Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 2006
Publication Date: August 15, 2007
Citation: Reding, M.E., Klein, M.G. 2007. Life History of Oriental Beetle and Other Scarabs, and Occurance of Tiphia Vernalis in Ohio Nurseries. Journal of Entomological Science. 42(3): 329-340. Interpretive Summary: The oriental beetle (OB) is an exotic scarab native to Japan or the Philippine Islands. It was first detected in the United States in New Haven, CT in 1920. OB occurs in many northeastern, mid-Atlantic, and mid-western states. It is a pest of turf and nursery crops in most of these states. Damage is caused by the larval stage, know as grubs, feeding on the roots of the crops. In general, OB has a 1-year life cycle. However, we found a number of individuals in several Ohio nurseries that had a 2-year life cycle. As a result, we initiated an investigation to study the life history of OB in northern Ohio. Knowledge of a pest’s life history is crucial for efficient management of the pest. We sampled several ornamental nurseries in northern Ohio to examine the life history of OB and other exotic scarabs. In addition, we examined the scarabs for the presence of parasitoids. We found four exotic scarabs (oriental beetle, European chafer (EC), Asiatic garden beetle (AGB), and Japanese beetle (JB)) in the nurseries sampled. OB and EC were the most common species found. In addition, they appear to be the most likely species to damage nursery crops. We found 5 to 60% of the OB populations having a 2-year life cycle. This suggests that OB has a relatively flexible life history, which would enable it to colonize a variety of climates. Moisture is probably one of the primary constraints to colonizing a location. We found a parasitic wasp (Tiphia vernalis) attacking OB and JB in the nurseries sampled. Rates of parasitization of OB ranged from 13 to 30%. The information on the life history of the exotic scarabs, will enable nursery growers to more accurately time insecticide treatments for control of these pests. In addition, the data on timing of parasitization of oriental and Japanese beetles by T. vernalis, will enable growers to time insecticide treatments so they don’t disrupt the activity of this natural enemy.
Technical Abstract: The oriental beetle is a serious pest of nursery crops in northern Ohio, USA, and various northeastern states. The larval stage damages plants by feeding on the roots. We examined the life history of the oriental beetle and several other exotic scarabs in ornamental nurseries of northern, OH. Four exotic scarabs, Asiatic garden beetle, European chafer, Japanese beetle, and oriental beetle, were found in this study. The oriental beetle and European chafer were the most common scarabs. A proportion of the oriental beetle population did not follow the normal development and had a 2-year life cycle. Tiphia vernalis Rohwer, an external parasite of oriental and Japanese beetle larvae, was found in all nurseries surveyed. The information on the life history of the above exotic scarabs, will enable nursery growers to more accurately time insecticide treatments for control of these pests. In addition, the data on timing of parasitization of oriental and Japanese beetles by T. vernalis, will enable growers to time insecticide treatments so they don’t disrupt the activity of this natural enemy.