June, '13] TOWXSEXD: COTTON SQUARE WEEVIL 311 



quiescent or inactive. The crop would have to ripen and be gathered 

 in the more humid season, and this fact would make the measure 

 impracticable in many districts. In any event this measure can only 

 be combined with the first above described, and not with the second. 



With regard to the fostering of the parasites, as outlined in the sec- 

 ond measure above, it should be noted that the only data at present 

 available indicate the possibility of the proportion of parasites falling 

 off later in the season from that above given. From lots collected 

 September 18 to October 11, 1912, by my assistant, ]\Ir. E. W. Rust, 

 at one point, San Jacinto, in the lower Chira valley, there w^ere secured 

 onh' one parasite to more than 50 weevils, the figures being 38 para- 

 sites to 1,998 weevils. The July and August, 1911, lots were from 

 the whole region, and showed 590 parasites to 2,978 weevils. One 

 locality can not show the average for the whole region; and more- 

 over 1912 can not be taken as an index to 1911, for the conditions 

 were dift'erent in the two years. The data show^ the need, however, 

 for an exhaustive investigation of the proportion of parasites to weev- 

 ils throughout the year, and the range of activity in temperature and 

 relative humidity of the weevil and each of its parasites. 



Longevity and Period of Inactivity 



Adult weevils were kept alive for thirty-tAvo days in Lima during 

 July and August, 1912, wdthout fight or food, in a small closed pill- 

 box, indoors, at a temperature of 64° to 66° Fahrenheit and during 

 outside conditions of high relative humidity. 



Mr. Rust noted in Piura during September and October, 1912, 

 that thirtj^-three to forty-five days after collection of infested squares, 

 while practically all adults of the weevil that had issued were dead, 

 nearly all to a large proportion of the larvae still left in the squares 

 were alive. The relative humidity is markedly less during September 

 and October in Piura than during July and August, which explains 

 this larval retardation, the squares having been noted to dry rapidly 

 during this season while in July and August they remained com- 

 paratively moist. It appears probable from this that the weevil 

 lasts through the dry season largely in the larval stage as well as in 

 the pupal and adult conditions. As the dryness increases from Sep- 

 tember to December, retardation of development in all stages be- 

 comes more and more marked until inactivity is reached, the return 

 of relative humidity in Piura in May and June awakening the weevil 

 to renewed activity. In all districts activity is lessened by a lowering 

 of the relative humidity. 



This period of inactivity, induced in both the square-weevil and 

 the boll-weevil by atmospheric aridity, enables these insects to be 



