Your May Colorado Insect Checklist

//Your May Colorado Insect Checklist

Your May Colorado Insect Checklist

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

 

DENVER METRO & BOULDER

Early May

Household/Miscellaneous Insects

Miller moths: Flights into areas often begin in early May.
Tick season: The next two months are the peak season for tick activity and spread of Colorado tick fever.

Lawns

Spider mites: Injury by banks grass mite increases. Clover mite populations should be decreasing.

Trees/Shrub Insects

Brownheaded ash sawfly: Continue to monitor ash for evidence of infestations.
Hackberry psyllid: Adults return to trees and lay eggs on the emerging leaves.
Honeylocust podgall midge: Adults begin laying eggs on new growth. First generation begins.
Pine needle scale: Crawler emergence typically begins around mid May, about the time of lilac peak bloom. Check infested plants.
Elm leaf beetle: Adults return to trees and chew holes in leaves.
Southwestern pine tip moth: Egg-laying occurs when new needles emerge on pines.
Honeylocust plant bug: Nymphs have hatched and begin to damage new growth.
Peach tree borer: Larvae causing peak injury to bases of trees at this time
Tent caterpillars: Larvae may be seen making tents on various fruit and shade trees. Forest tent caterpillars are also active.
Slugs: Slugs may cause peak damage to seedlings during cooler weather.
Cooley spruce gall: Eggs hatch and young nymphs move to feed on new growth. Galls are initiated.
Pine needle scale: Egg hatch may begin during warm seasons.

Late May

Household/Miscellaneous

Miller moths: Peak flights typically occur at this time.

Tree/Shrub Insects

Brownheaded ash sawfly: Peak period of injury in most seasons.
Pine needle scale: Crawler emergence typically begins around mid May, about the time of lilac peak bloom. Check infested plants.
Oystershell scale: Crawler emergence typically occurs in late May. Check infested plants.
Bronzed cane borer/rose stem girdler: Adults emerge from caneberries, currant, rose.
Oak borers: Treatments should be made to high risk sites.
Fruittree leafrollers: Leafrolling may begin to be observed on many trees/shrubs.
Elm leafminer: Egg laying by adults may be expected.
Hackberry psyllid: Current season galls begin to be visible as small eruptions on leaves.
Cooley spruce gall: Current season galls are readily visible upon close inspection. Small nymphs are present in chambers of the gall.
Rabbitbrush beetle: Peak feeding injury by larvae.
Pinyon tip moths: Larvae start to tunnel into terminals.
Douglas-fir tussock moth: Egg hatch may begin. Monitor infested trees.
Leafcurling aphids: Aphids curl the new growth of many plants at this time.
Currantworm: Larvae chew leaves of current and gooseberry. Damage starts in the interior of shrub.
European elm scale: Overwintered females feed intensively and begin to produce large amounts of honeydew.
European elm bark beetle: Adults emerge and feed on twigs. Most new transmission of Dutch elm disease occurs at this time.
Codling moth: Sprays after petal fall can help control the first generation. Monitor flights with pheromone traps.

Garden Insects

Seedcorn maggot: Early planted beans, corn, and melons are susceptible to seedcorn maggot damage.
Currantworm: Larvae chew leaves of current and gooseberry. Damage starts in the interior of shrub.
Strawberry injuries: Millipedes and slugs tunnel the ripening berries.
Narcissus bulb fly: Adult stages emerge and lay eggs on narcissus, daffodils, and hyacinth.
Flea beetles: Adults are present on cabbage family (crucifer flea beetles) and nightshade family (potato flea beetle) plants.


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

DENVER SOUTH AND EAST

Early May

Household/Miscellaneous Insects

Miller moths: Flights into areas often begin in early May.
Tick season: The next two months are the peak season for tick activity and spread of Colorado tick fever.

Lawns

Spider mites: Clover mite populations should be peaking and may begin natural decline.
Sod webworms, cutworms: Damage to lawns by webworms and cutworms begin at this time.

Trees/Shrub Insects

Hackberry psyllid: Adults return to trees and lay eggs on the emerging leaves.
Brownheaded ash sawfly: Pinhole feeding wounds indicate early stage infestations.
Honeylocust plant bug: Check trees for newly emerged nymphs.
Elm leaf beetle: Adults return to trees and chew holes in leaves.
Southwestern pine tip moth: Egg-laying occurs when new needles emerge on pines.
Walnut twig beetle: Overwintered adults in trunk bark move to branches and begin tunneling.
Honeylocust plant bug: Nymphs have hatched and begin to damage new growth.
Peach tree borer: Larvae causing peak injury to bases of trees at this time
Tent caterpillars: Larvae may be seen making tents on various fruit and shade trees. Forest tent caterpillars are also active.
Slugs: Slugs may cause peak damage to seedlings during cooler weather.
Cooley spruce gall: Eggs hatch and young nymphs move to feed on new growth. Galls are initiated.
Pine needle scale: Egg hatch may begin during warm seasons.
Zimmerman pine moth: Period ending during which larval control is possible.

Late May

Household/Miscellaneous

Miller moths: Peak flights typically occur at this time.
Honeybee swarms: Many honeybee colonies produce swarms during sunny days

Tree/Shrub Insects

Brownheaded ash sawfly: Peak period of injury in most seasons.
Pine needle scale: Crawler emergence typically begins around mid May, about the time of lilac peak bloom. Check infested plants.
Oystershell scale: Crawler emergence typically occurs in late May. Check infested plants.
Bronzed cane borer/rose stem girdler: Adults emerge from caneberries, currant, rose.
Oak borers: Preventive treatments should be made at this time at high risk sites
Fruittree leafrollers: Leafrolling may begin to be observed on many trees/shrubs.
Hackberry psyllid: Current season galls begin to be visible as small eruptions on leaves.
Cooley spruce gall: Current season galls are readily visible upon close inspection. Small nymphs are present in chambers of the gall.
Rabbitbrush beetle: Peak feeding injury by larvae.
Pinyon tip moths: Larvae start to tunnel into terminals.
Leafcurling aphids: Aphids curl the new growth of many plants at this time.
Currantworm: Larvae chew leaves of current and gooseberry. Damage starts in the interior of shrub.
Codling moth: Sprays after petal fall can help control the first generation. Monitor flights with pheromone traps.
Honeylocust plant bug: Injury usually peaks towards end of month.

Garden Insects

Seedcorn maggot: Early planted beans, corn, and melons are susceptible to seedcorn maggot damage.
Currantworm: Larvae chew leaves of current and gooseberry. Damage starts in the interior of shrub.
Strawberry injuries: Millipedes and slugs tunnel the ripening berries.
Narcissus bulb fly: Adult stages emerge and lay eggs on narcissus, daffodils, and hyacinth.
Flea beetles: Adults are present on cabbage, radish and related plants.
Slugs: Slug injury should continue at high levels.

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

 

2019-07-30T15:00:13-06:00