Hare, J.D., & Morgan, D.J.W. 1997 Mass-priming Aphytis: Behavioral improvement of insectary-reared biological control agents.. Biological Control 10(3): 207-214.
Notes: The introduced parasitoid, Aphytis melinus DeBach Hymenoptera: Aphelinidae), is used for augmentative biological control of California red scale, Aonidiella aurantii (Maskell) (Homoptera: Diaspididae) Commercially reared wasps are reared on oleander scale, Aspidiotus nerii Bouche (Homoptera: Diaspididae). Oleander scale covers lack the chemical, O-caffeoyltyrosine, a kairomone mediating host selection by A. melinus. Wasps reared on oleander scale but individually exposed, or primed, to O-caffeoyltyrosine more readily accepted California red scale for probing in laboratory bioassays and parasitized a greater proportion of available California red scale in the field than wasps reared similarly but not exposed to O-caffeoyltyrosine. Thus, it may be possible to improve host recognition of commercial, insectary-reared A. melinus by exposing them to O-caffeoyltyrosine prior to release. The goal of this study was to develop an inexpensive but effective means of priming thousands of wasps simultaneously to O-caffeoyltyrosine. The most effective method, but potentially the most expensive, was simply to spray parasitized oleander scale on their host plant with dilute O-caffeoyltyrosine prior to wasp emergence. In additional experiments, using controlled doses of synthetic O-caffeoyltyrosine applied to scale covers, primed wasps were shown to require both a lower minimum dose of O-caffeoyltyrosine for recognition and also respond to measured O-caffeoyltyrosine doses more consistently than unprimed wasps. The ability to maw-prime thousands of wasps prior to release is a crucial step toward realizing the concept of behavioral improvement of host selection of parasitoids on a commercial scale.