382 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



parasites have been received during the year from Japan, Korea, and 

 Hawaii. Colonies of a few species have been released in the field and 

 there is good reason to believe that some, at least, may be able to 

 establish themselves. Abroad the work is being conducted from 

 Yokohama, with substations at Koiwai in northern Hondo, Sapporo in 

 Hokkaido, and Suigen, Korea. A species of Tiphia has been collected 

 and reared at Koiwai and a shipment of 2,100 cocoons was dispatched 

 to Riverton, N. J., in October, where they arrived in good condition. 

 Around Yokohama a tachinid, Ochromeigenia ormioides, has been 

 found attacking the adult Japanese beetle, and a sizable shipment of 

 this species to New Jersey was made during June. From the region 

 of Sapporo a tachinid, Genteter cinerea, parasitic on the adult beetle, 

 has been collected in numbers and carefully studied. A large ship- 

 ment of this species was sent to New Jersey in October, 1922, and 

 beetles bearing eggs were found there the present summer, indicating 

 that the species has gained a foothold. Another parasite, a dexiid 

 fly, was collected and material bred in some quantitj'^ at Koiwai and 

 a shipment made to Riverton in October. It is too soon to say 

 whether this species has become established. A dexiid from Korea 

 is also under investigation and after further study may prove to be 

 a valuable parasite of the beetle. In addition to the above a Tiphia 

 from Korea gives promise of considerable value, as it occurs in the 

 spring of the year and thus supplements a fall species from northern 

 Japan. 



Enlargement of the foreign parasite work has been effected. Two 

 more experienced agents have been employed and are now in the 

 Orient, bringing the number of agents to four. The bureau is 

 fortunate to have the active cooperation of Japanese entomologists 

 in this work, which has added greatly to its effectiveness. A search 

 for parasites will be undertaken in China and India, where species 

 of the genus Popillia are numerous. In addition to the material 

 coming from Japan, a large shipment of the wasp Scolia manilae 

 was made from Hawaii into New Jersey, but it is doubtful whether 

 this insect will be able to withstand the rigors of this latitude and 

 climate. In this importation work the cooperation of quarantine 

 officials at San Francisco and Seattle, and also of officers of steam- 

 ship companies and express companies, has been of the greatest value. 



In addition to the beetle parasite work in Japan, attention has 

 been given by the agents there to obtaining, if possible, parasites 

 of other insects, such as the oriental fruit moth, citrus white fly, 

 camphor scale, red scale, Citricola scale, etc., and some introductions 

 have been made. The employees at Riverton are carefully investi- 

 gating the possibility of utilizing native parasites against the 

 Japanese beetle, and studies thus far indicate that but a very small 

 per cent of the insects are destroyed by native forms. 



Attention is also being directed to the utilization of possible 

 fungous and bacterial diseases of the Japanese beetle, particularly 

 those attacking the larval stage. Several bacterial diseases have 

 been isolated from dead or dying Japanese beetle grubs and cultures 

 made. From these cultures, tests are in progress to determine to 

 what extent the}^ are pathogenic, by inoculating healthy grubs in 

 the laboratory and the soil in the field. A species of Isaria from 

 France is being cultivated and experiments made to determine its 

 possible value when disseminated in infested pastures and elsewhere. 



