Pathogenicity of Leptolegnia chapmanii and other oomycetes from Argentina against Aedes aegypti and Aedes albopictus larvae from Misiones Province: potential for biological vector control

Abstract

Aedes aegypti and Aedes albopictus are major vectors of medically important arboviruses established in Misiones Province, Argentina, where projected expansion highlights the need for sustainable control. We evaluated sixteen Argentine oomycete isolates (eleven Leptolegnia chapmanii, one Leptolegnia caudata, three Leptolegnia spp., one Geolegnia helicoides) against larvae of both species. Mortality at 24 and 48 h was analysed using Firth’s penalised logistic regression with Šidák-adjusted pairwise comparisons. All isolates caused significantly higher mortality than controls at 48 h (P < 0.001). Four L. chapmanii isolates produced >80% mortality, providing the first quantitative evidence that Argentine oomycetes are pathogenic to Ae. albopictus.