Life history and pesticide susceptibility of Cybocephalus nipponicus Endrody-Younga (Coleoptera: Cybocephalidae) and a taxonomic revision of the Cybocephalidae of North America and the West Indies.

摘要

The life history of the predatory beetle Cybocephalus nipponicus Endrody-Younga was studied by rearing the beetle on the cycad aulacaspis scale, Aulacaspis yasumatsui Takagi. Mean developmental times of egg (7.3 +/- 0.8 days), larval (13.7 +/- 1.1 days), and pupal (18.6 +/- 1.6 days) stages were determined. Mortality in each life stage, adult longevity, and adult sex ratios also were measured. A clarification of differences between C. nipponicus and C. binotatus Grouvelle is included.;The susceptibility of the predatory beetles C. nipponicus Endrody-Younga and Rhyzobius lophanthae Blaisdell to six pesticides commonly used for treating cycad aulacaspis scale was tested. Three concentrations (half field rate, field rate, and twice field rate) of each pesticide were tested against both beetle species using a coated glass vial bioassay. Nearly 100% mortality in both beetle species occurred at all concentrations when treated with methidathion, dimethoate, and malathion. Insecticidal soap, fish oils, and imidacloprid were much less toxic. At half the simulated field rate, C. nipponicus had 33% survivorship with insecticidal soap, 23% survivorship with imidacloprid, and 17% survivorship with fish oil. At half the simulated field rate, R. lophanthae had 56% survivorship with insecticidal soap, 36% survivorship with imidacloprid, and 53% survivorship with fish oil. Mortality rate for each beetle species rose with increasing concentration of each pesticide.;The 17 species of Cybocephalidae in North America (including Mexico) and the West Indies are revised. Included are redescriptions of Cybocephalus aciculatus Champion, C. californicus Horn, C. nigritulus LeConte, C. nipponicus Endrody-Younga, C. schwarzi Champion, Pycnocephalus metallicus Sharp and a new combination of P. deyrolli (Reitter). Also included are descriptions of 10 new species: C. antilleus, C. caribaeus, C. iviei, C. kathrynae, C. randalli, C. geoffreysmithi and four as yet unnamed new species from Mexico. A key to species, illustrations of morphological features including detailed drawings of male genitalia, distribution data, and host lists are provided. The confusion involving C. nipponicus and C. binotatus Grouvelle is discussed and the differences between them are made evident.