710 



attributed to that pest. It would seem that the larva prefers cotton 

 seed and young cotton roots to the seed or young roots of maize, which 

 it often seriously attacks in the absence of the former. Unlike that 

 of H. ulileri, the larva of M. vesjpertinus seems to be abundant on 

 almost any type of soil. The chief damage is generally done on sandy 

 uplands. The eggs are laid on or near the surface of the soil and hatch 

 in about 9 to 10 days in July and about 20 in September. The larvae 

 at once begin their search for food ; they do not usually go deeper 

 into the soil than 3 to 3| inches, but during dry weather in the spring 

 of 1914, they occurred at 5 to 6 inches below the surface. A few 

 individuals can do a great deal of damage in a newly planted tobacco 

 field by boring through the plants. They are somewhat cannibalistic 

 and often appear to attack pupating insects. The papa is formed 

 in a cell in the soil 3 to 5 inches below the surface. The beetles do not 

 fly freely before sunset, differing from H. uhleri in this respect. An 

 average life-cycle takes 330 days : 12 for the egg, 305 for the larva 

 and 13 for the pupa. A nightjar, probably Chordeiles virginianus, 

 exercises natural control, the elytra of the beetles being frequently 

 found in its excreta in a field of maize where thousands of these insects 

 had congregated. A common field spider, Pencetia viridans, Htz., 

 which in autumn frequents the tops of maize, is another enemy of no 

 small importance. The Reduviid bug, A'piomerus crassipes, F., and 

 an Asilid fly, Prodacanthus brevipennis, Wied., have been seen to prey 

 on these beetles. Autumn and winter ploughing are the artificial 

 control advised. In a rotation of cotton, maize and oats, the oat 

 stubble should be left undisturbed after harvest, as the adults do not 

 frequent such fields for oviposition. After 15th September any 

 desired procedure may be followed in 'preparing for autumn cover 

 crops, as practically all eggs have been laid before this date. Although 

 this practice on any given field occurs only once in two or three years, 

 it is believed to be eft'ective in controlling this pest. Where M. ves'per- 

 tinus is injurious to tobacco, a handful of cotton seed placed half way 

 between the plants will keep the insect away from them until they 

 become sufficiently strong to withstand attack. 



Collins (C. W.). Dispersion of gipsy-moth larvae by the wind.— ?7.5. 

 Dept. Agric, Washington, B.C., Bull. no. 273, 24th August 1915, 

 23 pp., 6 plates, 1 map. 



In 1893, Wachtl and Kornauth described the aerostatic setae of the 

 first-stage larvae of Lymantria {Porthetria) dispar, L. (gipsy moth) 

 and L. inonacha, L. (nun moth), and suggested that these aerophores 

 assist in the dissemination of the young larvae through the air. The 

 latest observations on this subject were published by Shcherbakov 

 in 1914 [see this Review, Ser. A, iii, p. 43] and establish the fact that 

 these larvae are capable of soaring in a slight wind. 



In 1913, as a result of several experiments conducted along the 

 coasts of Massachusetts and New Hampshire and on the hills of the 

 latter State by using tanglefooted screens and cloth for traps, there . 

 were caught on 977 square feet, 289 first-stage larvae of L. dispar 

 which had been carried by the wind from 220 yards to 1 mile or more ; 

 in 1914, on 1,614 square feet of sticky surface, 346 larvae were taken 



