Regional Correlation of Gypsy Moth (Lepidoptera: Lymantriidae) Defoliation with Counts of Egg Masses, Pupae, and Male Moths

Autor: Michael L. McManus, C. Burnham, J. S. Elkinton, G. H. Boettner, C. W. Boettner, R. E. Rossi, C. Zhou, M. E. Hohn, Andrew M. Liebhold
Rok vydání: 1995
Předmět:
Zdroj: Environmental Entomology. 24:193-203
ISSN: 1938-2936
0046-225X
Popis: Three different gypsy moth, Lymantria dispar (L.), sampling techniques were compared for their spatial correlation with regional defoliation maps. Counts of gypsy moth pupae and egg masses under burlap bands, and counts of male moths in pheromone–baited traps were taken in a network of 150 plots distributed irregularly throughout Massachusetts. These counts were compared with aerial sketch maps of gypsy moth defoliation collected during the same period and digitized into cells (2 by 2 km) cells in a geographic information system. The spatial correlation between counts of the three gypsy moth life stages and defoliation was examined using indicator cross–correlograms. A cross–correlogram quantifies the spatial covariation between two variables by plotting the cross–correlation for a series of interpoint distances. Cross–correlograms indicated that there was substantial correlation between egg mass counts and subsequent defoliation. These correlations extended to 10 cells (20 km) in some cases. Similar patterns were observed for counts of pupae. In contrast, there was little cross–correlation between defoliation and counts of male moths. These results indicate that counts of egg masses (or pupae) under burlap bands may be the most suitable variable to measure for predicting gypsy moth defoliation on a regional scale. The lack of correlation between male moth counts and regional defoliation is discussed.
Databáze: OpenAIRE