The ultrastructure and histopathological changes in the ovarioles were tested in normal
adult fem... more The ultrastructure and histopathological changes in the ovarioles were tested in normal adult females and in those developed from solar energy treated pupae (53 C for 15 min) of Callosobruchus maculatus. The telotrophic ovarioles of C. maculatus contain germarium region followed by vitellarium region which constitutes the vitellarium. The germarium houses trophocytes and the vitellarium consists of ovarian follicles. At the germarium region of the ovariole, the trophocyte or nurse cell nucleus contains uniformly spaced clumps of heterochromatin. The cytoplasm contains numerous free ribosomes and mitochondria. At the vitellarium region, follicular epithelial cells form a layer around the oocyte, each cell contains a large oval nucleus with abundant heterochromatin, and the cytoplasm contains mitochondria, free ribosomes and dark spherical globules. Also the vitellarium includes the previtellogenic oocyte which is the most anterior one and two last vitellogenic oocytes at the posterior end as the yolk was deposited. Oocyte microvilli are interdigitated with those of the follicle cells. The ooplasm consists primarily of electron-dense yolk bodies and lipid droplets. These phases could be identified in the ovarioles of normal females and to a less extent in those of females developed from the treated pupae. In the ovarian follicles of the treated generation, degenerationof the cell components of trophocytes, follicular epitheliumand oocytes were themost obvious signs of damage. Also, lacking of yolk bodies and vacuolation in the border of the ooplasm were observed. The damage was more pronounced in the ovarioles of (F.) progeny of the treated generation.
Four varieties of the cowpea seeds (Local, Dokki331, Kareem7 and Aswany) were screened for their ... more Four varieties of the cowpea seeds (Local, Dokki331, Kareem7 and Aswany) were screened for their resistance to the bruchid, Callosobruchus maculatus F., a serious pest of stored pulses. Morphological characters like seed coat texture, volume and weight, were not found to be responsible for offering resistance to C. maculatus. Data revealed that the female weevil preferred the smooth surface for egg oviposition. The results also showed that Aswany was found to reduce the growth and development of C. maculatus, which were indicated by different parameters; larval penetration %, adult emergence %, total developmental time, susceptibility index and growth index. Seeds were analysed for protein profiles (SDS-polyacrylamide gel electrophoresis) to study the chemical basis of resistant to bruchid infestation. A negative correlation was indicated between the seed total protein content and the susceptibility index. SDS-PAGE analysis of seeds protein for the fore mentioned varieties revealed the presence of antinutrient chemicals that might impart resistance to C. maculatus. The role of these antinutritionals in relation to C. maculatus infestation is discussed.
Several studies have shown that the mainly granivorous carabid beetles, e.g. Amara spp., include ... more Several studies have shown that the mainly granivorous carabid beetles, e.g. Amara spp., include animal food in their diet to a considerable extent. We therefore hypothesized that the performance of these beetles would be enhanced by dietary mixing including both seeds and animal food. In order to test this, we conducted laboratory feeding experiments with adults and larvae of Amara similata. Both adults and larvae were subjected to different diet treatments including: seeds, houseflies, grasshoppers, earthworms, slugs and snails in pure and mixed diets. Larval survival, development time, pupal and teneral weights were used as indicators of food quality for the larvae. For the adult beetles, mass change was used as an indicator of food quality. We found seeds to be high-quality food, while all pure animal diets were of low quality for both adults and larvae. Animal foods added to the seed diet had both positive and negative effects. A mixed diet of all foods enhanced the mass gain of adults compared with the seed diet, but reduced larval performance dramatically. Earthworms and grasshoppers added to seeds increased the pupal and teneral weights, while reduced larval survival. Thus, A. similata is omnivorous with a mainly granivorous feeding habit. It may gain benefits on some fitness parameters and incur costs on others from preying or scavenging on animal food. Therefore, the overall fitness consequences of a mixed seed-animal diet are uncertain.
Assuming generalist feeding habits to be the original condition in carabid beetles, we tested
two... more Assuming generalist feeding habits to be the original condition in carabid beetles, we tested two alternative hypotheses about the evolution of food specialisation: that species specialised on prey that 1) were already of high quality to the generalists, or 2) were of low quality to the generalists due to chemical or other defences. We did this by evaluating in laboratory experiments the food quality to three generalist carnivore species of various prey types, selected among those on which carabids are known to have specialised (i.e. insects, earthworms, molluscs, seeds). The carabids used were adults of Pterostichus melanarius Illiger, Pterostichus versicolor Sturm and Carabus nemoralis Mueller. Insects were highquality food, earthworms were intermediate, and slugs and seeds were low quality food for all species. For C. nemoralis, earthworms were the most preferred prey. The results support the second hypothesis, that food specialisation evolved by breaking the defences of low quality but presumably abundant prey.
The ultrastructure and histopathological changes in the ovarioles were tested in normal
adult fem... more The ultrastructure and histopathological changes in the ovarioles were tested in normal adult females and in those developed from solar energy treated pupae (53 C for 15 min) of Callosobruchus maculatus. The telotrophic ovarioles of C. maculatus contain germarium region followed by vitellarium region which constitutes the vitellarium. The germarium houses trophocytes and the vitellarium consists of ovarian follicles. At the germarium region of the ovariole, the trophocyte or nurse cell nucleus contains uniformly spaced clumps of heterochromatin. The cytoplasm contains numerous free ribosomes and mitochondria. At the vitellarium region, follicular epithelial cells form a layer around the oocyte, each cell contains a large oval nucleus with abundant heterochromatin, and the cytoplasm contains mitochondria, free ribosomes and dark spherical globules. Also the vitellarium includes the previtellogenic oocyte which is the most anterior one and two last vitellogenic oocytes at the posterior end as the yolk was deposited. Oocyte microvilli are interdigitated with those of the follicle cells. The ooplasm consists primarily of electron-dense yolk bodies and lipid droplets. These phases could be identified in the ovarioles of normal females and to a less extent in those of females developed from the treated pupae. In the ovarian follicles of the treated generation, degenerationof the cell components of trophocytes, follicular epitheliumand oocytes were themost obvious signs of damage. Also, lacking of yolk bodies and vacuolation in the border of the ooplasm were observed. The damage was more pronounced in the ovarioles of (F.) progeny of the treated generation.
Four varieties of the cowpea seeds (Local, Dokki331, Kareem7 and Aswany) were screened for their ... more Four varieties of the cowpea seeds (Local, Dokki331, Kareem7 and Aswany) were screened for their resistance to the bruchid, Callosobruchus maculatus F., a serious pest of stored pulses. Morphological characters like seed coat texture, volume and weight, were not found to be responsible for offering resistance to C. maculatus. Data revealed that the female weevil preferred the smooth surface for egg oviposition. The results also showed that Aswany was found to reduce the growth and development of C. maculatus, which were indicated by different parameters; larval penetration %, adult emergence %, total developmental time, susceptibility index and growth index. Seeds were analysed for protein profiles (SDS-polyacrylamide gel electrophoresis) to study the chemical basis of resistant to bruchid infestation. A negative correlation was indicated between the seed total protein content and the susceptibility index. SDS-PAGE analysis of seeds protein for the fore mentioned varieties revealed the presence of antinutrient chemicals that might impart resistance to C. maculatus. The role of these antinutritionals in relation to C. maculatus infestation is discussed.
Several studies have shown that the mainly granivorous carabid beetles, e.g. Amara spp., include ... more Several studies have shown that the mainly granivorous carabid beetles, e.g. Amara spp., include animal food in their diet to a considerable extent. We therefore hypothesized that the performance of these beetles would be enhanced by dietary mixing including both seeds and animal food. In order to test this, we conducted laboratory feeding experiments with adults and larvae of Amara similata. Both adults and larvae were subjected to different diet treatments including: seeds, houseflies, grasshoppers, earthworms, slugs and snails in pure and mixed diets. Larval survival, development time, pupal and teneral weights were used as indicators of food quality for the larvae. For the adult beetles, mass change was used as an indicator of food quality. We found seeds to be high-quality food, while all pure animal diets were of low quality for both adults and larvae. Animal foods added to the seed diet had both positive and negative effects. A mixed diet of all foods enhanced the mass gain of adults compared with the seed diet, but reduced larval performance dramatically. Earthworms and grasshoppers added to seeds increased the pupal and teneral weights, while reduced larval survival. Thus, A. similata is omnivorous with a mainly granivorous feeding habit. It may gain benefits on some fitness parameters and incur costs on others from preying or scavenging on animal food. Therefore, the overall fitness consequences of a mixed seed-animal diet are uncertain.
Assuming generalist feeding habits to be the original condition in carabid beetles, we tested
two... more Assuming generalist feeding habits to be the original condition in carabid beetles, we tested two alternative hypotheses about the evolution of food specialisation: that species specialised on prey that 1) were already of high quality to the generalists, or 2) were of low quality to the generalists due to chemical or other defences. We did this by evaluating in laboratory experiments the food quality to three generalist carnivore species of various prey types, selected among those on which carabids are known to have specialised (i.e. insects, earthworms, molluscs, seeds). The carabids used were adults of Pterostichus melanarius Illiger, Pterostichus versicolor Sturm and Carabus nemoralis Mueller. Insects were highquality food, earthworms were intermediate, and slugs and seeds were low quality food for all species. For C. nemoralis, earthworms were the most preferred prey. The results support the second hypothesis, that food specialisation evolved by breaking the defences of low quality but presumably abundant prey.
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Papers by Shams El-Shamy
adult females and in those developed from solar energy treated pupae (53 C for 15 min) of Callosobruchus
maculatus. The telotrophic ovarioles of C. maculatus contain germarium region followed
by vitellarium region which constitutes the vitellarium.
The germarium houses trophocytes and the vitellarium consists of ovarian follicles.
At the germarium region of the ovariole, the trophocyte or nurse cell nucleus contains uniformly
spaced clumps of heterochromatin. The cytoplasm contains numerous free ribosomes and mitochondria.
At the vitellarium region, follicular epithelial cells form a layer around the oocyte, each cell contains
a large oval nucleus with abundant heterochromatin, and the cytoplasm contains mitochondria, free
ribosomes and dark spherical globules. Also the vitellarium includes the previtellogenic oocyte which
is the most anterior one and two last vitellogenic oocytes at the posterior end as the yolk was deposited.
Oocyte microvilli are interdigitated with those of the follicle cells. The ooplasm consists primarily of
electron-dense yolk bodies and lipid droplets.
These phases could be identified in the ovarioles of normal females and to a less extent in those of
females developed from the treated pupae. In the ovarian follicles of the treated generation, degenerationof
the cell components of trophocytes, follicular epitheliumand oocytes were themost obvious signs
of damage. Also, lacking of yolk bodies and vacuolation in the border of the ooplasm were observed.
The damage was more pronounced in the ovarioles of (F.) progeny of the treated generation.
enhanced by dietary mixing including both seeds and animal food. In order to test this, we conducted laboratory
feeding experiments with adults and larvae of Amara similata. Both adults and larvae were subjected to different diet
treatments including: seeds, houseflies, grasshoppers, earthworms, slugs and snails in pure and mixed diets. Larval
survival, development time, pupal and teneral weights were used as indicators of food quality for the larvae. For the
adult beetles, mass change was used as an indicator of food quality. We found seeds to be high-quality food, while all
pure animal diets were of low quality for both adults and larvae. Animal foods added to the seed diet had both positive
and negative effects. A mixed diet of all foods enhanced the mass gain of adults compared with the seed diet, but
reduced larval performance dramatically. Earthworms and grasshoppers added to seeds increased the pupal and teneral
weights, while reduced larval survival. Thus, A. similata is omnivorous with a mainly granivorous feeding habit. It may
gain benefits on some fitness parameters and incur costs on others from preying or scavenging on animal food.
Therefore, the overall fitness consequences of a mixed seed-animal diet are uncertain.
two alternative hypotheses about the evolution of food specialisation: that species specialised
on prey that 1) were already of high quality to the generalists, or 2) were of low quality to the
generalists due to chemical or other defences. We did this by evaluating in laboratory
experiments the food quality to three generalist carnivore species of various prey types,
selected among those on which carabids are known to have specialised (i.e. insects,
earthworms, molluscs, seeds). The carabids used were adults of Pterostichus melanarius
Illiger, Pterostichus versicolor Sturm and Carabus nemoralis Mueller. Insects were highquality
food, earthworms were intermediate, and slugs and seeds were low quality food for all
species. For C. nemoralis, earthworms were the most preferred prey. The results support the
second hypothesis, that food specialisation evolved by breaking the defences of low quality
but presumably abundant prey.
adult females and in those developed from solar energy treated pupae (53 C for 15 min) of Callosobruchus
maculatus. The telotrophic ovarioles of C. maculatus contain germarium region followed
by vitellarium region which constitutes the vitellarium.
The germarium houses trophocytes and the vitellarium consists of ovarian follicles.
At the germarium region of the ovariole, the trophocyte or nurse cell nucleus contains uniformly
spaced clumps of heterochromatin. The cytoplasm contains numerous free ribosomes and mitochondria.
At the vitellarium region, follicular epithelial cells form a layer around the oocyte, each cell contains
a large oval nucleus with abundant heterochromatin, and the cytoplasm contains mitochondria, free
ribosomes and dark spherical globules. Also the vitellarium includes the previtellogenic oocyte which
is the most anterior one and two last vitellogenic oocytes at the posterior end as the yolk was deposited.
Oocyte microvilli are interdigitated with those of the follicle cells. The ooplasm consists primarily of
electron-dense yolk bodies and lipid droplets.
These phases could be identified in the ovarioles of normal females and to a less extent in those of
females developed from the treated pupae. In the ovarian follicles of the treated generation, degenerationof
the cell components of trophocytes, follicular epitheliumand oocytes were themost obvious signs
of damage. Also, lacking of yolk bodies and vacuolation in the border of the ooplasm were observed.
The damage was more pronounced in the ovarioles of (F.) progeny of the treated generation.
enhanced by dietary mixing including both seeds and animal food. In order to test this, we conducted laboratory
feeding experiments with adults and larvae of Amara similata. Both adults and larvae were subjected to different diet
treatments including: seeds, houseflies, grasshoppers, earthworms, slugs and snails in pure and mixed diets. Larval
survival, development time, pupal and teneral weights were used as indicators of food quality for the larvae. For the
adult beetles, mass change was used as an indicator of food quality. We found seeds to be high-quality food, while all
pure animal diets were of low quality for both adults and larvae. Animal foods added to the seed diet had both positive
and negative effects. A mixed diet of all foods enhanced the mass gain of adults compared with the seed diet, but
reduced larval performance dramatically. Earthworms and grasshoppers added to seeds increased the pupal and teneral
weights, while reduced larval survival. Thus, A. similata is omnivorous with a mainly granivorous feeding habit. It may
gain benefits on some fitness parameters and incur costs on others from preying or scavenging on animal food.
Therefore, the overall fitness consequences of a mixed seed-animal diet are uncertain.
two alternative hypotheses about the evolution of food specialisation: that species specialised
on prey that 1) were already of high quality to the generalists, or 2) were of low quality to the
generalists due to chemical or other defences. We did this by evaluating in laboratory
experiments the food quality to three generalist carnivore species of various prey types,
selected among those on which carabids are known to have specialised (i.e. insects,
earthworms, molluscs, seeds). The carabids used were adults of Pterostichus melanarius
Illiger, Pterostichus versicolor Sturm and Carabus nemoralis Mueller. Insects were highquality
food, earthworms were intermediate, and slugs and seeds were low quality food for all
species. For C. nemoralis, earthworms were the most preferred prey. The results support the
second hypothesis, that food specialisation evolved by breaking the defences of low quality
but presumably abundant prey.