PINK BOLLWORM OF COTTON IN MEXICO. 5 



Rosalia, State of Chihuahua, at a point about 200 miles south of El 

 Paso. The other two infestations are located in the northern portion 

 of the State of Coahuila. One of these is at San Carlos, at a point 

 about 15 miles southwest of the town of Jimenez on the Rio Grande, 

 or about 40 miles approximately west of Eagle Pass, At this place 

 infestation has been found in fields in the immediate vicinity of the 

 gin. None of the insects were found in outlying fields. The other 

 infestation in the State of Coahuila is located at Allende. This 

 is about 40 miles from the nearest point on the Rio Grande. 



During the season of 1919 inspections were made by agents of the 

 Federal Horticultural Board in the cotton region between Matamoras 

 and Nuevo Laredo. No traces of infestation were found. Likewise 

 the cotton growing in the Imperial Valley in the State of Lower 

 California has been inspected with negative results. Inspection of 

 these regions will be continued, as the insect may at any time be- 

 come established along the Rio Grande by shipments of seed from 

 the interior of Mexico. 



The remarks above refer to infestations in growing cotton. The 

 pest is frequently brought to the border towns of Mexico in cotton 

 seed scattered in freight cars, and living specimens are constantly 

 being found under such conditions by the inspectors of the Federal 

 Horticultural Board. 



LIFE HISTORY. 



SUMMARY OF LIFE CYCLE. 



The moths of the pink bollworm emerge in the early spring and 

 summer from larvae which have passed the winter in cotton seed or 

 bolls. The eggs are laid soon after emergence on almost any part of 

 the plant. The incubation period is from 3 to 12 days and the larvae 

 begin feeding in the squares or bolls. During the spring and summer 

 the larval period occupies from 8 to 16 days, but in the fall and 

 winter it is extended over a period of from a few months to two years 

 or more. These two kinds of larvae, while indistinguishable taxo- 

 nomically, may be designated short-cycle or "summer" larvae and 

 long-cycle or " resting" larvae. Pupation takes place in the soil or 

 trash on the surface of the soil, in the summer stage, and in the 

 ground, seed, or lint in the resting larvae. The pupal period covers 

 from 6 to 20 days. The average length of the life cycle from egg to 

 egg during the summer is 31 days. 



LABORATORY METHODS. 



The experiments with the life history of the pink bollworm were 

 all conducted at Ciudad Lerdo, Durango, Mexico. An adobe house 

 was used for a laboratory. The adults were confined in 2-quart 

 fruit jars covered with cheesecloth for oviposition. Branches of 

 cotton plants containing leaves and squares, stuck in tubes of water 



