Z)-3-dodecenyl acetate, and dodecyl acetate, formulated in a 100:1:20-ratio mimicking the female-produced blend, and in a 100:56:100 off-blend ratio. The mode of action of these two blends was tested in mating disruption experiments in the field and in a greenhouse, as well as in a laboratory wind tunnel. Field treatments with both blends at 80 g pheromone per ha reduced male attraction to trap lures baited with 100 μg of female sex pheromone. In meshhouse treatments, these two blends were equally effective at reducing male attraction to traps baited with live females and mating of caged females. Subsequent flight tunnel tests corroborated that both blends reduced attraction of naive males to calling females, and pre-exposure of males with either dispenser blend for 24 hr resulted in a strongly reduced response to calling females. The pre-exposure effect was reversible, with males again responsive after 24 hr in clean air. The two dispenser formulations produced a similar effect on male behavior, despite the differences in blend composition. One mating disruption dispenser formulated with either the female-blend or off-blend elicited the same rate of male upwind attraction in a wind-tunnel bioassay. Sensory overload and camouflage, therefore, are contributing mechanisms to mating disruption using either blend. The off-blend, which is more economical to synthesize, is a valuable tool for further development of mating disruption against this major pest of potatoes in Latin America.
Analysis of sex pheromone glands of the apple leafroller Bonagota cranaodes Meyrick by gas chroma... more Analysis of sex pheromone glands of the apple leafroller Bonagota cranaodes Meyrick by gas chromatography coupled with mass spectrometry or electroantennographic detection showed the presence of 14 structurally related acetates and alcohols of the chain length 10 Ð18, including the main pheromone component (E,Z)-3,5-dodecadienyl acetate (E3,Z5Ð12Ac). Male antennae responded to the main compound, its Z,Z isomer, (E,Z)-3,5-tetradecadienyl acetate (E3,Z5Ð14Ac), and the monoenes (Z)-5-dodecenyl acetate (Z5Ð12Ac) and (Z)-9-hexadecenyl acetate (Z9 Ð16Ac). Traps baited with a four-component blend of E3,Z5Ð12Ac, Z5Ð12Ac, E3,Z5Ð14Ac, and Z9 Ð16Ac in a 100:5:5:100 ratio were signiÞcantly more attractive than the main compound alone. This improved trap lure is more suitable for monitoring population densities of B. cranaodes, and for detection of the onset of the seasonal ßight period. A more complete pheromone blend is of importance also with respect to current attempts to develop mating disruption for control of this major pest of apple in Brazil.
Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most impo... more Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most important insect of apple, will contribute to the development of safe control techniques. Synthetic apple volatiles in two doses were tested for antennal and behavioural activity in codling moth. Female antennae strongly responded to (Z)3-hexenol, (Z)3-hexenyl benzoate, (Z)3-hexenyl hexanoate, (±)-linalool and E,E-a-farnesene. Two other compounds eliciting a strong antennal response were the pear ester, ethyl (E,Z)-2,4-decadienoate, and its corresponding aldehyde, E,E-2, 4-decadienal, which is a component of the larval defence secretion of the European apple sawfly. Attraction of codling moth to compounds eliciting a strong antennal response was tested in a wind tunnel. Male moths were best attracted to a blend of (E,E)-a-farnesene, (E)-beta-farnesene and ethyl (E,Z)-2,4-decadienoate. The aldehyde E,E-2,4-decadienal had an antagonistic effect when added to the above mixture.
Volatile compounds were collected from apple branches (Malus domestica) at different developmenta... more Volatile compounds were collected from apple branches (Malus domestica) at different developmental stages, and the antennal response of codling moth females (Cydia pomonella) to these compounds was recorded by electroantennography coupled to gas chromatography. Presence of a range of terpenoid compounds, many of which had antennal activity, was characteristic for volatile collections from branches with leaves, and from small green apples. Nine compounds from branches with leaves and green fruit consistently elicited an antennal response: methyl salicylate, (E)--farnesene, -caryophyllene, 4,8-dimethyl-1,3(E),7-nonatriene, (Z)3-hexenol, (Z,E)-R-farnesene, linalool, germacrene D, and (E,E)-R-farnesene. The bouquet emitted from flowering branches contained in addition several benzenoid compounds which were not found after bloom. Small green apples, which are the main target of codling moth oviposition during the first seasonal flight period, released very few esters. In comparison, fully grown apples released a large number of esters, but fewer terpenoids. The study of apple volatiles eliciting an antennal response, together with a survey of the seasonal change in the release of these compounds, is the first step toward the identification of volatiles mediating host-finding and oviposition in codling moth females.
The Guatemalan moth Tecia solanivora is an invasive pest of potato in Central and South America. ... more The Guatemalan moth Tecia solanivora is an invasive pest of potato in Central and South America. The larvae infest potato tubers in the field as well as in storage facilities. The headspace of potato foliage and potato tubers was studied with regard to volatiles that mediate host-finding and oviposition in the Guatemalan moth. Foliage of three phenological stages, from sprouting to tuberization and flowering, released more than 30 sesquiterpenes. The main compounds were β-caryophyllene, germacrene-D-4-ol, germacrene-D, kunzeaol, and (E,E )-R-farnesene. Sesquiterpenes accounted for >90% of the headspace of green plants, whereas fresh potato tubers emitted only trace amounts of a few sesquiterpenes. Screening of headspace collections with antennae of Guatemalan moth females showed a strong response to several sesquiterpenes and monoterpenes that were emitted from foliage only. In addition, antennae responded to methyl phenylacetate, a floral fragrance that was released in large amounts from flowering plants and that was also present in tuber headspace. Female and male moths were attracted to methyl phenylacetate; this compound may accordingly contribute to female attraction to tuber-bearing potato plants in the field as well as to potato tubers in storage. Oviposition tests showed that females lay eggs near mature flowering plants. Eggs were laid in soil close to the plant and not on potato stems and foliage, which may be due to avoidance of terpenoid compounds released from green plant parts at close range. The results support the concept that potato volatiles mediate host-finding and oviposition behavior and that these compounds may become useful tools for management of the Guatemalan moth.
and (Z,Z)-8,10-dodecadien-l-yl acetate were identified as sex pheromone components or sex attract... more and (Z,Z)-8,10-dodecadien-l-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males of Cydia and Grapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds. Pammene, as weil as other Grapholita and Cydia responded to the monoenic 8-or 10-dodecen-l-yl acetates. Of the tribes Olethreutini and Eucosmini, Hedya, Epiblema, Eucosma, and Notocelia trimaculana were also attracted to 8,10-dodecadien-l-yl acetates, but several other Notocelia to 10,12-tetradecadien-l-yl acetates. The female sex pheromones of C. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella and Notocelia roborana were identified. (E,E)-and (E,Z)-8,10-dodecadien-l-yl acetate are produced via a common E9 desaturation pathway in C. splendana. Calling C. nigricana and C. fagiglandana females are attracted to wingfanning males.
Lepidopteran insects use sex pheromones to communicate for mating. Olfactory communication and ma... more Lepidopteran insects use sex pheromones to communicate for mating. Olfactory communication and mate-finding can be prevented by permeating the atmosphere with synthetic pheromone. Pheromonemediated mating disruption has become a commercially viable pest management technique and is used to control the codling moth, Cydia pomonella, a key insect pest of apple, on 160,000 ha worldwide. The codling moth sex pheromone, codlemone, is species specific and nontoxic. Orchard treatments with up to 100 grams of synthetic codlemone per hectare effectively control codling moth populations over the entire growing season. Practical implementation of the mating disruption technique has been realized at an opportune time, as codling moth has become resistant to many insecticides. We review codling moth chemical ecology and factors underlying the behavioral mechanisms and practical implementation of mating disruption. Area-wide programs are the result of collaborative efforts between academic research institutions, extension, chemical industries, and grower organizations, and they demonstrate the environmental and economic relevance of pheromone research. 503 Annu. Rev. Entomol. 2008.53:503-522. Downloaded from arjournals.annualreviews.org by 206.59.51.58 on 12/12/07. For personal use only. Pheromone: chemical signal produced and released by an organism, eliciting a behavioral response when perceived by a member of the same species Pheromone dispenser: device for controlled release of synthetic pheromone
. Pheromone-mediated communication disruption in Guatemalan potato moth, Tecia solanivora. Licent... more . Pheromone-mediated communication disruption in Guatemalan potato moth, Tecia solanivora. Licentiate dissertation. The Guatemalan potato moth, Tecia (Scrobipalpopsis) solanivora, is a serious potato pest in Central America and adjacent South American countries. Recently, it has been introduced to the Canary Islands, Spain. Insecticide treatments are not sufficiently effective against eggs and larvae of Guatemalan potato moth, which are protected from sprays in soil crevices and in galleries inside potato tubers, respectively. Deregulation of insecticides and restrictions in the use of the few available insecticides, parallel to a public demand for reduction of pesticide use in potato production, have increased the interest in biological control techniques. Behaviour-modifying chemicals, including sex pheromones, which target the adult life stage, are a particularly promising alternative to insecticides for control of Guatemalan potato moth. The aim of this research was to study T. solanivora sex pheromone and to investigate the feasibility of pheromone-mediated mating disruption as environmentally safe control technique. Chemical analysis of female pheromone gland extracts confirmed two previously identified compounds (E)-3-dodecenyl acetate (E3-12Ac) and (Z)-3-dodecenyl acetate (Z3-12Ac), plus an additional, saturated compound, dodecyl acetate (12Ac). These three compounds elicited significant male antennal responses by GC-EAD. Field trapping studies showed that a 100:1:20-blend of these compounds formulated at 1000 µg on rubber septa, captured more males than the main compound alone. This trap lure can accordingly be used in field traps for detection and population monitoring. During two years, potato fields were treated with a 100:56:100-blend of the three pheromone compounds formulated in polyethylene tube dispensers. Male attraction to E3-12Ac and Z3-12Ac is optimal at a 100:1 blend ratio, and only few males were attracted to traps baited with a 100:50-blend. Mating disruption pheromone dispensers, containing these two compounds in a 100:56 ratio, did not attract males in the wind tunnel or in the field. The application rate of the 100:56:100-blend of the three pheromone compounds was 28 g/ha in the first, and 86 g/ha in the second year. In both years, T. solanivora male attraction to synthetic pheromone traps were almost completely suppressed, indicating that sexual communication was disrupted. During the second year, additional tests confirmed that the pheromone treatment prevented matefinding and mating. Attraction to traps baited with live calling females was reduced by 89% in the pheromone treatment, during two months. In addition, matings in small field cages were significantly reduced. Visual observations showed that few males were observed in the pheromone-treated, as compared to the control field. At harvest, potato infestation was significantly lower in the treated field, as compared to control. Future studies will aim at the optimization of dispenser formulation, and area-wide implementation of the mating disruption technique for control of Guatemalan potato moth.
Volatile compounds were collected from apple branches (Malus domestica) at different developmenta... more Volatile compounds were collected from apple branches (Malus domestica) at different developmental stages, and the antennal response of codling moth females (Cydia pomonella) to these compounds was recorded by electroantennography coupled to gas chromatography. Presence of a range of terpenoid compounds, many of which had antennal activity, was characteristic for volatile collections from branches with leaves, and from small green apples. Nine compounds from branches with leaves and green fruit consistently elicited an antennal response: methyl salicylate, (E)--farnesene, -caryophyllene, 4,8-dimethyl-1,3(E),7-nonatriene, (Z)3-hexenol, (Z,E)-R-farnesene, linalool, germacrene D, and (E,E)-R-farnesene. The bouquet emitted from flowering branches contained in addition several benzenoid compounds which were not found after bloom. Small green apples, which are the main target of codling moth oviposition during the first seasonal flight period, released very few esters. In comparison, fully grown apples released a large number of esters, but fewer terpenoids. The study of apple volatiles eliciting an antennal response, together with a survey of the seasonal change in the release of these compounds, is the first step toward the identification of volatiles mediating host-finding and oviposition in codling moth females.
The adjustment of feeding behavior in response to hunger and satiety contributes to homeostatic r... more The adjustment of feeding behavior in response to hunger and satiety contributes to homeostatic regulation in animals. The fruit fly Drosophila melanogaster feeds on yeasts growing on overripe fruit, providing nutrients required for adult survival, reproduction and larval growth. Here, we present data on how the nutritional value of food affects subsequent yeast consumption in Drosophila adult males. After a period of starvation, flies showed intensive yeast consumption. In comparison, flies stopped feeding after having access to a nutritive cornmeal diet. Interestingly, dietary glucose was equally efficient as the complex cornmeal diet. In contrast, flies fed with sucralose, a non-metabolizable sweetener, behaved as if they were starved. The adipokinetic hormone and insulin-like peptides regulate metabolic processes in insects. We did not find any effect of the adipokinetic hormone pathway on this modulation. Instead, the insulin pathway was involved in these changes. Flies lacking...
In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtshi... more In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtship, through the odorant receptor Or67d. Long-lasting exposure to cVA suppresses male courtship, via a second channel, Or65a. In females, the role of Or65a has not been studied. We show that, shortly after mating, Drosophila females are no longer attracted to cVA and that activation of olfactory sensory neurons (OSNs) expressing Or65a generates this behavioral switch: when silencing Or65a, mated females remain responsive to cVA. Neurons expressing Or67d converge into the DA1 glomerulus in the antennal lobe, where they synapse onto projection neurons (PNs), that connect to higher neural circuits generating the attraction response to cVA. Functional imaging of these PNs shows that the DA1 glomerulus is inhibited by simultaneous activation of Or65a OSNs, which leads to a suppression of the attraction response to cVA. The behavioral role of postmating cVA exposure is substantiated by the observation that matings with starved males, which produce less cVA, do not alter the female response. Moreover, exposure to synthetic cVA abolishes attraction and decreases sexual receptivity in unmated females. Taken together, Or65a mediates an aversive effect of cVA and may accordingly regulate remating, through concurrent behavioral modulation in males and females. P olyandry, females mating multiply with different males, leads to a gender conflict over optimum mating rates and remating intervals. Polyandry is widespread in Drosophila and other insects. Females mate more than once, since a single mating does not yield sufficient sperm to match their egg production capacity, whereas high mating rates decrease female fitness and lifetime. This gives rise to a sexual conflict, which mediates pre-and postcopulatory selection on female traits that influence optimum mating rates and remating intervals 1-4 .
In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pherom... more In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases, and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of sensitivity and behavioural responsiveness to cVA in fed females is paralleled by a strong increase in receptivity to male courtship. Functional imaging of the antennal lobe (AL), the olfactory centre in the insect brain, shows that olfactory input to DA1 and VM2 glomeruli is also modulated by starvation. Knocking down insulin receptors in neurons converging onto the DA1 glomerulus suggests that insulin-signalling partly controls pheromone perception in the AL, and adjusts cVA attraction according to nutritional state and sexual receptivity in Drosophila females.
In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtshi... more In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtship, through the odorant receptor Or67d. Long-lasting exposure to cVA suppresses male courtship, via a second channel, Or65a. In females, the role of Or65a has not been studied. We show that, shortly after mating, Drosophila females are no longer attracted to cVA and that activation of olfactory sensory neurons (OSNs) expressing Or65a generates this behavioral switch: when silencing Or65a, mated females remain responsive to cVA. Neurons expressing Or67d converge into the DA1 glomerulus in the antennal lobe, where they synapse onto projection neurons (PNs), that connect to higher neural circuits generating the attraction response to cVA. Functional imaging of these PNs shows that the DA1 glomerulus is inhibited by simultaneous activation of Or65a OSNs, which leads to a suppression of the attraction response to cVA. The behavioral role of postmating cVA exposure is substantiated by the observation that matings with starved males, which produce less cVA, do not alter the female response. Moreover, exposure to synthetic cVA abolishes attraction and decreases sexual receptivity in unmated females. Taken together, Or65a mediates an aversive effect of cVA and may accordingly regulate remating, through concurrent behavioral modulation in males and females. P olyandry, females mating multiply with different males, leads to a gender conflict over optimum mating rates and remating intervals. Polyandry is widespread in Drosophila and other insects. Females mate more than once, since a single mating does not yield sufficient sperm to match their egg production capacity, whereas high mating rates decrease female fitness and lifetime. This gives rise to a sexual conflict, which mediates pre-and postcopulatory selection on female traits that influence optimum mating rates and remating intervals 1-4 .
ABSTRACT Mate recognition is crucial for reproductive isolation and for maintaining species integ... more ABSTRACT Mate recognition is crucial for reproductive isolation and for maintaining species integrity. Chemosensory-mediated sexual communication with pheromones is an essential component of mate recognition in moths. Confronted with sex pheromone stimuli released from conspecific and closely related heterospecific females, which partially overlap in chemical composition, male moths are under strong selection to recognize compatible mates. Here, we investigated the role of pheromone signals in premating communication in the sibling species Spodoptera littoralis and S. litura (Lepidoptera, Noctuidae). Further, we measured the reproductive consequence of conspecific vs. heterospecific matings. Both species use Z9,E11-14:Ac as the major pheromone compound, and the 11-component blend found in pheromone glands of S. littoralis comprises the compounds found in S. litura. Accordingly, S. littoralis and S. litura males readily responded to conspecific and heterospecific calling females in no-choice behavioural tests. In contrast, in a dual-choice test, S. littoralis males choose conspecific calling females, whereas S. litura males did not discriminate between conspecific and heterospecific females. In S. littoralis females, heterospecific matings had a negative fitness effect as compared to conspecific matings. Female longevity, egg-laying and hatching of larvae were significantly reduced by matings with heterospecific males. Reciprocal crossings, between S. litura females and S. littoralis males, were prevented by genital morphology, which is consistent with reduced heterospecific attraction of S. littoralis males in a dual-choice assay. On the other hand, matings between S. littoralis females and S. litura males, under a no-choice situation, show that interspecific matings occur in zones of geographical overlap and corroborate the idea that mate quality, in these closely related species, is a continuous and not a categorical trait.
Dispensers of E8,E 10-120H (codlemone), E8,E 10-12Ac (codlemone acetate), or both dispenser types... more Dispensers of E8,E 10-120H (codlemone), E8,E 10-12Ac (codlemone acetate), or both dispenser types were placed on the corners of 100 m' and 300 m' plots within apple orchards. Communication disruption of male codling moths, Cydia pomonella, was monitored with pheromone traps in the centres of these plots. In the 300 m2 plots, trap catch was reduced only by codlemone. In the 100 m' plots, trap catch was reduced in all three treatments, fewest males were caught in plots treated with both codlemone and codlemone acetate. Males were attracted to codlemone dispensers, they were also flying actively around the tree crowns, well above the dispensers. This behaviour was not observed in treatments with codlemone acetate, where male orientation flights were directed only towards the trap in the plot centre. The antagonistic effect of each of the four geometric isomers of codlemone acetate was shown by another trap test. Addition of 20% E,E-; E,Z-; Z,E-or Z8,ZIO-I2Ac decreased male attraction to traps baited with E8, E10-120H. pomonelfu: evidence for a behavioural role of dodecan-1
Discrimination of conspecific and heterospecific signals is a key element in the evolution of spe... more Discrimination of conspecific and heterospecific signals is a key element in the evolution of specific mate recognition systems. Lepidopteran pheromone signals are typically composed of several compounds that synergize attraction of conspecific and inhibit attraction of heterospecific males. Blends convey specificity, but not their single components, that are typically shared by several species. Many sex pheromones are blends of geometric or positional isomers of straight-chain acetates, while species-specific blends of analogous alcohols have not been described. We have, therefore, studied the attraction of tortricid moths to the geometric isomers (E,E)-, (E,Z)-, (Z,E)-and (Z,Z)-8,10-dodecadien-1-ol. Only one species responding to these alcohols seemed to be attracted to a blend of two isomers, while most species are attracted to only one alcohol isomer. Lack of a pronounced synergist or antagonist effect of the other geometric isomers explains the lack of specific attraction to isomer blends and reduces accordingly the number of specific communication signals composed of these alcohols. In comparison, many more species respond to the analogous (E,E)-, (E,Z)-, (Z,E)-and (Z,Z)-8,10dodecadienyl acetates and their binary blends. The acetate isomers all play a behavioural role, either as attractants, attraction synergists or antagonists, and thus promote specific communication with acetate blends. Male moths seem to discriminate the acetate isomers with greater precision than the analogous alcohols. It is proposed that discrimination is facilitated by steric differences between the four acetate isomers, as compared to the more uniform steric properties of the alcohols.
The behavioural response of Brazilian apple leafroller males, Bonagota cranaodes (Meyrick), to na... more The behavioural response of Brazilian apple leafroller males, Bonagota cranaodes (Meyrick), to natural and synthetic sex pheromone was studied in a wind tunnel. Calling females elicited upwind flights followed by landing and wingfanning at the source in 72% of the males tested. Female gland extracts, with the main compound (E, Z)3,5dodecadienyl acetate released at 100 pg/min, attracted 57% of the males to the source. Few males (1%) were attracted to the main compound alone, released at the same rate. Even a synthetic blend of all five gland compounds eliciting an antennal response, formulated according to their proportion in female gland extracts, was barely attractive (7%). Comparison of this synthetic blend and female gland extracts indicates a behavioural role of other gland compounds. Male attraction was significantly increased (34%) in response to a 100 : 5 : 5 : 5-blend of the main compound and three minor gland compounds, (Z)-5-dodecenyl acetate, (E, Z)-3,5-tetradecadienyl acetate, and (Z)-9-hexadecenyl acetate.
In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtshi... more In Drosophila, the male sex pheromone cis-vaccenyl acetate (cVA) elicits aggregation and courtship, through the odorant receptor Or67d. Long-lasting exposure to cVA suppresses male courtship, via a second channel, Or65a. In females, the role of Or65a has not been studied. We show that, shortly after mating, Drosophila females are no longer attracted to cVA and that activation of olfactory sensory neurons (OSNs) expressing Or65a generates this behavioral switch: when silencing Or65a, mated females remain responsive to cVA. Neurons expressing Or67d converge into the DA1 glomerulus in the antennal lobe, where they synapse onto projection neurons (PNs), that connect to higher neural circuits generating the attraction response to cVA. Functional imaging of these PNs shows that the DA1 glomerulus is inhibited by simultaneous activation of Or65a OSNs, which leads to a suppression of the attraction response to cVA. The behavioral role of postmating cVA exposure is substantiated by the observation that matings with starved males, which produce less cVA, do not alter the female response. Moreover, exposure to synthetic cVA abolishes attraction and decreases sexual receptivity in unmated females. Taken together, Or65a mediates an aversive effect of cVA and may accordingly regulate remating, through concurrent behavioral modulation in males and females. P olyandry, females mating multiply with different males, leads to a gender conflict over optimum mating rates and remating intervals. Polyandry is widespread in Drosophila and other insects. Females mate more than once, since a single mating does not yield sufficient sperm to match their egg production capacity, whereas high mating rates decrease female fitness and lifetime. This gives rise to a sexual conflict, which mediates pre-and postcopulatory selection on female traits that influence optimum mating rates and remating intervals 1-4 .
The behavioral mechanisms of mating disruption in Guatemalan potato moth Tecia solanivora were st... more The behavioral mechanisms of mating disruption in Guatemalan potato moth Tecia solanivora were studied using the sex pheromone components, (E)-3-dodecenyl acetate, (Z)-3-dodecenyl acetate, and dodecyl acetate, formulated in a 100:1:20-ratio mimicking the female-produced blend, and in a 100:56:100 off-blend ratio. The mode of action of these two blends was tested in mating disruption experiments in the field and in a greenhouse, as well as in a laboratory wind tunnel. Field treatments with both blends at 80 g pheromone per ha reduced male attraction to trap lures baited with 100 μg of female sex pheromone. In meshhouse treatments, these two blends were equally effective at reducing male attraction to traps baited with live females and mating of caged females. Subsequent flight tunnel tests corroborated that both blends reduced attraction of naive males to calling females, and pre-exposure of males with either dispenser blend for 24 hr resulted in a strongly reduced response to calling females. The pre-exposure effect was reversible, with males again responsive after 24 hr in clean air. The two dispenser formulations produced a similar effect on male behavior, despite the differences in blend composition. One mating disruption dispenser formulated with either the female-blend or off-blend elicited the same rate of male upwind attraction in a wind-tunnel bioassay. Sensory overload and camouflage, therefore, are contributing mechanisms to mating disruption using either blend. The off-blend, which is more economical to synthesize, is a valuable tool for further development of mating disruption against this major pest of potatoes in Latin America.
Analysis of sex pheromone glands of the apple leafroller Bonagota cranaodes Meyrick by gas chroma... more Analysis of sex pheromone glands of the apple leafroller Bonagota cranaodes Meyrick by gas chromatography coupled with mass spectrometry or electroantennographic detection showed the presence of 14 structurally related acetates and alcohols of the chain length 10 Ð18, including the main pheromone component (E,Z)-3,5-dodecadienyl acetate (E3,Z5Ð12Ac). Male antennae responded to the main compound, its Z,Z isomer, (E,Z)-3,5-tetradecadienyl acetate (E3,Z5Ð14Ac), and the monoenes (Z)-5-dodecenyl acetate (Z5Ð12Ac) and (Z)-9-hexadecenyl acetate (Z9 Ð16Ac). Traps baited with a four-component blend of E3,Z5Ð12Ac, Z5Ð12Ac, E3,Z5Ð14Ac, and Z9 Ð16Ac in a 100:5:5:100 ratio were signiÞcantly more attractive than the main compound alone. This improved trap lure is more suitable for monitoring population densities of B. cranaodes, and for detection of the onset of the seasonal ßight period. A more complete pheromone blend is of importance also with respect to current attempts to develop mating disruption for control of this major pest of apple in Brazil.
Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most impo... more Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most important insect of apple, will contribute to the development of safe control techniques. Synthetic apple volatiles in two doses were tested for antennal and behavioural activity in codling moth. Female antennae strongly responded to (Z)3-hexenol, (Z)3-hexenyl benzoate, (Z)3-hexenyl hexanoate, (±)-linalool and E,E-a-farnesene. Two other compounds eliciting a strong antennal response were the pear ester, ethyl (E,Z)-2,4-decadienoate, and its corresponding aldehyde, E,E-2, 4-decadienal, which is a component of the larval defence secretion of the European apple sawfly. Attraction of codling moth to compounds eliciting a strong antennal response was tested in a wind tunnel. Male moths were best attracted to a blend of (E,E)-a-farnesene, (E)-beta-farnesene and ethyl (E,Z)-2,4-decadienoate. The aldehyde E,E-2,4-decadienal had an antagonistic effect when added to the above mixture.
Volatile compounds were collected from apple branches (Malus domestica) at different developmenta... more Volatile compounds were collected from apple branches (Malus domestica) at different developmental stages, and the antennal response of codling moth females (Cydia pomonella) to these compounds was recorded by electroantennography coupled to gas chromatography. Presence of a range of terpenoid compounds, many of which had antennal activity, was characteristic for volatile collections from branches with leaves, and from small green apples. Nine compounds from branches with leaves and green fruit consistently elicited an antennal response: methyl salicylate, (E)--farnesene, -caryophyllene, 4,8-dimethyl-1,3(E),7-nonatriene, (Z)3-hexenol, (Z,E)-R-farnesene, linalool, germacrene D, and (E,E)-R-farnesene. The bouquet emitted from flowering branches contained in addition several benzenoid compounds which were not found after bloom. Small green apples, which are the main target of codling moth oviposition during the first seasonal flight period, released very few esters. In comparison, fully grown apples released a large number of esters, but fewer terpenoids. The study of apple volatiles eliciting an antennal response, together with a survey of the seasonal change in the release of these compounds, is the first step toward the identification of volatiles mediating host-finding and oviposition in codling moth females.
The Guatemalan moth Tecia solanivora is an invasive pest of potato in Central and South America. ... more The Guatemalan moth Tecia solanivora is an invasive pest of potato in Central and South America. The larvae infest potato tubers in the field as well as in storage facilities. The headspace of potato foliage and potato tubers was studied with regard to volatiles that mediate host-finding and oviposition in the Guatemalan moth. Foliage of three phenological stages, from sprouting to tuberization and flowering, released more than 30 sesquiterpenes. The main compounds were β-caryophyllene, germacrene-D-4-ol, germacrene-D, kunzeaol, and (E,E )-R-farnesene. Sesquiterpenes accounted for >90% of the headspace of green plants, whereas fresh potato tubers emitted only trace amounts of a few sesquiterpenes. Screening of headspace collections with antennae of Guatemalan moth females showed a strong response to several sesquiterpenes and monoterpenes that were emitted from foliage only. In addition, antennae responded to methyl phenylacetate, a floral fragrance that was released in large amounts from flowering plants and that was also present in tuber headspace. Female and male moths were attracted to methyl phenylacetate; this compound may accordingly contribute to female attraction to tuber-bearing potato plants in the field as well as to potato tubers in storage. Oviposition tests showed that females lay eggs near mature flowering plants. Eggs were laid in soil close to the plant and not on potato stems and foliage, which may be due to avoidance of terpenoid compounds released from green plant parts at close range. The results support the concept that potato volatiles mediate host-finding and oviposition behavior and that these compounds may become useful tools for management of the Guatemalan moth.
and (Z,Z)-8,10-dodecadien-l-yl acetate were identified as sex pheromone components or sex attract... more and (Z,Z)-8,10-dodecadien-l-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males of Cydia and Grapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds. Pammene, as weil as other Grapholita and Cydia responded to the monoenic 8-or 10-dodecen-l-yl acetates. Of the tribes Olethreutini and Eucosmini, Hedya, Epiblema, Eucosma, and Notocelia trimaculana were also attracted to 8,10-dodecadien-l-yl acetates, but several other Notocelia to 10,12-tetradecadien-l-yl acetates. The female sex pheromones of C. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella and Notocelia roborana were identified. (E,E)-and (E,Z)-8,10-dodecadien-l-yl acetate are produced via a common E9 desaturation pathway in C. splendana. Calling C. nigricana and C. fagiglandana females are attracted to wingfanning males.
Lepidopteran insects use sex pheromones to communicate for mating. Olfactory communication and ma... more Lepidopteran insects use sex pheromones to communicate for mating. Olfactory communication and mate-finding can be prevented by permeating the atmosphere with synthetic pheromone. Pheromonemediated mating disruption has become a commercially viable pest management technique and is used to control the codling moth, Cydia pomonella, a key insect pest of apple, on 160,000 ha worldwide. The codling moth sex pheromone, codlemone, is species specific and nontoxic. Orchard treatments with up to 100 grams of synthetic codlemone per hectare effectively control codling moth populations over the entire growing season. Practical implementation of the mating disruption technique has been realized at an opportune time, as codling moth has become resistant to many insecticides. We review codling moth chemical ecology and factors underlying the behavioral mechanisms and practical implementation of mating disruption. Area-wide programs are the result of collaborative efforts between academic research institutions, extension, chemical industries, and grower organizations, and they demonstrate the environmental and economic relevance of pheromone research. 503 Annu. Rev. Entomol. 2008.53:503-522. Downloaded from arjournals.annualreviews.org by 206.59.51.58 on 12/12/07. For personal use only. Pheromone: chemical signal produced and released by an organism, eliciting a behavioral response when perceived by a member of the same species Pheromone dispenser: device for controlled release of synthetic pheromone
. Pheromone-mediated communication disruption in Guatemalan potato moth, Tecia solanivora. Licent... more . Pheromone-mediated communication disruption in Guatemalan potato moth, Tecia solanivora. Licentiate dissertation. The Guatemalan potato moth, Tecia (Scrobipalpopsis) solanivora, is a serious potato pest in Central America and adjacent South American countries. Recently, it has been introduced to the Canary Islands, Spain. Insecticide treatments are not sufficiently effective against eggs and larvae of Guatemalan potato moth, which are protected from sprays in soil crevices and in galleries inside potato tubers, respectively. Deregulation of insecticides and restrictions in the use of the few available insecticides, parallel to a public demand for reduction of pesticide use in potato production, have increased the interest in biological control techniques. Behaviour-modifying chemicals, including sex pheromones, which target the adult life stage, are a particularly promising alternative to insecticides for control of Guatemalan potato moth. The aim of this research was to study T. solanivora sex pheromone and to investigate the feasibility of pheromone-mediated mating disruption as environmentally safe control technique. Chemical analysis of female pheromone gland extracts confirmed two previously identified compounds (E)-3-dodecenyl acetate (E3-12Ac) and (Z)-3-dodecenyl acetate (Z3-12Ac), plus an additional, saturated compound, dodecyl acetate (12Ac). These three compounds elicited significant male antennal responses by GC-EAD. Field trapping studies showed that a 100:1:20-blend of these compounds formulated at 1000 µg on rubber septa, captured more males than the main compound alone. This trap lure can accordingly be used in field traps for detection and population monitoring. During two years, potato fields were treated with a 100:56:100-blend of the three pheromone compounds formulated in polyethylene tube dispensers. Male attraction to E3-12Ac and Z3-12Ac is optimal at a 100:1 blend ratio, and only few males were attracted to traps baited with a 100:50-blend. Mating disruption pheromone dispensers, containing these two compounds in a 100:56 ratio, did not attract males in the wind tunnel or in the field. The application rate of the 100:56:100-blend of the three pheromone compounds was 28 g/ha in the first, and 86 g/ha in the second year. In both years, T. solanivora male attraction to synthetic pheromone traps were almost completely suppressed, indicating that sexual communication was disrupted. During the second year, additional tests confirmed that the pheromone treatment prevented matefinding and mating. Attraction to traps baited with live calling females was reduced by 89% in the pheromone treatment, during two months. In addition, matings in small field cages were significantly reduced. Visual observations showed that few males were observed in the pheromone-treated, as compared to the control field. At harvest, potato infestation was significantly lower in the treated field, as compared to control. Future studies will aim at the optimization of dispenser formulation, and area-wide implementation of the mating disruption technique for control of Guatemalan potato moth.
Associations between yeasts and insect herbivores are widespread, and these inter-kingdom interac... more Associations between yeasts and insect herbivores are widespread, and these inter-kingdom interactions play a crucial role in yeast and insect ecology and evolution. We report a survey of insect attraction to live yeast from a community ecology perspective. In the summer of 2013 we screened live yeast cultures of Metschnikowia pulcherrima, M. andauensis, M. hawaiiensis, M. lopburiensis, and Cryptococcus tephrensis in an organic apple orchard. More than 3000 arthropods from 3 classes, 15 orders, and 93 species were trapped; ca. 79% of the trapped specimens were dipterans, of which 43% were hoverflies (Syrphidae), followed by Sarcophagidae, Phoridae, Lauxaniidae, Cecidomyidae, Drosophilidae, and Chironomidae. Traps baited with M. pulcherrima, M. andauensis, and C. tephrensis captured typically 2.4 times more specimens than control traps; traps baited with M. pulcherrima, M. hawaiiensis, M. andauensis, M. lopburiensis, and C. tephrensis were more species-rich than unbaited control traps. We conclude that traps baited with live yeasts of the genera Metschnikowia and Cryprococcus are effective attractants and therefore of potential value for pest control. Yeast-based monitoring or attract-and-kill techniques could target pest insects or enhance the assemblage of beneficial insects. Manipulation of insect behavior through live yeast cultures should be further explored for the development of novel plant protection techniques.
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