Preference shifts in Bemisia tabaci (Aleyirodidae: Hemiptera) after the acquisition of mungbean yellow mosaic virus from Vigna radiata

The silver leaf whitefly, Bemisia tabaci (Aleyrodidae: Hemiptera), is a polyphagous pest and a major vector of plant viruses, causing significant economic losses globally. It exhibits a complex of cryptic species and is known to transmit various plant viruses affecting numerous crops globally. A study was conducted in Tamil Nadu, India, to identify the dominant cryptic species of B. tabaci on legume crops, leading to the establishment of laboratory colonies of the most common types. The research focused on the feeding preferences of these whiteflies on healthy green gram plants (Vigna radiata (L.) R. Wilczek) versus those infected with the Mungbean Yellow Mosaic Virus (MYMV). Biochemical changes in MYMV-infected green gram plants, compared to healthy ones, were analysed to understand their influence on whitefly feeding preference. The cryptic species Asia II 8 was found to be the most common in legume crops. The study assessed whether these whiteflies favoured healthy green gram plants or those infected with MYMV. Our findings revealed that when healthy whiteflies acquired the virus from the host, their preference shifted toward healthy plants. This shift is linked to the biochemical changes associated with the infection status of the host. Following viral infection, there was a decrease in total sugars and chlorophyll, while levels of protein, phenol, peroxidase, and polyphenol peroxidase increased. These results suggest that the virus modifies the vector's behaviour through a shared host, enhancing the pathogen's ability to disseminate within the ecosystem.