Adaptation and Invasiveness of Western Corn Rootworm: Intensifying Research on a Worsening Pest

Abstract

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is an established insect pest of maize (Zea mays L.) in North America.

Parental RNA interference of genes involved in embryonic development of the western corn rootworm, Diabrotica virgifera virgifera LeConte

“…Mutations in other members of the chromatin remodeler gene group are known to have gametogenic and/or embryonic effects in fruit flies (Daubresse et al, 1999;Deuring et al, 2000;Kehle et al, 1998;McDaniel et al, 2008); it remains to be seen if these genes would also serve as efficacious pRNAi targets for pest insect control. The ability of western corn rootworm to develop resistance to crop protection chemistries (Gray et al, 2009;Narva et al, 2013) and transgenic insect resistance traits based on Bt proteins (Gassmann et al, 2011) creates the need for new approaches to corn rootworm control to combine with existing technology. Regardless of the precise mechanisms, the ability to knock down the expression of genes involved with embryonic development to prevent rootworm eggs from hatching offers a unique opportunity to achieve control of western corn rootworms.…”

Use of chromatin remodeling ATPases as RNAi targets for parental control of western corn rootworm (Diabrotica virgifera virgifera) and Neotropical brown stink bug (Euschistus heros)

“…The introduction of maize transformed to express Bacillus thuringiensis (Bt) proteins for CRWcontrol is believed to have a significant positive impact on yields (Marra et al, 2012), which has been accompanied by as much as an 80% reduction in the use of chemical insecticides between 1995(Coupe and Capel, 2015. Unfortunately, the development of resistance of the western corn rootworm (WCR), Diabrotica virgifera virgifera, to a widely-deployed Bt toxin, Cry3Bb1 (Gassmann et al, 2011(Gassmann et al, , 2012, and its rapid adaptation to other management strategies, such as chemical insecticides (Meinke et al, 1998) and crop rotation (Gray et al, 2009;Levine and OloumiSadeghi, 1996) has increased the urgency to discover new insecticidal proteins and/or identification of new modes of action (MOA) for CRW control. The development of RNA interference (RNAi) technology for the control of WCR via transgenic expression of long double-stranded RNA (dsRNA) in maize provides an additional MOA againstWCR (Baum et al, 2007).…”

Entomopathogenic fungi in cornfields and their potential to manage larval western corn rootworm Diabrotica virgifera virgifera

“…This may be due in part to better adaptation of D.v. virgifera to soil pathogens because larvae live in the soil (Gray et al 2009), and in part to the high sensitivity of the other bait species to infections (Goettel and Inglis, 1997). This work highlights the importance of the insect species used to recover pathogens, and previous work has shown that the insect species used can influence the fungal strains recovered (Klingen et al, 2002).…”

“…Western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is a major pest of corn in the United States and Europe, with larvae that live in the soil and feed on corn roots (Gray et al, 2009). Current management relies in part on corn that produces toxins of Bacillus thuringiensis; however, development of Bt resistance and predominant use of conventional corn hybrids in Europe requires the exploration of other management tactics (Gray et al, 2009;Gassmann et al, 2011).…”

“…Current management relies in part on corn that produces toxins of Bacillus thuringiensis; however, development of Bt resistance and predominant use of conventional corn hybrids in Europe requires the exploration of other management tactics (Gray et al, 2009;Gassmann et al, 2011). Entomopathogenic fungi, especially hypocreallean Ascomycetes, occur widely in the soil (Scheepmaker and Butt, 2010) and kill a variety of insect species (Hajek and St. Leger, 1994), including larval and pupal D.v.…”