THE CANADIAN ENTMOLOGIST. 



As the larva approaches maturity and is about to change to a 

 chrysalis, the colour of the body gradually grows darker until it becomes 

 dark reddish brown, the sides nearly black. The minute whitish granu- 

 lations and the blue dots become mucli more distinctly visible, giving the 

 larva a very difterent appearance. It then selects some suitable spot in 

 which to pass the chryr.alis state, where it spins a web of silk in which its 

 hind feet are entangled, and having prepared and stretched across a silken 

 band to sustain its body in the middle, it casts its larva skin and remains 

 a dull brownish chrysalis until the following spring. 



This insect is widely distributed, being found throughout the greater 

 portion of the United States and Canada. The larva feeds on a number 

 of different trees, but chiefly aftects with us the apple, cherry, thorn and 

 basswood. 



THE USE OF APHIS-EXCRETION AND BENEFIT DERIVED 



THEREFROM. 



BY THOMAS G. GENTRY, GERMANTOWN, PA. 



It is well known to the popular as well as scientific world that the 

 Aphides secrete or rather excrete a peculiarly viscid and honey-like fluid 

 which forms one of the chief delicacies of Ants. That it was originally 

 designed to form an article of food for the latter is a supposition that 

 cannot be entertained for a single moment ; but that it is in some way 

 connected with the preservation of the soft and tender beings by Avhich 

 it is manufactured, there can be no reasonable doubt. Various opinions 

 have been hazarded, and not a few theories devised to account for its 

 probable origin and use and the material benefit which it secures to the 

 authors thereof, but these have been of such an unsatisfactory character 

 as not to merit the approval of the learned. 



While some writers have surmised its application to be connected in 

 some way with the wants of the newly-born Aphis, still the lack ot 

 evidence confirmatory of any such surmise has caused it to fall into 

 neglect and disuse. 



That this fluid has both a primary and a secondary purpose to subserve 

 in the economy of the plant louse is a fact the truth of which stands off 

 as gross as black from white. Recently, while engaged in the study of the 



