About Bemisia tabaci
The whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), is a highly destructive polyphagous insect pest with a global presence, originating from southern Asia and now prevalent in tropical regions worldwide except Antarctica. It inflicts substantial damage to agricultural crops, particularly in plant families like Solanaceae, Cucurbitaceae, and Fabaceae. Whiteflies feed on plant sap, causing economic losses by reducing crop productivity. Their rapid reproduction and ability to transmit numerous plant viruses, including Begomovirus, Carlavirus, Crinivirus, Ipomovirus, and Torradovirus, further exacerbate the devastation, affecting crops such as tomato, potato, soybean, cassava, okra, and chrysanthemum. The resulting viral infections lead to significant yield losses, impacting millions of dollars in revenue, with diseases like 'cassava mosaic' and 'cassava brown streak' having devastating effects in Africa. Whiteflies are considered a major agricultural menace worldwide.
The life cycle of Bemisia tabaci begins with the females laying pear-shaped eggs, approximately 0.2 mm in length, arranged in a semi-circular pattern on the front surface of leaves. After 5-9 days, depending on factors like host variety, temperature, and moisture, the eggs hatch into the first instar, also known as "crawlers." These whitish-yellow crawlers have a flat, oval, and scale-like appearance and subsequently transform into yellowish dome-shaped nymphs during the second instar. As they progress to the third instar, the nymphs become bright yellow after molting, gradually darkening and appearing slightly constricted in structure. The fourth instar nymphs exhibit a yellowish-white color, with bulging eyes visible through their integument, leading to this phase being referred to as the "pupal" or "red-eyed nymph" phase. The adult Bemisia tabaci emerges from the pupal case through an upturned "T"-shaped incision on the dorsal side. The complete life cycle of Bemisia tabaci takes around 16-31 days, with some variation.
Importance of Knowledge on Transcriptomics in white flies
The knowledge of transcriptomics in whiteflies holds crucial importance for effective pest management strategies. By studying the patterns of gene expression, researchers can identify key genes and molecular pathways involved in whitefly development, behavior, and response to environmental factors, including pesticides. This information helps in discovering novel targets for pest control, developing targeted pesticides, and understanding the mechanisms of pesticide resistance. Transcriptomics also aids in identifying genes responsible for whitefly vectoring of plant viruses, facilitating the development of interventions to disrupt virus transmission.
Additionally, it enables the design of RNA interference-based approaches to silence essential genes for pest control. Understanding host-plant interactions at the molecular level contributes to the development of resistant crop varieties. Overall, transcriptomics enhances the knowledge base for integrated pest management strategies, promoting more sustainable and effective methods to combat whitefly infestations and minimize crop damage while reducing the environmental impact of pest control measures.
About Experiment
For transcriptomics study, adult stages of two genetic groups of Bemisia tabaci i.e., Asia II 1 and Asia 1 were taken. Two groups A and B were designated to represent different conditions and time points.
Group 1: Adult tissue of pooled male and females of B. tabaci Asia 1
Group 2: Adult tissue of pooled male and females of B. tabaci Asia II 1.