Your April Colorado Insect Checklist

//Your April Colorado Insect Checklist

Your April Colorado Insect Checklist

April Colorado Insect checklist of some common insect-related events – Denver metro and Boulder, Denver South and East

 This is a generalized checklist of when some of the more important insect related events tend to occur in our area. Year to year variations are considerable – this should be used as a guideline to anticipate and help recognize common insect occurrences.

 

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April Colorado Insect Checklist - ArborScape Colorado Tree Service, tree trimming, tree removal, stump removal

DENVER METRO & BOULDER

Early April

Household/Miscellaneous Insects

Boxelder bugs, elm leaf beetles, cluster flies: Overwintered adults become increasingly active in and around homes during warm periods.
Carpet beetles: Early spring is often the period when adult stages are most frequently encountered in homes.
Millipedes: Nuisance movements into homes occurs following wet weather.
Tick season: Tick season usually has started and usually persists until high temperatures occur in early summer.
Ants: Foraging ants in homes are common until temperatures allow them to seek food outdoors.

Trees/Shrub Insects

Ips beetles: Major Ips beetle flights are likely to have started by this time and may threaten at risk spruce and pines.
Aphids on fruit trees: Spray oils on dormant trees to kill overwintered aphid eggs.
Cooley spruce gall: Controls are best applied before the insects make the egg sack in late April.
Zimmerman pine moth: Overwintered larvae remain exposed on the trunk and can be controlled at this time.
Borers: Remove and destroy damaged tree limbs and canes infested with borer larvae before insects emerge.
Honeysuckle witches’ broom aphid: Prune out old, damaged terminals that contain eggs.
European elm bark beetle: Pruned elm wood and logs should be destroyed prior to beetle emergence.
Conifer sawflies: Larvae feed on older growth of various pines.

Lawns

Denver billbug: Overwintered larvae may damage roots of turfgrass.
Turfgrass mites: Clover mites continue and banks grass mites begin to increase in droughty areas.
Sod webworms, cutworms: Damage to lawns by webworms and cutworms begin at this time.
Nightcrawlers: Tunneling activities and associated lawn lumps continue.
Midges: Non-biting midges emerge from ponds and mating swarms may be observed over lawns.

Late April

Tree/Shrub Insects

Brownheaded ash sawfly: Watch for pin-hole feeding wounds prior to peak feeding damage. Swarms of adult insects may be observed and eggs laid in leaves.
Cooley spruce gall: Insects continue development and usually begin to produce egg sack in late April.
Zimmerman pine moth: Overwintered larvae will may begin to move into trunk over the next few weeks.
Lilac/ash borer: Flights of adult moths may begin.
Poplar twiggall fly: Adults emerge and begin to lay eggs in emerging aspen shoots.
European elm bark beetle: Preventive sprays should be completed before adults emerge and fly.
Pinyon tip moth: Larvae remain exposed on bark and can be controlled at this time
Spider mites on pines: Oligonychus subnudus populations may increase rapidly on ponderosa and other susceptible pines
Spiny elm caterpillar: Small colonies of these caterpillars may be seen on willow, hackberry, aspen, elm and other trees.
Douglas-fir beetle: In forested areas, adult emergence, flights and tree attacks may begin.
Hawthorn mealybug: Overwintered stages on trunk move to twigs and feed.
Walnut twig beetle: Adults move from overwintering sites on trunk to intiate tunnels in twigs, branches.

Garden

Spinach leafminer: Egg laying and tunneling begins in older spinach foliage.


 April Colorado Insect Checklist - ArborScape Colorado Tree Service, tree trimming, tree removal, stump removal

DENVER SOUTH AND EAST

Early April

Household/Miscellaneous Insects

Swallow bugs: Overwintered swallow bugs become active in anticipate of returning migrant birds and bite humans.
Boxelder bugs, elm leaf beetles, cluster flies: Overwintered adults become increasingly active in and around homes during warm periods.
Carpet beetles: Early spring is often the period when adult stages are most frequently encountered in homes.
Tick season: Tick season usually has started and typically persists until high temperatures occur in early summer.
Ants: Foraging by field ants for sweet materials intensifies in homes.
Clover mites: Clover mite migrations into homes occur during warm days
European paper wasp: Overwintered queens start to establish new nests

Trees/Shrub Insects

Ips beetles: Major Ips beetle flights are likely to have started by this time and may threaten at risk spruce and pines.
Poplar twiggall fly: Larvae continue to leave galls and pupate in soil at the base of trees.
Cooley spruce gall: Controls are best applied before the insects make the egg sack in late April or early May.
Borers: Remove and destroy damaged tree limbs and canes infested with borer larvae before insects emerge.
Honeysuckle witches’ broom aphid: Prune out old, damaged terminals that contain eggs.
Conifer sawflies: Larvae feed on older growth of various pines.
Aphids on fruit trees: Spray oils on dormant trees to kill overwintered aphid eggs.

Late April

Household Insects

Ants: Foraging ants in homes are common until temperatures allow them to seek food outdoors.
Tree/Shrub Insects
Cooley spruce gall: Insects continue development and usually begin to produce egg sack in late April.
Lilac/ash borer: Flights of adult moths may begin.
Poplar twiggall fly: Adults emerge and begin to lay eggs in emerging aspen shoots.
Spider mites on pines: Populations may increase rapidly on ponderosa and other susceptible pines
Spiny elm caterpillar: Small colonies of these caterpillars may be seen on willow, hackberry, aspen, elm and other trees.
Douglas-fir beetle: In forested areas, adult emergence, flights and tree attacks may begin.
Brownheaded ash sawfly: Adults may lay eggs during warm days following bud break.
Zimmerman pine moth: Approximate treatment timing for overwintered larvae.

Lawns

Turfgrass mites: Clover mites continue to feed on lawns and enter homes in nuisance migrations.
Nightcrawlers: Tunneling activities and associated lawn lumps continue.
Midges: Non-biting midges emerge from ponds and mating swarms may be observed over lawns.

Garden

Spinach leafminer: Egg laying and tunneling begins in older spinach foliage.

Call us at 303-806-TREE or click here to schedule your free plant health care consultation now!

 

2019-07-30T15:06:44-06:00