88 CIRCTJLAB 16 8, IT. S. DEPARTMENT OE AGRICULTURE 



a few days. The gall begins to form after the first molt, and grows 

 to from 2 to 3 millimeters in diameter when mature. An excessive 

 number of galls on a single leaf causes it to fall from the tree. Pu- 

 pation occurs within the gall during late June and early July. 



An allied species, MesoJxomotoma camphorae* is reported to be 

 abundant in Taiwan and the Bonin Islands, but no further infor- 

 mation is available regarding it. 



Aside from the Chermidae mentioned, probably the most common 

 of the sap feeding pests are the thrips, of which two. PhToeothrips 

 nigra and Liothrips setijiodis. are of frequent occurrence in southern 

 Japan. These are found largely upon the buds and younger foliage, 

 and the effect is similar to that produced by thrips on other plants. 



Hitoka has recently reported from Kyushu a cerambycid (Py- 

 restes sp.) which bores into the branches of the younger camphor 

 and allied trees. There is apparently one generation per year, and 

 the adults emerge in May and June. 



The curculionid Hylohius macilentus (96) at times causes injury 

 to camphor in central and southern Japan, occasionally killing the 

 tree. The adults oviposit at the roots, and the larvae tunnel through 

 the inner layer of bark. 



Though a considerable number of other insects are listed as at- 

 tacking camphor, they seldom cause appreciable injury, and this tree 

 is relatively lightly attacked by insects as compared with other 

 forest trees. 



INSECTS ATTACKING POPLAR AND WILLOW 



A considerable number of insect species are recorded as attacking 

 poplar and willow in Japan and Chosen, and according to Hori 

 and Oshima (36) the most important of those upon poplar are 

 Porthetria (Lymantria) dispar. Stilpnotia salicis, MeJalopha anasto- 

 mosis. Melasoma popirfi, Popillia japonica, and Trichio campus 

 populi. 



The satin moth, Stilpnotia salicis (IJfl).is found in Japan, Chosen, 

 and China, and ranges in distribution westwards to Europe. Re- 

 cently it has become established in certain parts of North America, 

 having been found near Boston in 1920, in British Columbia the same 

 year, and in "Washington in 1922. Two broods a year are produced 

 in Japan, the adults appearing early in July and the middle of 

 September. The eggs are laid upon the leaves and hatch in 10 days. 

 The larval stage of the midsummer brood covers about six weeks 

 and the pupal stage two weeks. Hibernation is in the early larval 

 stage in a bag attached to a twig or branch, or in crevices in the 

 bark. In the middle of May these larvae leave the bag and begin 

 feeding, reaching maturity in one month. The cocoon is spun in 

 a folded leaf, or between a group of twigs bound together with silk, 

 in which case several cocoons are contained in each web. 



Centra lanic/era (1W) is found throughout all of the main islands 

 of Japan and also in Chosen and Siberia. There are two broods a 

 year, and the winter is passed in the pupal stage on the trunk or in 

 a sheltered place. The adults appear late in May and in July. The 

 egg, larval, and pupal stages cover 15. 30. and 14 days, respectively. 



Dk-ranura (Centra) vinula felina (149) is distributed throughout 

 the Far East and to Europe as well. A single brood is produced 



