The emerald ash borer, Agrilus planipennis Fairmaire, an invasive beetle from Asia causing large scale ash (Fraxinus) mortality in North America, has been extremely difficult to rear in the laboratory because of its long life cycle and cryptic nature of immature stages. This lack of effective laboratory-rearing methods has not only hindered research into its biology and ecology, but also mass production of natural enemies for biological control of this invasive pest. Using sticks from the alternate host plant, Fraxinus uhdei (Wenzig) Lingelsh, we characterized the stage-specific development time and growth rate of both emerald ash borer eggs and larvae at different constant temperatures (12-35 degrees C) for the purpose of developing effective laboratory-rearing methods. Results from our study showed that the median time for egg hatching decreased from 20 d at 20 degrees C to 7 d at 35 degrees C, while no emerald ash borer eggs hatched at 12 degrees C. The developmental time for 50% of emerald ash borer larvae advancing to third, fourth, and J-larval stages at 20 degrees C were 8.3, 9.1, and 12.3 wk, respectively, approximately two times longer than at 30 degrees C for the corresponding instars or stages. In contrast to 30 degrees C, however, the development times of emerald ash borer larvae advancing to later instars (from oviposition) were significantly increased at 35 degrees C, indicating adverse effects of this high temperature. The optimal range of ambient temperature to rear emerald ash borer larvae should be between 25-30 degrees C; however, faster rate of egg and larval development should be expected as temperature increases within this range.

Field-cage methods were developed to evaluate the abilities of Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), biocontrol agents of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), to parasitize, develop and overwinter following three late-season releases at both a northern (Michigan) and a southern (Maryland) location within the current North American range of A. planipennis. In August, September and October of 2009, five young green ash trees were selected at each location. Tetrastichus planipennisi and S. agrili were each randomly assigned to one of two cages attached to each tree, surrounding separate sections of trunk in which late-instar A. planipennis had been inserted. The following April, the caged trunk sections were dissected to determine the fate of each A. planipennis larva and the developmental stages of all recovered parasitoid progeny. At both locations, T. planipennisi and S. agrili were able to parasitize hosts and successfully overwinter (i.e., reach adulthood the following spring). For T. planipennisi, successful parasitism (i.e., parasitoid progeny reached adulthood) occurred for all caged releases in Maryland, but only for the August and September releases in Michigan. At both locations, percent parasitism by T. planipennisi was higher in August and September than in October. For S. agrili, successful parasitism occurred for all caged releases in Maryland, but only for the August release in Michigan. In Maryland, percent parasitism by S. agrili in August and September was higher than in October. The caging method described here should be useful in determining the climatic suitability of other regions before proceeding with large-scale releases of either species and may have utility in other wood-borer parasitoid systems as well.

Cleopus japonicus (Wingelmüller) was approved for release by ERMA as a biocontrol agent for buddleia (Buddleja davidii) in New Zealand in November 2005 and a massrearing programme was developed to provide the insects for the initial experimental releases. Twenty-five adults were placed in each cage (sex ratio :) with cut buddleia foliage contained in a 250 ml conical flask. Eggs are laid into purposefully-excavated cavities within the leaves and leaf buds. After one week, the infested foliage was transferred to large polyethylene storage bins and larvae reared through with fresh foliage added as required. Pupae were either left in situ or were harvested into a smaller plastic container for adult emergence. Emerged adults were transferred to Petri dishes containing cut buddleia leaves. After a maturation feeding phase ranging from 4-6 weeks, adults can be stored at 0°C for extended periods.