INSECTS ATTACKING LARGE FRUITS. 



87 



PLUM OUROULIO. 

 (Conotrachelus nenuphar Herbst.; Order, Coleoptera.) 



Diagnosis. Diseased and gummy, unripe plums falling to the 

 ground; within these plums a small, white, soft, footless grub. 

 Many of the plums hanging in the tree marked with a small, 

 crescent-shaped slit. 



Description and I/ife-history. This is the most formidable plum 



pest of this country. The adult 

 insect is a "small, rough, gray- 

 ish-black beetle about one-fifth 

 of an inch long, with a black, 

 shining hump on the middle of 

 each wing-case, and behind this 

 a more or less distinct band of 

 a dull, ochre-yellow color, with 

 some whitish marks about the 

 middle." The beetle belongs to 

 the family of curculios or snouted 

 beetles; the snout of our plum 

 weevil is rather short, but yet 

 easily made out. 



The eggs are laid in the young, green fruit shortly after it is 

 formed. The female cuts through the skin of the fruit with her 

 jaws, which are at the tip of the snout. She then enlarges this 

 hole, deposits an egg in it, pushing the egg well into the hole with 

 her snout. She next cuts a small, crescent-shaped slit in front of 

 the hole, so as to undermine the egg and leave it in a sort of flap 

 The object of the crescent slit is probably to wilt the flap, and 

 thus prevent the growing fruit from crushing the egg. The female 

 lays from 50 to 100 eggs. The larva, as soon as hatched, begins 

 to feed upon the pulp of the fruit, boring a winding channel to 

 the center, where it feeds around the stone. The larva, full-grown, 

 is about two-fifths of an inch long, soft, glassy white, with light- 

 brown head and without feet. The infested fruit usually drops 

 off' and falls to the ground before the larva finishes its feeding. 

 Within the fallen plum the larva completes its growth, crawls out 

 and into the ground for several inches, and changes to pupa. 

 After three or four weeks it emerges as an adult weevil ( beetle). 



48. PLUMCuRCUL,io:a, larva: 

 f>, pupa: c, adult: d, plum, showing 

 p.iru'ture and crescent made in ej, r 1;) .y- 

 irig. 



