The Two-winged Flies 
33 1 
well-defended insects, as bumble-bees, dragon-flies, and the fierce and 
active tiger-beetles. The robber-flies usually rest on the ground or on low 
Fig. 462. Fig. 463. 
Fig. 462.—A robber-fly, Stenopogon inquinatus. (Natural size.) 
Fig. 463.—A bumble-bee-like robber-fly, DasylLis soceata. (Natural size.) 
foliage, and fly quickly up with a buzzing sound when disturbed or attracted 
by prey. All the prey is caught on the wing, held in the long spiny feet of 
the robber-fly, and torn and sucked dry by the sharp piercing-beak. 
Fig. 464. —Diagram of wing of robber-fly, Erax cinerascens, showing venation. 
The larvae live chiefly in decaying wood or in soil containing decom¬ 
posing vegetable matter, and are also predatory, feeding on grubs and other 
Fig. 465. —Mouth-parts of robber-fly, Erax cinerascens. li., labium; hyp., hypopharynx; 
lb., labrum; mx., maxilla; mxl., maxillary lobe; mxp., maxillary palpus. 
underground or wood-boring insects. The pupae are curiously spiny, the 
spines being used as a sort of pushing or pulling organ when they get ready 
to come to the surface of the ground or dead tree to change into imagines 
Some of the species of the genera Laphria and Dasyllis (Fig. 463) look 
astonishingly like bumble-bees and wasps, probably a case of protective 
