Mark A. Coffelt

Parasitism of orangestriped oakworm (Lepidoptera: Saturniidae) eggs in the urban landscape

Abstract Orangestriped oakworm, Anisota senatoria (J. E. Smith), has caused widespread defoliation of oak trees in the urban landscape of southeastern Virginia since 1985. Egg masses were collected from 1988 to 1990 to determine the impact of native egg parasites on A. senatoria populations. The most abundant egg parasite was Aprostocetus new sp. and mean egg mass parasitism was 24.6%. The eupelmid Anastatus hirtus (Ashmead), a new host record, parasitized a mean of 11.7% of A. senatoria egg masses. The encyrtid Ooencytrus sp., a new host record, had a mean egg mass parasitism of 0.09%. Inundative releases of Trichogramma minutum (Riley) in 1989 and 1990 did not increase parasitism rates and mean egg mass parasitism was 2.3%. Parasitism of first generation A. senatoria egg masses was higher compared with second generation. The four egg parasites collected in this study parasitized 30% of A. senatoria egg masses and within egg mass parasitism was 7.9%. These relatively low parasitism rates may partially explain the presence of consistently high A. senatoria populations in southeastern Virginia.

Relationship Among Orangestriped Oakworm (Lepidoptera: Saturniidae) Frass Length, Frass Production, Host Plant, and Defoliation

Defoliation of urban oak trees by the orangestriped oakworm, Anisota senatoria (J. E. Smith), and associated frass has become a significant problem in southeastern Virginia. Measurements of frass length and production provided a decision-making guideline for A. senatoria management. Frass length was used to differentiate A. senatoria instars reared on Q. palustris (Muenchhausen), pin oak. Host plants significantly affected A. senatoria frass length and production per larva and host plants should be considered when determining instars. Frass length was longer and frass production higher when larvae were reared on Q. nigra (water oak), Q. phellos (willow oak), Q. coccinea (scarlet oak), and Q. palustris compared with six other species. Frass length was shorter in second, fourth, and fifth instars when larvae were reared on Q. alba (white oak) compared with six, eight, and five other species, respectively. Landscape fabrics were used to collect frass and recovered 90% of all frass deposited. Frass production...

Population biology of orangestriped oakworm (Lepidoptera: Saturniidae) in southeastern Virginia

Population biology of orangestriped oakworm, Anisota senatoria (J. E. Smith), was studied in southeastern Virginia. Egg mass size was larger on Quercus palustris Muench., pin oak, compared with Q. phellos L., willow oak. Females produced a sex pheromone that attracted male moths. Blacklight traps were not effective for monitoring A. senatoria adults. Peak male emergence occurred on 2 July, 4 days earlier than female. The mean life span was 33.5 days in the laboratory. Pupal mortality was high and only 1.2% of the pupae produced moths in 1989 and 1990. Pupae were capable of overwintering for two years in the field. The first report of a second generation from September - November was documented. Second generation A. senatoria oviposited more egg masses, infested more trees and had a longer development time compared with first generation. Large egg mass size, pupae that were capable of overwintering for two years and the presence of a second generation may partially explain the consistent A. senatoria popul...