THE LIFE-HISTORY OF A LEPIDOPTKROtTS INStiCT. 145 



list of tlie excessively minute Hymenoptera of the genera Trichogranima 

 and Telenomas, all of which have been raised by tlie merest accident 

 from eggs collected in the field. The five known kinds have always 

 been found on the eggs of twelve different species of American butter- 

 flies. Were this mode of collection more commonly and authentically 

 employed, doubtless the list would be vastly extended. It is a curious 

 fact, that there are no cases known to us of parasitic attack ujDon those 

 eggs which winter, and are therefore subjected for the longest period 

 to such chalices. I am inclined to believe that on the whole the 

 greatest destruction of lepidopterous life takes place in the egg-stage.'' 

 Certainly, if the very first larval stage be added to it, the statement 

 would be unquestionably true, but scarcely otherwise in iny opinion. 

 The escape of the more fortunate must be put down to (1) The minute- 

 ness of the objects ; (2) Their extreme numbers ; (3) The brevity of 

 their existence as eggs. 



Mr. Woodworth writes : — " I watched an Euvanessa antiopa while she 

 was laying perhaps one-third of the egg-mass ; at first, she seemed to pay 

 no attention to me although I was so close, but finally, probably on account 

 of my moving, she seemed to become restless, laid quite a number of 

 eggs on tojj of the others, and then, without warning, was off. I cut 

 the stem at once, and noticed on the mass of eggs a little hymenopterous 

 parasite (Telenomus graptae), which seemed to be depositing eggs also. 

 It would run across the egg mass, then pause a moment or two over two 

 or three eggs in succession, and then be off to another part of the egg- 

 mass and repeat the performance. The specimen was preserved, and 

 some of the eggs allowed to hatch, but no trace of parasitism appeared 

 in them." 



7. — On the way in which eggs are protected. — The eggs are almost 

 always laid on the food-j^lant in a state of nature although, if the species 

 be grass or root feeders, they may be sprinkled loosely on the gi-ound 

 among the roots of the plants on which the larvae feed. In the case of 

 eggs which are laid on the food-plant, those which belong to species 

 that will hatch and feed up the same year are usually laid on the 

 leaves, the colour being generally such as will harmonize with the colour 

 of the leaves on which they are placed. Those that will hybernate, are 

 usually of a dark colour, corresponding to the colour of the twig or stem 

 on which the egg is then most frequently deposited. Those that are 

 scattered on the ground, are usually of a dirt-coloured or pearly apjjear- 

 ance. In fact, the general colour is such as to protect the eggs from 

 spiders, birds, predaceous insects and other creatures that would feed 

 on them, and from parasites that would lay their eggs on them. 



Frequently jDcculiar developments are noticed. Thus, Geometra 

 vernaria lays its eggs one upon the other (to the number of about a dozen), 

 on the stems of Clematis vitalba, the rouleaux thus formed having every 

 appearance of a broken twig or leaf-stalk. The eggs of Tohjpe velleda 

 (an American species) are laid in strings, and are covered by hairs 

 from the tuft at the end of the abdomen of the female moth, so that the 

 whole closely resembles a hairy caterpillar. The female of Anisopteryx 

 aescularia, lays its eggs round and round a twig, covering them with the 

 scales from its anal tuft, until they fairly look like a slight thickening 

 of the twig. Sometimes the eggs are squeezed into crevices, the female 

 being provided with a long ovipositor, as in Tephrosia crepuscular ia, to 

 put them into deep crannies, quite out of sight. 



