Poster – The effect of natural enemy release on the control of Alternanthera philoxeroides

Author 

Coauthors 

Abstract

Alligator weed, Alternanthera philoxeroides is a perennial aquatic weed invasive in China. It detrimentally impacts native biodiversity and causes huge losses to shipping and aquaculture. Agasicles hygrophila is a leaf-feeding natural enemy which provides effective control of A. philoxeroides. In this study, the biological and physiological indices of A. philoxeroides‘ density, plant morphology, chlorophyll content, biomass, and the population size of A. hygrophila were investigated in condition-controlled experiments. The effect of different release sizes of A. hygrophila on the control of A. philoxeroides was also studied. The results showed that under the condition of 40 stems·m2, the release of 4 pairs of A. hygrophila was optimal. Under these conditions, the stable breeding and quantity increase of natural enemies can be guaranteed, and the best feeding and control effect on A. philoxeroides can be obtained. The results provide a theoretical basis for further optimization of the propagation and release of A. hygrophila.

Keywords 

A. philoxeroides 

invasive weed 

natural enemy 

release 

control effect 

Highlights 

Significant correlation between the number of natural enemies and target weed biomass 

Under the condition of 40 stems per m2, 4 pairs of A. hygrophila provided the best effect 

As the number of natural enemies increases, the average chlorophyll content in the leaves decreases