The Insects of July
Sun spiders and Strawberry root weevils: Moving into homes with hot
weather.
Peach tree borer: Egg laying begins and time
to start preventive sprays.
Elm leaf beetle: The first of two or perhaps
three generations become full grown and move down the trunk to pupate.
Black vine weevil: Adults notch the leaves of euonymous and rhododendron.
Leafcutter bees: Cut out leaves on roses,
lilacs and other plants indicatestheir presence.
Cooley spruce gall: Peak emergence from galls
and migration to Douglas fir.
Pinyon pitch mass borer: Adult emergence
continues and egg laying begins.
Mountain pine beetle: Adult emergence begins.
Codling moth: Second and most damaging
generation begins to lay eggs
in late July.
Pearslug: Larvae damage plum and cotoneaster.
Elm aphids: Excrete a large amount of honeydew
on leaves.
Apple maggot: Expect the emergence of adult flies and onset of egg
laying.
Mexican bean beetle: Larvae begin to damage beans.
Colorado potato beetle: Peak period of larval injury and end of 1st
generation.
Tomato hornworms: Peak damage by larvae occurs
over the next month.
Potato/tomato psyllids: Yellow or purple new
growth symptoms begin to appear on infected plants. Spray when green, disk-like insect
larvae first detected on the backs of leaves.
Tobacco budworm: Early evidence of injury to
geraniums, petunias and nicotianabegins to appear.
Information courtesy Whitney Cranshaw, Department of Biogricultural Sciences and Pest
Management, Colorado State University.
