14 



NEW YORK STATE MVSEUM 



entomoloijist who seeks some melhod of controlling^ injurious species. A 

 knowledije of the life history and habits of an insect pest is almost essential 

 to a person attempting to control it, because there is usually some weak 

 point in its life history which may he taken advantage of in devising a 

 practical mi-tiiod of keeping it in check. The haljits of insects are con- 

 sequently of great practical importance. 



Egg. All insects develop from eggs which i)reseiU widely variable forms 

 in different species and are frecpiently of e.xceedingly beautiful design. 

 They may be placed rn clustt-rs, bunches or singly ; on or in leaves, bark, 

 food products, etc.; tucked in all manner of crevices, dropped at random in 

 the grass, or buried in the soil. They may be arranged in single or double 

 rows, placed in bands about a twig, left unj^jrotected or covered with hairs 

 or scales or sheltered by a gummy secretion. A great many eggs are 

 nearly smooth and globular, but those of many butterllies and some moths 

 are somewhat elongated, delicately ribbed and with the surface broken into 

 innumerable smaller areas by minor riilges. The eggs of a number of true 

 bugs are nearly barrel-shapeil and are crowned with a ring of small sjiines. 

 Certain minute fruit flies ( 1 )ros()i)hila) deposit theirs in tU-caying fruit and 

 were it not for tlu- curious api)endages extending on the surface of the 

 semili(|tiid nidus, the embrNo wouKl probably suffocate for want of air. 

 The lace-winged lly (Chrysopaj is of interest because of her peculiar stalked 

 eggs [pi. 20, fig. 18^1 placed in clusters on leaf or twig This curious 

 arrangement is believed to be for the jjurpose of prexcnting earlier hatching 

 individuals from devouring their unde\'elopeil relaiixcs. The eggs of a 

 Californian red spider, T e I r a n \- c h us m \- 1 i 1 a s p i d i s, are remarkal)le ' 

 for the umbrella handlelike stem projecting in tin- air. from the tip of which 

 strantls of silk railiatc- an<l are attached at a little distanci' to the sui)porting 

 surface. This tlevice jjrobably affords mor.- security on account ot the 

 elastic fastening. Man)- insect eggs are depositetl in masses and their form 

 is frequently modified by the supporting surface or surrounding eggs. 

 Some species, like the tussock moth and the tent caterpillar, protect their 



' 1902 Wootlworth, C. \V. Cal. Agric. Exp. Sta. Bill. 145, p. 5. 



