RESPONSES OF THE COMMON SOOTY WING SKIPPER TO PATCHES OF HOST PLANTS

Dispersion patterns of eggs and larvae of Pholisora catullus (Lepidoptera: Hesperiidae) changed when size of patches and distance between patches of its host plant (Chenopodium album) changed. With patches widely spaced, large patches had more eggs and larvae per patch but fewer per plant than did smaller patches. Ovipositing females in widely spaced patches encountered patches at frequencies proportional to the patch diameters plus a small detection distance. Though females laid slightly more eggs per encounter in large patches than in smaller patches, larger patches had many more plants and, therefore, fewer eggs per plant. When the spacing between patches was reduced, female skippers laid proportionately more eggs in large patches and fewer in smaller patches, and numbers of eggs per plant no longer differed among patch sizes, a shift due to the greater tendency of females to fly by small patches without landing when the patches were closer together. -from Authors