ECONOMIC ZOOLOGY ENTOMOLOGY. 53 



as reported by Lafont (E. S. R., 24, p. 359). A lygeid bug, Dicuches humiiin, 

 was found to transmit the parasite from plant to plant. 



On the transmission of Leptomonas davidi of euphorbias by a hemipteron, 

 Nysius euphorbise, A. Lafont (Vompt. Rend. Soc. Biol. [Paris], 10 {1911), 

 No. 2, pp. oS, 50). — Experiments conducted show that a lygeid (.V. euphorbice) 

 conveys the flagellate parasite L. davidi from diseased to healthy plants. 



American Psyllidae, I, II (Triozinae), D. L. Ceawford (Pomona Jour. Ent., 

 2 (1910), Nos. 2, pp. 228-237, figs. 2; J,, pp. 3^7-362, figs. 3).— In the first paper 

 the author presents a provisional key to the genera and species of the subfamily 

 Triozinae, together with descriptions of 4 new species belonging to the genus 

 Trioza. In the second paper 14 species and 1 variety of Trioza are described 

 as new. 



Three species of apple plant lice in Oregon, H. F. Wilson (Oregon Sta. 

 Circ. 12, pp. 3S). — A brief account is given of 3 species of plant lice that are 

 causing serious damage to the apple in Oregon, namely, the green, brown, and 

 woolly aiH'lo aphis. An account of remedial measures is included. 



Aphididae of southern California, V, E. O. Essig (Pomona Jour. Ent., 2 

 (1910), No. //, pp. 335-338, figs. 2).— In this fifth paper (E. S. R., 24, p. 559) 

 the author deals with Aphis licdcrw and Ncctarophora pisi. 



A new mealy bug infesting walnut, apple, ajid pear trees, E. O. Essio 

 (Pomona Jour. Ent., 2 (1910), No. J/, pp. 339-3.'i5, figs. 2). — A mealy bug found 

 to infest walnut, apple, and pear trees in Ventura County, Cal., is described as 

 Pscudococcus bakeri n. sp. The species has not as yet become of economic 

 importance. 



The citrus mealy bug, E. O. Essig (Pomona Jour. Ent., 2 (1910), No. Jf, 

 pp. 289-320. figs. 9). — This paper deals with the general history and distribu- 

 tion of Pseudococcus citri in California, its destructiveness, and quarantine 

 measures, gives technical descriptions of the male and female, and discusses its 

 life history, bionomics, natural enemies, and artificial control. 



A synonymic bibliography is ajiix^nded. 



Some further observations on the scale insects (Coccidse) of the Uganda 

 Protectorate, R. Newstead (Bui. Ent. Research, 1 (1910), No. 3, pp. 185- 

 199, figs. 10). — Nine species and 1 variety, representing the genera Inglisia, 

 Lecanium, Ceroplastes, Dactylopius, Chionaspis, and Diaspis, are described 

 as new. 



The alfalfa caterpillar (Eurymus eurytheme), V. L. Wildeemuth (U. 8. 

 Dept. Agr., Bur. Ent. Circ. 133, pp. 1',, figx. S).— This circular is a partial report 

 of work done by the author in the Imperial Valley, Cal., during 1910. 



During the last 4 years the caterpillars of this butterfly have been reported 

 as feeding on, and in some cases doing a large amount of damage to, growing 

 alfalfa in the Southwest. In 1906 it was i-eported to be injuring lucern fields 

 in Bighorn County, Wyo., and the following year damaging alfalfa at Hanford, 

 Cal., and it is known to have injured alfalfa in Utah and Kansas. In Salt 

 River and Yuma valleys, Ariz., and in the Sacramento Valley and in the irrigated 

 alfalfa regions of south-central California, the pest is quite numerous during 

 certain years and causes more or less damage. The injury during 1909 in the 

 Imperial Valley, Cal., resulting in a loss of hundreds of dollars on a 320-acre 

 ranch and similar losses on other ranches, led to the inauguration of the investi- 

 gations here reported. In the West this insect is known to occur from Mexico 

 northward into the Dominion of Canada, thus covering the chief alfalfa growing 

 section of the United States. 



Descriptions are given of the various stages in the life of this insect. There 

 were found to be 4 distinct generations in the Imperial Valley in 1910, the last 

 being less distinct than the others. The first generation covered the period 



