Effect of Tomato spotted wilt virus infection on settling, oviposition, and feeding preference of Frankliniella fusca (Thysanoptera: Thripidae)

Phytoarboviruses utilize multiple transmission mechanisms. These mechanisms range from passive transport of viruses to complex intricate interactions between the vector and the virus. Influences of phytoarboviruses on their vectors vary with the intricacy of interactions between them. Thrips-transmitted Tomato spotted wilt virus (TSWV) belongs to the most complex category. TSWV is transmitted in a persistent propagative manner. TSWV is known to positively influence behavior and fitness of Western flower thrips, Frankliniella occidentalis (Pergande). However, it is not sure if the effects are similar on all TSWV transmitting thrips species. The objective of this study was to evaluate the effect of TSWV on settling, feeding, and ovipositional behavior of viruliferous and non-viruliferous tobacco thrips, Frankliniella fusca (Hinds). Bioassays with a Y-tube olfactometer indicated no differences in settling behavior between viruliferous and non-viruliferous F. fusca on TSWV-infected and non-infected peanut (Arachis hypogaea L.) plants. In a subsequent experiment, viruliferous and non-viruliferous female thrips were allowed to oviposit on TSWV-infected or on non- infected peanut leaflets. Results revealed that more eggs were oviposited on non-infected leaflets than on TSWV-infected leaflets. Also, viruliferous thrips produced more eggs than non-viruliferous thrips. Thrips feeding preference experiments are currently in progress; their results will also be presented. Results thus far indicate that TSWV-infection could have a positive influence on F. fusca also. Their ovipositional preference towards non-infected peanut leaflets indicates that it could be potentially beneficial for virus spread. This intricate interaction may support a mutually beneficial relationship and may favor co-evolution.