A Revision of the Australian Species of Stethorus Weise (Coleoptera: Coccinellidae)

Abstract

The adult and larva of Sterhorir.s,/enPs/rulis sp. n. are described and S. histrio Chazeau recorded from Australia for the first time. S . lo.utoni Britton and Lee is shown to be a synonym of S. nigripes Kapur. Additional information is given for the adults of S. vaguns (Blackburn), S. nigripes and S. hisrrio, and their larvae are described. Keys are provided to adults and last instar larvae of the Australian species. IntroductionThe large genus Stethorus Weise has a world-wide distribution, but only three species have been described from Australia. Blackburn ( I 892) described S. vagans (in Scymnus Kugelann), Kapur (1948) described S. nigripes and redescribed S . vugans, while Britton and Lee (1972) described S . loxtoni and figured the male genitalia and larvae of all three species. The adults are minute black beetles and both adults and larvae are predators of tetranychid mites.In a study of the morphology of larval coccinellids, a new species of Stethorus was recognised in material collected from coastal Queensland and is described below. In addition, a number of anomalies noticed between S. nigripes Kapur and S. nigripes sensu Britton and Lee, similarities between the latter and S . histrio Chazeau, and similarities between S . nigripes Kapur and S. loxtoni indicated that a revision of the Australian species of Stethorus was warranted.The following abbreviations are used for institutions and collectors: ANlC

Evaluation ofStethorus nigripes [Col.: Coccinellidae] for biological control of spider mites in California almond orchards

“…

Stethorus nigripes KAPUR (= S. loxtoni BRITTON & LEE) was importedfrom Australia in 1978 and released in California during 1978-1980. Laboratory and field cage studies evaluated aspects of S. nigripes" biology considered likely to affect establishment.

…”

The New Zealand species ofStethorusWeise (Coleoptera: Coccinellidae)

“…Mouthparts similar to those of S. Jenestralis Houston (Houston 1980) except for slight differences in length of setae and palps. Maxillary and labial palps less than twice as long as wide; posterior setal pair on mentum-submentum usually not reaching base of median pair (as in fig.…”

“…As described by Houston (1980) and Gordon & Chapin (1983) except: anterior third of genital plate (Fig. 12) twisted more than 90 0 to posterior part; spermatheca (Fig.…”

“…13) unpigmented and lightly annulate with thick cornu, long narrow nodulus, and short pointed ramus. Last instar larva As described by Britton & Lee (1979), Houston (1980), and Gordon & Anderson (1979 Remarks. The presence of a spermatheca was overlooked by previous authors except Whitehead (1967a).…”

Density dependent prey‐feeding time ofStethorus bifidus(Coleoptera: Coccinellidae) onTetranychus lintearius(Acari: Tetranychidae)

“…The endemic Stethorus bifidus (Kapur) (Coleoptera: Coccinellidae) is found throughout New Zealand (Houston 1990) and is a specialist predator of mites. It is often found in T. lintearius colonies before and after they collapse.…”