FEDERAL HORTICULTURAL BOARD. 511 



The only new infestations determined in Mexico are tlie scattered 

 fields opposite Candelaria, in the Great Bend district, already noted. 



Until conditions in INIexico materially improve there seems to be 

 little likelihood of an}^ serious effort being made on the part of the 

 Mexican Government or planters to eliminate cotton culture in the 

 Laguna or other infested regions and to take steps similar to those 

 taken in Texas to exterminate the insect. No wide survey of Mexican 

 cotton growing is possible under existing political conditions. 



The research work conducted at the Lerdo station in the Laguna 

 has been maintained throughout the year with very satisfactory re- 

 sults. Some fort}^ to fifty thousand larvse were collected in the fall of 

 1918 for winter, spring, and early summer observation and experi- 

 mentation. It is believed that by the end of this season the full bio- 

 logical data of the insect will have been worked out, so that this sta- 

 tion can thereafter be discontinued. It is too early at this writing to 

 determine the amount of damage wliich this insect has caused to this 

 year's crop in the Laguna and elsewhere- in Mexico. The loss to the 

 crop of 1918 amounted to approximately 30 per cent, involving, as it 

 did, much of what would have been the second and third pickings. 

 From 100 bolls picked at random in late September ^\ere taken 920 

 larva^. The normal yield of the Laguna is yqvj high, and even with 

 this reduction a profitable crop v.as secured. 



The practical control experiments carried out in cooperation with 

 leading planters in the Laguna liavc indicated the possibility of a 

 large reduction of loss by cultural methods; namely, fall cleaning 

 and destruction of old plants and the replanting with clean seed. 

 This is substantially the control SA^stem now practiced in Egypt and 

 is possible under such low labor cost as obtains in Egypt and in Mex- 

 ico, Lender the labor scale in the United States the intensive clean-up 

 methods required would be almost prohibitive in cost. 



Tlie important phases of the work in the Laguna have been (1) a 

 continuation of life-history studies of the insect; (2) the determina- 

 tion of the importance of alternative food plants, such as okra and 

 possible native Mexican and Texas malvaceous plants related to cot- 

 ton — a considerable quantity of seeds of these plants having been 

 collected in Texas, and the plants are now being grown in the Laguna 

 for the purpose of this experiment; (3) determination of control 

 possibilities by poisoning and by cultural methods; (4) determina- 

 tion of the amount of damage tliroughout the season: and (e) the 

 determination of the extent of natural distribution and of the possi- 

 bilities of distribution througli the agency of irrigation canals. 



With respect to alternative food plants this work has shown that 

 Hibiscus and other plants closely related to cotton may serve as hosts 

 for the pink bolhvorm, but has fully demonstrated the fact that cot- 

 ton is much the favored ho.st plant. In this connection studies of the 

 last two years have indicated that under conditions obtaining gen- 

 erally in Texas cotton is practically the sole food plant of the insect. 



TEXAS BORDER QUARANTINE SERVICE. 



The Texas border inspection and quarantine service to prevent the 

 movement of cotton and cottonseed into the United States has been 

 continued activolv duriufr the year under the j>eneral direction of 

 Mr. R. Kent Beattie. The volume of the work has necessitated a 



