THE CONCHUELA. 



27 



NYMPHS. 



Fig, 2.— The conchuela: Nymph, first instar. 

 Enlarged 21 diameters. (Original.) 



(Figs. 2-6.) 



First instar. — In the first instar the head and thorax are deep brown. 

 The abdomen is deep slate-gray with a middorsal series of shiny 

 black spots, whitish at the marginal incisures between which iust 

 inside the margin of each segment is a spot of deep brown. Speci- 

 mens in this stage vary in length 

 from 1 to 1.75 mm. and in width 

 from 1 to 1.5 mm. according to 

 individual variation and age. 



Second instar. — The head and 

 thorax of the nymphs in the 

 second instar are shiny black, 

 the thorax being margined with 

 yellowish or orange -red. The 

 abdomen above is dark viola- 

 ceous, the venter paler. There 

 is a series of Mack spots on 

 the dorsum of the abdomen as 

 in the first instar and a ventral series of black spots is sometimes 

 present along middle one to each of the last four segments. The 

 abdominal segments above and below have a yellowish or orange-red 

 border, which narrows posteriorly. The length of second-instar 



nymphs varies from 1.6 

 to 2.5 mm., and the 

 width from 1.3 to 2 

 mm. 



Third instar. — T h e 

 nymphs in the third in- 

 star are much like those 

 of the second but are 

 subject to greater vari- 

 ation in color. There 

 is more or less olivace- 

 ous along the middle of 

 the venter of the thorax. 

 The abdomen usually 

 has a pale violaceous 

 ground color and dark 

 violaceous spotting. The ventral series of spots is usually distinct, 

 consisting of one spot on each of the segments from the fourth to the 

 eighth, the anterior spot being the smallest. Frequently inside the 

 reddish border on each segment from the second to the ninth is a 

 more or less thickened crescentic black mark. Corresponding 



Fig. 3.— The conchuela: Nymph, second instar. 

 ameters. (Original.) 



Enlarged 21 di- 



