Pathogenicity of Four Serratia Marcescens Strains to the Pea Aphid, Acyrthosiphon Pisum, and the Squash Bug, Anasa Tristis

Abstract

Serratia marcescens, the causal agent of cucurbit yellow vine disease (CYVD), is transmitted by the squash bug, Anasa tristis. It is unclear whether a S. marcescens strain from one niche can colonize another niche. We tested the ability of four S. marcescens strains to produce pathogenic effects on aphids and squash bugs and evaluated differences in the effects of these strains on the insects.These data suggest that the CYVD strain of S. marcescens is not pathogenic to the pea aphid in low concentrations, while low concentrations of the non-CYVD strains increased the mortality rate of pea aphids. Additional data suggests that the CYVD strain is not pathogenic to the squash bug and that the non-CYVD strains shorten its life span. The trypanosome-like protozoans observed in the abdomen contents of squash bugs were confirmed by DNA sequencing to belong to the family Trypanosomatidae.