Background： In coevolutionary interactions between brood parasites and their hosts, host parents are under strong selection to evolve defenses against parasitism. Egg rejection is an efficient and common defense agai...Background： In coevolutionary interactions between brood parasites and their hosts, host parents are under strong selection to evolve defenses against parasitism. Egg rejection is an efficient and common defense against parasitism, although some apparently suitable hosts do not reject cuckoo eggs.Methods： Sparrows Ploceidae are widespread throughout the Old World, and they have a suitable diet for rearing cuckoos, but still they are rarely exploited by brood parasites. To solve such puzzle, we conducted artificial parasitism and cross-fostering experiments in Russet Sparrow （Posset cinnomomeus）.Results： The present study showed that Russet Sparrows have no egg recognition ability, but recognize their own nestlings and eject alien chicks or starve them to death. They may use visual cues in chick recognition, although they accept sister species Tree Sparrow （Posset montonus）.Conclusions： By rejecting nestlings of foreign species, Russet Sparrows have succeeded to escape from the brood parasitism by cuckoos and other parasites. Our studies shed light on the puzzle why some species are not utilized by cuckoo parasites as hosts,展开更多
In order to survey on sparrows parasites （Passer domesticus）, 100 samples were collected from the citrus gardens of Amol＇s City. The surface of their body checked for presence of ectoparasites. The blood samples to...In order to survey on sparrows parasites （Passer domesticus）, 100 samples were collected from the citrus gardens of Amol＇s City. The surface of their body checked for presence of ectoparasites. The blood samples took from their wings for blood parasites. At the laboratory, the body of sparrows opened and the gastrointestinal checked for endoparasites. The intestine opened and scratched carefully to find worms. Worms kept in alcohol-glycerin （10%）. Eggs ＆ oocysts of the parasites checked, by fecal floatation test. The result shows that the infection with Railletina is 1%, Ascaridia galli （2%）, Heterakis gallinarum （4%）, eggs of A. galli （5%）, oocyst of Eimeri （28%）, Dermanyssus gallinae （1%）. 11% of the sparrows infected with Plasmodium in their bloods.展开更多
A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid （LA; 18：2n-6） and linolenic acid ratios （LNA; 18：3n-3） on growth induces, feed utilization and tissue fatty acid pr...A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid （LA; 18：2n-6） and linolenic acid ratios （LNA; 18：3n-3） on growth induces, feed utilization and tissue fatty acid profile of freshwater prawn, Macrobrachium rosenbergii post-larvae （PL）. The experiment was conducted in cubic indoor fiberglass tanks, each holding 700 L in triplicate. Post-larvae with an average weight of 20.8 ± 0.20 mg were stocked at 80 PL m2. Five experimental isocaloric （15.06 MJ kgl digestible energy）, and isonitrogenous （30.45% digestible protein） diets were formulated by blending of soybean oil and linseed oil to containing five dietary LA/LNA ratios （7.80, 2.75, 1.28, 0.65 and 0.30）. The highest survival values were recorded for prawn PL fed diet containing 0.65 LA/LAN ratios. Growth indices of PL significantly increased （P 〈 0.05） with decreased dietary LA/LAN ratios to 0.65. The same trend was observed for the highest （P ≤ 0.05） protein efficiency ratio, protein productive value, fat retention, energy retention and best feed conversion ratio. The total whole tissue polyunsaturated fatty acid composition of M. rosenbergii PL was dominated by LA followed by LAN. Post larvae fed the diets containing higher LA/LNA ratios showed a higher tissue LA/LNA ratio. The obtained findings revealed that fatty acid patterns ofM. rosenbergii PL were influenced by fatty acid profiles of diets. The diet containing 0.65 LA/LNA ratio is recommended to obtaining optimum growth performance and feed utilization for M. rosenbergii PL.展开更多
The goal of this study was to discover Scatella tenuicosta Collin （Diptera： Ephydridae） for the first time as a pest on blue-green algae Spirulina platensis. This algae has been recognized as a very important comme...The goal of this study was to discover Scatella tenuicosta Collin （Diptera： Ephydridae） for the first time as a pest on blue-green algae Spirulina platensis. This algae has been recognized as a very important commercial product in the world today and as one of the most promising ones among the other microscopic algae due to its richness in polyunsaturated fatty acids, as well as in gamma-linolenic acid （GLA）, and in pigments including phycocyanin, myxoxanthophyll and zeaxanthin. Both immature and adult development stages ofS. tenuicosta have been studied under the temperature of 15±2℃. The development times for eggs, larval stages, including first, second, and third one, and for pupae as well as for adults were found to be 1.4, 1.0, 1.1, 1.1, 3.0 and 8.7 respectively. Some pest control practices ofS. tenuicosta on S. platensis have been also examined in this study.展开更多
The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas, Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots.. This is done for the purpose of find...The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas, Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots.. This is done for the purpose of finding a replacement for conventional insecticides which has been found to be harmful to man. The seed oil was applied topically at the rate of 0.1, 0.2, 0.3 and 0.4 mL per insect. There were a total of 20 insects per Petri-dish. There were four replicates per treatment. Insect mortality was recorded on 12 hourly basis for 48 hours. The results of insects treated with all dosage rates of C. nucifera showed a significantly higher mortality when compared with the control. In the case ofH. annus, insect mortality ranged from 40-100, 70-100, 60-100 and 80-100% and for J. curcas the result ranged from 0.0-100, 40-100, 80-100 and 80-100% for rates of 0.1, 0.2, 0.3 and 0.4 mL, respectively, from 12 hrs to 48 hrs post application. The control experiment remained at 0% level throughout the period of the experiments.展开更多
Three fibrinolytic proteases, which were designated as BPGFP1, BPGFP2 and BPGFP3 individually, were purified from the gut extract of larvae of Boettcherisca peregrina fed on artificial diet containing fibrin rich...Three fibrinolytic proteases, which were designated as BPGFP1, BPGFP2 and BPGFP3 individually, were purified from the gut extract of larvae of Boettcherisca peregrina fed on artificial diet containing fibrin rich pig blood coagulated block. BPGFP1 consists of two subunits with MW 32 000 and 30 000. Both BPGFP2 and BPGFP3 are monomer with MW 40 000 and 28 000, respectively. These three proteases are similar in substrate and inhibitor specificity. All of them possess high activities against fibrinolytic protease specific substrates such as fibrin, Chromzym P, Chromzym UK and S 2288. They also strongly hydrolyze trypsin specific substrates Bz Phe Val Arg NA, cBz Gly Pro Arg NA, Bz Pro Phe Arg NA and Bz Val Gly Arg NA. PMSF, STI, LBTI and SBBI can inhibit activity of these proteases. Activities of these three fibrinolytic proteases were found to be maximal at alkaline range of pH 9.0～10.0.展开更多
Developmental changes in hemolymph ecdysteroid level, ecdysteroid synthesis by prothoracic glands （PGs） in vitro, prothoracicotropic hormone （PTTH） activity in brain extracts, and PTTH activity in the hemolymph we...Developmental changes in hemolymph ecdysteroid level, ecdysteroid synthesis by prothoracic glands （PGs） in vitro, prothoracicotropic hormone （PTTH） activity in brain extracts, and PTTH activity in the hemolymph were measured during the fifth larval instar of the Eri silkworm, Samia cynthia ricini. The changing patterns of hemolymph ecdysteroid level and ecdysteroid synthesis by laGs in vitro are similar to each other, with maximums on day 9. However, on this day, hemolymph ecdysteroid level was substantially higher than ecdysteroid synthesis by PGs in vitro suggesting a high PTTH activity in the hemolymph on day 9. Moreover, the changing pattern of PTTH activity in brain extracts is also similar to that of PTTH activity in the hemolymph, both peaking on day 9. However, on this day, activity in brain extracts was much smaller than PTTH activity in the hemolymph implying that most PTTH synthesized by the brain is secreted to the hemolymph and the brain stores a very little amount of PTTH. This study provides unique insights onto the hormonal regulation of ecdysteroid synthesis in the Eri silkworm and is useful for our future studies on signal transduction of insect neurolaelatides.展开更多
Growing evidence exists that aposematic and toxic prey may be included in a predator＇s diet when the predator experiences physiological stress. The tree sparrow Passer montanus is known to have a significant portion ...Growing evidence exists that aposematic and toxic prey may be included in a predator＇s diet when the predator experiences physiological stress. The tree sparrow Passer montanus is known to have a significant portion of aposematic and toxic ladybirds in its natural diet. Here, we present experi- ments testing the attack and eating rate of the tree sparrow toward the invasive aposematic harle- quin ladybird Harmonia axyridis. We wondered whether the sparrow＇s ability to prey on native ladybirds predisposes them to also prey on harlequin ladybirds. We compared the attack and eat- ing rates of tree sparrows of particular age and/or experience classes to test for any changes during ontogeny （hand-reared x young wild-caught xadult wild-caught） and with differing perceived lev- els of physiological stress （summer adult ~ winter adult）. Winter adult tree sparrows commonly at- tacked and ate the offered ladybirds with no evidence of disgust or metabolic difficulties after in- gestion. Naive and wild immature tree sparrows attacked the ladybirds but hesitated to eat them. Adult tree sparrows caught in the summer avoided attacking the ladybirds. These results suggest that tree sparrows are able to cope with chemicals ingested along with the ladybirds. This pre- adaptation enables them to include ladybirds in their diet; though they commonly do this only in times of shortage in insect availability （winter）. Young sparrows showed avoidance toward the chemical protection of the ladybirds.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31672303 to CY,31472013 and 31772453 to WL)
文摘Background： In coevolutionary interactions between brood parasites and their hosts, host parents are under strong selection to evolve defenses against parasitism. Egg rejection is an efficient and common defense against parasitism, although some apparently suitable hosts do not reject cuckoo eggs.Methods： Sparrows Ploceidae are widespread throughout the Old World, and they have a suitable diet for rearing cuckoos, but still they are rarely exploited by brood parasites. To solve such puzzle, we conducted artificial parasitism and cross-fostering experiments in Russet Sparrow （Posset cinnomomeus）.Results： The present study showed that Russet Sparrows have no egg recognition ability, but recognize their own nestlings and eject alien chicks or starve them to death. They may use visual cues in chick recognition, although they accept sister species Tree Sparrow （Posset montonus）.Conclusions： By rejecting nestlings of foreign species, Russet Sparrows have succeeded to escape from the brood parasitism by cuckoos and other parasites. Our studies shed light on the puzzle why some species are not utilized by cuckoo parasites as hosts,
文摘In order to survey on sparrows parasites （Passer domesticus）, 100 samples were collected from the citrus gardens of Amol＇s City. The surface of their body checked for presence of ectoparasites. The blood samples took from their wings for blood parasites. At the laboratory, the body of sparrows opened and the gastrointestinal checked for endoparasites. The intestine opened and scratched carefully to find worms. Worms kept in alcohol-glycerin （10%）. Eggs ＆ oocysts of the parasites checked, by fecal floatation test. The result shows that the infection with Railletina is 1%, Ascaridia galli （2%）, Heterakis gallinarum （4%）, eggs of A. galli （5%）, oocyst of Eimeri （28%）, Dermanyssus gallinae （1%）. 11% of the sparrows infected with Plasmodium in their bloods.
文摘A 90-day experiment was conducted to investigate the effects of different dietary linoleic acid （LA; 18：2n-6） and linolenic acid ratios （LNA; 18：3n-3） on growth induces, feed utilization and tissue fatty acid profile of freshwater prawn, Macrobrachium rosenbergii post-larvae （PL）. The experiment was conducted in cubic indoor fiberglass tanks, each holding 700 L in triplicate. Post-larvae with an average weight of 20.8 ± 0.20 mg were stocked at 80 PL m2. Five experimental isocaloric （15.06 MJ kgl digestible energy）, and isonitrogenous （30.45% digestible protein） diets were formulated by blending of soybean oil and linseed oil to containing five dietary LA/LNA ratios （7.80, 2.75, 1.28, 0.65 and 0.30）. The highest survival values were recorded for prawn PL fed diet containing 0.65 LA/LAN ratios. Growth indices of PL significantly increased （P 〈 0.05） with decreased dietary LA/LAN ratios to 0.65. The same trend was observed for the highest （P ≤ 0.05） protein efficiency ratio, protein productive value, fat retention, energy retention and best feed conversion ratio. The total whole tissue polyunsaturated fatty acid composition of M. rosenbergii PL was dominated by LA followed by LAN. Post larvae fed the diets containing higher LA/LNA ratios showed a higher tissue LA/LNA ratio. The obtained findings revealed that fatty acid patterns ofM. rosenbergii PL were influenced by fatty acid profiles of diets. The diet containing 0.65 LA/LNA ratio is recommended to obtaining optimum growth performance and feed utilization for M. rosenbergii PL.
文摘The goal of this study was to discover Scatella tenuicosta Collin （Diptera： Ephydridae） for the first time as a pest on blue-green algae Spirulina platensis. This algae has been recognized as a very important commercial product in the world today and as one of the most promising ones among the other microscopic algae due to its richness in polyunsaturated fatty acids, as well as in gamma-linolenic acid （GLA）, and in pigments including phycocyanin, myxoxanthophyll and zeaxanthin. Both immature and adult development stages ofS. tenuicosta have been studied under the temperature of 15±2℃. The development times for eggs, larval stages, including first, second, and third one, and for pupae as well as for adults were found to be 1.4, 1.0, 1.1, 1.1, 3.0 and 8.7 respectively. Some pest control practices ofS. tenuicosta on S. platensis have been also examined in this study.
文摘The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas, Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots.. This is done for the purpose of finding a replacement for conventional insecticides which has been found to be harmful to man. The seed oil was applied topically at the rate of 0.1, 0.2, 0.3 and 0.4 mL per insect. There were a total of 20 insects per Petri-dish. There were four replicates per treatment. Insect mortality was recorded on 12 hourly basis for 48 hours. The results of insects treated with all dosage rates of C. nucifera showed a significantly higher mortality when compared with the control. In the case ofH. annus, insect mortality ranged from 40-100, 70-100, 60-100 and 80-100% and for J. curcas the result ranged from 0.0-100, 40-100, 80-100 and 80-100% for rates of 0.1, 0.2, 0.3 and 0.4 mL, respectively, from 12 hrs to 48 hrs post application. The control experiment remained at 0% level throughout the period of the experiments.
文摘Three fibrinolytic proteases, which were designated as BPGFP1, BPGFP2 and BPGFP3 individually, were purified from the gut extract of larvae of Boettcherisca peregrina fed on artificial diet containing fibrin rich pig blood coagulated block. BPGFP1 consists of two subunits with MW 32 000 and 30 000. Both BPGFP2 and BPGFP3 are monomer with MW 40 000 and 28 000, respectively. These three proteases are similar in substrate and inhibitor specificity. All of them possess high activities against fibrinolytic protease specific substrates such as fibrin, Chromzym P, Chromzym UK and S 2288. They also strongly hydrolyze trypsin specific substrates Bz Phe Val Arg NA, cBz Gly Pro Arg NA, Bz Pro Phe Arg NA and Bz Val Gly Arg NA. PMSF, STI, LBTI and SBBI can inhibit activity of these proteases. Activities of these three fibrinolytic proteases were found to be maximal at alkaline range of pH 9.0～10.0.
文摘Developmental changes in hemolymph ecdysteroid level, ecdysteroid synthesis by prothoracic glands （PGs） in vitro, prothoracicotropic hormone （PTTH） activity in brain extracts, and PTTH activity in the hemolymph were measured during the fifth larval instar of the Eri silkworm, Samia cynthia ricini. The changing patterns of hemolymph ecdysteroid level and ecdysteroid synthesis by laGs in vitro are similar to each other, with maximums on day 9. However, on this day, hemolymph ecdysteroid level was substantially higher than ecdysteroid synthesis by PGs in vitro suggesting a high PTTH activity in the hemolymph on day 9. Moreover, the changing pattern of PTTH activity in brain extracts is also similar to that of PTTH activity in the hemolymph, both peaking on day 9. However, on this day, activity in brain extracts was much smaller than PTTH activity in the hemolymph implying that most PTTH synthesized by the brain is secreted to the hemolymph and the brain stores a very little amount of PTTH. This study provides unique insights onto the hormonal regulation of ecdysteroid synthesis in the Eri silkworm and is useful for our future studies on signal transduction of insect neurolaelatides.
文摘Growing evidence exists that aposematic and toxic prey may be included in a predator＇s diet when the predator experiences physiological stress. The tree sparrow Passer montanus is known to have a significant portion of aposematic and toxic ladybirds in its natural diet. Here, we present experi- ments testing the attack and eating rate of the tree sparrow toward the invasive aposematic harle- quin ladybird Harmonia axyridis. We wondered whether the sparrow＇s ability to prey on native ladybirds predisposes them to also prey on harlequin ladybirds. We compared the attack and eat- ing rates of tree sparrows of particular age and/or experience classes to test for any changes during ontogeny （hand-reared x young wild-caught xadult wild-caught） and with differing perceived lev- els of physiological stress （summer adult ~ winter adult）. Winter adult tree sparrows commonly at- tacked and ate the offered ladybirds with no evidence of disgust or metabolic difficulties after in- gestion. Naive and wild immature tree sparrows attacked the ladybirds but hesitated to eat them. Adult tree sparrows caught in the summer avoided attacking the ladybirds. These results suggest that tree sparrows are able to cope with chemicals ingested along with the ladybirds. This pre- adaptation enables them to include ladybirds in their diet; though they commonly do this only in times of shortage in insect availability （winter）. Young sparrows showed avoidance toward the chemical protection of the ladybirds.
