Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), the silverleaf whitefly, is a phloem sucking polyphagous whitefly on hosts ranging from weed species to economically important crops (Muniz 2000; Simmons et al. 2008; Abd-Rabou and Simmons 2010). B. tabaci can lead to yield losses from direct feeding and fungal growth caused by its secretions of honeydew. This whitefly also is a vector for plant diseases. B. tabaci has also been found to transmit at least 111 plant viruses with some viruses causing 100% crop loss (Jones 2003).
Currently, the primary control strategy for this pest is synthetic insecticide applications. However, over reliance on chemical controls can cause resistance to build in insect pest populations reducing their effectiveness. In B. tabaci populations, resistance to organophosphate, organochlorine, pyrethroid, and neonicotinoid insecticides have already been observed (Elbert and Nauen 2000; Vassiliou et al. 2011; Ahmad and Khan 2017). De Marchi et al. (2021) found no control with application of the neonicotinoids, imidacloprid and thiamethoxam. A non-chemical control option could be used to reduce the reliance on chemical controls and possibly slow insecticide resistance.
Ultraviolet (UV) radiation covers wavelength ranges 100 nm to 400 nm which is shorter than that for light visible to humans. It is divided into three bands UVA, UVB, and UVC. UVA radiation wavelengths range from 315 nm to 400 nm. It has been found to attract some insects, especially nocturnal insects (Barghini and Souza de Medeiros 2012; Shimoda and Honda 2013). Honeybees, Apis mellifera L. (Hymenoptera: Apidae), have UVA receptors in their eyes which allows them to visually see some UVC wavelengths (Menzel and Blakers 1976). When exposed to UVA radiation, Drosophila melanogaster Meigan (Diptera: Drosophilidae) adults had increased longevity and fecundity, while their offspring had elevated survival rate of eggs to emergence (Zhou et al. 2016). However, supplemental UVA light on B. tabaci caused lower fecundity and lower egg fertility (Dáder et al. 2014)
UVB radiation has wavelengths ranging from 280 nm to 315 nm. Certain doses of UVA + UVB radiation, or just UVB radiation, have deterred the settling of B. tabaci on treated plants (Prieto-Rulz et al. 2019). UVB has caused DNA lesions in the spider mite Tetranychus urticae Koch (Acari: Tetranychidae) causing failure to molt and eventual death (Murata and Osakabe 2017). Exposure to UVB was found to cause a reduction in populations of the psyllid, Strophingia ericae Curtis (Hemiptera: Aphalaridae) (Salt et al. 1998). There was a decrease in survival of wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae), when exposed to UVB radiation (Sabockyte et al 2023).
The wavelengths of UVC radiation range from 100 nm to 280 nm. It has germicidal effects and is used to disinfect and sterilize. Exposure to UVC radiation caused a reduction in the spider mite T. urticae on strawberries, Fragaria × ananassa Duchesne (Rosales: Rosaceae) (Short et al. 2018; Montemayor et al. 2023). Increase morality was observed in tephritid fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), with exposure to UVC. Juvenile mortality and reduction in egg hatching was observed after exposure to UVC in the mosquito, Culex quinquefasciatus Say (Diptera: Culicidae) (Munawar et al. 2021).
A couple of studies have tested the effect of UVC on whiteflies. UVC irradiation has been found to increase mortality of adult greenhouse whitefly Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) (Poushand et al. 2017). UVC applications were also found to lower the number of all life stages of this whitefly on tomato, Solanum lycopersicum L. (Solanales: Solanaceae) (Leskey et al 2021). This study tested UVC radiation at wavelength 254 at 2 different distances, and at 4 different times per distance, to assess an effect on the hatch rate for eggs of B. tabaci.