Agriculture Reference
In-Depth Information
sulfur 30 days or more before bud swell and dormant horticultural oil sprays
at bud swell through green tip are quite effective ways of managing this
pest. Spinosad can be tank-mixed with the oil. Summer
Bacillus thuringiensis
sprays can help manage the larvae and mating disruption strips are avail-
able. According to the National Sustainable Agricultural Information Ser-
vice, “The peach twig borer has many natural enemies and parasites, includ-
ing the parasitic wasps
Paralitomastix varicornis
,
Macrocentrus ancylivorus
,
Euderus cushmani
,
Hyperteles lividus
,
Erynnia
species and
Bracon gelechi-
ae
, as well as the grain mite
Pyemotes ventricosus
. The California gray ant,
Formica aerata
, can be beneficial when it preys on peach twig borer, but it
unfortunately also protects aphids and scales. Other predators of the peach
twig borer include lacewings, ladybugs, and minute pirate bugs. Beneficial,
predatory insects can be attracted to the orchard by habitat plantings, cover
crops, and hedgerows.”
Beetles and Plant Bugs
Several beetle and plant bug species are pests of fruit tree crops in North
America. The most serious is plum curculio, which attacks a wide range of
stone and pome fruits and has severely limited organic tree fruit production
in eastern North America.
Plum Curculio
Plum curculio is an extremely serious pest of pome and stone fruits in east-
ern North America, roughly east of the longitude line running through Man-
itoba and Texas. Adults are beetles with characteristic weevil snouts. They
emerge from cocoons in the soil in early spring and fly to the trees, where
they feed on buds, flowers, and developing fruits. They lay eggs in develop-
ing fruits, and the female cuts a crescent-shaped slit underneath the eggs,
creating a flap that prevents the eggs and larvae from being crushed by the
expanding fruit cells.
The larvae tunnel through the fruits, feeding near to but not on stone
fruit seeds. The larvae will feed on pome fruit seeds, but they are crushed
