Queen and forager sizes of Bombus affinis cresson (Hymenoptera : Apidae)

This study explores the relationships of selected body measurements in the bumble bee Bombus affinis, and reviews the literature regarding measuring b umble bees. We found that in foraging workers of this species, collected ov er 3 sequential years from the same forest sites, compound-eye length, head length, head width, radial-cell length, scapus length, tibia length, and w ing length all predicted dry weight, a measure of overall size. These same variables, except for head length, also predicted queen weight. Workers had a higher variance in their radial-cell length than queens, and queens had higher variances in their glossa length and weight than workers. In all 13 regression analyses between body size measurements, worker correlation coef ficients (r(2) values) were higher than those for queens. Worker size, meas ured as head width (a strong predictor of body weight), increased with time during 2 out of 3 flight seasons.