TRICHIURA CRATAEGI. 491 



little stronger on the thoracic than on the abdominal segments. The 

 dorsal warts are still in evidence and fairly well-developed, and the 

 ear-like tubercles are still fairly prominent. The warts are of a bright 

 red or deep orange colour, and the longitudinal and jutting transverse 

 lines are yellowish. (In one larva these short transverse lines were 

 very dark and scarcely noticeable.) In the fifth instar (May 19th) the 

 hairs are very long, the dorsal ones brown, but becoming whitish 

 towards the tip. The head is dull, black, with whitish and red-brown 

 hairs ; the scutellum is dull red ; the subspiracular warts are about as 

 well-developed as the dorsal, which are flattened, but show up some- 

 what distinctly on the 6th, 7th and 8th abdominal segments. The 

 supraspiracular warts are now only to be detected on the thoracic 

 segments ; the prothoracic ear-like tubercles are still fairly well- 

 developed (Bacot). 



Vakiation of larva. — The larva is very variable. Newman says 

 that in some examples the orange markings on the side are tinged or 

 irrorated with white, and alternate with pure white amorphous blotches, 

 which form a broad irregular stripe on each side. Bacot writes that 

 there is considerable variation in the larvaa in the fourth instar, but 

 when full-fed, those of one brood that he once had, separated into two 

 very distinct forms : 



(1) Dark brown, with deep red dorsal tubercles, an interrupted pale yellow or 

 cream-coloured band down either side of the back. This band is formed by a 

 slightly oblique stripe on each segment. These stripes are white centrally and 

 yellow at ends. The lateral hairs are white, and the dorsal golden brown. 



(2) A form that suggests in some respects the larvae of M. castrensis and P. 

 trifolii. It is rather darker in colour, both lateral and dorsal hairs are reddish- 

 brown ; the dorsal stripes are less interrupted at the segmental incisions, and are 

 deep red instead of cream colour. On each segment, just below these stripes, there 

 is a subdorsal row of blue spots, and below these, again, a faint yellow spiracular 

 line. The spiracles of this form are greyish-white in colour, those of the first form 

 are darker and less conspicuous. The short transverse stripes are quite gone from 

 the dorsum of the first form and only faintly developed in the second. 



There are forms connecting these two extremes, and others equally 

 distinct as those described are possibly to be obtained. Buckler gives 

 (Larvae Brit. MotJis, pi. xlix., figs. 2b, 2c, 2d, 2e, 2f) five very different 

 figures of adult larvae : 



(1) Black, with bright red trapezoidals, an orange-yellow supraspiracular line 

 running from the 1st to the 8th abdominal, a grey spiracular line running from 

 the 1st abdominal to the anal flap and including the white spiracles, the ventral 

 surface yellowish (fig. 2b). 



(2) Black, with two red spots on the dorsum of each segment, yellow seg- 

 mental incisions, white spiracles, and a broken white spiracular line ; blackish 

 ventral area (fig. 2c). 



(3) Whitish, with a broad brown mediodorsal band, widening at the centre of 

 each segment, and containing dull brownish-yellow dorsal spots in place of the red ; 

 faint brownish-grey segmental incisions and subsegmental lines ; a fine blackish 

 longitudinal line separates the whitish subdorsal and supraspiracular areas (fig. 2d). 



(4) The dorsal area yellow, with a black median dorsal line, and black, dorsal, 

 segmental incisions ; a black cincture running round the centre of each segment 

 transversely, and containing the two red dorsal spots; the supraspiracular line 

 black ; the spiracles red ; the ventral area (below supraspiracular line) dull purplish- 

 grey (fig. 2c). 



(5) The dorsal area continuously black, forming a diamond-shaped marking 

 on each segment, each one united broadly with that before and behind ; the wide 

 part of each mark carrying two red dorsal spots on each segment. The lateral areas 

 white, the subspiracular line yellowish, the ventral area brownish (fig. 2/). 



Newnham records a form in which the usual white dorsal lines are 



