December, '19] 



FROST: ANAL COMB 



447 



Fig. 26. — 1, Laspeyresia inolesta Busck; 2, Sparganothis indaeusalis Walk.; 

 3, Archips rosaceana Harris. 



advantage to these larvae but on the contrary would be a decided dis- 

 advantage because it would toss the frass beyond their reach. Again, 

 Laspeyresia pomonella Clem., is strictl}' a boring insect, working within 

 the fruit. As might be supposed an anal comb would be of no use to a 

 larva in a burrow of this sort. The larva pushes its frass from its 

 burrow and has no need of a comb. Finally three other larvae were 

 examined representing the leaf-mining habit namely, Tischeria mail- 

 foliella Clem., Lithocolletes blancardella Fab., and Ornix geminatella 

 Packard. Here again the anal comb would be of no use to the larvae 

 because they are confined betw^een the epidermal layers of the leaves 

 and the frass could not be tossed away from the body. 



On the other hand the larvae, feeding externally on the leaves or 

 fruit or more or less protected by curled or dried leaves, do not show 

 any definite correlation between the habits of the larvae and the posses- 

 sion of the anal comb. For example, Stenoma algidcUa Walk., and 

 Graphiphora alia (Authors) possess no anal comb while other larvae 

 as Sparganothis inda:usalis Walk., Eulia velutinana Walk., Archips 

 rosaceana Harris, Ancylis nuhecidana Clem., Peronea sp., and Las- 

 peyresia prunivora Walsh, have a distinct anal comb. 



It is evident that in some cases, at least, a definite correlation 

 exists but the writer does not intend this article to be conclusive as 

 but a very small number of larvie arc consideretl. Some one witli a 

 long series of larvae available may find the correlation even more 

 interesting. 



