OF THE STATE ENTOMOLOGIST. 89 



time, there stood ray little ChaUis as immovable as a statue at her 

 post. She may be touched with the finger while thus engaged, or 

 even crushed, as I have often inadvertently done in my attempts to 

 capture her, but nothing short ot this actual violence can move her 

 from her position. With such wonderful perseverance and devotion 

 do these living atoms of creation perform their allotted part in the 

 complicated economy of nature. 



The egg thus deposited hatches into the little footless larva pre- 

 viously mentioned. This larva is so admirably described by Dr. Fitch, 

 in a single sentence, that 1 can not do better than copy his descrip- 

 tion : "Under these scales I have repeatedly met with a small mag- 

 got, three-hundredths of an inch long, or frequently much smaller, of 

 a broad oval form, rounded at one end and tapering to an acute point 

 at the other, soft, of a honey-yellow color, slightly translucent and 

 shining, with an opaque brownish cloud in the middle, produced by 

 alimentary matter in the viscera, and divided into segments by faintly 

 impressed transverse lines." (Fig. 34, c.) 



The only motion of which this small grub is capable is a slight 

 extension and contraction of its body, particularly at the two extrem- 

 ities, by which its form is correspondingly modilied. 



There is usually but one larva under each scale, and I have never 

 seen more than two. In the earlier part of the season it is seen ad- 

 hering to the body of the Bark-louse, but later it is found in the midst 

 of the eggs or their remains. 



The Ohalcis-fly itself is a beautiful object under the microscope. 

 Its length is a little less than half a line, or about one-twenty-fifth of 

 an inch, though I have captured a few specimens considerably smaller, 

 being but little more than one-third of a line. I at first supposed that 

 these smaller individuals were males, but all the specimens that I 

 have examined have proved to be females. Their color is a uniform 

 pale lemon yellow. The only variation from this color is in the minute 

 mandibles, which are reddish brown. There are three coral red occelli 

 on the summit of the head, and the ovipositor, which lies in a groove 

 on the underside of the abdomen, exhibits a slight reddish tint. The 

 wings are thickly beset, over nearly their whole surface, with bristly 

 points, and their margin is ornamented with a long fringe. 



But a better idea of the appearance of Xhis little insect will be 

 obtained from the magnified figures which accompany this article 

 (Fig. 34 a showing fjeriect fly, h the greatly magnified antenna, and 

 G the larva) than from any verbal description. 



By observations, made as late as the first week in November, the 

 opinion is confirmed that the Chalcis of the Bark-louse has two broods 

 in a year. By the middle of September we find many of this year's 

 scales pierced with the round holes through which the first brood of 

 Chalcides has escaped; and late in the fall we find, under about an 

 equal number of scales, the fully-grown larvre of the second brood, 

 sometimes with the eggs of the Bark-louse upon which they have sub- 

 sisted all consumed, and sometimes with a few remaining ; and in this 

 state they undoubtedly pass the winter. This second brood must ap- 

 pear in the winged lorm early enough next summer to deposit the 

 eggs from which the first brood of next year will proceed. 



Dr. LeBaron found that in 1870, in different orchards in DuPage 

 county, Illinois, only one in fifteen of the scales examined contained 

 healthy eggs — so effectually has this little Aphelinus^ assisted by 

 other enemies, such as mites and lady-birds, done its work 



