Molecular detection of reproductive symbionts and parthenogenesis experiments in Tuta absoluta from Argentina: facing potential for sustainable and specific pest control strategies

Abstract

Tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a key pest oftomato crops. Specific and environmentally friendly control strategies against thispest, such as the sterile insect technique (SIT), are under development and sexual re-production has emerged as a key focal point to ensure its success. In the present study,we analyzed four representative T. absoluta populations from Argentina, focusing onthe molecular detection of endosymbionts potentially associated with reproductiveabnormalities and on determining whether parthenogenesis can occur under labora-tory conditions. Larvae of T. absoluta were collected in commercial tomato plantationsfrom La Plata and Mar del Plata (both in Buenos Aires province), Bella Vista (Corrientesprovince), and Yuto (Jujuy province). Tuta absoluta adults were evaluated by standardPCR for the presence of reproductive endosymbionts (Wolbachia sp., Spiroplasma sp.,Arsenophonus sp., Cardinium sp., and Rickettsia sp.). For parthenogenesis assays, 20–23virgin females from each T. absoluta geographic population were life-long isolatedin Petri dishes with a tomato leaf. Fecundity, fertility, and female longevity were es-timated and compared with results from mated females from each population. Ourresults showed the presence of a unique endosymbiont (Wolbachia sp. supergroup B,sequence type 41). Fecundity of the unmated females was significantly lower than fe-cundity of mated females in all T. absoluta populations. In addition, unmated femalesonly laid infertile eggs. In conclusion, the absence of parthenogenesis in T. absolutafrom representative geographic populations supports the implementation of SIT andmating disruption as effective control strategies against this pest in Argentina.