550 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
spiracular row on each side, but the latter usually are black-tipped 
on the abdominal segment. A double row on the venter envelops the 
larvapods. 
Arge macleayi (Leach) feeds on wild cherry. The larva resembles 
that of the species that feeds on willow. 
Famiry ACORDULECERIDAE 
The Acorduleceridae is a small family and, as now constituted, con- 
tains only one genus, Acordulecera. This group needs further study 
and must be revised before it will be possible to definitely indentify 
many of its species. 
These insects are small, the full-grown larva being less than 14 inch 
long, with blackish or hght head, greenish body, distinct lateral lobes, 
and each segment with transverse rows of slight tubercles bearing 
short stiff setae. These larvae feed eregariously, and occasionally 
some species become so abundant locally in the Northeastern States 
that their feeding on groups of such trees as butternut, hickory, and 
the oaks attracts attention. The available records indicate that in 
the Northeast there is usually one generation, but some species occa- 
sionally have at least a partial second. These insects hibernate in the 
cocoon stage in the ground, the adults emerge in May and June, and 
= 
larvae are found from June to August. 
Famiry DIPRIONIDAE 
The family Diprionidae includes many of the most serious de- 
foliators of conifers. Several species are of foreign origin and are 
now well established in this country. Ross (367) gave the diagnostic 
characters of the adults as follows: Antennae composed of 13 or more | 
segments, serrate in the female, and pectinate or bipectinate in the 
male. Mesosterno-pleural sutures atrophied, mesoscutellum with an- 
terior margin V-shaped, posterior margin with an extremely narrow 
and cordlike postergite. Tuibiae without pr eapical spurs; apical spurs 
of front tibiae simple. 
The full-grown larvae usually range from about 34 to 1 inch in 
length. The body is cylindrical. usually yellowish or greenish with 
ore ayish, brownish, or blackish stripes or rows of black spots, and with 
the segmentation distinct. A number of species are similar in appear- 
ance and habits and it is not possible to positively identify some of 
them in the larval stage ( Yuasa, 439). 
Until recent years comparatively few species have attracted atten- 
tion as serious defoliators. Since about 1900, however, the large-scale 
plantings of conifers in solid blocks of a single species undoubtedly 
has materially favored the increase of certain sawflies, which now are 
causing considerable concern to plantation owners and foresters in 
the Eastern and Northern States. Although many nearctic species 
have been described, little has been published on the life history and 
habits of some of them, and undoubtedly further study will prove that | 
a few, at least, are identical. ‘The more important species are discussed 
in the following pages. 
The full-grown larva of Monoctenus melliceps (Cress.) is about 5% | 
to 84 inch in length, the head ght brown with black eye spots, ne | 
yeaa: is dull green with three dark longitudinal stripes, and the legs 
