Family Lyonetiidae 
Lyonetiids 
This family contains numerous species of tiny moths, the majority of which 
belong to the genus Bucculatrix. At least 18 species are known to feed on trees in 
eastern America (/48). 
Adults of the genus Bucculatrix have the vertex of the head rough or tufted. and 
the face smooth which extends into a point below the eyes. The wings are lanceolate 
and broadly fringed with markings of brown, black, or silver. Larvae are cylindrical 
and greenish and have well-developed legs and prolegs. Pupation occurs within 
longitudinally ridged or ribbed silken cocoons. 
Bucculatrix pomifoliella Clemens, the apple bucculatrix. is widely distributed 
in southern Canada and the Eastern United States. Its hosts are apple. black cherry. 
serviceberry. and hawthorn. Full-grown larvae are dark yellowish-green tinged with 
red. have brown heads. and are about 6 mm long. Winter is spent in cocoons spun 
on the lower surfaces of twigs. foliage. or fruit. The color of the cocoons differs 
according to the larval host—white on apple. pale tannish-ochreous on service- 
berry. reddish-brown on black cherry, and dark brown on hawthorn. There is one 
generation per year in the North and two in the South. 
The birch skeletonizer. 5. canadensisella Chambers. is a common species in 
southern Canada and throughout the birch-growing regions of the Eastern States 
from Maine to North Carolina and Minnesota. Paper birch appears to be the favored 
host. but several other birches and possibly alder are also attacked. The adult has a 
brown and white body and a wingspread of about 9 mm. The forewings are marked 
with diagonal white bars and the hindwings have broad fringes of scales. Full- 
grown larvae are yellowish green, with hairs projecting from white tubercles. and 
are about 6 mm long. 
Adults are active from late June to late July and lay their eggs singly here and 
there over the leaves. Hatching occurs in about 2 weeks and the young larvae enter 
the leaves to feed, forming serpentine mines. From 3 to 4 weeks later they emerge 
through the lower surface and spin webs within which they molt. After molting, 
they leave the webs and feed externally as skeletonizers until they reach maturity. 
Full-grown larvae drop to the ground and spin short. brown cocoons in which they 
spend the winter on the undersides of fallen leaves or other debris. There is one 
generation per year. 
Outbreaks occur at frequent intervals. often over large areas, and last for 2 or 3 
years. Defoliation may be severe but it seldom causes much tree mortality. The 
defoliated trees may be so seriously weakened. however. that they are attacked and 
killed by the bronze birch borer. 
The oak skeletonizer, B. ainsliella Murtfeldt. occurs from southern Canada and 
the Lake States to North Carolina and Mississippi. Its hosts are various species of 
oak and chestnut. The adult has a wingspread of about 8 mm. The forewing is 
largely blackish. with paler areas outlining an oval, blacker patch on the inner 
margin. Full-grown larvae are yellowish green and about 5 mm long. 
The winter is spent in the pupal stage in cocoons. The cocoons are white. about 3 
mm long. and ridged longitudinally. Adults are active in April and May and again in 
July and August. Eggs are laid on the undersides of leaves. First-stage larvae enter 
the leaves to feed. forming serpentine or blotch mines. Older larvae feed externally 
on the lower surface. often completely skeletonizing the leaves (fig. 41) (475). Two 
generations per year have been recorded in Michigan and Massachusetts. Outbreaks 
occasionally occur over large areas. 
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