Damage caused by Japanese beetles

Click following links to read about Japanese beetles and the damage caused by them to many plant species. This insect can be controlled by using entomopathogenic nematodes. http://www.ca.uky.edu/entomology/entfacts/ef451.asp

http://www.landscape-america.com/problems/insects/japanese_beetle.html

http://ipm.illinois.edu/fieldcrops/insects/japanese_beetles/

http://www.turf.msu.edu/japanese-beetle

http://urbanext.illinois.edu/turf/whitegrub.html

Links to interaction between entomopathogenic nematodes and japanese beetles

http://www.ncbi.nlm.nih.gov/pubmed/9784356

http://esa.confex.com/esa/2007/techprogram/paper_32669.htm

http://www.entomology.wisc.edu/mbcn/nema508.html

http://ohioline.osu.edu/hyg-fact/2000/2001.html

http://esa.confex.com/esa/2008/techprogram/paper_35315.htm

Efficacy of Heterorhabditis indica and Steinernema minuta against the Japanese beetle

Efficacy of four new entomopathogenic nematode strains including Heterorhabditis indica strains MP17 and MP111, Heterorhabditis sp. strain MP68 and Steinernema  minuta strain MP10 from Thailand was tested against the second  instar larva of the Japanese beetle, Popillia japonica in laboratory bioassays. This study demonstrated that the strains of both H. indica and Heterorhabditis spp. were more efficacious against P. japonica that the strain of Steinernema  minuta. However, when comparisons were made among the strains of Heterorhabditis nematodes, MP111 strain of H. indica was the most efficacious against the second instar larva of Japanese beetle . Read following paper on the virulence of entomopathogenic nematodes from Thailand on Japanese beetle.

Maneesakorn, P., An, R., Grewal, P.S.and Chandrapatya, A. 2010. Virulence of our new strains of entomopathogenic nematodes from Thailand against second instar larva of the Japanese Beetle, Popillia japonica (Coleoptera: Scarabaeidae). Thai Journal of Agricultural Science.43: 61-66.

Kill Japanese beetles (Popillia japonica) with Entomopathogenic Nematodes

• The Japanese beetle, Popillia japonica, is a most economically important pest of many ornamental plants and turf grasses.

• Larvae of these beetles are called white grubs that generally feed on roots of over 300 plants but their primary food source is grass roots. Severe damage caused by these grubs can result in dead patches of turf that can be picked up like a loose carpet.

• Adults mostly feed on leaves and flowers by chewing the tissue between the veins, a type of feeding called skeletonizing.

• Chemical insecticides including Imidacloprid (Merit), Chlorpyrifos, Isofenphos, and Diazinon are generally used to manage white grubs but due to human health and environment pollution concerns their use is restricted.

• Currently, environmentally safe biological control agents including a milky disease causing bacterium Bacillus popilliae (Milky spores) and entomopathogenic nematodes have been used to control this pest.

• Three entomopathogenic nematodes including Heterorhabditis bacteriophora GPS11 and TF strains, H. zealandica X1 strain and Steinernema scarabaei have been considered to be the most effective species against Japanese beetle grubs.

• It has been demonstrated that the application of H. bacteriophora GPS11 and TF strains, H. zealandica X1 strain and S. scarabaei at rate of 2.5 billion infective juveniles per hectare can cause about 96, 98 and 100%, respectively control of Japanese beetle grubs infesting turfgrass (for more information read Grewal et a., 2005).

• Nematodes can be applied using traditional sprayers that are used for the application of insecticides.

• Nematodes perform better when they are applied to target small stages of grubs.

• Nematodes also survive better and remain efficacious when field/lawns are irrigated before and after nematode applications.

How Entomopathogenic Nematodes kill Japanese beetles

• When the infective juveniles are applied to the soil surface or thatch layer, they start searching for their hosts, in this case Japanese beetle grubs.

• Once a Japanese beetle grub has been located, the nematode infective juveniles penetrate into the Japanese beetle grub body cavity via natural openings such as mouth, anus and spiracles.

• Infective juveniles of Heterorhabditis also enter through the intersegmental members of the grub cuticle.

• Once in the body cavity, infective juveniles release symbiotic bacteria (Xenorhabdus spp. for Steinernematidae and Photorhabdus spp. for Heterorhabditidae) from their gut in grub blood.

• In the blood, multiplying nematode-bacterium complex causes septicemia and kills Japanese beetle grubs usually within 48 h after infection.

• Nematodes feed on multiplying bacteria, mature into adults, reproduce and then emerge as infective juveniles from the cadaver to seek new larvae in the soil.

References

1. Grewal, P.S., Koppenhofer, A.M., and Choo, H.Y., 2005. Lawn, turfgrass and Pasture applications. In: Nematodes As Biocontrol Agents. Grewal, P.S. Ehlers, R.-U., Shapiro-Ilan, D. (eds.). CAB publishing, CAB International, Oxon. Pp 147-166.