258 EXPERIMENT STATION RECORD. 



unsatisfactory in several respects. Of the various poisoned baits tested 

 the one made of bunches of freshly cut grass dipped into a 1 to 80 solu- 

 tion of Paris green and water, and also the one made of bran and Paris 

 green at the rate of 1 lb. of the latter to 50 lbs. of the former which was 

 moistened, proved of small value as compared with the dry bait com- 

 posed of bran or middlings and Paris green. The advantages claimed 

 for the last are (1) it can be applied in drills about the margins of the 

 fields and thus serve as a barrier; (2) it can be easily and uniformly 

 applied with the onion seed drill ; (3) it can be applied in drills along 

 the side of the rows of onions; and (4) the trouble of mixing with water 

 and ladling out in piles in the moist bran method is avoided. 



A study in insect parasitism, L. O. Howard ( U. 8. Dept. Agr., 

 Division of Entomology Bui. 5, tech. ser.,pp. 57, Jigs. 24). — In 1895 the 

 author undertook the careful investigation of the life history of the 

 white tussock moth (Orgyia leucostigma), continuing the work until the 

 autumn of 1896. So far as possible an endeavor was made to study the 

 exact details of the fluctuations in the numbers of the moth. In 1895 

 there was a rapid and enormous increase in their numbers, but by the 

 time the third generation had been reached, in September, it was noticed 

 that parasitic and predaceous insects were also present in enormous 

 numbers. The cocoons of the second generation were found to be the 

 rallying point of immense numbers of ichneumon and chalcis flies. At 

 the beginning of these studies but 7 parasites of this moth were known, 

 but at the close of them tha author had found 15 hymeuopterous primary 

 parasites, viz., Pimpla inquisitor, P. conquisitor, P. annulipes, Amorphota 

 orgyiee, Meteorus communis, M. hypantrice, Limneria sp., L. valida, The- 

 roniafulvescens, Apanteles hyphantria\ A. delicatus, Chalcis ovata, Ptero- 

 malus cupriodeus, Gratotechus orgyice, Telenomus orgyice; G dipterous 

 primary parasites, viz., Frontina aletice, F. frenchii, Tachina mella, 

 Eupliorocera claripennis, Exorista griseomicans, Winthemia 4-pustulataj 

 14 hymeuopterous hyperparasites, viz., Hemi teles toivnsendi, Bathyrix 

 meteori, B. pimplce, Adistola americana, Otacustes periliti, Habrocytus 

 thyridopterigis, Pezomachus insolitus, Spilochalcis debilis, Eupelmus lim- 

 neria', Dibrachys boucheanns, Elachistus cacoeocifv, Elasmus atratus, Syn- 

 tomosphyrum esurus, Asecodes albitarsis ; 3 probable parasites, viz., 

 Ichneumon subcyaneus, I. cceruleus, and Allocota (Hemiteles) tln/ridop- 

 terigis; and 11 scavengers, viz., Helicobia helicis, fiarcophaga spp. 2, 

 Plwra nigriceps, P. incisuralis, P. fasciata, P. agaraci, Limosina sp., 

 Homalomyia scalaris, Oaurax ancliora, Neoglaphyroptera birittata, and 

 Diplosis sp. A species of Chrysopa was reared from a cocoon mass and 

 the larva' of Anthrenus ravins were found feeding upon dead pupae 

 and empty egg masses, as also was the mite of the genus Tyroglyphus. 

 Other active agents noted were an undetermined plant disease and the 

 Heteroptera, Podisus spinosus, Euschistus servus, and Prionidus cristatus. 



In all there were raised in the course of the study 2,122 primary para- 

 sites, of which 185 were dipterous and 1,937 hymeuopterous. The number 

 of secondary parasites, it is estimated, was about 1,000. The new species 



