Biological management of mustard aphids by lady bird beetle & effect of future climate change in aphid population in Chitwan, Nepal

In Chitwan, the negative consequences of pesticide in controlling aphid population have been increased. So, an experiment was conducted to assess the potentiality of biological control of aphid population replacing pesticides in the perspective of changing weather and climate. The monitoring and management of mustard aphids to determine effects of climatic factors including climate change in future and control of the population by ladybird beetles was conducted during Winter Season from December 2019 to March 2020. The research was carried out both in laboratory and field situations. Climatic parameters such as relative humidity were positively related with aphid population. Temperature has a negative relation with the population of aphids. It means warmer temperatures may not increase the population of aphids in future, i.e., climate change in future may have negative relation with aphid population. Elevated CO2 was negatively correlated with aphid population, and so the implication of climate change. Populations of aphids were potentially managed by predator-ladybird beetles at all stages, especially at adult stage. The population of aphids changes accordingly with the climatic and weather factors and ladybird beetles found perfectly effective in managing aphid population in the district.