Effects of Ageratina adenophora and Chromolaena odorata Invasion on the Insect Diversity in Tea Garden Communities

PurposeTo reveal the influence intensity of the invasion by Ageratina adenophora and Chromolaena odorata on the structure and function of insect community in tea garden, and to provide scientific basis for the further studies on the evolution mechanism of the invaded tea garden community and ecological management of tea garden.

MethodThe tea gardens with different invasion degrees (non-invaded, slightly-invaded and severely-invaded) of A. adenophora and C. odorata were selected as the sampling plots. The insects over ground in the sampling plots were collected by using pitfalls and yellow sticky cards, and the effects of the invasion by A. adenophora and C. odorata on the insect diversity in the tea garden community were analyzed by calculating and comparing Shannon-Wiener diversity index (H), Simpson dominance index (C), Pielou evenness index (E), Margalef richness index (D) and Jaccard similarity index (q).

Results8033 insects were collected from the all sampling plots belonging to 38 species, 37 families, and 11 orders. The dominant groups are Hymenoptera (67.19%), Diptera (15.25%), Collembola (5.39%) and Homoptera (4.68%), which account for 92.51% of the total number of insect specimens. As the invasion by A. adenophora and C. odorata aggravated, the species and numbers of insects in tea garden communities changed with varying degrees, the indexes H, E and D decreased, the index C increased, the similarity of the species composition of the insect community decreased.

ConclusionThe invasion of A. adenophora and C. odorata could significantly affect the structure and function of the insect community in tea garden, causing the change in the composition and structure of insect community, and decreasing insect diversity and species composition similarity among insect communities.