effective chemical control method (Hodges et al. 2003). This is not surprising given that

oils have long been used to control armored scale insects. The oil not only covers the

insects and suffocates them but also covers the surface of the plant making it difficult for

crawlers to settle onto the plant (Howard and Weissling 1999). Soaps are quite popular

with homeowners; but they must be applied frequently, in some cases once a week

(personal observation). The effective application of pesticides for control of CAS is

difficult due to the scale's tendency to heavily infest the abaxial surface of leaves, which

is difficult to spray (Howard and Weissling 1999). In the case of C. revoluta, the

architecture of the plant itself, with the margins of the leaflets curling down and inward to

form an arch on the abaxial surface of the leaflet, makes foliar treatments inefficient

(Hodges et al. 2003). Frequent or "as needed" applications of oils seems to be the most

effective technique for controlling CAS, and by mixing oil with contact pesticides such as

malathion, even greater scale mortality can be achieved (Hodges et al. 2003). The use of

systemic pesticides such as dimethoate and contact pesticides like methidathion has

yielded mixed results, being very effective in some instances and completely ineffective

in other cases (Hodges et al. 2003). Imidacloprid used as a soil drench can be very

effective, but Howard and Weissling (1999) found that this product had to be mixed at

very high concentrations to be effective. This product can also be used as a foliar spray.

 The reproductive biology of C. nipponicus makes it a good biological control

agent. Alvarez and Van Driesche (1998a) found that, at low scale densities, C.

nipponicus was able to maintain its populations and maintain populations of euonymus

scale, Unaspis euonymi (Comstock), and San Jose scale, Quadraspidiotusperniciosus

(Comstock), in check. In the presence of greater scale densities, C. nipponicus will