Search

Aedes albopictus, ever since, its distribution from country to country, has been known to transmit many viruses (like dengue) to human. The vector possesses enormous plasticity in habitat adoptability. The distribution pattern revealed that maximum population was collected from rural areas during rainy season, at temperature 31-40 oC and RH 41-50 %. The population was collected from clear water having plastic bottom. The small quite places are more productive breeding places having EC (≤ 1000 µS/m), TDS (≤ 500 ppm) and DO (2-5 mg/l). The larval population was mostly established in the areas having exposed shady conditions and have less distance from human habitation. Flora such as spirogyra, grasses and algae, and predators such as damselfly, water bugs and beetles showed affinity with Ae. albopictus population. Stagnant clear water bodies are considered as potential breeding sites for dengue vector.

Aedes aegypti L. and Culex quinquefasciatus Say, which are the major vectors of dengue and yellow fever, respectively, could be managed in an effective way by targeting their immature stages. In the present study, we evaluated the effects of interspecific competition between Ae. aegypti and Cx. quinquefasciatus on their fitness and biology. This experiment consisted of three treatments: Ae. aegypti and Cx. quinquefasciatus together (interspecific competition treatment abbreviated as In-Aa and In-Cq), only Ae. aegypti (Aa), and only Cx. quinquefasciatus (Cq). Larval development was significantly slower in In-Aa as compared to Aa and that of In-Cq compared with Cq. The pupal weight of In-Aa (2.25 mg) was significantly lower as compared to Aa (2.45 mg) while there was no difference in pupal weight between In-Cq (2.55 mg) and Cq (2.37 mg). Fecundity of In-Aa females was significantly lower than Aa females but no difference was found between In-Cq and Cq. The hatching percentage of In-Aa (52.65) compared with Aa (67.83) and In-Cq (67.17) compared with Cq (71.30) was similar. Importantly, the intrinsic rate as well as biotic potential in co-habitating insects was significantly lower than their respective non-co-habitants. Therefore, it could be concluded that co-occurrence of Ae. aegypti and Cx. quinquefasciatus has a strong potential to induce negative impact on their life history traits due to interspecific competition.

Oxycarenus hyalinipennis Costa (Lygaeidae: Hemiptera) has attained the status of major insect pest drastically affecting the value and production of the cotton crop. The main objective of the study is to estimate losses caused by O. hyalinipennis (10, 20, 30, 40, 50, 60 pairs release / boll) identified on boll weight, fiber characteristics (mike, staple length, staple strength, lint index and Ginning Out Turn), seed index and seed germination, under semi opened bolls of two Bt genotypes (MNH-886 and MNH-456). The offered O. hyalinipennis density is directly proportional to GOT while inversely proportional to boll weight, seed index, germination, lint index, mike, staple length and staple strength. All morphological parameters revealed highly significant but negative correlation with offered densities of O. hyalinipennis. Linear regression model showed that fiber characteristics affected significantly by O. hyalinipennis. Thus, a long term sustainable IPM strategy must be implemented to curtail this bug population under check.