82 



epidermis of the leaf. Should a beetle be met by the wheel bug it is 

 at once lifted in the air on the tip of the bug's proboscis. 



In its earlier stages the leaf -mining locust beetle appears to be well 

 protected from the attacks of true parasites, the eggs being inclosed 

 in an armor-like covering, and the pupa remaining out of sight in the 

 snug retreat of the mine, but still we have reared in a single season 

 no less than four different species of parasites, and Dr. Harris men- 

 tions and describes still another species (Ichneumon hlspse) which has 

 thus far remained unknown to us. These four species of parasites are 

 as follows: 



Trichogramma odontotse How. — Was reared quite commonly from the egg masses of 

 this beetle. In cases of parasitism all the eggs of an egg mass were generally 

 parasitized, and only in a few instances were two or three parasitized eggs found 

 where the rest produced larva?. The fly emerges usually from the underside of 

 the egg and gnaws its way through the leaf. Dr. Howard described this and the 

 other three species which will be mentioned below, in Volume I of Entomologica 

 Americana (pp. 117-118). 



Derostenus primus How. — A few specimens of this chalcis fly were obtained from 

 the egg masses of the Odontota. The breeding of one of these species from the 

 peculiar pupae of a Eulophus would seem to indicate that it may in all cases be a 

 secondary parasite, and that the specimens bred from the egg of the Odontota may 

 have fed in the larva state upon the larva- or pupae of Trichogramma odontotae. 



Sympiezus uroplatse How.— Upon opening the mines we observed in a few instances 

 a whitish hymenopterous larva feeding externally on the Odontota larva and having 

 already devoured the posterior half of its body. The host larva was of course dead 

 when thus found. Whether or not this parasite in its earlier stage lives within the 

 Odontota larva has not been ascertained. It appears to be very rare, and of the 

 three specimens observed only one was raised to the perfect insect. It formed a 

 naked black pupa within the mine. 



Spilochalcis odontota How. — This parasite was observed emerging from the Odontota 

 pupa, and no doubt lives as larva within that of the Odontota. The parasitized 

 pupae can be distinguished from the healthy ones by being darker and rigid. Upon 

 opening such pupae the parasite larva, apparently full-grown, was found to occupy 

 the empty cavity, but the specimens thus disturbed died without changing to pupa. 

 Only one winged parasite was obtained from a pupa which was left undisturbed in 

 the mine. 



The Ichneumon hispa described by Harris was obtained by him from the pupa of 

 Odontota '/ua>]r<ii<i (=rosea) and 0. scutellaris (=dorsalis). It may belong to the 

 Braconidae. Harris's description was published in 1835 (Boston Journ. Nat. Hist., 

 Vol. I, p. 150). 



REMEDIES. 



From what has been said in regard to the feeding habits of the leaf- 

 mining locust beetle it is obvious that whatever of a remedial nature 

 is employed must be directed toward the beetles, since the larvae 

 are completely hidden in their mines in the leaves during their 

 short lifetime, and the eggs and pupae are similar \y protected from 

 contact poisons. The beetles can be killed by means of the arsenicals 



