HOW TO KNOW THE INSECS 



many an unfortunate Insect suffers from their attacks. There are 

 many known species, some of which are quite large. Gray Is the 

 predominating color. Their choice of habitat Is much varied In 

 different species. The collector who wishes to get the largest 

 number of species v.'lll visit a v/lde variety of regions. 



11b Top of head not hollowed 12 



12a Anal cell open (a), or closed near the wing margin, the 

 anal vein always reaching the margin. (The Bee Flies) Fig. 209. 



Family 30, BOMBYLIIDAE 



209. Sparnopollus fulvxis Wled. 



Black, thickly covered with golden 

 yellow hairs. Frequent, hovering over 

 flowers or alighting on them. Length 

 9-10 mm. 



There is considerable variation in 

 size and shape of the bee flies. Many 

 of them look like fluffy little balls 

 lazily dangling over a flower, where 

 they feed on pollen and nectar. The 

 larvae are parasitic on other Insects. 

 Since the hairs, which rub off easily, 

 3. are necessary for identification the 

 be very careful with specimens of this family. 

 closed, remote from wing margin (a); anal vein 

 sometimes wanting. (The Dance Flies) 



Family 33, EMPIDAE 



Figure 2 



collector must 



12b Anal cell 



never reaching margin, 

 (in part) Fig. 210. 



Figure 210, 



Fig. 210. Rhamphomyia rava Lw. 



Head, thorax and abdomen feebly 

 marked with brown. Eyes dark 

 reddish brov/n. Wings and legs 

 yellowish brown. Length about 9mm. 



Who has not watched with wonder 

 the swarms of small to medium sized 

 flies, often seen floating with up 

 and down movements in the shade of 

 a tree? They are predacious, 

 luckily, - the world would soon be 

 overrun with Insects if many of 

 them were not set against the others. The family is a large one 

 but no one knows much about the Iowa species. 

 13a A spurious (extra) vein running diagonal ly between the 

 third and fourth veins (a), bisecting the anterior cross vein; 

 anal cell closed near wing margin. (The Flower Flies.) Fig. 211. 



Fami ly 39, SYRPHIDAE 

 Fig. 211. Syrphus ribesli L. 



Blackish with pale yellov/ markings. Its 

 larvae feed on the melon aphis. Length 

 7-8 mm. (From U.S.D.A.) 



The flower flies are doubly valuable. 

 Many of them feed in their larval state 

 on plant lice and m.ealy bugs. Nearly all 

 of them make a valuable contribution in 

 pollinating plants. They look like bees 

 and often act like them, which doubtless 

 gives them much protection from the birds 

 and other enemies. This is one of the 

 largest families of Dlptera. 



101 



Figure 211, 



