THE YOUNG NATURALIST. 



229 



ZYGiENA MELILOTI. 



By C. S. GREGSON. 

 At page 224, of the " Young Naturalist," Mr. Webb considers Z. meliloli 

 to be a form of Z. trifolii. That our young friends may not be misled by 

 mere opinions, let us ask Mr. Webb to give us what knowledge he may have 

 upon this question. In the meantime, let us look at the facts. First then, 

 Z. trifolii is an exceedingly variable species, specimens occuring commonly in 

 the same locality, in different seasons from 1 inch 4 lines, to 2 inches in ex- 

 panse. From five distinct bright red spots upon its opaque upper wings, to 

 three spots or blotches and to one long irregular mass of red, and sometimes 

 to suffused red wings, having only dark margins into which the red blends ; 

 sometimes the red spots are large, sometimes they are scarcely perceptible. 

 It also varies very much in its hind wings. Often the underwing is broadly 

 bordered with a somewhat irregular bright bluish green, often the border 

 is narrow. Of the difference in the shape of the antennae, I think Mr. 

 Doubleday wrote some years ago in the " Entomologist," so I leave that 

 point ; but will note the difference in the shape of the upper- wings. The 

 costa of trifolii is straighter for a greater distance along the wing than in 

 meliloti, then drops down short to the tip, making the wing more pointed 

 than in meliloti, 



Meliloti is a most invariable species, both in size and markings. Its 

 range in size is from one inch one line down to eleven lines, average size one 

 inch, and is invariably semi-transparent. Its central mark is placed at the 

 fork of the sub-costal and median nerve and is mostly cuniform, the point of 

 the arrowhead being between the spring of the nerves. Sometimes it is a slightly 

 pointed oval, whilst in trifolii this mark goes to all sorts of shapes, except to 

 these named ; the costa of meliloti is straight for a less distance than in 

 trifolii, and drops down further from the apex, thus giving the wing a 

 rounder point than in trifolii. Its antennas are shorter, and the thickened 

 part narrower and less club-like, and the whole insect seems more fragile 

 than small specimens of trifolii. It is like a race horse, to a carriage horse, 

 trifolii is coarser bred. I thought this subject was settled years ago. Doubleday 

 placed it at first as a reputed British species, not as a variety, but gave it as a 

 variety of trifolii in his synonyms, but afterwards he admitted it as a species. 

 In my Continental collection are seven specimens, two are one inch two lines, 

 and the other five average one inch. Then they are about one line larger 

 than the average in my series of about 30 English specimens, but the average 

 size of trifolii from the Continent is much more. 



I have gone more fully into this matter than perhaps is necessary, but 

 questions like these are better gone into as they arise, and should Mr. Webb 



