The moth, which is out in late June and in July, occurs in woods and plantations; also said to be found in meadows, and on rough waste ground, as well as in marshes and salterns. The distribution is much as in the last species, but it is plentiful in East Yorkshire, and the range extends to Cumberland and Northumberland.

Six-spot Burnet (Zygæna filipendulæ).

This species (Plate [147], Figs. 3-5) is the most generally common of our Burnets. Perhaps the most frequent form of variation in the spots of the fore wings is that in which the outer pair run together, and so form a blotch; but union of the middle pair is not an uncommon occurrence. In ab. cytisi, Hübner, the three pairs of spots are each united, so that the fore wings have three separate blotches, and when these are of a dull scarlet instead of the usual crimson, ab. ramburi, Lederer, is represented. Occasionally, all the spots are united, as in ab. cytisi, and the blotches thus formed are connected by reddish streaks in various modifications leading up to ab. conjuncta, Tutt, which has all the spots merged into a large blotch, extending over the disc of the fore wings. From the normal crimson, the spots and the hind wings vary now and then to orange (aurantia, Tutt), or to yellow (ab. flava, Robson = cerinus, Robson and Gardner); intermediate shades between these two extremes, and the typical coloration, are rather more frequent. I am indebted to Mr. R. Adkin for the loan of the example of the yellow form shown on Plate [148], Fig. 6. Pink, and orange, forms have been noted from various parts of England, but they seem to occur, or have been found, more especially in Cambridge and the north-east corner of Essex. Fig. 7, Plate [148], represents an example of ab. chrysanthemi, Hübner, and is copied from Oberthür's Etudes d'Entom., xx., Plate [8], Fig. 134. A few specimens referable to this form, probably not exceeding half a dozen altogether, have been recorded as taken in England. In typical filipendulæ the dark blue border of the hind wings is narrow, but in ab. hippocrepidis, Stephens (tutti, Rebel), the borders are rather broad. Another character of this form is that the nervule upon which the sixth spot is placed is here of the ground colour, and therefore divides the spot. (Plate [147], Fig. 3.) At Northwood, Middlesex, I have found this form in May and June, and also in the Weybridge district, Surrey, in late July; and, it may be added, there was a flourishing colony of Z. trifolii hard by in each locality. For this reason, plus the fact that trifolii ♂ is known to pair with filipendulæ ♀, I hold the opinion that hippocrepidis is a hybrid. It may be noted here that hybrids have been raised from the crossing of filipendulæ and loniceræ; the sexes of loniceræ and trifolii pair somewhat readily, and the hybrid offspring of such pairings are fertile.

2 Pl. 148.
1.New Forest Burnet, ab. confusa.2, 3, 4, 5.Five-spot Burnet, vars.
6, 7. Six-spot Burnet, vars.

2 Pl. 149.
1.Festoon Moth: caterpillars and cocoons.
2.Triangle Moth: caterpillars.

It seems, then, that trifolii, loniceræ, and filipendulæ have not, so far, lost the power of fertile cross-pairing. Wherever colonies of two of the kind exist within visiting distance of each other, there, it appears, we may reasonably expect to find hybrids.