NO. 7 TROTECTIVE ADAPTATIONS McATEE 37 



species eating them, the insects composed from 40 per cent to 90 per 

 cent of the total food. 



In another study of the elTect of birds upon a severe irru])tion of 

 grasshoppers in California, H. C. Bryant estimated that birds were 

 destroying daily more than 120.000 grasslioppers \wr s(|uare mile in 

 the infested area.' 



In countries, notably Africa, where migrations of large numbers 

 of locusts are of regular occurrence, various species of birds have more 

 or less specialized in following these flights and feeding on the mi- 

 grants, so much so. in fact, as to earn for themselves the name of 

 locust birds.' 



Number of identifications of Saltatoria, 18,784; percentage of 

 identifications among those of all insects, 9.6506; percentage of 

 species in this group among all insect species known, 1.6398. 



Other enemies. — All stages of the Saltatoria are much sought for 

 by various animals. The larvae of Cantharid beetles and of bee flies 

 (Bombyliidae) subsist upon the eggs, as do also certain mites, and 

 the egg masses of some species are dug up and devoured by various 

 mammals, as moles, mice, spermophiles, and skunks. The nymphs 

 and adults fall a prey to vertebrates of nearly all sizes and descrip- 

 tions, ranging from bears, through coyotes, foxes, badgers, skunks, 

 civetcats, weasels, vv^ood rats, squirrels, spermophiles, moles, shrews, 

 and mice, to lizards, tortoises, snakes, salamanders, frogs, and toads. 

 If any seek to escape their land enemies by jumping into the water, 

 they are snapped up by fishes. The adults are destroyed in large 

 numbers by parasitic diptera and hymenoptera. Most of the predatory 

 invertebrates are fond of grasshoppers, this l)eing j^iarticularly true of 

 dragonflies, tiger beetles, ground beetles, robber flies, digger wasps, 

 and spiders. In the case of the latter, S. W. Bilsing found grass- 

 hoppers in 20 per cent of the webs of Epeira trifoUimi, in 35 per cent 

 of those of Argiope riparia, 44 per cent of those of A. irifasciata, and 

 in 53 per cent of those of Agale)ia nacvia. Grasshoppers are parasit- 

 ized by nematodes and protozoa and are subject to bacterial and fungal 

 diseases, which last are said sometimes to destroy them " in myriads." 



Discussion. — The Saltatoria or leaping Orthopteroidea are promi- 

 nent in the insect world more through average large size and the 



*Univ. California Publ. Zoo!., vol. 11, no. i, pp. 16-17, Nov. i, 19 12. 



'See Badenoch, L. N., True tales of tlie insects, pp. 127-128, 1899; La Ikuinic, 

 W., Beihefte z. Tropenpflanzer, vol. 11, no. 2, pp. 65-128, Apr., 1910; Agr. Journ. 

 Cape of Good Hope, vol. 18, pp. 820-833, 1901 ; vol. 19, pp. 99-106, 165-171, 

 248-262, 1901 ; vol. 28, pp. 364-366, 1906; Trans. -South African Phil. Soc, vol. i, 

 p. 193, 1880. 



