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We compared the morphological characteristics of the scale covers and bodies of 2 economically important scale species, California red scale, Aonidiella aurantii (Maskell), and oleander scale, Aspidiotus nerii (Bouche), to determine their protective value against predation by the coccinellid Rhyzobius lophanthae (Blaisdell). We also compared the morphology of the mandibles of R. lophanthae with that of Chilocorus cacti (L.), a specific predator of diaspidid scales. A higher percentage of R. lophanthae larvae survived when they fed on 2nd-and 3rd-instar A. aurantii and all stages of A. nerii than when they fed on gravid and parturient A. aurantii. Adult R. lophanthae took longer to consume 3rd-instar A. aurantii than 3rd-instar A. nerii and were frequently unable to penetrate the scale body of gravid and parturient A. aurantii. Predator preference for scale stage and species reflected the ease with which it was able to penetrate the scale cover and body of its prey. The hardened scale cover of gravid and parturient A. aurantii when coupled with the sclerotized scale body provided the scale with substantial immunity to predation by R. lophanthae for approximately two-thirds of the scale life span. We conclude that R. lophanthae is unlikely to suppress A. aurantii populations below those of economic concern when it is the sole biological control agent present. In contrast, the entire life span of A. nerii is vulnerable to predation, and this species appears to be suppressed to low densities by R. lophanthae.

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We compared egg parasitization of two sporadic pests of avocado, Persea americana Miller, by Trichogramma platneri Nagarkatti reared on Sitotroga cerealella (Oliver) (=smaller parasitoids) with those reared on Trichoplusia ni (Hübner) (= larger parasitoids) in the laboratory. Large T. platneri females invested less time than smaller parasitoids in obtaining offspring from eggs of either Amorbia cuneana Walsingham or Sabulodes aegrotata (Gueneé). Furthermore, large T. platneri invested substantially more time (ca. 3‐fold) in obtaining offspring from S. aegrotata than A. cuneana eggs. These investment times positively correlated with percentage egg‐load retained by a female after it had ceased exploiting a host species. This occurred even though the offspring produced by a parasitoid from either host species manifested the same size and fecundity (= quality). Host species utilization in the laboratory mirrored that observed in the avocado groves of southern California following augmentative release of commercially produced T. platneri (Oatman & Platner, 1985). Explanations for these differences in host utilization are discussed along with their implications for augmentative biological control.

Numerous errors and confusion in the literature concerning the genus Trichogramma in Japan have necessitated a formal review of this genus. This review corrects and updates Trichogramma host and distribution records from Hokkaido to the Ryukyu Islands, redescribes and designates a lectotype for T. jezoense Ishii, records two Trichogramma species new to Japan (T. ostriniae Pang and Chen and T. lingulatum Pang and Chen) and describes three new species (T. yabui Honda and Taylor, T. okinawae Honda, and T. aomoriense Honda). Additionally a key to the species is provided for the 14 known Japanese species as are ITS-2 DNA sequences and SEM micrographs of male genital capsules for the majority of the species to aid biocontrol workers in Trichogramma identification.Key words: Taxonomy; species description; Japanese Trichogramma; DNA sequence; male genital capsule * To whom correspondence should be addressed at: E-mail: jhonda@email.sjsu.edu † Present address: Department of Entomology, 320 Morrill Hall, University of Illinois, 505 S. Goodwin Ave., Urbana, IL 61801, USA ‡ Present address: 349 Asano, Munakata 811-3415, Japan DOI: 10.1303DOI: 10. /aez.2006 never verified. Test releases using Hirai's cultured material was later used for O. furnacalis control in corn fields in 1992 -93 (Yoshizawa, 1995. Trichogramma brassicae Bezdenko, another imported species of Trichogramma, was used in test releases for the control of M. brassicae in sugar beet fields in 1997 (Iwasaki et al., 1998) and for the control of P. xylostella in greenhouses in 1999 (Miura et al., 2001). Again their establishment has not been confirmed.Despite the considerable international attention that Trichogramma has received as an important biological control agent, its taxonomy remains inadequately understood for a number of reasons. For example, the collection and curation of these minute (approximately 0.5 mm) parasitic wasps has proven difficult and greatly slowed the accumulation of study material . Moreover, the early disregard of type specimens has caused much confusion in the literature. Because a number of type specimens are lost, unusable, or described inadequately, many species names have been applied incorrectly and inconsistently in the literature (Pinto et al., 1978;Pinto and Stouthamer, 1994;Pinto, 1999). Finally, Trichogramma taxonomy also suffered from an absence of consistent distinguishing morphological characters (Pinto, 1999). This dilemma was partially resolved by Nagarkatti and Nagaraja (1971) who discovered the importance of the male genitalia as a diagnostic taxonomic character. DNA sequences have also been proposed as an aid to identification and used in a number of studies to characterize Trichogramma species (Pinto et al., 1997;Silva et al., 1999;Stouthamer et al., 1999).The history of Trichogramma taxonomy in Japan exemplifies many of the taxonomic difficulties prevalent in the genus. For example, Nakagawa (1900) was the first to record Trichogramma from Japan by describing in morphological detail, the adult of a Trichogra...