Influence of temperature on certain biological attributes of an aphidophagous ladybeetle, Coccinella septempunctata Linnaeus, feeding on mustard aphid, Lipaphis erysimi (Kaltenbach), at five different temperatures, vi...Influence of temperature on certain biological attributes of an aphidophagous ladybeetle, Coccinella septempunctata Linnaeus, feeding on mustard aphid, Lipaphis erysimi (Kaltenbach), at five different temperatures, viz. 20, 25, 27, 30 and 35℃ was investigated. Its developmental period was shortest (11.7±0.09days) at 35℃ and longest (20.6±0.35 days) at 20℃. Developmental rate increased with increase in temperature. Hatching percent, larval survival, adult emergence and growth index were maximum at 30℃ and minimumat 20℃. Oviposition period and fecundity were highest at 30℃ and lowest at 20℃. A positive linear relationship exists between temperature and developmental rate and negative correlation between the duration of immature life stages and temperature. The proportion of developmental period allocated to each immature stage was found to be similar at each temperature regime. Thus, 30℃ was found as the most suitable for C. septempunctata amongst the five temperatures tested.展开更多
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 invasive multicolored Asian ladybeetle, Harmonia axyridis （Pallas） （Coleoptera： Coceinellidae）, aggregates inside dwellings during winter to avoid cold weather. This adaptive behavior disturbs homeowners, bec...The invasive multicolored Asian ladybeetle, Harmonia axyridis （Pallas） （Coleoptera： Coceinellidae）, aggregates inside dwellings during winter to avoid cold weather. This adaptive behavior disturbs homeowners, because of the large numbers of individuals that aggregate, which induces allergic reactions. The migratory flight patterns of this species have been well documented, with individuals preferentially moving toward prominent and high color contrast elements. However, the factors involved in the selection of aggregation sites by this species have yet to be elucidated. Here, we evaluated the influ- ence of （i） the density of individuals and （ii） the type of available shelters on decisions by H. axyridis to settle and aggregate under shelters. A dual choice bioassay conducted in the laboratory demonstrated the presence of mutual attraction to conspecifics. We also found that individuals preferentially settled under red covered shelters compared to transparent shelters, and that the type of shelter outweighed the effect of social interactions among conspecifics. Moreover, this experiment was performed under non-wintering conditions, providing the first evidence that aggregative behavior in this species can also occur under those specific conditions.展开更多
文摘Influence of temperature on certain biological attributes of an aphidophagous ladybeetle, Coccinella septempunctata Linnaeus, feeding on mustard aphid, Lipaphis erysimi (Kaltenbach), at five different temperatures, viz. 20, 25, 27, 30 and 35℃ was investigated. Its developmental period was shortest (11.7±0.09days) at 35℃ and longest (20.6±0.35 days) at 20℃. Developmental rate increased with increase in temperature. Hatching percent, larval survival, adult emergence and growth index were maximum at 30℃ and minimumat 20℃. Oviposition period and fecundity were highest at 30℃ and lowest at 20℃. A positive linear relationship exists between temperature and developmental rate and negative correlation between the duration of immature life stages and temperature. The proportion of developmental period allocated to each immature stage was found to be similar at each temperature regime. Thus, 30℃ was found as the most suitable for C. septempunctata amongst the five temperatures tested.
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 invasive multicolored Asian ladybeetle, Harmonia axyridis （Pallas） （Coleoptera： Coceinellidae）, aggregates inside dwellings during winter to avoid cold weather. This adaptive behavior disturbs homeowners, because of the large numbers of individuals that aggregate, which induces allergic reactions. The migratory flight patterns of this species have been well documented, with individuals preferentially moving toward prominent and high color contrast elements. However, the factors involved in the selection of aggregation sites by this species have yet to be elucidated. Here, we evaluated the influ- ence of （i） the density of individuals and （ii） the type of available shelters on decisions by H. axyridis to settle and aggregate under shelters. A dual choice bioassay conducted in the laboratory demonstrated the presence of mutual attraction to conspecifics. We also found that individuals preferentially settled under red covered shelters compared to transparent shelters, and that the type of shelter outweighed the effect of social interactions among conspecifics. Moreover, this experiment was performed under non-wintering conditions, providing the first evidence that aggregative behavior in this species can also occur under those specific conditions.
