60 INSECTS AFFECTING VEGETATION 



haps a scar on the outside of the fruit and the gum which exudes 

 from it. Sometimes, however, a malformation of the fruit results. 

 Here in the pit, the pupal stage is passed, and during the latter part 

 of August, the adult beetle emerges. The fruit usually does not fall 

 until just previous to the exit of the inhabitant. 



During the period of bloom and just before and after this pe- 

 riod, the beetles may be obtained by jarring, just as is done for the 

 circulio. Jarring should be kept up just as long as the beetles are 

 obtained, for one little beetle obtained early in the season amounts 

 to a good deal. It must be borne in mind that the gouger does not 

 thin the fruit as does the curculio, but that the gouged fruit re- 

 mains until late, drawing on the strength of the tree about as much 

 as a perfect plum. 



As most of the fruit falls before the beetles make their exit, im- 

 mediate destruction of fallen fruit will make away with many beetles. 

 Hogs accomplish this very nicely but if hogs are objectionable, pick 

 up the fruit by hand and bury it just as soon as it falls. The 

 arsenites do not seem to prove as beneficial as we could wish, but no 

 doubt they will pay for the application. Prof. C. P. Gillett of Colo- 

 rado, recommends the hand picking of all gouged fruit. This com- 

 bines the benefits obtained by thinning, with those resulting from 

 the death of the insect. (Bui. 24, Mich. Agr. Exp. Sta.) 



The Plum Leaf-Miner. The plum leaf-miner in its injurious 

 stage is a smooth, greenish white larva, one-sixth inch or less in 

 length, found during late June and early July feeding between the 

 outer layers of the leaf. Hatching from an egg attached to the under 

 surface of the leaf, the larva penetrates the tissue and first eats a 

 narrow linear mine an inch or less in length, then widens the mine 

 so as to produce an irregular, more or less ovate blotch about one- 

 half inch long. The part of the leaf so injured turns brownish and 

 dies. From three to twelve mines are often found in a single leaf. 

 The trees become partially defoliated and the fruit may fall pre- 

 maturely. When continued for a series of years this injury tends to 

 weaken the vitality of the tree and to injure the size and quality of 

 the crop. 



The adult of the plum leaf-miner is a small bronzy black moth 

 having an expanse of one-seventh to one-fifth inch. The forewings 

 are crossed bjr a shining white band on the outer third, and the head 

 bears a conspicuous orange tuft. These moths emerge from cocoons 

 at or near the surface of the ground during the daytime in the lat- 

 ter part of May and in early June. During the day they remain 

 quietly on the bark of the trunk and larger branches, none being 

 found on the leaves. Several hundred moths are often found on 

 a single tree ; when disturbed they suddenly take flight and most of 

 them settle on the opposite side of the tree. They gradually de- 

 crease in numbers, and about the middle of June they disappear. 



God furnishes the ideal winter quarters for the cocoon. The 

 plum leaf-miner has proved to be a difficult insect to control, owing 

 to the fact that from the time the larva leaves the egg it feeds en- 

 tirely within the leaf out of reach of any poison spray. Measures 



