354 



EwiNG (H. E.). U.S. Bur. Ent. Three new Species of peculiar and 

 injurious Spider Mites. — Proc. Ent. Soc. Washington, D.C., xxiv, 

 no. 4, April 1922, pp. 104-108. 



The new species described are Paratetranychus heteronychus, from 

 specimens collected in California and labelled " date mite " ; 

 Eupalopsis pavoniformis (peacock spider-mite), from Hawaii, on 

 Hibiscus ; and Phytoptipalpus transitans, from Pusa, India, in galls 

 of Zizyphus jujuba. The new family Phytoptipalpidae is erected 

 for the last-named species. 



Thompson (W. R.). U.S. Bur. Ent. On the Taxonomic Value of 

 Larval Characters in Tachinid Parasites (Dipt.). — Proc. Ent. Soc 

 Washington, B.C., xxiv, no. 4, April 1922, pp. 85-93, 20 figs. 



In view of the practical possibility of the existence of the phenomenon 

 of poecilogon}', it is evident that the biologist cannot safely rely on 

 the appearances presented by any given stage of the animal with 

 which he has to deal, and must therefore become thoroughly acquainted 

 with all its transformations. This paper is offered as an example 

 of how possible errors may occur by identifying Tachinids by the study 

 of the morphology of the adults only. In the material forming the 

 subject of this paper three types of larvae were found corresponding 

 to adult females, all determined by Dr. J. "Villeneuve as Paraphorocera 

 senilis, Rond., the Tachinid parasite of Pyrausta nubilalis, Hb. Each 

 of these larval forms is morphologically distinct, the differences in 

 the bucco-pharyngeal armature being well marked, and the material 

 examined is sufficiently extensive to prove the relative constancy 

 of the characters. The differences between the adult flies corresponding 

 to the three forms of primary larvae are slight, and have to do chiefly 

 with the colour and distribution of pollen of the head and thorax. 



One of these forms corresponds to P. gratiosa described by Brauer 

 and von Bergenstamm, and the other is named senilis var. " c." 



It does not appear advisable to create new specific or varietal 

 names to cover these three types, especially as the synonymy of this 

 species is already fairly extensive. 



Fenton (F. a.) & Hartzell (A.). Control of the Potato Leafhopper. 



— Iowa Agric. Expt. Sta., Ames, Circ. 77, March 1922, 4 pp., 

 5 figs. 



Directions are given for the preparation and application of Bordeaux 

 mixture for the control of leaf-hoppers [Empoasca mali, Le B.] causing 

 tipbum of potatoes. Although the spray is effective even after the 

 hopperbum has started, it should be applied as soon as the adults 

 are noticed on the vines. In fields of about 20 acres a traction sprayer 

 of 100 U.S. gal. capacity, producing from 150 to 2001b. pressure at 

 the nozzle and spraying four rows at a time, proved most effective, 

 but in larger fields a power outfit is required. The management of 

 the spray boom is important. The central nozzle should be high 

 enough to enable the tops of the plants to be completely covered 

 by the spray, and the side nozzles should be turned upwards at an 

 angle of about 45° so as to cover thoroughly the lower surface of the 

 leaves. For the earlier sprays the lateral nozzles should point inwards, 

 one slightly forwards and the other slightly backwards, but when 

 the vines are larger they should be turned completely in the opposite 



