336 THE WHITE COFFEE—LEAF MINER. 
rower to the end. The head is flat, rounded in front, and is fre- 
quently much retracted within the prothorax, when its lobes show 
through the skin of the prothorax. The jaws (mandibles) have 
' three teeth at the end,* and are covered in repose by the upper lip 
(labrum). The head on each side, has two eye-spots (ocelli), of 
which the anterior is the larger, and about nine hairs. The three 
segments of the thorax bear each a pair of jointed legs; the third, 
fourth, fifth, sixth and ninth or last segment of the abdomen bear 
each a pair of fleshy projections which serve as feet, so that the 
larva may be considered as sixteen-legged. From each side of the 
back of each abdominal segment, arise three hairs, of which the 
anterior or shortest is directed forward, while the two others are 
directed backward. The third hair is twice or more than twice 
as long as the second, being nearly equal in length to the breadth è 
of the segment. The thoracic segments have all three hairs di- 
rected forward ; the second hair is the longest, and an additional 
hair arises from the outer edge of the back of each segment. i 
The mine.— The habitation of the larva is a mine, which 1$ 
made in the leaf by eating out the soft green substance (paren- 
chyma) between the upper skin (epidermis) and the framework of 
the leaf, laying the framework bare, but leaving the epidermis 
intact, except at the point where (I suppose) the larva enters the 
leaf. Atthis point the wound heals up and forms a lenticular sca! 
twenty-five hundredths of a millimeter in length, and fifteen 
hundredths of a millimeter in breadth, raised a little above the 
general surface of the leaf. The epidermis which covers ’ 
mine becomes rusty brown, sometimes almost black in the — 
The excrement (frass) adheres irregularly to its under ee 
Sometimes a portion of the under surface of the leaf opposite ; 
mine also turns brown. ar 
When the eggs are laid in sets, as hereafter to be described, 1 
mines of the separate larvee usually become united, an 
mines of two sets may be united into one. woi, 
One mine fifteen millimeters long and ten millimeters ih 
contained seven larvæ, the scars arranged in two groups ° 
and three respectively. Another scar was near. easel 
As many as five mines, all inhabited, have been found i 
leaf and even eight mines made by ten larvæ, though ™ aan 
some of the larvæ had escaped. 
* Guérin says (Mém. etc., p. 13) that they are pidentate. 
d even ™° 
