THE CROW AND ITS RELATION" TO MAN. 25 



Records of crows feeding on bees (Apoidea) are few and usually 

 restricted to single insects in individual stomachs. 



Wasps (Vespoidea and Sphecoidea) of various kinds are not un- 

 common articles of diet, and to certain beneficial species attention 

 must be called. Digger wasps (TipMa), one of the most important 

 insect enemies of the white grub, were found in 19 of the 1,340 stom- 

 aches, a total of' 24 individuals being eaten. This is indeed a limited 

 number and is very small in comparison with the enormous number 

 of adult May beetles- (Pkyllophaga) , parents of the white grub, which 

 the crow destroys. This may be explained by the fact that most 

 of the Pkyllophaga eaten are adults, the grubs, which the wasps para- 

 sitize, being taken less frequently. Of course, it is highly probable 

 that some of the larvae eaten had been parasitized and then their 

 consumption by the crow resulted in the destruction of the eggs or 

 larvae of these beneficial insects. It can not be claimed, though, that 

 in its feeding on white grubs the crow is doing anything but good, 

 regardless of how many may be parasitized, as in no way are the in- 

 terrelations between the wasp and the grub disturbed by this indis- 

 criminate destruction. Of the other wasps, members: of the genera 

 Polistes and Odynerus appeared most frequently. Sawflies (Ten- 

 thredinidae), which include the injurious currant and pear slugs, are 

 seldom eaten by crows. Parasitic ichneumons were found in a few 

 stomachs, though never in great quantities. 



Miscellaneous insects. 



Other orders of insects are poorly represented in the crow's food, 

 together forming less than three-fourths of 1 per cent. Most of 

 these are aquatic forms, occurring in stomachs of crows secured in 

 marshy regions. Dragonflies (Odonata) and their nymphs, caddis- 

 flies CTrichoptera) and their larvae inclosed in odd cases of sticks 

 and stones, mayflies (Ephemeridae), dobsons (Gorydalis cornutus), 

 and a few other neuropterous insects comprise the bulk of this food. 

 In . no case were insects of economic importance taken in large 

 numbers. 



SPIDERS. 



While spiders form a large portion of the food of nestling crows 

 (see p. 62), the adults eat but few — less than half of 1 per cent of the 

 annual food. Most of these belong to the wolf, or running, spiders 

 (Lycosidae), terrestrial forms, some species of which grow to consid- 

 erable size. A few jumping spiders (Attidae), daddy longlegs (Pha- 

 langida), and a single orb- weaver (Argiopidae) also were found. 

 Spiders as a whole, being indiscriminately predacious, are doubtless 

 beneficial. The wolf spiders, however, which comprise the largest 

 portion of this part of the crow's food, are restricted in their feeding 

 to terrestrial forms, so that many of the injurious herbivorous species 



