Life History of Oriental Beetle and Other Scarabs, and Occurrence of Tiphia vernalis in Ohio Nurseries

The oriental beetle, Anomala orientalis Waterhouse, is a serious pest of nursery crops in northern Ohio and a number of other states because the larvae damage plant roots. In 3 ornamental tree nurseries (field production) in Ohio, the composition of scarab larvae, their life histories, and parasitism rates were examined. Four exotic scarabs, Asiatic garden beetle (Maladera castanea Arrow), European chafer (Rhizotrogus majalis Razoumowsky), Japanese beetle (Popillia japonica Newman), and oriental beetle, were found in this study. The oriental beetle and European chafer were the most common species found. Up to 60% of the oriental beetle population required 2 yrs to complete development, which is much higher than the commonly reported 15% or less in northeastern states. Tiphia vernalis Rohwer, an external parasite of oriental beetle and Japanese beetle larvae, was found in all nurseries surveyed. As much as 31% and 60% of the sampled oriental beetle and Japanese beetle populations, respectively, were parasitized, depending on date and nursery.