INSECT ENEMIES OF EASTERN FORESTS 581 
Virginia. Its food plants are wild and cultivated roses. The young 
larvae begin feeding by skeletonizing patches from the underside of 
the leaflets, later eating so as to cause holes in the leaflets, and finally 
eating all but the largest veins. The full-grown larvae form cells 
in the pruned ends of rose shoots or in pieces of soft wood or pith, 
in which they transform to the adult stage. In its southern range this 
species has two generations a year, but in its northern range it prob- 
ably has only one. Middleton (300) discussed this species, which 
was formerly known as L'mphytus cinctipes Nort., the coiled rose- 
worm. 
The larvae of Macremphytus tarsatus (Say) and WM. varianus 
(Nort.) are rather common defoliators of Cornus spp. in the North- 
eastern and Lake States. In each species the larva has a shiny black 
head, and the body is densely covered with a white powdery secretion. 
In the early instars the body is whitish, but when nearly full grown the 
back is creamy yellow marked with grayish-black transverse bands or 
spots, and the venter and legs are yellowish. They have one genera- 
tion annually. The adults emerge over a rather long period, from 
the latter part of May through July. Larvae may be found from 
July until October. In the laboratory the full-grown larvae bore 
into and successfully pupate in cork stoppers, so in nature it is prob- 
able that they form their cells in pith or in decaying wood on the 
ground. The winter is passed as prepupal larvae and some may re- 
main in diapause in their cells for one or more years. 
SUBFAMILY BLENNOCAMPINAE 
The brown-headed ash sawfly (Zomostethus multicinctus Roh.) 
(fig. 168) is about 34 inch long as a full-grown larva. It is yellowish 
white or greenish white, and the head is brownish and much smaller 
than the thorax. This species is sometimes a serious defoliator of red 
ash and white ash, particularly of shade trees. It is widely distrib- 
uted throughout the eastern and central parts of the United States, 
having been recorded from the New England States, Maryland, the 
District of Columbia, Virginia, Kansas, and Michigan. There is one 
generation each year. The adults emerge about the time the leaf buds 
of the ash show green, which is usually late in April or in May, the 
maximum emergence in a locality depending somewhat on weather 
conditions. The eggs are laid in the tissue of the developing leaflets. 
The young larvae at first eat holes in the leaflets, but later consume 
entire leaf areas. In the vicinity of Washington, D. C., the larvae 
may complete their growth by the latter half of May, but in parts of 
New England it is sometimes the third week in June before they are 
fully grown. . The prepupal larvae pass the summer, fall, and winter - 
in earthen cocoonlike cells constructed in the topsoil. 
‘The larva of the black-headed ash sawfly (Zethida cordigera 
(Beauv.)) is whitish with a yellowish tinge. It is about 34 inch long 
when full grown. The head is shiny black and the thoracic legs black- 
ish brown. The head is dark brown in the prepupal stage. Its dis- 
tribution, food plants, habits, and life history are very similar to those 
of Tomostethus multicinctus, and it also occasionally causes serious 
defoliation of shade trees. 
