on baldcypress and ornamental spruce. The adult is an elongate-oval convex, rusty- 
yellow or brown beetle with green reflections, and it is about 4.5 mm long. Fuil- 
grown larvae are sparsely covered with short hairs. Small clusters of longer hairs 
occur at the lower, outer edges of each body segment. 
The winter is spent in the larval stage in cells in the soil. Pupation occurs in the 
spring and adults begin to emerge by early May. They feed on the needles of the 
host, chewing from the edges into the midrib. In light infestations, feeding is 
generally limited to the needles on new growth; whereas in heavy infestations 
needles over the entire crown may be attacked and entirely consumed. Where this 
occurs, infested stands appear as if scorched by fire. The larvae feed on the roots of 
grasses and herbaceous vegetation until fall, and then move deeper into the soil 
where they spend the winter. Infestations tend to occur on pines growing along the 
edges of stands bordering on grassland, or on isolated groups of pines growing in 
fields or yards. Severe infestations have been recorded in pine plantations in 
Florida, Georgia, and the Gulf Coast States. The biology of the species in Loui- 
siana has been reported (368). 
The locust leafminer, Odontota dorsalis (Thunberg), occurs in southern Canada 
and throughout most of the Eastern United States. Its favored host is black locust, 
but several other tree species such as apple, birch, beech, cherry, elm, oak, and 
hawthorn are also attacked occasionally. The adult is an elongate, flattish beetle 
about 5 to 6 mm long. The head is black and the thorax and most of the wing covers 
are bright orange. The inner edge of each elytron is black, with the blackened area 
widening posteriorly. The elytra are also deeply pitted, and each elytron bears three 
longitudinal ridges. A full-grown larva 1s yellowish white, somewhat flattened, and 
a little longer than the adult. 
The winter is spent in the adult stage in bark crevices or under debris on the 
ground. Overwintering adults emerge in the spring about the time the leaves begin 
to unfold, and feed for a short time on the leaves, skeletonizing the lower surfaces 
and eating holes in them. Eggs are deposited on the lower surfaces of leaves in 
groups of three to five. They overlap like shingles on a roof, are glued together, and 
are covered with excrement. All the larvae from a given group of eggs bore into a 
leaf and feed in a common mine. Later, they separate, and each larva feeds in its 
own mine. Before reaching maturity, a larva may mine several leaves. Pupation 
occurs in the mine, and there is one generation per year. 
Outbreaks of the locust leafminer occur practically every year somewhere within 
its range, and black locust trees on tens of thousands of hectares are often defoli- 
ated. The defoliated trees are seldom killed, however, unless the damage is incurred 
during poor growing seasons. At such times trees may be killed in large numbers 
(605). The eulophid parasite, Closterocerus tricinctus (Ashmead), 1s reported to 
have destroyed over 50 percent of the pupae in West Virginia infestations (/258). 
Direct control is seldom attempted in the forest, but is sometimes desirable in parks 
and other recreational areas. 
The imported willow leaf beetle, Plagiodera versicolora (Laicharting) (fig. 
113), an introduced species, was first reported in this country from Staten Island, 
N.Y., in 1915 (589). It is now widely distributed in the Eastern States and southern 
Canada (it has also been reported from Alaska) where it feeds on several varieties of 
willow and poplar. The adult is moderately stout, oval, and about 3.5 to 4.5 mm 
long. It is metallic blue or greenish blue, and sometimes tinged with red or bronze. 
Full-grown larvae are almost jet black and about 5 mm long. Rows of protuberances 
run both across and along the body. 
264 
