PINK BOLEWOEM OF COTTOiST IiST MEXICO. 



38 



Busck (8) bred the pink boll worm from Gossypium tomentosum in 

 Hawaii, but did not find it in milo; King (9) reports it from hanbuk 

 (Abutilon sp.) in Africa; and Gough (12) records mallow (Malva sp.). 

 Willcocks (7) states that the food plants in Egypt are bamia or okra 

 {Hibiscus esculentus), teel or hemp (Hibiscus cannabinus) , and holly- 

 hock (Althaea rosea). 



A number of malvaceous plants were grown beside heavily infested 

 cotton on the laboratory grounds and several became infested. 

 Okra (Hibiscus esculentus) became rather heavily infested in every 

 instance when grown in close proximity to cotton. Table XVII 

 is a complete record of all the seed pods grown on 30 plants at 

 the laboratory during the season of 1919. From August 14 to 

 December 3, 590 seed pods were examined with the following results:- 

 66.7 per cent were infested with live larvae and pupae, and the total 

 infestation, including seed pods that were unmistakably infested but 

 in which no larvae or pupae were found, was 73.8 per cent. The in- 

 fested seed pods averaged 2 larvae, pupae, and exit holes. 



Table XVII. — Seed-pod examination of Okra (H. esculentus). 



Num- 

 ber of 

 pods. 



Pods infested. 



Infestation. 



Num- 

 ber of 



infested 

 pods 



without 

 larvae 



or 

 pupae 



present. 



Num- 

 ber of 

 exit 

 boles. 



Remarks. 



Num- 

 ber. 



Per 

 cent. 



Larvae 

 total. 



Num- 

 ber of 

 pupae. 



Pupae 



and 



larvae. 



38 

 33 

 60 

 50 

 100 

 100 

 50 

 84 

 20 

 20 

 35 



11 

 9 



36 

 35 

 69 

 79 

 45 

 66 

 12 

 17 

 15 



28.9 

 27.2 

 60.0 

 70.0 

 69.0 

 79.0 

 90.0 

 78.5 

 60.0 

 85.0 

 42.8 



9 

 9 



48 

 85 

 105 

 106 

 92 

 147 

 37 

 35 

 21 









 

 





 5 

 4 

 5 

 

 

 



9 

 9 

 48 

 85 

 105 

 111 

 96 

 152 

 37 

 35 

 21 



3 

 1 

 1 

 3 



13 



13 

 2 

 5 

 1 

 1 

 



















25 



37 



13 



8 







1 







Green pods. 



Do. 



Do. 



Do. 



Do. 



Do. 

 Dry pods. 



Do. 



Do. 



Do. 

 Green pods. 



590 



394 



66.7 



694 



14 



708 



43 



84 





From this one observation it seems that when attacking okra the 

 pink bollworm is more inclined to pupate in the seed pods than in 

 the bolls when cotton is attacked. No plausible explanation can be 

 given as to why this should occur. 



The manner of attack and feeding habits in okra are essentially 

 the same as in cotton, but no larvae were ever found feeding in the 

 flower buds or flowers. 



Double seeds or three or four seeds are frequently webbed together 

 in much the same manner as double seed in cotton, though the work 

 is not so clean and particles of frass are usually found attached to 

 them. Plate IV shows full-grown larvae feeding in okra pods. 



One important point to be determined is whether the species is able 

 to sustain and perpetuate itself on okra alone as a food plant. Two 



