Bean leaf beetle: Pathogens transmitted

Bean pod mottle virus (BPMV)
Comovirus particles: An electron micrograph of virus particles from the family Comoviridae. This virus family includes viruses such as bean pod mottle virus. This image is from the Virus Information Data Exchange.Comovirus particles: An electron micrograph of virus particles from the family Comoviridae. This virus family includes viruses such as bean pod mottle virus. This image is from the Virus Information Data Exchange<.

This pathogen was first described from garden bean (Zaumeyer and Thomas 1948<) and later discovered in soybean (Skotland 1958<, Walters 1958<). This virus is in the Comovirus group and is partly characterized by having two single stranded RNAs (ribonucleic acid) encapsulated by coat proteins that form an icosahedral structure (i.e., a polyhedron with 20 faces) (Matthews 1991<, Šutić et al. 1999<). Two subgroups of BPMV have been identified in nature (Ref Gu and Ghabrial). Although one subgroup (subgroup II) caused more severe symptoms, the two subgroups can reassort, recombine, or a single virus particle can contain RNA-1 from both subgroups (known as a partial diploid) (add references).

On soybeans, bean pod mottle virus may cause a severe systemic mottling with a puckering of leaflets and mottling of pods and seed coats (Stace-Smith 1981<); however, symptomatic response varies by soybean variety (Walters 1970<, Scott et al. 1974<, Windham and Ross 1985<) and soybean stage at inoculation (Windham and Ross 1985<) and planting date (Giesler er al. 2002<). Additionally, the foliar symptoms of bean pod mottle virus are masked by cool temperatures (Walters 1970<).

There can be a reduction in yield in bean pod mottle virus-infected plants resulting from reduced seed size and pod set (Watlers 1970<). This affect on soybean yield is most severe when soybeans are infected as seedlings (Demski and Kuhn 1989<). Seed-infection either does not occur (Skotland 1958<, Schwenk and Nickell 1980<) or occurs at a very low infection-rate (Lin and Hill 1983<), with virus usually present in the seed coat (Schwenk and Nickell 1980<). Additionally, when present, bean pod mottle virus-symptoms can be difficult to distinguish from other viral symptoms, e.g., soybean mosaic virus, (Marking 2000<).

The bean leaf beetle is the primary vector for bean pod mottle virus (Mueller and Haddox 1980<). This virus is the most prevalent soybean viruses in the North Central states (Giesler er al. 2002<). Possible sources of primary inocula include: soybean seed, overwintering bean leaf beetles, and perennial legumes (Krell et al. 2003<, Bradshaw et al. 2007<).

Other viruses transmitted by bean leaf beetles

Quail pea mosaic virus (QPMV)<

Southern bean mosaic virus (SBMV)<