LEAF-AREA AND TOUGHNESS - EFFECTS ON NESTING MATERIAL PREFERENCES OF MEGACHILE-ROTUNDATA (HYMENOPTERA, MEGACHILIDAE)

Nesting material preferences were obtained when the alfalfa leafcuttin g bee, Megachile rotundata, was exposed to 11 crop species over 2 nest ing seasons. In general, hi. rotundata demonstrated a graded preferenc e response when collecting leaf cuttings from these species. The major ity of plants were moderately preferred over one or both seasons, but extreme preference responses were consistently observed for buckwheat and anik alfalfa leaves. These responses were opposite, however, as M. rotundata universally preferred foraging from buckwheat and avoided c utting anik alfalfa. Leaf toughness did not influence preference withi n this study, but surface area affected choice when the mean leaf area of a species was <1 cm(2).