Diversity of insects in organic Asiatic pennywort farms in Thailand

摘要

In this study, we investigated species composition and diversity of insects in three organic farms of Asiatic pennywort. The farms were in Chainat, Bangkok and Nonthaburi provinces of Thailand. Insect pests and their predators and parasitoids were collected monthly from November 2014 to October 2015 by sweeping them up from pennywort plants with a sweep net or sucking them up from the ground with a vacuum suction. The calculated Shannon-Wiener diversity index and Simpson's index of diversity were the highest for insects found in the farm in Chainat, followed by the farms in Nonthaburi and Bangkok. The lowest Simpson's index of diversity was found for insects in the farm in Bangkok (0.47) and the highest was found in the farm in Chainat (0.87). The highest values of Simpson's index of diversity were recorded during the rainy season, followed by during the summer and winter. According to the Sorensen's coefficient, the three insect communities overlapped considerably (or were quite similar). In the three organic Asiatic pennywort farms sampled, various types of insects were found: harmful insects, non-pests, parasitoids and predators. Organic farming is a way to increase heterogeneity and insect biodiversity in the area. The insects in Chainat farm were the most diverse, but the insect communities in all three areas overlapped to a great degree. Many types of insects were found on Asiatic pennywort plant. They are unique and play an important ecological role of lives on Earth.