86 PLANT-BUGS INJURIOUS TO COTTON BOLLS. 



Records based upon 14 batches of eggs deposited in the laboratory 

 indicate that the average number of eggs deposited per batch is high 

 as compared with most Pentatomids. These records gave an average 

 of 31.4 eggs per batch, the range in number being from 10 to 42. 



In its selection of food plants TJiyanta custator has thus far exhibited 

 a preference for grains and cotton, although this may be only the nat- 

 ural consequence of the fact that these are the principal crops grown 

 in the section of the cotton belt where this Pentatomid is most abun- 

 dant. At Tlahualilo, Durango, Mexico, where this bug was common 

 in July, 1905, it was not found on alfalfa as were several other cotton- 

 infesting plant-bugs, nor has it thus far been reported as occurring in 

 alfalfa fields in Texas. A specimen of TJiyanta custator in the fifth 

 nymphal instar, immediately after being brought into the laboratory 

 from the cotton field, fed upon eggs of the conchuela, exhibiting the 

 only instance of a predatory habit which has been observed in this 

 species. 



In the cotton fields this bug is commonly found feeding on the 

 cotton squares and bolls — when feeding being frequently completely 

 hidden by the bracts. This habit of concealment, together wath its 

 small size and inconspicuous color, makes it much more difficult of 

 detection when present on cotton plants than are the other cotton- 

 infesting Pentatomids which have been dealt with in the foregoing 

 pages. The preference of the bug for the bolls over other portions of 

 the cotton plant is fully as well marked as it is in the case of the 

 conchuela. 



Gregariousness is also as well marked a characteristic of this species 

 as of the conchuela. 



In October, 1897, Mr. J. D. Mitchell, in testing, at Victoria, Tex., 

 the possibility of trapping the cotton boll weevil by lights, captured 

 4 specimens of TJiyanta custator in a one-night trial of 3 lights. °^ A 

 specimen was taken at a light by Mr. J. C. Crawford at San Antonio, 

 Tex., in May, 1905, and one by Messrs. Crawford and Pratt at CotuUa, 

 Tex., on May 12, 1906. It is possible that trap lights might be suc- 

 cessfully used against this insect in badly-infested fields of grain or 

 cotton, for in the localities above mentioned where specimens have 

 been captured by this means the species is comparatively scarce and 

 the chances of capture proportionally reduced. 



SEASONAL HISTORY. 



The writer has found TJiyanta custator in cotton fields in greatest 

 abundance in September and October. In view of its occurrence in 

 moj-e or less destructive numbers in grain fields in northern and north- 

 western Texas it seems likely that the time of its appearance in great- 

 est numbers in cotton fields may be dependent upon the harvesting 



a Bul. 18, Div. Ent., U. S. Dept. Agr., p. 88, 1898. 



