114 



extended. Suitable dusting machinery by wheel-traction power 

 has now been devised, motor power dusters proving unsuitable. 

 The tobacco hornworm [Protoparce] can be best dealt with by dusting 

 machinery, and, owing to labour shortage, one application of twice 

 the usual amount of lead arsenate was sometimes more economical 

 than two smaller ones, and produced good results. Calcium arsenate 

 is not recommended for tobacco. It is hoped to reduce the hibernating 

 hornworms by means of insecticides applied to the suckers, which 

 often grow a great deal after the tobacco crop is housed. On shade 

 tobacco in Florida, experiments are being made with a mixture of 

 lead arsenate and tobacco dust, lead arsenate alone, Paris green and 

 calcium arsenate all being dangerous. The introduction of parasites 

 from Cuba of the sugar-cane moth borer [Diatraea saccharalis cram- 

 bidoides] has continued on a much larger scale, and it will now be 

 possible to decide whether they can survive the Louisiana winter. 

 They are at present the most promising means of control. The 

 destruction of old maize stalks, in which the larvae can spend the 

 winter, is strongly advocated. As several new areas of infestation 

 have been discovered, a general survey of infested territory is to be 

 made. 



A brief outline is given of work carried out in connection with pests 

 of Citrus fruits in California and Florida ; insects affecting mango, 

 guava, avocado and other sub-tropical fruits ; greenhouse insects, 

 including the strawberry root worm [TypopJionis caneUus], which has 

 developed into a serious pest of roses grown under glass ; Mediterra- 

 nean fruit fly [Ceratitis capitata] and melon fly [Dacus ciicurhitac] ; 

 pests of the algaroba bean ; fruit-flies and other fruit pests in the 

 Canal Zone, Panama ; and the camphor thrips [Crypiothripsfloridensis]. 

 The outlook of the bee industry, which is growing in extent and im- 

 portance, and the lines of work to be followed in this connection, are 

 discussed. 



Newcomer (E. J.). U.S. Bur. Ent. Winter Killing oJ Codling Moth 

 Larvae. — //. Econ. Ent., Concord, N.H., xiii, no. 6, December 

 1920, pp. 441-442. 



Observations made in the arid section of Washington State show that, 

 with a minimum temperature ranging from -20° to -25° F. during 

 the winter, about 80 to 90 per cent, of the codling moth larvae are 

 killed. Wherever the temperature had been below -25° F., all larvae 

 protected only by bark or burlap bands were killed. The effect of 

 similar temperatures in more humid regions has not been ascertained. 



Spuler (A.). Winter Killing of the San Jose Scale. — //. Econ. Ent., 

 Concord, N. H., xiii, no. 6, December 1920, pp. 443-444. 



Records made in various localities show that the percentage of 

 larvae of the San Jose scale [Aspidiotiis perniciosus] killed by cold 

 during the winter of 1919-20 exceeded the average of the previous 

 ten years. 



ViCKERY (R. K.). Petroleum Insecticides. — Jl. Econ. Ent., Concord, 

 N.H.. xiii, no. 6, December 1920, pp. 444-447. 



In view of the scarcity of petroleum and its resulting high cost, the 

 discovery of an equally efficient insecticide is of great importance. 



