Pests to Watch For in Denver in June

As summer begins to arrive in June, the danger from ticks begins to subside. To learn more about these dangerous pests, read our posts on the pests to watch for in April and in May.

However, there are a number of other insects on the The Colorado State University Extension Office’s extremely handy calendar listing all the pests in the Denver area you should keep an eye out for around your home and garden in the month of June.

Flying carpenter ants are usually on the move at this time of year and according to the CSU Extension office, “Large numbers of winged forms carpenter ants usually emerge from a nest during spring or early summer. They accumulate at windows and doors trying to find new nesting sites. Winged forms inside a home indicate a three- to four-year-old infestation that has considerable damage potential.”

Carpenter ants are often mistaken for termites. And while carpenter ants are usually not as serious a problem for homeowners as are termites, given time, they can do quite a bit of damage.

To learn more about carpenter ants, visit the CSU Extension Office’s website at https://extension.colostate.edu/topic-areas/insects/carpenter-ants-5-554/

The other pests to watch for in June include:

Household Insects

• Miller moths: Moths move to mountains with warm weather.

Tree/Shrub Insects

• Pine needle scale: Crawler emergence usually is continuing and declining during this period.
• Oystershell scale: Continue to monitor emergence of crawlers. Peak crawler period often occurs in early June.
• Honeysuckle witches’ broom aphid: Damage to new growth begins to become evident.
• Douglas-fir tussock moth: Egg hatch often is peaking during this period. Monitor infested trees.
• Elm leafminer: Early evidence of damage, small mines, may be observed.
• Striped pine scale: Crawler emergence typically begins in early June.
• Eriophyid mites: Gall making occurs on many plants. Highest populations of leaf vagrants present.
• Spruce spider mite: Populations begin to increase on spruce, juniper
• Douglas-fir tussock moth: Intensify monitoring of infested sites as feeding damage increases.
• Honeylocust plant bugs: Peak injury by nymphs. Damage will end soon.
• European elm scale: Females swell as they begin to mature eggs. Heavy production of honeydew.
• Fruittree leafrollers: Peak populations of larvae are generally present.
• Elm leaf beetle: Egg laying and egg hatch often peaks at this time.
• Cottonwood leaf beetle: Egg laying begins on cottonwood.
• Bronzed cane borer/rose stem girdler: Peak period of egg laying in caneberries, currant, rose.
• Honeylocust borer, bronzed birch borer, oak borers: Adults often emerge by mid-June. Beetles feed on leaves and then lay eggs on bark.
• Juniper spittlebug: Spittle masses become obvious as nymphs become fully grown.
• Lilac leafminer: Typical period of peak injury to leaves of lilac, euonymus, privet
• Lawns Spider mites: Populations should be decreasing rapidly with warm weather.

Garden Insects

• Flea beetles: Several species attack garden plants. Seedlings may need protection.
• Winged carpenter ants: Ant swarming often occurs during sunny afternoons following rainstorms.

Household Insects

• Strawberry root weevil: Adults begin to move into homes.

Tree/Shrub Insects

• Cottony maple scale: Females swell and produce conspicuous egg sacks.
• Spruce spider mite: Typical period of peak populations.
• Striped pine scale: Crawler emergence in progress.
• Pinyon spindlegall midge: Adults emerge and lay eggs at base of needles.
• Rose leafhoppers: Peak injury to foliage of rose.
• Elm leafminer: Peak injury typical at this time.
• Poplar borer: Adults often begin to emerge from aspen in late June.
• Douglas-fir tussock moth: Typical peak period of injury. Monitor infested trees.
• Peach tree borer: Adult emergence typically begins. Monitor flights with pheromone traps.
• Cooley spruce gall adelgid: First emergence from spruce galls and migration.
• Honeylocust spider mite: Populations begin to build towards their midsummer peak.
• Elm leaf beetle: Injury by generation one beetles become evident. European elm scale: Eggs begin to hatch and crawlers settle on leaves.
• Pinyon pitch mass borer: Adult emergence begins.

Garden Insects

• Potato/tomato psyllid: Flights of migrating psyllids arrive in state and start to colonize garden plants.
• Colorado potato beetle: Peak period of egg laying on potato and eggplant.
• Flea beetles: Populations usually have peaked during this period.
• Twospotted spider mite: Populations start to increase on a wide variety of garden plants.

Miscellaneous

• Honey bee swarms: This is commonly a time for peaks in swarming.
• Winged carpenter ants: Ant swarming often occurs during sunny afternoons following rainstorms.

Here at Pure Pest Co. we’re always ready, willing, and able to help keep your home pest free. Give us a call at 720-325-4500 or contact us through our website to schedule your service today!