212 REPORT OF THE COMMISSIONER OP AGRICULTURE. 



was quite numerous, but when the second brood began to make their 

 cases, about the end of September, the apple trees were a 8oriy wight to 

 the orchardist. I have frequently counted from twenty-five to thirty 

 separate mines in a single leaf, from whit'h one can see what a great 

 dp*in this insect must have caused upon the vitality of the plant. In 

 early October, when permanent hibernating quarters had been taken up, 

 the tree trunks and larger branches were fairly covered with the clus- 

 tering cases. I have counted forty-seven on a spot of bark not larger 

 than a dime. In the crotches of the limbs, in the crevices of knots, and 

 in similar places they were particularly abundant. They were also to 

 be found upon the grass and sticks at the*base of the tree. 



The individuals of the first brood transform to pupae almost im- 

 mediately upon permanently fastening their cases, but the members of 

 the last brood hibernate in the larva state. A case opened at any time 

 during the winter will be found to contain a short thick yellow larva 

 differing considerably from the mining form. (A description of both 

 forms will be found at the end of this account.) In this state the insect 

 remains until some time in March or April, depending upon the severity 

 of the season, when it transforms to the dusky yellow pupa. The moth 

 issues a week or so after the pupa is formed. This season the first moth 

 issued on March 16th ; but that it was much ahead of its time was shown 

 by the fact that not a leaf was to be seen upon the trees. 



Food plants. — At various times during the summer this same species 

 was observed not alone upon the apple, but upon several varieties of 

 cultivated pear trees and upon Crataegus in the department grounds. 

 In September they were found in great numbers in the leaves of wild 

 cherry trees in an old cemetery at Alexandria, Va. 



Natural enemies. — Many of the cases were found in the webs of nest- 

 ing spiders, upon different parts of the trees, but whether the spiders 

 feed upon them or whether the case would protect them it is hard to 

 say. The moths, however, would probably be unable to issue from the 

 cases thus caught. 



Large numbers were destroyed by ants. I have repeatedly observed 

 two or more ants take hold of a case on opposite sides and tear it open, 

 either devouring or carrying off the inclosed larva 'or pupa. 



Two hymeuopterous parasites have been bred from the cases of the 

 resplendent shield bearer, the one a Microgaster, in large numbers, and 

 the other a Chalcid in but a single instance. 



Remedies. — Obviously the only remedy for this insect, when its inju- 

 ries have become severe enough to attract attention, is to destroy the 

 cases in the winter time. The bark of the tree can be slightly scraped 

 and many thus destroyed, or it can be painted over with some insectici- 

 dal solution. A mixture of kerosene and water in the proportion of 

 about 3 to 100 by volume, put on with a whitewash brush or sprayed 

 from a fountain pump, would probably prove efficacious. A mixture of 

 lime and sulphur in the proportions of one-half bushel shell lime to six 

 pounds powdered sulphur, dissolved and brought to the consistency of 

 a whitewash with hot water, was applied to the trees in the department 

 grounds last fall. It had the effect of killing all of these case bearers 

 which it reached, and undoubtedly destroyed all of the woolly apple 

 lice {Eriosoma lamgera Hausmann) which woie above ground, as well as 

 all the bark lice {Mytilaspis pomicorticis Kiley) which it touched. It is 

 also claimed for this mixture tbat it has a beneficial effect in warding 

 off the so-called " blight." 



These remedies can, however, simply aim at a greater or less reduc- 

 tion of the numbers. Nothing like an extermination can be hoped for 



