CARNIVOROUS BUTTERFLIES — CLARK 495 



tlie longer season in the south this must indicate a fourth brood not 

 observed by Mr. Edwards, Avho mentioned that he had received 

 caterpiUars from Washington, T>. C, as late as October 4, Mr, 

 Scudder surmised that it is probable that there is an added brood in 

 the south, for Abbot records a caterpillar in Georgia as changing to 

 a chrysalis on April 14, which indicates a parent on the wing in 

 March, at the opening of the spring, and so an entire brood in ad- 

 vance of the valleys of West Virginia. 



As remai-ked by Mr. Scudder, the winter is probably passed in the 

 chi-ysalis, but it is not impossible, as conjectured by him, that it may 

 also winter as a butterfly, for battered specimens have been taken 

 on the wing very early in the year before the complete unfolding of 

 the leaves. 



Oviposition. — The female butterfly, as observed by Miss Morton, 

 flutters about and finally settles on the aphids, carefully selects a 

 place in the midst of them, and deposits an egg, always on the under- 

 side of the twig, Mr. Fletcher confirmed this observation, and 

 noticed that the female runs all over the clusters of aphids with a 

 twitching walk something like a wasp. 



While the eggs are usually deposited in the mass of aphids, both 

 Miss Morton and Mr. Fletcher noticed that they are sometimes laid 

 on tlie bark near the aphids and occasionally on adjacent leaves. 



I have watched two females placing eggs on the bark on the under 

 side of the twigs just below the aphid clusters, an inch or so away. 

 In these instances the exudation from the aphids was so very copious 

 that I imagine the butterfly was deterred from alighting upon them. 

 In both cases the females fluttered close to the patches for some 

 minutes before suddenly alighting just beneath them. 



Eggs. — The eggs are easily found by brushing off the aphids from 

 the branch. There may be a dozen or moi'e in a single colony of 

 aphids, but in that event they are probably laid b}^ several females. 

 Miss Morton saw two females lay three or four eggs, and from one to 

 four caterpillars of the same size is the usual complement for each 

 aphid colony on alder. But later in the summer where the butter- 

 flies are common there may be a dozen or so caterpillars of all sizes 

 from the very smallest to the fully grown in a large cluster. 



As described by Mr. Scudder the eggs, which are much flattened 

 and twice as broad as high, are faint green, almost colorless, and 

 glistening. During deposition they are covered with a thin 

 albuminous deposit Avhicli makes it difficult to get any proper view of 

 their texture. Their surface is smooth and glistening, though still 

 very faintly punctulate, broken up by very slight, slender, and equal 

 I'ounded elevations into polygonal cells the height of which is a little 

 greater than the width. They are very different from the usual type 



