Use of a gut content ELISA to detect whitefly predator feeding activity after field exposure to different insecticide treatments

Abstract

A 2-year commercial-scale study was conducted to qualitatively evaluate the effect of different insecticide treatment regimes on the predator complex attacking Bemisia tabaci (Gennadius) in cotton. In 1996 three insecticide regimes were compared: a rotation of conventional broadspectrum insecticides or one of two different regimes based on the initial use of the insect growth regulators (IGRs), buprofezin and pyriproxyfen. In 1997 the same three regimes plus an untreated control were compared; split-plots were sprayed once for Lygus hesperus Knight control using a broad-spectrum insecticide. Relative feeding activity for each predator species was compared between treatment regimes by analyzing the gut contents of predators for the presence of whitefly remains using a whitefly-specific enzyme-linked immunosorbent assay (ELISA). The ELISA results were combined with predator density data to obtain a qualitative pesticide impact index for each predator group. In total, we analyzed the gut contents of 32 262 field-collected predators, representing nine different taxa. Of these, Pseudatomocelis seriatus (Reuter), Spanagonicus albofasciatus (Reuter), and spiders consisting primarily of Misumenops celer (Hentz) are shown to be whitefly predators for the first time. Predator populations were usually reduced in plots that received applications of broad-spectrum insecticides for B. tabaci and L. hesperus control, but there were few treatment differences in the proportions of predators containing whitefly remains in their guts. However, the feeding activity of certain predator species in fields sprayed with broad spectrum insecticides was significantly reduced compared with those in IGR-based and control treatments. Overall, insecticide regimes using IGRs were less lethal to the whitefly predator complex than regimes consisting of only conventional, broadspectrum insecticides, but differences in predator feeding activity on whitefly between the various insecticide treatment regimes were minimal.

Differential impact of adults and nymphs of a generalist predator on an exotic invasive pest demonstrated by molecular gut-content analysis

“…The principal limitation of custom-developed monoclonal antibodies (MAbs) has been their capacity to examine only single interactions but, once developed, they can be used to screen large populations against individual target (typically pest) prey (e.g., Hagler and Naranjo 2005). In contrast, field-based analysis of predation using specific PCR has often focused on examining the dynamics of predation upon multiple prey, including pest (Harper et al 2005;Harwood et al 2007;Zhang et al 2007) and non-pest (Agustí et al 2003;Harper et al 2005;Juen and Traugott 2007;Harwood et al 2007) species.…”

Utilizing rabbit immunoglobulin G protein for mark-capture studies on the desert subterranean termite, Heterotermes aureus (Snyder)

“…Although we only tested rabbit IgG as a termite mark, there are other highly specific proteins and protein-based ELISAs that could be used for termite dispersal studies. For example, rabbit IgG and chicken IgG marks have been used for MRR type studies to simultaneously examine the intercrop dispersal of the convergent lady beetle, Hippodamia convergens Guérin-Méneville (Hagler and Naranjo, 2005) and flight behavior of glassy-winged sharpshooter, Homalodisca vitripennis (Germar) (Blackmer et al, 2004(Blackmer et al, , 2006. Recently, highly specific ELISAs have also been developed to less expensive proteins found in soy milk, bovine milk, and chicken egg whites (Jones et al, 2006).…”

“…Hagler et al (1992) were the first to demonstrate the feasibility of marking arthropods with a foreign protein such as rabbit immunoglobulin G (IgG) and, in turn, identify the protein by a sensitive protein-specific enzyme-linked immunosorbent assay (ELISA). From this, various protein markers have been applied to study the dispersal characteristics of a wide variety of insects including delicate parasitoids (Hagler et al, 2002), predators (Hagler and Naranjo, 2005), herbivores (Blackmer et al, 2004;Jones et al, 2006), honeybees (DeGrandi-Hoffman and Hagler, 2000), and ants (Buczkowski and Bennett, 2006). Recently, rabbit IgG was proven in laboratory studies to be effective for marking the eastern subterranean termite, Reticulitermes flavipes (Kollar) and H. aureus Hagler et al, 2009).…”

Identifying the predator complex of Homalodisca vitripennis (Hemiptera: Cicadellidae): a comparative study of the efficacy of an ELISA and PCR gut content assay

“…In short, we believe that once the burden of developing a pest-speciWc mAb is overcome (note: we contracted out the work to develop the mAb which cost US $12,000 and took a year to develop), the cost eYciency and simplicity of conducting an ELISA is more conducive for mass-screening predators than PCR (Sheppard and Harwood 2005). An example of a study that exploits the power of using a pest-speciWc ELISA to screen Weld-collected predators is given by Hagler and Naranjo (2005). In that study, over 32,000 predators, representing nine diVerent taxa, were screened at minimal assay and labor costs to identify predators of the silverleaf whiteXy, Bemisia tabaci (Gennadius).…”