46 
lower cuticles, remaining untouched. In order to get at this inner 
substance the larva must bore or mine into the leaf, and hence 
Reaumur’s term, Mineurs des feuilles.* There is also another point 
of difference in the manner of feeding between the external feeders and 
the leaf-miners. Dr. Wood draws attention to this point (Ent. Mo. 
May., vol. 26, p. 2), when speaking of mining larvae and their well 
developed muscles that move the head from side to side, which, he says, 
“ is the movement these larvie employ in feeding instead of the usual 
up and down one of external feeders.” 
There are two chief kinds of mines, the gallery and the blotch. 
The gallery mine is simply the space out of which the parenchyma of 
the leaf has been eaten by the larva, and usually appears as a flat 
thread-like track, running in a more or less serpentine manner in the 
leaf. It gradually increases in width as the larva grows, and usually 
ends in an elongated ovoid space, where the larva makes its exit from 
the leaf. In the gallery mine the larva simply moves forward as it 
feeds, filling the mine behind it w'ith its excrement. In certain species 
the gallery will wind round itself, and in that case will usually develope 
into the blotch mine. The blotch mine has two forms, the flat and 
the arched or domed mine. The flat blotch appears as a continuous 
more or less uniformly pale space in the leaf. The domed blotch has 
usually the upper surface arched over. The larva causes the mine to 
assumed this shape by making one or more puckers in the leaf cuticle 
opposite the surface to be arched. This it does by covering parts of 
the cuticle with silk. The parts so covered then wrinkle up, drawing 
the edges of the mine nearer together and so forcing the opposite 
cuticle to form a dome. This arrangement may easily be seen in the 
mines of Lithocolletis mexuaniella in evergreen-oak leaves. The blotch 
mine made by the larger leaf-miners, such as the Gelechiids, often 
assumes quite a bladdery appearance. The blotch miners can wander 
about their mines at will and occasionally \ve find more than one larva 
in the same mine, but as a general rule the leaf-miner lives alone, or, as 
Reaumur says (Mem., vol. iii., 1st men., p. 5) “ ils vivent dans line 
grande solitude.” 
The British Lepidopterous leaf-miners at present number, in round 
figures, three hundred and fifty species. Though they mostly belong 
to the smaller moths, known as the Tineina, there are a few repre¬ 
sentatives among the larger species, the imagines of -which will be 
found in most collections of the Macro-Lepidoptera. For the sake of 
convenience the leaf-miners may be divided into four sections: — 
Section A. — Containing those species in w'hich the mining habit 
is confined to the earlier larval stadia. ( Adscita, Rerun-aria, Yponomeuta, 
Buccalatrix, Orni.r, Gracilaria (Phylloporia ?)) 
Section B.—Those species of which the larva* continue to mine 
leaves throughout the feeding stages, but move from one leaf to another 
at will ( Rafiad.es, Tortn.v, Anstotelia, Depressaria, Cnleophora, Elachista, 
(h'tliotaelia, Bedellia ). 
Section C. — Containing those species which pass all the feeding 
stages in the same mine, only quitting the mine when about to pupate 
(Nepticula (most), Lencoptera, Lyonetia, Eriocrania, Heliozela). 
Section D.—Those species which only quit the mine as perfect- 
insects ( Lithocolletis , Phyllocnistis, Tischeria.) 
* Meiuoires vol. iii, 1st mem., p. ] (1737.) 
