Host plant influence on susceptibility of Bemisia tabaci (Hemiptera: Aleyrodidae) to insecticides

Abstract

A resistance monitoring program conducted for the polyphagous whitefly, Bemisia tabaci (Gennadius), in Imperial Valley, CA, USA generated a large set of LC50s for adults collected from broccoli, cantaloupe and cotton crops over a four-year period. A vial bioassay and, subsequently, a yellow-sticky card bioassay produced similar temporal profiles of relative susceptibilities to the pyrethroid insecticide bifenthrin. Both bioassays revealed that whiteflies collected from broccoli were significantly less susceptible to bifenthrin compared to the other two crops. A similar finding was observed for endosulfan and the mixture of bifenthrin+endosulfan in the yellow-sticky card bioassay. The possibility that seasonal differences contributed to the observed differences in susceptibility provided the impetus to conduct a reciprocal transfer experiment using broccoli (or kale) and cantaloupe grown simultaneously in the field and greenhouse. Whitefly adults collected from an organic farm over three consecutive weeks had significantly higher LC50s on kale than those collected the same day on cantaloupe. After culturing in the greenhouse on broccoli or cantaloupe and testing again, LC50s remained significantly higher on broccoli after one week and again at the F1 generation. In contrast, whiteflies originating on kale in the field and transferred to cantaloupes in the greenhouse had significantly reduced LC50s at the F1 generation. When tested against the bifenthrin+endosulfan mixture, significantly higher LC50s were generated for whiteflies reared on broccoli in the greenhouse at one week and the F1 compared to the field source from cantaloupes. The consistently higher LC50s for whiteflies on broccoli and other Brassica spp. crops, compared to cantaloupes or cotton, point to statistically significant host-plant influences that are expressed in both field-collected and greenhouse-reared populations of whiteflies.

A link between host plant adaptation and pesticide resistance in the polyphagous spider mite Tetranychus urticae

“…The "preadaptation hypothesis" for insecticide resistance has been supported by surveys of the literature (11,12) although the comparisons drawn between herbivores and natural enemies or between chewing and sucking herbivores may be confounded by taxonomy, thus calling for other forms of experimental and observational evidence (12). It is now well accepted that herbivore exposure to different plant allelochemicals can affect the toxicity of pesticides (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Moreover, metabolic resistance to pesticides is known to commonly rely on the increased expression of one or more genes encoding detoxification enzymes and formal evidence that many of these detoxification enzymes can metabolize both plant chemicals and pesticides is accumulating (26,27).…”

Efecto de plantas hospederas en la inducción enzimática detoxificativa de Bemisia tabaci (Gennadius)

“…Thus, Tian and Guo (1996) using different host plants as diet in Heliothis armigera, found differential responses of this insect to Deltamethrin. Castle et al (2009) found a high correlation between whitef ly populations developed in broccoli and high values of LC 50 to Bifenthrin. In the case of weeds (I and II) can be seen, that the host has a significant effect on the resistance to B. tabaci to Bifenthrin.…”

“…Por tal motivo, el conocer el efecto del hospedero sobre las enzimas detoxificativas, puede ser utilizada como referencia en estudios de resistencia, dando evidencia teórica para el uso seguro y racional de plaguicidas (Castle et al, 2009). Debido a lo anterior el objetivo de este trabajo fue investigar el efecto de inducción enzimática detoxificativa, de seis plantas hospederas sobre la susceptibilidad de B. tabaci.…”

“…Therefore, knowing the effect of the host on detoxifying enzymes can be used as a reference in studies of resistance, giving theoretical evidence for the safe and rational use of pesticides (Castle et al, 2009). Because of this, the purpose of this study was to investigate the effect of the induction of detoxifying enzyme, of six host plants on the susceptibility of B. tabaci.…”

“…De este modo, Tian y Guo (1996) utilizando diferentes plantas hospederas como dieta en Heliothis armígera, encontraron respuestas diferenciales de este insecto a la Deltametrina. Castle et al (2009) encontraron una alta correlación entre poblaciones de mosquita blanca desarrollada en brócoli y valores altos de CL 50 a Bifentrina. Para el caso de las malezas (I y II) podemos observar, que los hospederos tienen un efecto importante en la resistencia de B. tabaci a Bifentrina.…”