Scanning electron microscopy was done to describe the morphology of antennaof adult male and fe- male ladybeetle, Coccinella septempunctata . Eleven-segmented, scaly antennawas 950μm in male and 980 μm in female. El...Scanning electron microscopy was done to describe the morphology of antennaof adult male and fe- male ladybeetle, Coccinella septempunctata . Eleven-segmented, scaly antennawas 950μm in male and 980 μm in female. Electron micrographs reveal the occurrence of eight typesof sensillae, viz. chaetica ( Ch) , trichoidea (Tr) , basiconica (Ba) , campaniformia (Ca) ,ampucellaceous (Am) , scolopalia (Sc) , placoidea (PI) and hook shaped sensilla on the antennae ofmale and female ladybeetles. Ch had long external-process, with base surrounded by membranous socketand the length was 60 and 70 μm in male and female ladybeetle, respectively. Sensillae Tr weredistally curved and inserted into depression, 9.0 and 15 μm long in male and female ladybeetle,respectively. Sensillae Ba were cuticular peg-like and 0.57 and 0.70 μm long on the male and femaleantennae. Sensillae Ca were small dome-like and had diameter of 3.0μm in both the sexes. SensillaeAm were pit-like in appearance and the diameter of the pit was 1.2 and 1.5 in male and femaleladybeetle, respectively. Sensillae PI were elliptical sunken plates like in both the sexes.Sensillae Sc were broad at their apex and pointed at their tip, 2.5μm. A single hook-shapedsensilla of 21.0 μm in length was present on male antenna only. Ch, Ca, Am, and PI were almostsimilar in numbers in both the sexes. Sensillae Tr were more numerous on the male antenna and Bawere more numerous on the female antenna.展开更多
The effects of environmental parameters on insect development have been studied extensively. But the reasons for 2 differential developmental rates within same cohort under varying environmental factors have not been ...The effects of environmental parameters on insect development have been studied extensively. But the reasons for 2 differential developmental rates within same cohort under varying environmental factors have not been explored. For the purpose, in this study the existence and stability of slow and fast development under 5 photoperiods （i.e., 8L： 16D, 10L ： 14D, 12L ： 12D, 14L ： 10D and 16L ： 8D; light and dark hours per day） and its effect on body mass and reproductive attributes in 2 aphidophagous ladybirds, Menochilus sexmaculatus （Fabricius） and Propylea dissecta （Mulsant） was examined on Aphis craccivora Koch at 27 4- 1 ~C temperature. A clear bimodal （2 peaks, where the first peak represented the fast developing and the 2nd peak slow developing individuals） pattern of distribution at each photoperiod was found. The proportion of slow and fast developing individuals in a cohort differed with photoperiods. The slow developing individuals were more in numbers at 8L ： 16D, in equal numbers at 14L ： 10D and in less numbers at 16L： 8D, indicating that the variation in emergence was owing to exogenous cues influenced differential rates of mortality. Slow developing individuals had female biased sex ratio, higher longevity and lower body mass than fast developing individuals. Fast developing females laid higher numbers of eggs with higher egg viability than slow developing females. Study of such variations in development at different photoperiods is helpful to understand its role in the development of insects particularly ladybirds and permits the selection of fast developing bioagents for their use in biocontrol of pest species.展开更多
基金the Department of Higher Education,Government of Uttar Pradesh, India for providing financial assistance in the form of Centre of Excellence in Biocontrol of Insect Pests
基金Department of Higher Education, Government of Uttar Pradesh, India for providing financial assistance in the form of Centre of Excellence in Biocontrol of Insect Pests.
文摘Scanning electron microscopy was done to describe the morphology of antennaof adult male and fe- male ladybeetle, Coccinella septempunctata . Eleven-segmented, scaly antennawas 950μm in male and 980 μm in female. Electron micrographs reveal the occurrence of eight typesof sensillae, viz. chaetica ( Ch) , trichoidea (Tr) , basiconica (Ba) , campaniformia (Ca) ,ampucellaceous (Am) , scolopalia (Sc) , placoidea (PI) and hook shaped sensilla on the antennae ofmale and female ladybeetles. Ch had long external-process, with base surrounded by membranous socketand the length was 60 and 70 μm in male and female ladybeetle, respectively. Sensillae Tr weredistally curved and inserted into depression, 9.0 and 15 μm long in male and female ladybeetle,respectively. Sensillae Ba were cuticular peg-like and 0.57 and 0.70 μm long on the male and femaleantennae. Sensillae Ca were small dome-like and had diameter of 3.0μm in both the sexes. SensillaeAm were pit-like in appearance and the diameter of the pit was 1.2 and 1.5 in male and femaleladybeetle, respectively. Sensillae PI were elliptical sunken plates like in both the sexes.Sensillae Sc were broad at their apex and pointed at their tip, 2.5μm. A single hook-shapedsensilla of 21.0 μm in length was present on male antenna only. Ch, Ca, Am, and PI were almostsimilar in numbers in both the sexes. Sensillae Tr were more numerous on the male antenna and Bawere more numerous on the female antenna.
文摘The effects of environmental parameters on insect development have been studied extensively. But the reasons for 2 differential developmental rates within same cohort under varying environmental factors have not been explored. For the purpose, in this study the existence and stability of slow and fast development under 5 photoperiods （i.e., 8L： 16D, 10L ： 14D, 12L ： 12D, 14L ： 10D and 16L ： 8D; light and dark hours per day） and its effect on body mass and reproductive attributes in 2 aphidophagous ladybirds, Menochilus sexmaculatus （Fabricius） and Propylea dissecta （Mulsant） was examined on Aphis craccivora Koch at 27 4- 1 ~C temperature. A clear bimodal （2 peaks, where the first peak represented the fast developing and the 2nd peak slow developing individuals） pattern of distribution at each photoperiod was found. The proportion of slow and fast developing individuals in a cohort differed with photoperiods. The slow developing individuals were more in numbers at 8L ： 16D, in equal numbers at 14L ： 10D and in less numbers at 16L： 8D, indicating that the variation in emergence was owing to exogenous cues influenced differential rates of mortality. Slow developing individuals had female biased sex ratio, higher longevity and lower body mass than fast developing individuals. Fast developing females laid higher numbers of eggs with higher egg viability than slow developing females. Study of such variations in development at different photoperiods is helpful to understand its role in the development of insects particularly ladybirds and permits the selection of fast developing bioagents for their use in biocontrol of pest species.
