340 



BRITISH MOTHS. 



647. The Least Yellow Underwing (Tryphama 



interjecta) . 



547. THE LEAST YELLOW UNDERWING. 

 The colour of the fore wings is rusty-brown, 

 sometimes inclining to brick dust-red, and 

 having a broad but imperfectly defined band 

 of smoky-brown on the hind margin : this 

 band is intei-sected throughout by a pale line ; 

 the discoidal spots are indistinctly outlined in 

 dark brown, and there are several other short 

 and narrow transverse darker markings : the 

 hind wings are yellow in the middle and on 

 the hind margin ; smoky-black on the costal 

 margin, and having a broad smoky-black band 

 before the hind margin ; the inner margin is 

 clouded with the same smoky-black ; there is 

 a crescentic discoidal spot of the same black 

 tint united with the black on the costal mar- 

 gin ; the head and thorax are of the same 

 rusty colour as the fore wings ; the body is 

 gray-brown. 



The CATERPILLAR rests in a straight position 

 on the stems of its food-plant, and when 

 shaken or annoyed it falls to the ground rolled 

 in a ring, but very soon resumes the straight 

 position and crawls with rapidity : the head 

 is narrower than the second segment, into 

 which it is partially received ; it is porrected, 

 flat, rather glabrous, and not notched on the 

 crown; the body is obese and rather velvety, 

 and has the divisions of the segments strongly 

 marked ; it is somewhat attenuated at the 

 anterior extremity, and has the twelfth seg- 

 ment dorsally slightly swollen : the prevailing 

 colour of both head and body is putty-colour ; 

 the head has two dark brown marks down the 

 face, and outside of each of these is a pale 

 mark ; the body has a narrow rnedio-dorsal 

 white stripe, bordered on each side by brown 

 slightly darkc-r than the ground colour ; near 



the medio-dorsal on each side is another nar- 

 row white stripe similarly bordered, and dif- 

 fering only in being somewhat less distinct ; 

 on each side in the region of the spiracles, but 

 just above them, is a broader and triple stripe, 

 the outer portion on each side being whitish, 

 the middle reddish ; and this compound stripe 

 is also bordex-ed with brown, particularly on 

 its upper margin ; the dorsal area is orna- 

 mented with a number of intensely black dots; 

 on the second segment these are very minute 

 and apparently without much arrangement; 

 on the third they form a straight transverse 

 series and are eight in number ; on the fourth 

 they also form a straight series and are six in 

 number; on the following segments, the fifth 

 to the eleventh, both inclusive, they are also 

 six in number on each segment, but no longer 

 form a straight series ; two near the anterior 

 margin of the segment are larger than the 

 rest, the next on each side stands back about 

 the middle on the dorsal area of the segment, 

 and the third on each side is nearer the an- 

 terior margin ; the twelfth segment has four 

 of these black dots arranged in a perfect 

 square ; the ventral is slightly darker than 

 the dorsal area, and has a double series of 

 black dots below the compound lateral stripe : 

 the legs are pale, semitrausparent, and shining; 

 the claspers are semitransparent, and each has 

 a distinct black dot and a crescentic black 

 mark above it : in the interspaces between 

 the stripes which I have described there is a 

 further indication of stripes, but these are 

 very inconspicuous : it feeds on dock, mallow, 

 grass, &c. &c. 



The MOTH appears on the wing in July, and 

 occurs occasionally in most of our English 

 counties as far north as Yorkshire, and also 

 very generally in Ireland ; but I do not re- 

 collect seeing any Scotch localities re- 

 corded. (The scientific name is Tryphcena 

 interjecta.} 



Obs. Like Tryphcena iam.thina,ih\s species 

 is very uniform in tint and constant in its 

 markings ; but compared with either ianthina 

 wfimbria, it is very unattractive in appear- 

 ance. 



