THE CONCHtTELA. 23 



Due credit has not hitherto been given plant-bugs for their part 

 in diminishing the yield of cotton and lowering the quahty of the 

 lint. This failure to connect the injury with the cause, as has been 

 pointed out, is largely due to a lack of understanding of the nature 

 of the injury, as well as to the fact that plant-bugs have always been 

 found in cotton fields and except in rare instances no good criterion 

 for judging the amount of loss has been afforded. Field agents of 

 this Bureau, engaged in investigating cotton insects, frequently have 

 met cotton growers in northern Texas who ascribed the shriveled 

 condition of the locks of bolls damaged by these bugs to dry weather. 

 In Florida some cotton growers have explained damage of this same 

 kind as due to the prevalence of wet weather. 



Summarily it may be stated that locally plant-bugs frequently 

 cause large losses and throughout large sections of the cotton States 

 cause small but appreciable losses which it is important should be 

 determined in a less cursory manner than heretofore. 



PLANT-BUGS AS DISSEMINATORS OF PLANT DISEASES. 



Various plant-bugs have been suspected of transmitting fungous 

 and bacterial diseases of plants, but as yet there appears to have 

 been no careful investigation of this matter. That the transmission 

 of the spores of cotton boll anthracnose (ColletotricJium gossypii 

 Southworth) by plant-bugs from one boll to another is possible 

 requires no demonstration. An investigator would rather be con- 

 cerned with the extent to which these cotton-frequenting insects are 

 responsible for the spread of the disease. It is highly probable that 

 the bacillus of the cotton boll ^^rot" {Bacillus gossypinus Stedman) 

 may be disseminated to a greater or less extent by means of plant- 

 bugs whose mouth setae would furnish a means of direct entrance of 

 the organism to the interior of the boll. The entire subject is one 

 which offers a field for interesting and valuable research, but for the 

 present no estimate can be made of the damage to cotton indirectly 

 caused by plant-bugs through dissemination of pathogenic fungi and 

 bacteria. 



THE CONCHTJELA. 



{Pentatoma ligata Say.) 



(PI. I, fig. 1.) 



HISTORY. 



The conchuela" was described in 1831, but first became known as 

 an insect of economic importance when, in August, 1902, specimens 

 were received from a correspondent of the Bureau of • Entomology, 



a This is the common name used for this insect by the natives of the Laguna Dis- 

 trict of Mexico. It is a Spanish word meaning " little shell " and is based on a fancied 

 resemblance to a shell. 



