﻿76 SEVENTH ANNUAL KEPORT 



patches, the light parts being hyaline. The antenna3 are reddish- 

 brown, yellow beyond the middle and dark brown toward tips; the 

 ovipositor has the terebra dark and the sheaths yellow with dark 

 brown extremities. Full descriptions of the species under the name 

 of Lahena grallator have been published by Mr. Cresson* and by 

 Mr. Walsh, f who bred it from hickory wood infested with the larva of 

 Cerasphorus cinctus^ a longicorn beetle. This fact shows that the 

 Useful Labena is not confined in its attacks to the larva of Ohryso- 

 bothris, as the other species seems to be. I bred this fly from aChry- 

 feobothris larva infesting an apple tree. It was handed to me by Mr. 

 W. W. Tipton, of Burlington, Kansas, j ust as it was spinning a delicate 

 transparent cocoon, and Mr. T. felt sure that he had made a grand dis- 

 covery, and that entomologists had all been wrong in not stating that 

 the flat-headed apple tree borer makes a cocoon. Persons unfamiliar 

 with parasitism in the insect world are apt to jump to such hasty con- 

 clusions ; and it is only necessary in this connection to say that the 

 Chrysobothris never does make a silken cocoon, and that whenever 

 sucli is found in its burrow, its contents should not be crushed, but 

 allowed to mature and escape. 



Where the Chrysobothris breeds in felled oak logs or in stumps,it 

 is often destroyed by ants, and they doubtless frequently reach it 

 even in growing trees, especially when the entrance is exposed, as 

 just described by Mr. Titts. 



remedies'. 



In treating of the means to be employed against this Flat-headed 

 borer, one important fact should be borne in mind. The natural 

 breeding place of the insect is undoubtedly in the old decaying oaks 

 of our woods, and I have known it to swarm in old postoak stumps 

 from which the tops had been felled for a number of years. In fact 

 it prefers partially dead or injured trees to those which are thrifty and 

 vigorous, and partly for this reason, and partly because rough, cracked 

 bark forms a better nidus for the female to lay her eggs, the species 

 is most abundantly found on the southwest side of young apple trees 

 where they are most apt to get injured by sunscald. Sickliness in the 

 tree, injury from the whifiletree or other cause, therefore, predispose 

 to its attacks. It is for this reason that transplanted trees, checked as 

 they are in their growth, usually fare badly. But there is yet one 

 other predisposing cause which few people suspect, and that is reck- 



•Proc. Phil. Ent. Soc. Ill, pp. 400-1. 



t Trans. Ac. Sc. of St. Louis, III, pp. lt>2-3. 



