144 tflE entomologist's RECORf). 



5. — On the arrangement of the eggs when laid. — The methods 

 adopted by the parent moths in the disposition and arrangement of the 

 eggs when laying them are very various ; some lay their eggs side by 

 side in clusters ; others lay them also in clusters, but with one egg 

 partially overlapping another ; others again deposit them solitarily, 

 either scattering them loosely on the ground as is the habit of Hcpialus, 

 or attaching them to the bark, to a twig, to a leaf, or on a leaf-bud ; 

 whilst the Micropterygidae and Adelidae are provided with a cutting 

 apparatus, with which they cut out pockets in the leaf and deposit the 

 egg within. There is the same resemblance between closely allied 

 species in the manner in which they deposit their eggs, which we found 

 to obtain in regard to shape. The eggs of the Pyralides almost always 

 have their edges overlapping, imbricated as it is called ; this imbrication 

 is almost unknown in the Noctu.*: and Geometr.b, although among the 

 former it occurs in the sub-genus Viminia of the genus Acronycta, the 

 allied sub-genus Cuspidia having the eggs laid solitarily, whilst among 

 the Geojietr.« the imbricated arrangement obtains in the case of 

 Eiujonia quercinaria. The imbricated method of egg-laying must, to a 

 certain extent, depend upon the shape and general flatness of the egg. 



G. — On the perils of eocj-life. — It is generally supposed, although 

 perhaps not altogether correctly, that a greater destruction of insect life 

 takes place in the egg stage than in any other. Of the great number of 

 fertile eggs laid by insects, only a small percentage come to maturity. 

 Some females, as we have seen, lay considerably more than a tliousand 

 eggs apiece, and yet, year by year, save under very exceptional condi- 

 tions, only about the same average number of imagines is met with. 

 The destruction takes place in all the stages, and it is hard to say in 

 which stage it is the most complete. It may be that natural selection 

 protects one species moi'e perfectly in one stage, another sjjecies in 

 another stage, Init, so far, young larva? appear to be the particular form 

 against wliich destructive agencies are most active. It must, however, 

 be admitted, especially in the case of eggs laid in large batches in the 

 same spot, that, if an attack thereon is made by some voracious ento- 

 mophagous enemy, the destruction is absolutely complete. Scudder 

 records on one occasion leaving a Pyrameis cnrtiw/ entrapped on a thistle, 

 and in a brief time she laid several eggs ; but when he went a second 

 day to see if there were others, he found only the bases of tlie eggs 

 which had been laid by her, with a single exception ; this egg presented 

 a peculiar a})})earance, for a pair of ants were tugging at it, and had 

 just succeeded in piercing it aljove, so that the egg was spoiled for him. 

 Tlie same author says, " The chief offenders are mites and spiders of 

 different kinds, and ants, who seem as fond of animal as of the sweeter 

 vegetable juices." Mr. Edwards writes : — " Tliere is a monstrous waste 

 of eggs in Grapta inten-ogationis ; out of the tliousands which must have 

 been laid by, say, thirty females, hardly twenty butterflies resulted. I 

 have watched the eggs, and they are caiTied off and no trace left, I sujipose 

 by spiders. I liad a lot of PapiUo ajax eggs laid in a keg, over paper, and 

 had left them there to hatch, though I usually cut off the stem and hatch 

 the eggs in the house. I took off the cloth one evening to let the eggs get 

 the night air, and in the morning, there was no trace of an egg on the 

 plant. So it happened with atalanta. Nor are tliese mimite objects 

 by any means free from tlie attacks of parasites, which pass their entire 

 existence within this narrow comijass. Witness the not inconsiderable 



