April, '11] townsend: cotton square-weevil 243 



in the montana on the east slope of the Andes, but facts point to the 

 probabiHty of its presence there. After careful study of the matter 

 and comparison of the conditions in each case, it seems evident that 

 the symptoms of the hielo and the effects and habits of the weevil 

 are quite coincident throughout; and therefore that this damage which 

 has been generally mistaken during the last forty-five years in Peru 

 for the effects of cold and humidity, followed by heat, is in reality 

 due to a close relative of the boll-weevil, working in the same manner 

 as the latter. 



A few persons had maintained the belief that the hielo was due to 

 some insect or other animal organism, but no one had succeeded in 

 finding the culprit. During the year 1910, in September of which I 

 first discovered the weevil, the damage has been much lighter than 

 usual, few of the weevils probably being present as compared with 

 former years. 



It was ascertained that about twenty-three days elapse from egg 

 to adult during September and October. This time is doubtless 

 shortened in November and December, until the hot weather of Jan- 

 uary puts an effectual stop to further breeding and causes the weevil 

 to seek gestivating quarters. During the colder weather of July and 

 August the life-C3^cle period is probably fully four weeks. 



The adult weevils vary in length from 2.25 to 3.5 mm., and in width 

 from .75 to 1.5 mm. On first issuing they are distinctly yellowish in 

 color, but become grayish or darker with age. There is a patch of 

 darker shade at the junction of the bases of elytra, due to fainter 

 pubescence, and a less distinct one on each of the elytra posteriorly, 

 producing the effect of a faint pattern. 



Search during September and October, for weevils feeding and 

 ovipositing in the squares, gave an average everywhere in the cotton 

 region of Piura Department of one weevil to about twenty or twenty- 

 five squares. Yellowed and dried hanging squares and fallen squares 

 collected in the field gave a high percentage of infestation, which has 

 not yet been computed but will doubtless average eighty per cent or 

 more. 



Two species of parasites have been reared in considerable numbers 

 from the weevil grubs in the infested squares. They are probably 

 Bracon sp. and Urosigalphus sp. Both are about equally abundant, 

 though perhaps the latter is somewhat the more numerous. The 

 percentage of parasitism has not yet been determined, but the indi- 

 cations so far are in the neighborhood of thirty per cent and perhaps 

 very much more. 



The heat from January to March in the northern coast strip of 

 Peru is excessive, and the rainfall is practically nil for long periods 



