G64 EXPERIMENT STATION EECOED. [Vol. 87 



(1911), pp. 11, figs. 2).— This lepidopteran (Chloridea virescens) is a very 

 serious pest in the tobacco-growing sections of Florida, Georgia, Alabama, and 

 Louisiana. Although common in North Carolina, South Carolina, and Virginia, 

 it is much laes injurious there than in the more southern part of its range iiud is 

 rarely injurious in Kentucky and Tennessee. In addition to tobacco, the species 

 has been recorded in the' United States as attacking deer grass (Rhexia vir- 

 ginica), geranium, and ageratum, and has been reported to feed upon wild 

 solanaceous plants, including ground cherry (Physalis viscosa) and other 

 species of the same genus, and Solanum seiglinge. 



Eggs are deposited singly on the leaves and in Florida during the growing 

 season of tobacco hatch in from 3 to 5 days. The young larvae migrate to and 

 reach the buds in about 24 hours. Studies have shown the larval period to 

 cover from 18 to 31 days during May and June, the pupal stage varying during 

 the summer from 13 to 21 days. The emergence of adults from tlie ground is 

 affected materially by moisture conditions, it having been observed that a great 

 many moths often appear at the expiration of a dry period. In captivity moths 

 laid an average of 334 eggs. The average duration of* the life cycle during May 

 and June, 1916, was determined to be 37.5 days. 



A larval parasite (Toxoneuron sp.) is said to be its most important enemy. 

 In control work 30 different insecticide formulas were tested during the seasons 

 from 1913 to 1916. Of all the poisons used Paris green, arsenate of lead, and 

 golden antimony sulphid applied directly to the bud with corn meal as a carrier 

 gave the most promising results, there being, however, a great variation in the 

 fcfl3clency and cost in their application. A mixture of 1 lb. of arsenate of lead 

 and 75 lbs. of corn meal has proved to be the most eflicient combination, the 

 loss from burning which follows the use of Paris green thus being eliminated. 

 For the best results the buds must be treated twice a week until topping has 

 been completed. Other supplementary control measures recommended include 

 the removal from the field and destruction of suckers, 55 per cent of those 

 removed having been found tu be infested ; the removal at the end of the season 

 of the tobacco plants that remain standing in the fields; patching of holes in 

 the cheesecloth and gates kept closed where tobacco is grown under cloth ; 

 destruction of plants left growing within and around old seed beds ; and the 

 covering and walling in of seed beds with cloth so as to prevent the entrance of 

 moths. 



Some recent advances in knowledge of the natural history and the control 

 of mosquitoes, T. J. Headlee CNeto Jersey Stas. Bui. S06 (1916), pp. 5-26, figs. 

 10). — Reference is first made to the influence of salinity on the development 

 of certain species of mosquito larvje, an account of studies of which by Chl- 

 dester has been noted (E. S. R.. 37, p. 259). Studies in the laboratory and 

 salt marsh have shown " that highly saline water (10 to 15 per cent) is favor- 

 able to the growth of the wrigglers of the white-banded salt-marsh mosquito 

 (Aedcs soUicitans) and injurious (deadly if sufliciently high) to the wrigglers 

 of the brown salt-marsh mosquito (A. cantator), while only slightly salt water 

 (6 to 8 per cent) is favorable to the latter and injurious to the former. The 

 younger the larvae the more acutely are they affected by the degree of salinity." 



A method of rapidly tracing the migrating mosquitoes to their origin by use 

 of an automobile, starting In uninfested territory close to the infested area 

 and collecting at regular distances, 0.5 to 2 miles, until the mosquito zone had 

 been traversed and uninfested country found on the other side, resulted in 

 the discovery of the breeding places of many broods. This method is illus- 

 trated by a diagram. It was clearly shown in one case by collections between 

 8 and 9.30 p. m. that Culex ijipicns migrated a distance of 2.5 miles from its 



