9900 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
Other Weevils on Eastern Trees 
From time to time other, less common weevils become noticeable 
either because of their abundance or the damage caused by their attack 
ina localized area. Their appearance and the character of the damage 
are briefly described in the following paragraphs. 
The pine gall weevil (Podapion gallicola Riley) forms galls on the 
twigs of scrub, pitch, and red pines. The spherical gall is formed 
on the 2- -year- -old twigs, and appears merely as an enlargement of 
the stem. The interior is hard and woody. The galleries are full 
of liquid resin while the larvae are active, but in an “old, vacated gall 
the resin hardens. The eggs are pr obably laid in the 1-year-old twigs 
in June, and they may be laid singly, in which case the gall is small, 
or several may be laid in a small area along the stem, causing a much 
larger, compound-gall. Little is known of the life histor ys although 
in available literature it is stated that the ege or larva remains in the 
wood without forming the gall until the following spring. The 
writer has found full-grown larvae in galls in northern Minnesota in 
early May and small larvae in fr eshly formed galls in northern Michi- 
gan in August. One or more adults may develop i in a gall. 
Dorytomus subsimilis Blatch. feeds as a larva in “the catkins of 
poplar. IMyrmex myrmex (Hbst.) breeds in the dead and dying twigs 
of sycamore killed by the sycamore blight, and the adults feed on the 
fruiting bodies on the bark. 
Pseudocneor rhinus setosus Roelofs, a Japanese weevil, is fairly com- 
mon in and near New Haven, Conn. It was first reported from West- 
ville on burr marigold in 1920, and in 1932 foliage injury was noticed 
in West Haven on hemlock, J apanese barberry, C Salifornia privet, and 
lilac. The hemlocks had been moved from a nursey in Westville, 
where the insect was first found, about 1922. and Britton (60) stated 
that apparently this was the source of the West Haven infestation. 
Some of the trees had died and others were severly injured by the de- 
foliation. In 1934 injury was reported chiefly on rhododendron, 
mountain laurel, and deutzia. This weevil is about 5 mm. long, stout, 
and light to dark brown mottled with transverse bands of brown and 
black. The elytra are striate, with white lines in the grooves and 
whitish spots on the apical half. The elytra are apparently fused, 
thereby preventing flight, so natural dissemination will be slow. There 
is no information available on the immature stages. 
Polydrusus impressifrons Gyll., a European species, has been taken 
in New York and Connecticut on a variety of trees, chiefly willow, 
poplar, birch, and plum. The adult is about 5 mm. long, and is light 
metallic green. The eggs are laid in May or June under loosened bark 
on dead stubs or scars. The larva is white, slender, and legless. It 
goes into the soil and eats the roots. Pupation takes place in the 
spring. The young adults eat the developing buds and the unfolding 
leaves. P. americanus Gyll., a native species, is common on beech. 
Thylacites incanus 1., 1s a rather recent European introduction, and 
has been reported from Massachusetts and Long Island. Barbey ( 
stated in 1925 that it is 8 to 11 mm. long, brown in general colts a 
brownish-gray scales having a metallic reflection. The antennae are 
reddish-brown, and the elytra are finely striated and punctured. The 
larva is at times a serious pest of pines and spruces in Europe. It 
