CUCUMBER PESTS 
attacks. Peas, blossoms and leaves of 
the apple and numerous other cultivated 
and wild plants are devoured. 
Control 
In many instances control measures 
are necessary. Cheap coverings are espe- 
cially desirable for small plantings and 
may be very practicable for extensive 
fields. When no coverings are used the 
plants may be started early in hothouses 
and set out after they are well establish- 
ed. If the plantings are made directly 
in the field an excess of seed should be 
used to allow for the destructiveness of 
the beetles. 
Poison sprays, such as arsenate of lead 
or Paris green, aid much in controlling it, 
but successive applications are necessary, 
because of the rapid growth of the plants. 
The poisons are sometimes added to Bor- 
deaux mixture and serve as a remedy for 
fungous diseases as well. In small 
patches pyrethrum is an _ excellent 
remedy. 
Repellents such as land plaster or gyp- 
sum soaked in turpentine or kerosene or 
tobacco dust placed around the hills will 
tend to drive the beetles away. Bordeaux 
mixture is also considered a good repel- 
lent. 
E. O. Essie 
Common or Greenhouse White Fly 
Aleyrodes vaporariorum Westw. 
General Appearance 
The adult white flies are about three- 
fiftieths of an inch long, the males being 
slightly smaller than the females. The 
bodies are yellow and the wings pure 
white. The eggs are exceedingly small, 
oblong in shape, at first light green, grow- 
ing black with age and attached by a 
short stipe. The larvae are light in color, 
transforming to flat pupae about three- 
hundredths of an inch long; oblong-oval 
in shape; light green and supporting 
noticeable wax-like rods or spines, which 
makes this species readily distinguish- 
able from all others. 
Life History 
The eggs are laid upon the leaves of 
the plants, each female depositing over 
100. These hatch in about two weeks 
861 
into larvae which begin feeding very 
shortly and after three moults, covering 
nearly a week, they become pupae, which 
after two more weeks are ready to emerge 
as adults. These feed during their life 
of thirty days. 
Tomatoes and cucumbers suffer most. 
Fumigation as for scale insects is the 
best method of control, but emulsions and 
resin sprays are effective. 
E. O. Essia 
Western Twelve-Spotted Cucumber 
Beetle 
Diabrotica soror Lec. 
General Appearance 
A. small green black spotted beetle 
about the size of, and often mistaken by 
farmers for, a ladybird beetle. The ven- 
tral surface is entirely black. The lar- 
vae are white and subterranean in habits, 
so are seldom met with. 
Life History 
The eggs are laid in early spring 
around the bases of the food plants from 
one-half to one-fourth of an inch under 
the ground. They hatch quickly and the 
white grubs begin feeding upon the roots. 
The pupal cells are made near the sur- 
face and in about two weeks the adult 
beetles emerge. The broods overlap 
throughout the summer, there being two 
distinct generations. The adults hiber- 
nate during the winter. 
Food Plants 
Beets, melons, cucumbers, squashes, 
beans, corn, cabbages, peas, zinnias, 
daisies, orange, alfalfa, peanuts, potatoes, 
spinach, lettuce, mustard, roses and 
chrysanthemums. 
Control 
It is seldom necessary to resort to con- 
trol measures for the larval forms, though 
they often do much damage. For the 
adults, however, control measures are of- 
ten urgent. Poison sprays applied to the 
tender growth are very effective. 
Natural Enemies 
Two natural enemies prey upon this 
beetle; one a tachinid fly, Celatoria dia- 
broticaee Shim., and the other a spider, 
Xysticus gulosus Keys. 
BH. O. Essie 
