THE WHITE-WINGED BIBIO: ITS FOOD, ETC. I13 



despoiling the gardens and fields of every blossom. Reaumur, the noted 

 insect anatomist, saw that, not being provided with mandibles, it was un- 

 able to gnaw the buds and petals in the manner ascribed to it, yet 

 thought that it might cause their blight by sucking their juices. Both 

 of these expressed views were doubtless erroneous, and its frequenting 

 buds and blossoms is, upon the best authority, for the innocent purpose 

 of sipping the nectar of the blossoms and the gummy secretions of the 

 opening buds. {Inxect Transformations, pp. 266-7.) 



The larvae are generally believed to feed almost entirely upon decay- 

 ing vegetable matter. Some of them which had been found "in 

 bunches " in an asparagus bed, in Missouri having been sent to Mr. 

 Walsh for name and habits, after rearing the fly from them he wrote as 

 follows of the larvae : 



They feed exclusively on dead vegetable substances in a moist and 

 decaying state, and are not very particular as to what that substance 

 may be. Years ago I had a parcel of them feeding on damp leaves in 

 a glass vase, and on putting several dozen of our common " oak apples." 

 into the vase, I was surprised to find that they, most of them, quitted 

 the leaves and burrowed into the oak apples. I have always found 

 them as you did — in large crowds together. They should not be 

 destroyed, as they do no harm in either the larva or the fly state. {Prac- 

 tical Entomologist, ii, 1867, p. 83.) 



The earlier statements of injuries to growing vegetation were probably 

 from surmise only, and not based on actual observation. Thus, in con- 

 nection with a plea made for the robin, upon the ground that it destroyed 

 so many of these larvce — from one to two hundred in afresh condition 

 having been taken from the stomach of a single bird — it was said : " The 

 larvse are very destructive, feeding on the roots of plants, and injuring 

 strawberry plats, vines, borders, etc. They live in swarms, perforating 

 the ground like a honey-comb, the fly depositing all its eggs in one 

 place" (Glover, in llept. Comniis. Agriculture ior 1864, p. 441). 



Eaten by the Robin. 



The food of the robin, Merula migra/oria, during the early weeks 

 of its appearance in the spring, consists largely of the larvae of this fly. 

 Of two robins examined in the month of March by Prof. S. A. Forbes, 

 State Entomologist of Illinois, sixty-seven per cent of the contents of 

 the stomachs consisted of this larva, and the same larva was found by 

 Prof. Jenks, of Brown University, to constitute about nine-tenths of the 

 food of the robins examined by him in Massachusetts in February and 

 March, 1858 (S. A. Forbes, in Trans. III. Stale Horticul. /S'oc, xiii, 

 1879, P- 128). 

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