﻿THE PINK BOLLWORM 11 



The question of the extent to which the pink bollworm moth is 

 attracted to lights is one which has been discussed extensively in the 

 literature. In Hawaii, Busck (S) found that there is no attraction 

 to lights under the conditions prevailing where he worked. Loftin, 

 McKinney, and Hanson {14) made extensive tests in the Laguna 

 region of Mexico, but failed to find any definite indications of such 

 attraction. Fletcher (7), working in India, and Matsumoto (16), 

 working in Korea, also failed to find much attraction to lights. How- 

 ever, several Egyptian investigators, including Gough and Willcocks, 

 have found moths coming to lights under certain conditions (i, p. 

 238.) Gough captured a large number of specimens in light traps 

 in the warehouse in which cottonseed was stored, and Willcocks with 

 18 traps captured about 19,000 moths in three months, but did not 

 consider that this was enough to warrant the use of light traps as a 

 control measure. 



It is very probable that the differences in the observations are due 

 to the varying conditions under which they were made. It is well 

 known that insects are much more strongly attracted to lights under 

 certain climatic conditions than under others. 



The explanation of the Egyptian observations may perhaps be 

 found in the climate of the locality in which they were made. It is 

 also possible that the quality of the lights used by the various ex- 

 perimenters may help to explain the discrepancies. At any rate, it 

 seems to be clearly indicated that under no known conditions is 

 there attraction sufficient to be of any importance in control work. 



Considerable attention has been paid in various countries to the 

 food plants of the pink bollworm. In Egypt the insect has been 

 found breeding in okra, hemp, and hollyhock. There are similar 

 records from India. In the Hawaiian Islands it has been found in 

 various species of cotton and in HiMscus youngianus. From Brazil 

 there are records of its occurrence in C ochlospermum insigne and 

 Bomhax monguba (^). 



The most extensive studies of the alternative plants of the pink 

 bollworm have been conducted in Mexico {1^). Okra and hollyhock 

 were frequently found infested, as was a native desert plant, 

 Ilihiscus rardiophyllus Gray. A hirge series of malvaceous plants 

 from the Ignited States were planted for the purpose of observation. 

 The following eventually Vjecame infested in greatei- or lesser degree : 

 Tlihificus rocrineuH Walt., //. militaris Cav., Kosteletskya virginica 

 L., nihificus syriacus., and MalvaMrum nmeyricamwi (L). 



Several expei-irnents were performed to determine whether the 

 pink bollworm could live over from year to year when supplied with 

 any of these alternative food plants. Special attention was paid to 

 okra. In no case did the insect live under such conditions. This 

 lesiilt appears to have been due primarily to the fact that the seed 

 pods of okra and related phirils crack open on drying, so that the 

 larvae webbed up in them drop (f) the ground and become subject to 

 tlie influence of moisture and (he attacks of enc^uiies. It is more 

 tliari lil«'ly, however, that undei- some conditions tiie insect may be 

 able to peipetiuite itself on these phmts. 



In Texas and Louisiana, where rioncottoii zones \\\\\(\ been main- 

 tained for the purpose of stamj^ing ou( the pink bollworm, the 



