SPECIES INJURING THE FRUIT. 33 



spines. The posterior tibiae are expanded just beyond the middle 

 into fanlike dilations. 



This insect is essentially an enemy of the fruit of the Opuntias. 

 Although it has been observed very commonly in Texas, it has never 

 been found to injure the joints. Like the bugs of the genus Che- 

 linidea. it and its immediate relatives are gregarious in their habits. 

 The range extends from Mineral Wells, Tex., southward to Browns- 

 ville and westward to El Paso. 



descriptive. 



The Egg. 



Egg. — Length, 1.5 mm.; width, 1 mm. Dark brown in color, cylindrical, 

 sharply truncate at both ends, surface very finely roughened. Toward the 

 upper end the lid appears as a raised spot with a light ring. Placed with ends 

 contiguous on cactus spines, from 12 to 25 on a spine, sometimes several strings 

 alongside of each other on the same spine. Length of egg stage, about 27 days. 



The Nymphal Stages. 



First inatar. — When first hatched, the bugs are slightly less than 4 mm. in 

 length, orange in color, but soon change to a reddish hue. Antennae brown, 

 4-jointed, club and first joint equal, second joint slightly longer, basal joint 

 barely one-half the length of the others; all joints covered with hairs, those on 

 the club shorter. Legs reddish, hairy; tarsi dark brown, having shorter hairs. 

 Head reddish ; eyes brown ; pronotum reddish and armed with a pair of erect 

 spines; abdomen reddish, with four pairs of red spines located on the first, 

 second, fourth, aud fifth segments. Margins of abdomen with a row of six 

 erect spines, those at base being longest. Each spine terminates in a short, 

 black, motile bristle. The third and fourth pairs of spines are located on a 

 raised callosity. Length of this stage. 7 days. 



Second instar. — Length, 5 mm. Antennae lighter in color than in previous 

 stage, except club, which is dark brown ; front and middle pairs of legs yellow, 

 posterior pair darker, dilations on tibiae now appearing; terminal tarsal joints 

 bearing claw, which is dark brown; head, thorax, and pronotum dark brown: 

 front of head yellow, abdomen reddish. Spines as in first stage, the pronotal 

 spine being twice the length of the others. Length of this stage, 7 days. 



Third instar. — Length. 6 mm. General color of body brown; antennae, except 

 club, and front and middle pairs of legs yellow ; club of antennae and posterior 

 legs brown, except joints and tarsi, which are yellow ; callosities on pronotum 

 and margins of abdomen whitish, those on abdomen black. An additional pair 

 of spines appears on thorax. Length of this stage, 13 days. 



Fourth instar. — Length, 9 mm. Antennae as in third stage. General color 

 dull velvety black and speckled as if dusted with white powder; sparsely 

 covered with shiny, white hairs, those on posterior legs longer and more dense; 

 Abdomen reddish beneath. Length'of this stage, five days. 



Fifth instar. — Length, 13 mm. Same coloration as preceding stage, hairs 

 apparently more dense, pronotal spines yellow at base. Thorax well defined. 

 Wing-pads have now appeared, extending over pronotum, yellow. Abdomen 

 yellow, beneath black. Length of Ibis stage, 7 days. 



50975°— Bull. 113—12 3 



