433] LARVAE OF THE TENTHREDINOIDEA—YUASA 115 



are wood-borers attacking conifers, those of the Tremecinae boring in 

 deciduous trees. Tremex columba, or three races of this species which 

 infest maple, elm, apple, pear, beech, oak, and sycamore, are the best- 

 known examples. The food-plants of only three American species are 

 known, these including Slrex cyaneus and Urocerus albicornis. Larvae of 

 the Siricinae have not been examined. 



Tremex Jurine 



Larvae conspicuously large; body cylindrical, slightly flattened on 

 the venter; large, robust, usually bare except on head and tenth abdominal 

 segment; whitish or creamy white; setae microscopic; head semiglobose, 

 slightly wider than high on cephalic aspect, semicircular in profile, pro- 

 duced to the ventral half of the front, then suddenly truncated, pale brown- 

 ish; mandibles and coilae deep brown; antennae apparently one-segmented, 

 conical; antacoria partly chitinized and bearing a few small setae; ocel- 

 larae wanting; depression mesad of antennaria which is sometimes called 

 the "eye" is a pretentorina; vertical furrows concealed by overhang- 

 ing prothorax; clypeus small, light in color; labrum transverse, con- 

 vex, thick, asymmetrical, without median emargination, but with a 

 notch on the right third of slightly oblique cephalic margin; mandibles 

 strong; mandacuta distinct, brown; mandibularia narrow, inconspicu- 

 ous, maxilla fleshy except subgalea, stipes large; palpi two-segmented, 

 small; galea conical, brown, small, arising from broad shoulder which 

 bears a few tiny setae on the lateral portion; lacinia round, lobe-like, 

 bearing three rows of brown setae, which decrease in length on cephalic 

 or dorsal side; labium compact, submentum narrow, transverse, mem- 

 branous, mentum convex, lobe-like, deeply emarginate on cephalic margin, 

 ligula round, fitting into the emargination of mentum, palpi small, two- 

 segmented, second segment much smaller than first, conical and brown, 

 sericos large, transverse, distinct, crescentic; prothorax large, produced 

 dorsad and cephalad, overlapping the caudal third of the head; mesothorac- 

 ic and metathoracic segments about one-half the length of abdominal seg- 

 ments except the first abdominal which is only little longer than the meta- 

 thorax; thoracic legs rudimentary, mamma-like, short, tipped with tiny 

 chitinized spot, borne on fleshy conical pedal lobe; cervical sclerites want- 

 ing; sternum with transverse subtriangular lobes which meet on the meson 

 in front of median lobe between and slightly cephalad of prothoracic legs; 

 metaspiracles as large as abdominal spiracles; abdomen slightly and uni- 

 formly tapering to the caudal end; annulation indistinct on dorsum, 

 apparently with but one annulet, the venter with two annulets, the 

 second annulet larger than the first; sublateral lobe prominent, extending 

 the entire length of segment as a single oblique elevation; spiracles large, 

 brown; ninth abdominal segment a little shorter than the eighth; tenth 



