WING DAMAGE IN OVERWINTERING POPULATIONS OF MONARCH BUTTERFLY AT 2 CALIFORNIA SITES

Overwintering monarch butterflies collected from two California sites did not show a progressive wing deterioration. Butterflies collected e arlier in the season showed magnitude of wing area loss (almost-equal- to 2%) similar to that in butterflies collected later in the season. W ing damage frequencies attributed to wing area loss among males increa sed significantly in March and were associated with mating activity. F emales did not show this increase in wing damage frequency but had a s ignificantly greater total wing area loss than males. Although hind wi ngs were damaged more frequently than forewings, the amount of missing wing area was not significantly different.