I8 



Trichogramma odontotae How. Reared from egg masses. 



In nearly every case where one egg was parasitized, all of the 



eggs in the mass were similarly attacked. The adult parasite 



' gnaws its way out through the leaf, emerging from the upper 



surface. 



Derostenus primus How. A chalcid reared from ftgg 

 masses, but is thought to be a secondary parasite on Tricho- 

 gramma odontotae. 



Sympiezus uroplaitae How. A hymenopterous parasite, the 

 white larvae of which was found feeding externally upon the 

 larvae of O. dorsalis. 



Spilochdcis odontotae How. Seen emerging from pupa of 

 0. dorsalis. This is an internal parasite. 



Ichneumon hispa Harris. Bred from pupa of 0. dorsalis. 



The young larva of the wheel bug {Prionidus cristatus) is also 

 reported to feed upon the larvae and adults of this species. They kill 

 the larvae by piercing them with their beak through the epidermis of 

 the leaf. 



REMEDIES. 



■ In spite of the fact that this insect is a very serious pest, little has 

 been done in the way of attempting to control it. One of the remedies 

 suggested is the burning of all leaves and trash under the trees late in 

 the fall, in order to destroy the hibernating adults, but, judging from 

 observations made by the writer in April, 1905, little can be accomplished 

 in this way unless the material is very dry. On April 3 several adults 

 were found at Leesburg, Ohio, in the fine leaf mold just at the surface of 

 the soil. As this material is generally damp it will not readily burn, and 

 the burning of the leaves and coarser rubbish above would not seriously 

 affect the insects. Furthermore, it is very poor policy to destroy the 

 natural protection to the soil late in the fall, leaving the ground bare 

 over winter. 



A study of the life history of this insect, together with its method 

 of feeding, seems to indicate that the weakest point in its life, and the one 

 that can be the most easily and effectively attacked, is during the adult 

 stage. This period covers that time from the first appearance of the 

 adults in the spring until egg laying, which begins about the latter part 

 of May. During this time the adults are feeding upon the leaves of the 

 trees, and generally upon the upper surface, so that a thorough applica- 

 tion of an arsenical poison should be effective. This treatment would not 

 be practicable for application on large forest areas, but in those cases 

 where a few locust trees are grown for ornament, or small commercial 

 plantations are being cultivated for posts or poles, such applications 

 might be advisable. 



