| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4504088 | Biological Control | 2012 | 7 Pages |
Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) is a solitary egg parasitoid that has been released in the United States since 2007 for biocontrol of the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Field and laboratory trials with ash logs infested with EAB eggs were conducted in Michigan between 2009 and 2010 to improve methods for monitoring the establishment of O. agrili. Naturally occurring EAB eggs were collected in both parasitoid-release and control (non-parasitoid-release) plots to compare with the EAB egg-sentinel log (ESL) technique. In three parasitoid-release plots, >50% of ESLs had O. agrili-parasitized eggs ranging from 3.9% to 48.2% egg parasitism after one week of field exposure. No EAB eggs were attacked by O. agrili on the ESLs deployed in control plots. In the laboratory, 100% of ESLs exposed to O. agrili inside rearing jars for one week had parasitized-eggs (68.5% egg parasitism). Deployment of ESLs detected low levels of parasitism by O. agrili in all three ash stands where O. agrili was released in previous years. In contrast, collection of naturally occurring EAB eggs detected the parasitism in only one of these three parasitoid-release ash stands. No parasitism was detected in control ash stands with either method. These findings indicate that populations of O. agrili released in previous years had successfully overwintered and established in the released ash stands by 2010, but had not yet dispersed to the control stands.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Oobius agrili is a solitary egg parasitoid of emerald ash borer (EAB). ► It was recently introduced to the USA for biocontrol releases against EAB. ► EAB egg-sentinel ash logs were developed to detect parasitism by O. agrili. ► Field deployment of such sentinel logs detected 3.9–48.2% EAB egg parasitism. ► This method is useful for monitoring the establishment and dispersal of O. agrili.
