A carina 245 



satisfactory. Water and food are introduced through a thistle-tube 

 inserted through a hole in the cover. (This hole in the cloth is kept 

 below the margin of the tumbler when not in use.) A small layer of 

 non-absorbent cotton protects the spider from drowning when the sand 

 is moistened. 



Food. Adult spiders should be fed upon grasshoppers and other 

 Orthoptera, one insect every three or four days. When these are not 

 available, cultured blue-bottle flies (Calliphora erythrocephala) are 

 sufficient. [See p. 415-] 



Since the newly hatched spiders apparently are to a large extent ex- 

 clusively cannibalistic, it has been considered necessary to permit them 

 to feed upon each other for the first three or four days. To conserve 

 stocks the spiders should be separated after this period and fed fruit 

 flies (Drosophila spp.). [See p. 305.] 



Temperature. For storage: 40 to 50 F. For breeding, oviposition, 

 and hatching of young spiders: room temperature. 



Light. Spiders should not be exposed to direct sunlight. 



Moisture. A somewhat damp habitat is natural. Satisfactory con- 

 ditions of moisture are secured as described above. 



Breeding. Females captured in the fall will lay fertile eggs. Virgin 

 females raised through the winter may be mated with males, which may 

 be distinguished from immature females by their bulbous palpi. 



Egg cases should be separated from adult spiders before hatching. 

 The eggs hatch within three or four weeks. 



References 

 Family Argiopidae 



For feeding of Aranea sericata see p. 242. 

 Family Thomisidae 



For feeding of Olios see p. 242. 



Order acarina 



CULTURE OF NON-PREDACIOUS, NON-PARASITIC MITES 

 (ORIBATOIDEA AND TYROGLYPHOIDEA) 



Arthur Paul Jacot, Asheville, North Carolina 



A CELL FORMED of a microslide, a glass ring, and a large cover 

 has proved most satisfactory. The rings may be 20 x 5 mm. with 

 a # 2 cover glass 22 mm. in diameter. The center of the slide should 

 be etched (with hydrofluoric acid blocked in with paraffin) to give it 

 a rough surface to enable certain species to walk with ease. The ring 

 may be fastened with Canada balsam. The top of the rim must be 

 coated with a very thin film of vaseline, paraffin, or some other sub- 

 stance which will make an air-tight seal with the cover, or the included 



