Zygena Trifolit. 437 
Larva of Zygena, No. 1 (late T'rifoli) . 
Body with short white hairs scattered over it, with 
very few black hairs mixed with the white on the back. 
Head and fore-legs black; head with transverse upper- 
lip and membrane at base of antenne, white ; ground- 
colour pale yellowish, arranged in five lines, one dorsal 
and two lateral on each side ; dorsal line broad, yellower 
in the fold formed by the hind margin of each segment ; 
on each side of the dorsal line, a row of black spots, two 
on each segment, of which the anterior spot is the larger, 
somewhat semicircular, with the flat side turned towards 
the anus, but coming to a point on the back ; posterior 
spot narrow, curved on the anterior margin, approaching 
in shape to a lunule ; in the segment immediately follow- 
ing the head, the dorsal spots are confluent, the anterior 
being greatly reduced in size, the anterior margin of 
this segment is partially margined with blackish, leaving 
the middle portion of the yellowish ground-colour, below 
which row of spots, a broad pale yellowish line with a 
yellow spot in the fold, formed by the hind margin of 
each segment, but this spot is not very conspicuous, 
below which line another row of black spots on each side, 
two on each segment, of which the anterior is larger and 
curved backwards, and bears the black spiracles, but 
very often the lower portion of this spot which bears the 
black spiracles, is separated from the rest, and sometimes 
dwindles down to a mere dot. No minute black spot 
below the smaller of the two lateral spots, as is often the 
case in IMilipendule; below which row of spots is the 
lower lateral line, and below this line and the feet is a 
row of dusky spots bearing a pale transverse lunule in 
the lower portion of each, but which lunule is sometimes 
absent, or nearly so; a dusky, very narrow streak at the 
base of the feet ; pro-legs and underside yellowish, with 
a dusky interrupted line down the middle of the belly. 
Feeds on the large Trefoil found in marshes (and on that 
plant only). 
Described June, 1866, from larve found in marshy 
ground in Stowe Wood; confirmed by others found in 
Tilgate Forest in a similar locality, and since confirmed 
by examination from year to year. 
Take a Filipendule larva, give it a much clearer and 
cleaner ground-colour, diminish its spots below the limit 
