410 Records of the S A. Museum 



miK'h Avifler than in the imago. As successive instars are attained, the eyes 

 become larger and more rounded. 



Below is a description of each stage of the life history, following which is a 

 table giving the average measurements of several specimens of each. The life 

 history is illustrated on pi. xi, fig. 1 to 9. 



The egg. Surface with small hexagonal reticulations. Colour pearly white 

 when first laid, ochraceous, with red eye spots as development proceeds. Length, 

 1-32 mm.; widest diameter, -52 mm., rather more as the enclosed bug attains 

 larger proportions. 



First instar nymph. Head somewhat conically produced in front of the 

 small, widely separated eyes ; vertex nearly twice as wide as the synthlipsis, which 

 is one-third of the width of the head. Anterior and intermediate tarsi less than 

 twice as long as the claws. (The longer claw of the pair terminating each tarsus 

 is measured.) Lower edge of the posterior fulchra with a row of fine striae as in 

 the adult. Swimming hairs rather sparse on po.sterior tarsus, almost absent on 

 the tibiae The colour is transparent whitish, with the eyes red, the guard hairs 

 black, and the swimming hairs and a streak on the inner margin of the posterior 

 tarsus dark brown. After the bug commences to feed the abdomen is dark owing 

 to contained food, but as the instar draws to a close true pigmentation is slightly 

 developed on the underside of the abdomen. Length, 1-8 to 1-9 mm. 



Second instar nymph. Head less conically produced in front of the eyes 

 than in previous instar; vertex slightly more than one and a half times the 

 synthlipsis, which is three and a half times in the width of the head. A some- 

 what poorly developed ventral keel is now present, but the abdominal gutters are 

 hardly apparent ; the guard hairs are arranged as in the adult. A space on the 

 venter between these is brown, and a faint dark streak appears on the underside 

 of the posterior femora. Posterior femora, tibiae, and tarsi subequal in length. 

 Anterior tarsi more than three times as long as claws, intermediate tarsi three 

 times as long as claws. The swimming hairs on the posterior tarsi are denser, 

 and a sparse fringe appears on the posterior tibiae. licngth, 2-3 to 2-5 mm. 



Third instar mjmph. Head evenly rounded in front of eyes. Vertex about 

 one and a half times the synthlipsis, which is one-fourth of the width of the head. 

 The wing pads have appeared and extend past the first third of the thorax. 

 Anterior and intermediate tarsi about three and a half times as long as their 

 claws. Swimming fringes are developed on both margins of the posterior tibiae 

 and tarsi. Limbs and under-surface in parts sooty ; head ochraceous. Length, 

 3-2 and 3-56 mm. 



Fourth instar nymph. Vertex about one and a half times the synthlipsis, 

 which is 4-4 to 5-27 times in the width of the head. The wing pads extend to 



