278 IREXE D. DOBROSCKY. 



THE FAUNA OF BIRDS' NESTS. 



Besides the inhabitants that parasitize birds, there were found 

 a great variety of other insects and animals of lower orders. 

 They use the nests as a place to hibernate or to breed ; in the 

 latter case the larvae feed on the animal and vegetable debris 

 in the bottom of the nest. These commensals are namely sow- 

 bugs, spiders and mites, and numerous species of insects. 



The common sow-bug was encountered several times in the 

 nests of robins. As these nests are usually damp it is not 

 surprising that this animal should be found in them. 



Spiders of several species are found in almost all bird nests, 

 especially during the winter months. The majority of the spiders 

 found in the nests of robins, crows, house wrens, bluebirds; chip- 

 ping, song, and field sparrows, catbirds, and woodthrushes were 

 in the immature stages. Egg-sacs were also found in the nests 

 of bluebirds and house wrens during the winter months. 



Numerous mites were found in the nests of crows, robins, 

 house wrens and house sparrows. These were identified by H. 

 E. Ewing as belonging to five distinct species. 



Of the Collembola or spring-tails two species were encountered 

 frequently in the nests of crows, woodthrushes, catbirds, song 

 sparrows, red-eyed vireos, and robins. These were identified by 

 J. \V. Folsom as Entomobrya assuata, a new species, yellowish 

 orange in color; and a smaller purple species, Isotoma arborea. 



A species of Psocids, a group to which the common book-louse 

 belongs, was found in nests of robins and house sparrows in 

 appreciable numbers all year round. 



Two species of thrips (Physopoda) occured in the nests of 

 robins and field sparrows. Limothrips denticornis is an European 

 species three records of which have been reported from New York. 

 The writer collected this species on two occasions from bird nests 

 and there is another record from wheat heads. The common 

 mullein thrips, Neoheegcria verbasci, was louncl in a number of 

 nests. 



Several adult Hemiptera, or what may be truly termed " bugs," 

 were found in the nests of robins. Where they were probably 

 hibernating. They were leaf-eaters belonging to the Family Tin- 

 and the Family Capsidae. 



