|
Beetles that are black with red or yellow spots often feed on scale in-
sects. The famous vedalia came from Australia to control cottony-cushion
scale, and another Australian lady beetle was imported for citrophilus
mealybugs. One of the chief indictments against DDT is that it kills these
friendly insects.
MAY BEETLES (Phyllaphaga spp.), also called June beetles, June bugs, and
daw bugs; known in the larval state as white grubs. The beetles are
large, an inch or more long, stout, reddish brown or black. The dirty
white, hairy, wrinkled grubs resemble those of Japanese beetles but are
twice the size. They lie on their sides in the soil, with the hind end, shiny
from the dark body contents showing through, almost touching the legs.
There are many species, and the life cycle varies according to location,
being completed in a year in some species in the South and taking 2 or
3, sometimes 4, years in the North.
The adults appear in spring after trees have come into leaf, and they
fly at night, feeding on many shade trees and shrubs. They lay their eggs
in sod, the grubs injuring grass roots the first fall and the next season
feeding on roots of all kinds of cultivated plants-corn, potatoes, beans,
carrots, strawberries, roses, etc. Those with a 3-year cycle pupate the next
spring and transform into beetles in earthen cells but do not come out
to fly until the third spring.
Control. Lead arsenate is still used for preventing injury to lawns, 10
pounds per 1000 square feet, and is somewhat preferred to DDT. Chlordane and aldrin are also successfully used in grub-proofing. Treating soil
with chlordane or lindane before planting strawberries keeps them protected from white grubs. In heavy flight years trees and shrubs can be
sprayed with lindane or chlordane to protect foliage.
MEXICAN BEAN BEETLE (Epilachna varivestis). This large lady beetle, one
of the very few harmful members of that group, is surely known
to every backyard gardener who has tried to grow a few beans. Snap
beans and lima beans are particularly favored; it leaves soybeans to the
Japanese beetles.
The beetles are broad, convex, 1/3 inch long, coppery yellow with 16
black dots. They hibernate in trash or weeds and after beans are up in
spring move over to feed and lay groups of orange eggs on underside of
leaves. The larvae are orange yellow, fat and fuzzy, with rows of black-
tipped spines. They skeletonize leaves in a lacy pattern, eating out everything but epidermis and veins.
|