2/0 



ENTOMOLOGY 



twisted or branched (Figs. 262, 89) to hold the pollen, do not 

 occur on other than pollen-gathering species of insects. Cau- 

 dell found that out of 200 species of Hymenoptera only 23 

 species had branched hairs and that these species belonged 

 without exception to the pollen-gathering group Anthophila, 



FIG. 263. 



w 



Adaptive modifications of the legs of the worker honey bee. A, outer aspect of 

 left hind leg; B, portion of left middle leg; C, inner aspect of tibio-tarsal region of 

 left hind leg; D, tibio-tarsal region of left fore leg; a, antenna comb.; b, brush; c, 

 coxa; co, corbiculum; f, femur; pc, pollen combs; s, spur; sp, spines; ss, spines; t, 

 trochanter; ti, tibia; v, velum; w, wax pincers; 1-5, tarsal segments; i, metatarsus, 

 or planta. 



no representative of which was found without such hairs. 

 Similar branched hairs occur also on the flower-frequenting 

 Bombyliidse and Syrphidse. 



The most extensive modifications in relation to flowers are 

 found in Pronuba, as already described, and above all in 

 Apidse, especially the honey bee. 



Honey Bee. The thorax and abdomen and the bases of the 

 legs are clothed with flexible branching hairs (Fig. 262), 



