Xie, Y.P., Lambdin, P.L., & Lynch, C. 2008 Feeding behavior of Scymnillus horni (Coleoptera: Coccinellidae) on the Elongate Hemlock Scale, Fiorinia externa (Hemiptera: Diaspididae).. Proceedings of the XI International Symposium on Scale Insect Studies, Oeiras, Portugal, 24-27 September 2007. ISA Press Lisbon, Portugal 322 pp.

Notes: Abstract: The feeding behavior of the coccinellid predator Scymnillus horni (Gordon) on the diaspidid scale insect Fiorinia externa Ferris was assessed. S. horni searched for prey by tapping its antennae on the infested needle and moving in one of four recognition patterns (random, zigzagged, circle or combination of these patterns). The predator preferred to feed on male scales in all developmental stages compared to the female stages. The medial and posterior sections of the tests were most frequently damaged by S. horni. Rarely was the entire scale insect consumed by the predator. The average consumption rate was 4.1 (0-9) prey daily, with predators consuming 27 to 54 prey during a 10-day observational period. There appeared to be a trend for greater damage and a higher consumption rate as the number of potential prey increased. Adult predators survived from 32 to 45 days under laboratory conditions.