254 Nebraska State Horticultural Society. 



bears a long, high, sharply edged, black hump. The apple curculio has a 

 long, slender, almost forwardly directed beak, in the female as long 

 as the body but in the male only one-half as long, broadens from the 

 elytral bases towards the tips and each elytron bears a pair of 

 conspicuous tubercles. These differences are very evident upon com- 

 paring the accompanying cuts of the two species. As the two differ 

 fully as much in life history and methods of attack as in appearance, 

 it is best to consider them separately in this respect. The plum 

 curculio, being evidently the commoner of the two, will be considered 

 first. 



LIFE HISTORY OF THE PLUM CURCULIO. 



The insect passes the winter in the adult beetle state, hiding under 

 fallen leaves, loose bark, rubbish piles or any other similar retreat, and, 

 after spring has developed until the first buds are well formed, 

 begins to appear upon the trees. In Nebraska during 1905 and 1906 

 this appearance took place about the middle of May. The sexes mate 

 and the female beetles immediately begins to deposit eggs within the 

 very young growing fruit. Puncturing the skin with the small jaws at 

 the end of her beak she inserts the latter and begins an excavation 

 just beneath the skin, devouring the pulp as removed. When the 

 cavity has been completed she withdraws her beak and turning 

 about deposits an egg therein. Then the characteristic deep cres- 

 cent-shaped cut is made in the fruit in front of the egg. Oviposition 

 continues from the appearance of the curculios in May through June, 

 "When it is at its maximum, July and August, and during her life each 

 female deposits from fifty to two or three hundred eggs. Of course, 

 not all of the beetles survive for this long period, but they begin to 

 die off rapidly in July and only a very few live until the end of August. 

 The egg of the plum curculio is white, oval, in size about one-thirtieth 

 of an inch long by one-third as wide. In four to six days they hatch, 

 giving forth small, yellowish white footless larvae which begin to eat 

 their way through the fruit and about the stone or core, forming 

 irregular and tortuous burrows, and ultimately, except often in the 

 case of cherries, causing the fruit to fall. When full grown the larva 

 is about one-third of an inch long, yellowish white with a brownish 

 head, and with a double row of bristles down each side. They remain 

 in the fruit altogether three or four weeks, the maximum of emergence 

 occuring about the third week in .luly, although the total period 

 begins in latter June and continues throughout August. On leaving 

 the fallen fruit the larva immediately buries itself in the earth, 

 usually to a depth of an inch or less up to two inches, rarely more, 



