BIOLOGICAL AND MICROBIAL CONTROL Biology, Life History, and Laboratory Rearing of Spathius galinae (Hymenoptera: Braconidae), a Larval Parasitoid of the Invasive Emerald Ash Borer (Coleoptera: Buprestidae)

Spathius galinaeBelokobylskij&Strazanac is a recentlydescribedparasitoidof theemerald ash borer, Agrilus planipennis Fairmaire, in the Russian Far East, and is currently being considered for biocontrol introduction in the United States. Using A. planipennis larvae reared with freshly cut ash (Fraxinusspp.)sticks,weinvestigatedthebiology, lifecycle,andrearingofS.galinae inthelaboratoryunder normal rearing conditions (25 1 C, 65 10% relative humidity, and a photoperiod of 16:8 [L:D]h).Our study showed that S. galinae took approximately 1 mo (29 d) to complete a single generation (from egg to adult) under the laboratory rearing conditions. After eclosion fromeggs, larvae of S. galinaemolted four times to reach the Þfth instar, which then spun cocoons for pupation and development to adults. Adult femalewaspshadamediansurvival timeof7wkwith fecunditypeaking3wkafteremergencewhenreared in groups (of Þve females andÞvemales) and2wk in single pairs. Throughout the life span, a single female S. galinae produced a mean ( SE) of 31 ( 3.0) progeny when reared in groups, and a mean ( SE) of 47 ( 5.3) progeny when reared in single pairs. Results from our study also showed that S. galinae could beeffectively rearedwithA.planipennis larvae reared inbothgreen(FraxinuspennsylvanicaMarshall) and tropical [Fraxinus uhdei (Wenzig) Lingelsh] ash sticks. However, the abortion (unemergence) rate of S. galinae progenywasmuch higher (20%)when rearedwith host larvae in green ash sticks than that (2.1%) in tropical ash sticks.