490 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



bonducella in Florida, and in Proc. U. S. Nat. Mus., vol. 26, p. 772, he 

 described Marmara arhutiella mining leaves of arbutus trees in Seattle, 

 Washington. In Proc. Ent. Soc. Wash., vol. 8, p. 97, he also described 

 Marmara opuntiella mining leaves of Opuntia sp. in Southern Texas. 

 Marmara (Gracilaria) elotella was likewise described by him in Proc. 

 Ent. Soc. Wash., vol. 9, p. 102, but the host plant was not given. A 

 Marmara sp. mines orange peels in southern California but the adult 

 has never been determined. 



Clemens (Proc. Ent.^Soc. Phila., vol. 2, 1863-64, pp. 6-8) claims that 

 Marmara salictella changed from the flat mining larva to a more cylin- 

 drical form which has fairly well developed legs and prolegs, and es- 

 capes from its mine to spin its cocoon in some convenient protected 

 place, this cocoon being covered with a characteristic globular or 

 frothy ornamentation. Busck also ascribes the above habits to M. 

 opuntiella, M. guilandinella, and M. arhutiella although no actual ob- 

 servations were made on the last named species. M. fulgidella and 

 M. smilacisella it is also claimed form the frothy characteristic cocoon 

 of this genus. Marmara elotella, however, differs from all the above 

 species in regard to the formation and situation of its cocoon. 



Present Distribution in Massachusetts 



An examination of apple twigs at various points throughout Massa- 

 chusetts has indicated a rather widespread prevalence for this species 

 within the state. It has been found more abundantly, however, in 

 apple trees on the grounds of the Massachusetts Agricultural College 

 and orchards adjoining, than elsewhere. The reason for this localized 

 occurence is unknown. 



Character and Extent of Injury 



Infested apple twigs show the long, narrow, tortuous, serpentine 

 mines which are very characteristic of all Marmaras. They are readily 

 recognized by the yellowish-brown color and slight swelling of the 

 bark over the tunnels, while the normal bark is dark brownish in color. 

 The moths seem to prefer two-year-old twigs upon which to oviposit, 

 usually selecting sucker-like growths. However, the larvae are oc- 

 casionally to be found mining in any branch which has a thin, smooth, 

 epidermal covering. The mouth parts of the larvae are profoundly 

 altered and specialized for living beneath the cuticle of the bark, which 

 they separate from the "greenbark" below by cutting through a row 

 of cells by the action of their circular, saw-like mandibles. From the 

 origin of each mine the tunnel gradually widens from about 0.5 mm. at 

 the beginning, to 7-8 mm. as it nears completion. The average 

 length is between two and three feet. These tunnels do not penetrate 



