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 Mexico materiaUy improve there seems to be 

 little likelihood of any 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 tliose 

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

 cotton growing is possible mider existing political conditions. 



The research work conducted at the Lerdo station in the Laguna 

 has been maintained throughput the year with very satisfactory re- 

 sults. Some forty to fifty thousand larvaj were collected in the fall of 

 1018 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 Avhich 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 were taken 920 

 larva?. The normal yield of the Laguna is very high, and even with 

 this reduction a profitable crop was secured. 



Tlie 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 x)f old plants and the replanting with clean seed. 

 This is substantially tlic control sj^stem no^y practiced in Egypt and 

 is i^ossible under such low labor cost as obtains in Egypt and in Mex- 

 ico. Under the labor scale in the United States the intensive clean-up 

 methods required would be almost prohibitive in cost. 



The impoi-tant 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 nialvaceous 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 throughout the season; and (e) the 

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

 bilities of distribution through 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 bollworm, but has fully demonstrated the fact that cot- 

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

 last two years have indicated that mider 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 actively during the year under the general direction of 

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



