154 THE CANADIAN ENTOMOLOGIST. 



species of that genus, except that Tischeria ambrosmfoliella feeds also on 

 Atnbrosia artetnisifolia. Butalis matutella feeds on A. trifida and on 

 Asters ; but not, so far as is known, on any other species of Ambrosia, nor 

 on Helia7ithus or Heliopsis. A. trifida seems to be a point from which 

 they radiate, so to speak, to other Compositce. 



In the pubUshed description of Biicadatrix anibrosicefoliella I find that 

 I have omitted to mention the minute tuft of brown scales on the dorsal 

 margin of the fore wings, and that in the sentence which reads, " the 

 scales between the black internal edging of the arc, and the costal margin, 

 are ochreous," the word " dorsal " should be substituted for " costal." 



The larvte of several species of Bucailatrix are known in Europe ; 

 but in* this country, until now. Dr. Clemens' " mere mention " of the larva 

 of B. pomifoliella Clem., is all that has been published. Briefly the larval 

 habits of the genus may be thus summarized : The larva while very young 

 mines in leaves, and leaving the mine, it feeds externally, moulting once 

 in a little cocoonet, and again in a singular ribbed cocoon, where it passes 

 the pupa stage. Dr. Clemens says truly that the larva of B. pomifoliella 

 feeds on apple leaves, and pupates " in an elongate, dirty white, ribbed 

 cocoon," but this, with a brief description of the larva in one of its 

 stages, is about all of the information that he gives us about it. B. pomi- 

 foliella is not uncommon in this region (Kentucky), but I have never met 

 with the larva, and until I met with the larva of B. ambrosicefoliella^ larvae 

 of this genus have been unknown to me. 



I have elsewhere suggested that, owing to certain structural resem- 

 blances of the pups of Bticculatrix and Lithocolletis, it would be found, 

 when the larva of Bticculatrix was dissected, that it belonged to the same 

 larval group with Lithocolletis, Gracillaria, etc. In this group of larvae 

 the mouth parts are in the first stages very imperfect, the maxillae, and 

 both maxillary and labial palpi, are either entirely wanting or very rudi- 

 mentary, and the other mouth organs are of very difi:erent form and struc- 

 ture from that of ordinary caterpillars. At some subsequent moult (first, 

 third or fifth, as the case may be — varying in different genera and species 

 of the group) this " ordinary " form is assumed, and I have therefore 

 usually mentioned the imperfect form as the " first " form, and the other 

 as the " second " or " ordinary " form. My suggestion as to Biicculatrix 

 was that, where the mouth parts of the larva in its first stage were 

 examined, it would be found to have mouth parts of the " first " form, 

 because in its pupa state certain structures of the head and 2nd segment 



