EXPERIMENT STATION BULLETINS 191 



were brought in on August 1 and the flies emerged on August 8. This would seem 

 to indicate that the parasite in question has more than one host. 



The writer was asked several times during his stay in Alger county why it was 

 that the potato-beetles were so few in that region during the summer just passed. It 

 is not at all unlikely their attacks were materially reduced by this parasite. 



WHEAT-HEAD FLY. 

 (Meromyza amerlcana. Fitch.) 



Specimens of rye, having the heads bleached out to a dry, straw-color, while the 

 leaves and stem below the upper joint were apparently healthy, were sent by Mr. Geis- 

 niar on July 10. They were placed in a cage, and on August 2, the adults emerged. The 

 larva of this tly works just above the top joint in rye, wheat and some grasses, eating 

 out the succulent base of the stem at this point. The only remedial measure yet known 

 is the rotation of crops. 



THE FI-AT-HEADED APPLE-TREE BOREK. 

 {Chrysobothris femorata. Fab.) 



Flat-headed Apnle-tree Borer {Chrynobotlnis femorata), from C. V. Riley, Insects of 



Missouri, 2d Rep. 



This insect bores into the trunks and larger limbs of apple trees, doing very great 

 damage. It is the worst borer of the apple, while it w'orks also in oak, peach, soft 

 maple, weeping willow, mountain ash, box-elder, pear, linden, beech and cherry. 



The eggs are said to be laid on the bark in June and during the fore part of July. 

 The larvie work at first in the sap-wood, making cavities between the bark and the 

 wood, ejecting their excrement through small openings in the bark. Late in the 

 summer or early in the fall they penetrate into tlie solid heart-wood to pass the 

 winter, ceasing at this time to eject castings, instead, packing their waste in the 

 cavities just vacated. It takes two or three years for them to become perfect, winged 

 insects. The larva that does all this damage is white and soft. uiii)rotected other- 

 wise than by its liabitation. The front end of the body, or the thorax, is very broad 

 and oval and the head small. The holes bored by this insect are not round, but 

 oval in section, fitting the form of the thorax. 



ItEMEDIBS. 



Now, borers are difficult things to fight under all circumstancis. and no course of 

 treatment is known which will entirely eradicate them. Nevertheless, every one that is 

 killed is just so much gained for the general good. There are three practices that 

 have been found useful, though no one of them or all of them combined will rid an 

 orchard of an insect that breeds in so many host trees. They are the same old remedies 

 recommended by Dr. Fitch many years ago and which have not since been improved 

 upon. 



They consist in protecting by means of a wash, buuling the trunk with paper, and 

 digging out the young larvie. 



Wliitewash or whitewasli and glue, apjjlied to the trunk and large limbs is said to 

 have a very beneficial eilect. It sliould be applied early in June, and kept on in good 

 condition through most of July. Soft soap is also used for this jiurpose. 



Second, binding paper about the trunk and larger linil)s. For this purpose news- 

 paper is best used next the tree and Vniilding paper outside. 



Third, searching for the young larvse during August and September. At this time the 

 young have not gone into the sap-wood, but live in cavities just under the bark, the 

 excrement being pushed out through small holes. When any suspicious waste is seen 



