REPORT OF THE ENTOMOLOGIST. 241 



this parasite are usually found within the body of oi>e of the loaf-min- 

 ing larvae. The parasitic larv^ae are pale inilli:- white in color, with the 

 ahmentary canal blackisli ; they are Jong and slender in form. 



A verj^ small tachina tly was also bred, both from the northern and 

 southern specimens. 



01!^^ PEEDACEOUS LEPIDOPTEllOUS IIn'SECTS. 



As nearly all of the insects which belong to the order licpidoptera, 

 which includes butterliies and moths, are in the caterpillar state purely 

 vegetable feeders, the life history of any species which vary from tliis 

 rule is of considerable scientific interest; and whcD, as is the case with 

 those about to be described, these insects destroy other insects which 

 are noxious, they become of interest to the practical man as well as to 

 the scientist. 



The insect popularly known as the cottony maple scale (Piilvinaria 

 inmimerabilis, Eathvon) has become a serious pest in many localities. 

 In its adult state it is an oval brownish scale about one-fourth of an 

 inch in length. From beneath its body projects a mass of white cottony 

 excretion, Avhich covers the eggs and young lice and also renders the in- 

 sect very conspicuous. It is found in large numbers on njaplc, box-eldei', 

 and sycamore trees, and lately it has become common on grape-vines. 



This insect is not an easy one to contend against, and hence any nat- 

 ural check to its increase is of high interest. During the past year I 

 discovered a Lepidopterous enemy of this pest, whicii I described in a 

 IDaper reap before the Saratoga meeting of the American Association 

 for the Advancement of Science.* I will quote jnirt of this paper : 



THE COCCID-EATING DAKRUMA. 



(Dalcrmna coccidivora, Comstock.) 



Order Lepidoptera; family Pyralidae, 



While studying a colony of the cottony maple scale (Pulvinaria innumcraullh, Kalh- 

 von) which was foimd on a branch of Ncf/undo accroidea in Wash; ns^ ton, I was sur- 

 prised to find a Pyralid larva liyino; within the cottony mass excreted'by one of these 

 insects. On fnrther examination i t was found that very many of the bark-iice afforded 

 retreats for similar larvae. This, with the iiict that the eggs deposited by such indi- 

 Tiduals, or the young lice developed from them, had been destroyed, indicated that the 

 Pyralid larvae were predaceous. One of these larvae was placed in a ghiss tube witli 

 a bark-louse, the eggs of which had not been destroyed. These eggs had j list hatched 

 and the cottony excretion was s%v arming with the young lice. Tiio larva soon made 

 its way imder this mass, and after si)inniug a delicate silicon tube about its bod v, began 

 to devour the young lice greedily. The larva was placed in the tube at o j). in. ; at 9 

 a. m. the following day it, was found that fully one-third of tho lice had beou de- 

 stroyed, showing that if these larvae occur in great numbers they must prove au effi- 

 cient check to the spread of this post of our shade-trees. It is an interesting fact 

 bearing upon this point that as yet this bark-louse has not beonmo commou iu Wash- 

 ington. Careful search revealed only a few sporadic individuals except upon a singlo 

 box-elder tree ; and there the lu-edaceous caterpillars were so numerous that it was 

 with difficulty that any scales were found not infested by them. 



Although the caterpillar is well protected, living as it' does Avithiu the mass of cot- 

 tony excretion, it spins about its body a delicate silken tube. This tube reminds one ■ 

 of that spun by Galleria, but it is more delicate ; and when spun within the cottony 

 mass, it is with difficulty distinguished from it. When a branch is thickly infested 

 by I'ulvinaria these tubes extend iTom one bark-louse to another. Tlic caterpillars are 

 very active, moving freely about within these silken passages from beneath one scale 

 to another. 



At the time my observations were made (June 24), many of the caterpillars were full 



* This paper was published in th© North Ameri.cau Entomologist, vol. i, pp. 85-2'.>. 

 16 AQ 



