CUKCULIOS THAT ATTACK WALNUT AND HICKORY. 9 



Creek, W. Va., 400 young nuts were gathered at random from the 

 lower branches of four black walnut trees growing in a pasture 

 field. Of this lot of nuts 289 contained 466 egg punctures and the 

 remaining 111 were sound. In another instance in the locality last 

 mentioned 1,447 infested nuts dropped from one tree during the 

 season. 



So far as observations have been made, the black walnut curculio 

 seems much more abundant and injurious in the latitude of Mary- 

 land and West Virginia than within the range of the black walnut 

 farther to the north. In the vicinities of Trenton, N. J., Lancaster, 

 Pa., Kochester and Lockport, N. Y., and Wallingford, Conn., a num- 

 ber of bearing black walnut trees were examined without finding 

 any evidences of the presence of the curculio. Locality records by 

 various entomologists and observations made during the present in- 

 vestigation indicate a southern rather than a northern range for this 

 species. 



LIFE HISTORY. 



The egg (PI. IV, B; PL V, A) is oval, oblong, creamy white, sur- 

 face delicately granulose, 1 mm. long by 0.7 mm. wide. Eggs that 

 are deposited in young, tender nuts are placed beneath the flap of 

 skin within a crescent-shaped puncture eaten out of the side of the 

 nut (PL IV, E, G). In the more solid husk of half -grown nuts the 

 eggs are inserted in less elaborate punctures which resemble pin 

 pricks and extend directly into the husk. (PL V, B.) These sim- 

 ple egg punctures in the more nearly mature nuts are usually formed 

 in groups of from three to six on the side of the nut. 



About a dozen eggs deposited in nuts on the trees on July 15 

 hatched on the morning of July 22 and an equal number deposited 

 on July 16 hatched on July 23, an incubation period in both cases 

 of 7 days under natural conditions. Two other lots of eggs laid 

 and kept in an open insectary hatched in five and six days, respec- 

 tively. In West Virginia oviposition begins normally during the 

 last days of May and continues through June and most of July. 



The larva (PI. TV, C) is creamy white with brown head, legless, 

 and fusiform. It assumes naturally a curved position and is sparsely 

 clothed with short, stiff hairs. The length is 11 mm. and the thick- 

 3 mm. As soon as hatched it begins to feed from the side of 

 the oviposition wound, and. in young nuts, soon devours the whole 

 mterior. In the older nuts feeding is done chiefly in the husk. The 

 infested nut adheres to the branch until <li<- Larva is a< least half 

 grown, and then drops, the l:n\a continuing <<> feed while the nut 



