950 Popular Editions of Station Bulletins of the 



Most remarkable of the peculiarities of tree 



Sex crickets is the fact that the male attracts the female 



attraction not only by music, but by a feast, both furnished 



of tree by his own body. When singing, which is evi- 



crickets. dently to attract the female, the upraised wings 



disclose upon the body of the male a peculiar rounded 



depression with elevated margin, which contains numerous hollow 



glandular hairs, and two paired openings from much branched glands 



within the fore-body of the insect. The secretion of these glands 



is eagerly consumed by the female cricket which mounts upon 



the back of the male and feeds in the depression for several minutes 



previous to the actual mating, while the crossed antennae of the pair 



are touched and rubbed one upon the other in what appear to be 



mutual caresses. 



Two of the three forms mentioned, the snowy 



Economic tree cricket and the narrow-winged tree cricket, 



importance live quite largely in apple, plum and cherry orchards 



of tree but are also somewhat common on the raspberries and 



crickets. on walnut. During their early life they are probably 



beneficial, at least not injurious, as they live to quite 



an extent on other insects — including even their own weak or disabled 



relatives. On dissecting several snowy crickets (nymphs of the 



fourth and fifth instars), the crops of about half of them were found 



to contain a large proportion of materials of insect origin, while in 



the others vegetable matter predominated, including leaf tissue and 



fungous threads and spores. 



The insect remains that could be identified were those of their 

 own or their mates' cast-off skins, broken pieces of insects' eyes, 

 probably those of plant lice, and, in practically all cases, portions of 

 the protective coverings and of the bodies of San Jose scales. In 

 one cricket's crop remains of twenty-four scales were found, with 

 others probably present but not identifiable. This discovery led to 

 an experiment to test the destruction of scales by crickets, and in 

 laboratory tests a single cricket ate from 300 to 900 scales nightly, 

 both covering and insect below. This would indicate that where 

 crickets occur on scale-infested trees they make this pest a consid- 

 erable part of their diet; yet the scale is constantly spreading in 

 orchards that are well stocked with crickets. They can never be 

 depended upon to control the scale, and if injurious in other ways, 

 as they seem to be, the destruction of the scales should not be allowed 

 to count heavily in their favor. 



During the later stages of their lives tree crickets live largely on 

 vegetable tissue; and may do some slight harm by eating holes in 

 leaves. They are also said, in some places, to cause considerable 

 damage by eating holes in fruit, in which they produce a very char- 

 acteristic injury. The opening through the skin of the peach or 

 plum will be small, just large enough to allow the head and thin 



