AMOUNT OF DAMAGE TO COTTON BY PLANT-BUGS. 21 



estimated that the damage to the crop for the season 1903-4 was 

 between 10 and 15 per cent. This loss on the one plantation accord- 

 ing to this estimate was between 1,200 and 1,500 bales. A study 

 was made of the losses occasioned by these pests in 1905 on the 

 above-mentioned plantation, and the results in detail are considered 

 under the subject of ' ' Destructiveness " of the conchuela. Briefly, 

 this damage on the entire plantation approximated between 5 and 10 

 per cent, and for one section of 120 acres where the bugs had been 

 most abundant, the destruction as estimated December 4-6, 1905, 

 amounted to 30 per cent of all bolls, including unopened bolls, and 

 41 per cent of all bolls open at that time. 



In this country damage by plant-bugs, with the exception of that 

 by the cotton stainer, has never attracted so much attention as has 

 that by the conchuela in Mexico. Nevertheless, after the character- 

 istics of plant-bug injury have been brought to one's attention, a per- 

 son is generally impressed with the frequency with which it is met 

 in the cotton fields. The appearance of the conchuela as an enemy 

 of miscellaneous crops in western Texas, near Barstow, in 1905 led to 

 an investigation, in connection with which estimates were made of the 

 damage of the insect to cotton in that locality. As has been stated in 

 a paper dealing with this outbreak, it was estimated that about 10 

 per cent of the cotton was destroyed near Barstow in 1905. In one 

 field on August 11, 30 per cent of the bolls had been ruined, but the 

 disappearance of the majority of the insects and the continuance of 

 the fruiting of the plants resulted in the percentage of injury being 

 ultimately reduced by one-half. 



Plant-bugs occur in cotton fields in the northern half of the State of 

 Texas in much greater abundance than in the southern half, and in 

 1905, special attention having been given for the first time to the 

 occurrence of plant-bug injuries, it was evident that the aggregate 

 losses from this cause must have been large. It is impossible to ap- 

 proximate the total loss chargeable to the work of plant-bugs in 1905, 

 but it is almost certain that for northern Texas an estimate of 4 or 5 

 per cent of all bolls is not too high. As a matter of fact the writer's 

 personal examinations in many cotton fields in the section of Texas 

 referred to indicated that this estimate is much too low. Plant- 

 bugs (Pentatomids) were especially abundant near one corner of a 60- 

 acre cotton field at Dallas, Tex., used for experimental purposes by 

 this Bureau. On September 9, 1905, 43 green cotton bolls were 

 picked at random in the section of the field referred to, and of these 

 -29, or 68 per cent, were damaged by the bugs, about 50 per cent being 

 ruined and the others showing badly stained lint. On November 4, 

 25 bolls were picked at random in a section of the field where these 



