Location: Beneficial Insects Introduction Research Unit
Project Number: 8010-22000-031-014-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jun 1, 2020
End Date: Sep 30, 2021
Objective:
The Asian longhorned beetle (ALB) is a high-risk invasive insect pest attacking various hardwood trees. Native to China and Korea, ALB has been detected since the late 1990s in North America and targeted for eradication. The beetles can be difficult to detect, especially in large forested areas, and new introductions are possible. Biological control is a valuable option for reducing established
and incipient populations in areas where intensive management methods such as chemical control or removal of infested trees are prohibitively expensive and/or environmentally undesirable.
Information on the occurrence of natural enemies of Asian longhorned beetle in South Korea is not available in scientific literature and must be obtained through new field work. Our goal is to discover, import and evaluate candidate parasitoids from South Korea for the biological control of ALB in the US. Specific objectives are (1) conducting surveys to discover ALB parasitoids in South Korea; and (2) identifying, importing and evaluating collected parasitoids in the US.
Approach:
For Objective 1, surveys will be conducted in northeastern natural forests (Hwacheon, Gangwon Province) and urban planted forests in Inchon-Seoul (Gyeonggi Province) and Busan-Ulsan (South Gyeongsang Province) areas in South Korea. At each survey site, we will deploy 5-10 sentinel logs infested with ALB eggs (along with ALB adults) and young larvae, once per month, from June to September (i.e., starting when overwintering parasitoids start emerging and continuing throughout the active period of ALB oviposition and larval development). We will also conduct sampling of infested trees by removing barks with ALB eggs or young larvae from naturally infested trees. All sentinel logs will be collected back after a 3-week exposure in the field and dissect to collect parasitized eggs or larvae and determine the fate of each exposed ALB egg or larva. Percentage parasitism will be determined. All parasitized ALB eggs or larvae will be reared until the parasitoids have developed into pupae or adults before they are shipped to the US. PI will travel to South Korea to participate the survey in August.
For Objective 2, all field-collected and live parasitoids (cocoons/pupae or adults) will be shipped to ARS-BIIRU for quarantine evaluations. The ARS-BIIRU has an APHIS certified quarantine facility and acquired import permits to allow the importation of ALB natural enemies from Asia. New parasitoid species will be described. All candidate parasitoids will be reared on ALB. The ARS-BIIRU has continuously maintained an ALB colony. If a colony of the parasitoid can be successfully established, the parasitoid will be evaluated for its efficiency, host specificity and climatic adaptability. The efficiency of candidate parasitoids will be investigated by collecting basic biological information such as percentage parasitism, temperature dependent development time, host stage preference and fecundity. Candidate parasitoids will be tested with some common North American cerambycids that are closely related to ALB.
