After 2 to 5 weeks of feeding they pupate
on the leaf, the pupa somewhat resembling the larva but with the spines
pushed down near the leaf. Beetles for the second generation emerge in
about 10 days and may feed on pods as well as leaves.
Control. The easiest method is frequent dusting with rotenone, although a rotenone or DDD spray may be more effective. Note that that
is DDD, an analog of DDT. The latter is singularly ineffective with
Mexican bean beetles considering how readily it kills the good lady
beetles. Methoxychlor, another DDT analog, is good.
ROSE CHAFER (Macrodactylus subspinosus),
familiarly known as rose bug.
This is a tan, slender, long-legged beetle, 1/2 inch long feeding on
roses, peonies, and sometimes other flowers, in some regions ruinous to
foliage of grapes and elms, occasionally other fruits and trees. The larvae,
small, white grubs, winter in the soil, especially in sandy areas. They feed
briefly on roots of grasses and weeds, then pupate, with beetles emerging
as grapes are coming into bloom and continuing through the June rose
bloom. There is only one generation a year.
Control. Spraying or dusting with DDT or chlordane is quite effective.
Some rose gardens, in a region where rose bugs are particularly numerous, have been protected with cheesecloth fences around the beds.
, also called sweet potato beetles and gold bugs. There
are a number of species, all feeding on members of the morning
glory family, all leaf eaters. They are rather small, not over 1/4 inch long,
very broad, with the body so nearly covering the head they look like
tortoises. They are usually yellow or gold with black dots or stripes. The
larvae look like moving bits of dirt because they carry about their own
excrement and cast skins, packed onto posterior spines.
Control. Spray or dust with DDT, lead arsenate, rotenone, or cryolite.
WHITE-FRINGED BEETLE (Graphognathus spp.),
a probable immigrant from
South America, first found in Florida in 1936. The several species
known collectively as white-fringed beetle appear in portions of 8 south-
eastern states, infesting about 100,000 acres of farm crop and nursery land
in Louisiana, Mississippi, Alabama, North Carolina, Georgia, and Tennessee. The beetle is brownish gray, covered with fine short hairs, and
with faint white stripes on the wing covers which are fused so it cannot
fly. All the adults are females. They start laying eggs soon after emergence in June or July and continue through 2 or 3 months of feeding.
The eggs, cemented in small masses on plant stems, stones, or debris,
hatch in 2 to 6 weeks to small, legless grubs which feed below ground
on stems, taproots, and seed of several hundred garden plants.