Effect of temperature on the development and consumption of Phaenochilus kashaya (Coleoptera: Coccinellidae), a predator of the cycad aulacaspis scale,Aulacaspis yasumatsui

The cycad aulacaspis scale (CAS), Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae), is a serious pest of ornamental cycads in the southeastern United States. In Florida, CAS was first reported in Miami in 1996 and is now present in 43 Florida counties. Chemical control of CAS can be effective, but it is expensive, and insecticides must be frequently and regularly applied. Recent surveys of natural enemies in Thailand identified a new potential biological control agent of CAS. The objective of this study was to examine the temperature requirements and consumption rates of Phaenochilus kashaya Giorgi and Vandenberg (Coleoptera: Coccinellidae). Survival, developmental time and number of scales consumed by P. kashaya were measured at four constant temperatures (20, 25, 30 and 35°C). In addition, adult longevity and consumption were recorded at three constant temperatures (20, 25 and 30°C). Phaenochilus kashaya completed development to adulthood at temperatures ranging from 20 to 30°C. The highest survival rate (48%) was obtained at 25°C, and the accumulated degree-days for this species was 714. Phaenochilus kashaya is a voracious predator of CAS, consuming 380 scales during the larval stage and an estimated 4700 scales during the adult stage. Adult longevity varied from 59 days at 30°C to 220 days at 20°C for females, and 31 days at 30°C to 148 days at 20°C for males. The intrinsic rate of increase (r _m) was 0.34 at 20°C, which is high compared with other coccinellid species. According to this study, P. kashaya has the potential to be an effective biological control agent of the CAS in Florida.