INSECTS INJURIOUS TO AGRICULTURE IN JAPAN 87 



The monophlebine coccid Drosicha (W ' arajicoccus) corpulenta (64,) 

 is a common pest of oak, chestnut, and Pasamia spp. in central Japan. 

 There is a single brood each year, the eggs being laid in rubbish be- 

 neath the tree in May and June and hatching in early December. In 

 the spring of some years the adult females may be observed in large 

 numbers upon the trunk and larger branches of the host plants. 

 They are very conspicuous because of their unusual size, as they often 

 attain a length of 16 millimeters. 



INSECTS ATTACKING CHESTNUT 



Among the Lepidoptera the species most frequently found upon 

 chestnut are Nygmia flava, Dickocrocis punctiferalis, Dictyoploca 

 (Caligula) japonica, and Btauropus (Quadricalcarifera) perdix. 

 The only one of these of any consequence is D. punctiferalis, which 

 has already been discussed (p. 27) as a pest of peach and cherry. 



Of the beetles attacking this host the most important from the 

 commercial point of view are the various species of weevils which 

 infest the nuts. Gurculio (Balaninus) dentipes (95) is the most 

 serious of these and in some sections attacks a large portion of the 

 nuts. One brood is produced each year, and the winter is passed in 

 the mature larval stage in the soil. The adult beetles appear in June 

 and July, and the eggs are deposited in holes eaten into the bur. 

 When mature, the larvae leave the nuts and enter the soil. G. 

 camelliae (184) and Attelabus jekeli are also at times quite serious 

 pests, the former having a life history identical with that of G . 

 den tipes. 



The cerambycid Stenygrmww l^-notatumi is frequently found in 

 Japan boring in the trunk and larger branches. During June and 

 July the adult beetles of Popillia japonica feed quite extensively upon 

 the blossom clusters, and occasionally Drosicha covpulenta may be 

 seen in fairly large numbers upon the trunk and branches. 



INSECTS ATTACKING CAMPHOR TREES 



The most important pest of camphor in Japan is the chermid 

 Triozo. camphor ae (161, 163) which ranges in distribution from 

 Honshu, Shikoku, and Kyushu in Japan proper, to Taiwan and 

 China. It was first referred to in literature under the above name 

 by Sasaki in 1905, but was not described until five years later. This 

 pest is found on practically every camphor tree within its range, and 

 in many cases causes serious injury. There is one brood a year, and 

 the winter is passed in the pupal stage within the gall on the leaf. 

 The most serious injury occurs on young trees, and growth may be 

 retarded to a considerable extent, or in severe cases the tree may be 

 killed. In practically all instances the attack is limited to those 

 portions of the trees within 10 feet of the ground, as the powers of 

 flight of the adult female are relatively weak. The adults appear 

 during April and May, being most abundant during April. Dis- 

 persion is largely brought about by the wind. A short time after 

 emergence oviposition is begun, and during this period the adults are 

 often present in clouds about the trees. The eggs are laid singly or 

 in small groups on the under sides of the leaves and hatch within 



