Pathogenicity of Serratia marcescens to hazelnut weevil (Curculio dieckmanni)

The hazelnut weevil (Curculio dieckmanni Faust.) is a major pest of Asian hazel (Corylus heterophylla Fisch.) in China. Dead hazelnut weevil larvae were examined and the associated pathogenic bacterium was identified as Serratia marcescens Bizio. This significantly shortened the lifespan of hazelnut weevil. Larval weight was reduced as a function of S. marcescens concentration and exposure time. The structure of infected midgut cells was altered, with necrosis of the wall tissues and many cells becoming dislodged, creating cavities. The S. marcencens strain inhibited digestive enzyme activity and protective enzymes in the midgut of adult hazelnut weevil. Inhibition on S. marcencens strain increased with treatment time. S. marcescens directly destroyed the midgut cells and interfered with digestive and protective enzymes. This decreased the food intake and increased mortality of hazelnut weevil. S. marcescens appears to be an effective bacterium for the control of hazelnut weevil but requires further study, including biological formulation development and field application.

Automated summary

The study revealed that Serratia marcescens Bizio significantly shortened the lifespan of hazelnut weevil, impacting larval weight and digestive enzyme activity. This bacterium destroyed midgut cells, interfered with digestive and protective enzymes, leading to reduced food intake and increased mortality of hazelnut weevil.