42 LEAF-MINING INSECTS 



their works with sprightly accounts of the ways of these 

 little creatures. Men like De Geer and Raeumur found 

 them full of interest. To catch the spirit of these old-time 

 naturalists one cannot do better than to read De Geer's 

 account 1 of a "yellow mining larva which makes galleries in 

 the leaves of the rose." This leaf -miner was first discovered 

 by De Geer in 1737. Many years afterward, when bi- 

 nomial names become current, Goeze gave it the scientific 

 name Nepticula anomalella. De Geer's account is quaint 

 and painstaking. Let the flavor of the times and of De 

 Geer's personality justify the rambling length of it. It 

 would seem to be the first time that an inquiring eye had ever 

 lighted on an Nepticulid larva. It is certainly the first 

 account of the rearing of one. 



In autumn, in the months of September and October, we find 

 on the roses (whether wild or growing in the gardens) leaves which 

 are marked with brown streaks which are wavy and, as it were, 

 entwined in one another. If we examine these streaks we soon 

 perceive that they are the work of insects, that they are channels 

 mined by tiny insects in the interior of the leaves. If one holds 

 them towards the light one may see distinctly the mining insect 

 at the larger end of the channel. 



The insects which make these passage-ways are particularly 

 noteworthy on account of their very unusual form which departs 

 widely from that of all their kind at present known. They are 

 true caterpillars, but caterpillars of an altogether new and special 

 sort. They are very small, their length is at most but two lines 

 (4 mm.) . They are of a beautiful yellow color bordering on orange 

 but the head is brown. The body is divided into twelve segments 



and tapers posteriorly The transparency of the skin 



allows one to see some of the internal structures The 



head is supplied with two, flat, slender teeth well adapted for 



1 Translation by Mrs. Tothill from De Geer's Memoires, Vol. 1, p. 446, 

 el. seq. 



