THE PINK BOLLWORM. 5 



The collection which I have was secured from the seed room of one of the 

 ginneries in Shanghai and from the fields at Tungchow, about 12 hours' ride 

 by boat up the river from Shanghai, The infestation is more or less general 

 throughout China ; however, there may be some small areas where it is not 

 present. A majority of the cotton grown within a radius of 100 miles of 

 Shanghai is shipped into that port before being ginned, and from evidences 

 found at the ginning establishments there is no doubt but what all those re- 

 gions are infested. In fact, the larvse are so numerous that by going into the 

 seed room of the gins a person may secure any number of them within a very 

 short time, as they may be seen crawling around over the seed and on the 

 walls. 



PRESENT DISTRIBUTION IN MEXICO. 



As far as absolutely definite evidence shows, the pink bollworm 

 is confined to three localities in Mexico, one of which is the Laguna 

 district, a valley isolated by mountain ranges about 200 miles from 

 the Texas border. The Laguna, in which the bulk of the total Mexican 

 crop is produced, consists of about 1,200 square miles of land. Mr. 

 August Busck, on a trip to Mexico in the early part of 1917, ob- 

 tained samples of cotton seed from 40 of the estates in that region. 

 Thirty of these samples were found to be infested and later records 

 indicate infestation on ranches from which no insects in the seeds 

 were received. In short it is evident that through the shipment of 

 cotton seed from one part of the Laguna to another and possibly 

 through the flight of the insect, the pink bollworm has become gen- 

 erally established there. Although the distribution of the pest is 

 naturally irregular at the present time, it is certain that it will be- 

 come uniform in the course of a few years, and that most energetic 

 steps must be taken by the planters to control or eradicate the insect. 

 Other localities known to be infested in Mexico are Allende, about 

 40 miles south of Eagle Pass, and the Trevino ranch, immediately 

 opposite Del Rio. In both cases the infestations were the result of 

 the receipt of seed from the Laguna. 



NATURE AND AMOUNT OF DAMAGE. 



The pink bollworm affects cotton production in several ways. In 

 the first place it destroys a certain number of bolls or portions of 

 bolls, in which case the lint produced is short and kinky (fig. 1 ) . The 

 injury, . however, does not end with the reduction in the yield of 

 lint. The crop of seed is correspondingly reduced, and what is ob- 

 tained is of light weight and poor grade. In the crushing of 

 Egyptian seed in England it was found that the oil content was 

 lower than normal by about 20 per cent, and that the oil actually 

 secured was of dark color and comparatively low value. The work 

 of the insect is also of importance in connection with seed for plant- 



