Bug boom: 6 pests to watch out for in 2020

Kent County

Clockwise from upper left: The American dog tick, Asian giant hornet, hemlock woolly adelgid, mosquito, laternfly and gypsy moth caterpillar. (Photos courtesy: Bugwood.org)

GRAND RAPIDS, Mich. (WOOD) — Summertime brings a new cloud of pests outside and this year is no different.

With more people staying home because of the coronavirus pandemic, backyards are busier at a time when plenty of insects are thriving.

From “murder hornets” to mosquitoes, here are six bugs experts from Michigan State University say you should watch out for:


(An undated photo shows a male and female gypsy moth. Photo courtesy: USDA/APHIS PPQ/Bugwood.org)

Status: The invasive insect whose feces rained down from trees in Newaygo County last month is now transitioning to moth stage. Caterpillars on MSU’s campus began spinning their cocoons last week.

(An undated photo shows total defoliation caused by gypsy moth caterpillars in Washington state’s Haddam Meadows State Park. Photo courtesy: Karla Salp/Washington State Department of Agriculture/Bugwood.org)

Why they’re trouble: While most caterpillars feed on one plant species, gypsy moths eat 300 types of trees and woody shrubs. Their favorite is oak trees. The caterpillars travel up the tree to feed at night and move down its trunk during the day.

MSU Extension entomologist Deb McCullough says this is the worst year for gypsy moth outbreaks since the 1990s, with more Michigan communities reporting caterpillars.

Hot spots: While much of the northern half of lower Michigan has reported gypsy moth outbreaks, northwestern lower Michigan has been hit the hardest, including Cadillac, Manistee, Higgins and Houghton lakes, Alpena and Gladwin.

(An undated image of the gypsy moth caterpillar. Photo courtesy: Jon Yuschock/Bugwood.org)

In the Croton-Hardy Dam area near White Cloud, some people reported hearing the caterpillars munching on leaves and feces raining down from trees.

MSU researchers estimate the Roscommon area contained a million gypsy moth caterpillars per acre. With each caterpillar eating a square meter of leaves, some trees were completely defoliated.
McCullough says caterpillar feces coated walkways at welcome centers along US-127 and I-75, which visitors tracked into the buildings.

Entomologists are unsure what fuels gypsy moth outbreaks, but suspect weather conditions play a role. McCullough says gypsy moth populations typically increase for three years before a decline due to disease.

What you can do: Instead of trying to catch and kill gypsy moths, which only live for a few days, McCullough recommends tracking down their egg masses at the end of July.

McCullough says female moths, which cannot fly, lay one egg mass. Most of these tan-colored egg clusters are high up trees on the underside of branches and range from nickel-sized to 3 inches. Some lay eggs on the sides of buildings.

(An undated photo shows gypsy moth egg masses attached to a tree. Photo courtesy: Daniela Lupastean/University of Suceava/Bugwood.org)

Property owners can kill the layers of eggs by scraping the mass off the tree and into a bucket of soapy water. Professionals can also treat trees with infestations in spring.


(An undated image shows an adult hemlock woolly adelgid removed from its host plant and cleaned for magnified imaging. Photo courtesy: Kelly Oten/North Carolina Forest Service/Bugwood.org)

Status: This invasive insect from Japan is dormant during summer, but state forestry employees are now busy working to treat trees that the sap-sucking hemlock woolly adelgid has latched onto. Beginning around Nov. 1, the bugs will feast on the trees.

The adelgid produces two generations in a year, with new eggs laid in spring.

(An undated photo shows damage to a patch of hemlock trees. Photo courtesy: Jason Van Driesche/Bugwood.org)

Why they’re trouble: While the hemlock woolly adelgid is small and immobile, it’s a major threat to Michigan’s 170 eastern hemlock trees. This pest can suck the life out a tree in four to 10 years.

McCullough says hemlocks are a “foundation species” to Michigan’s ecosystem, impacting the chemistry of soil and water, controlling lakeshore erosion with its roots and providing a cooler habitat for numerous creatures.

“It would just be terrible if it really gets going here,” she said.

The hemlock woolly adelgid was discovered in Michigan in 2015. Since then, “we’ve seen some (trees) really decline,” said McCullough.

Foresters are now focused on containing the pest, all-female genetic clones.

A Michigan Department of Natural Resources map shows areas where the hemlock woolly adelgid has been found.

Hot spots: The hemlock woolly adelgid is concentrated along West Michigan’s lakeshore from Mason County south to Allegan County. Entomologists believe the lake’s effect on Michigan’s winters protects the adelgid from the harshest cold, which otherwise could kill it off.

McCullough suspects mild conditions last winter did little to kill adelgids.

“I think they’re thriving,” she said.

Etomologists suspect birds that land in hemlock trees may carry adelgids from tree to tree.

What you can do: If you live close to a lake, McCullough recommends examining hemlock trees for these pests, which are small, round white and cottony from the material they secrete as they feed.

Hemlock woolly adelgids range from one-sixteenth of an inch to a quarter-inch in size and are found on the underside of hemlock tree twigs at the base of the needles. They’re most visible November through July.

(An undated photo shows hemlock woolly adelgids on containerized western hemlock. Photo courtesy: Steven Katovich/Bugwood.org)

If you find the hemlock woolly adelgid, contact an arborist to treat the tree. McCullough says it’s relatively inexpensive and effective.

(An employee of Great Smoky Mountains National Park Soil drenches hemlocks with imidacloprid. Photo courtesy: Great Smoky Mountains National Park Resource Management , USDI National Park Service, Bugwood.org)


(An undated photo shows an adult female mosquito. Photo courtesy: Joseph Berger/Bugwood.org)

Status: Mosquitoes are very weather dependent, thriving in warm temperatures and standing water.

Because of a fair amount of spring rain and snowmelt “we had a pretty good population of summer mosquitoes,” according to MSU bug expert Howard Russell.

With recent rains and warmer temperatures, mosquito populations could pop in the coming days. Russell says when an area gets 2 to 3 inches of rain, summer mosquitoes emerge 10 to 14 days later.

In the right conditions, it takes mosquitoes about a week to transition from egg to biting adult.

Why they’re trouble: Mosquitoes are carriers of diseases that are dangerous to humans, including zika virus, West Nile virus and Eastern Equine Encephalitis, which killed six southwest Michigan residents in 2019. Last year’s EEE outbreak led to aerial spraying for mosquitoes in many counties before freezing conditions killed off the mosquito population.

generic mosquitoes_1535405305957.jpg.jpg

The rush to rid the area of mosquitoes likely led to Grand Rapids’ jump on Orkin’s 2020 list of “Top 50 Mosquito Cities.” Grand Rapids rose 10 spots to No. 19 on based on the number of customers who sought mosquito services from the company from April 1, 2019 to March 31, 2020.

mosquito trap 061215_102233
(A 2015 photo shows a mosquito trap.)

Hot spots: Mosquitoes will thrive anywhere where standing water remains for at least a week.

Last week, Ottawa County health officials confirmed a resident tested positive for Jamestown Canyon virus, also from mosquitoes. Earlier this month, the Kent County Health Department announced some mosquitoes trapped in four zip codes tested positive for West Nile.

In June, state officials announced the Asian tiger mosquito, which can transmit dengue, chikungunya and Zika viruses, had been found in Wayne County. The Asian tiger mosquito typically can’t survive Michigan’s harsh winters, but has established itself in neighboring Ohio, Indiana and Illinois.

(An undated photo shows an adult Asian tiger mosquito. Photo courtesy: Jim Occi/BugPics/Bugwood.org)

What you can do: Curb the mosquito population by dumping any standing water outside where their eggs may be hatching. Make sure your doors and windows have tight-fitting screens without holes that would allow mosquitoes to slip through.

You should also protect yourself from mosquito bites by using an EPA-registered insect repellent and wearing long sleeved shirts, pants and socks outdoors if possible.


(An undated image shows the American dog tick. Photo courtesy: Gary Alpert/Harvard University/Bugwood.org)

Status: Michigan is home to 30 types of ticks that are generally active from April to September. However, ticks are hardy and can overwinter. The most common one, the American dog tick, is typically active from May through July.

Russell says this year’s tick count is comparable to 2019, but tick populations have been growing and spreading across Michigan over the past decade.

Last year, Michigan residents sent in 1,412 ticks to the state. That’s more than triple the number of tick submissions in 2015.

Why they’re trouble: The blacklegged tick can carry the bacteria that causes Lyme disease, which can cause muscle loss, meningitis, joint swelling and heart rhythm changes if untreated. Ticks can also transmit Rocky Mountain spotted fever, anaplasmosis, tularemia, and ehrlichiosis.

(An undated photo shows a blacklegged tick. Photo courtesy: Scott Bauer/USDA Agricultural Research Service/Bugwood.org)

The good news: The Michigan Department of Health and Human Services says studies have shown infected ticks must be attached to their host for 36 to 48 hours to transmit the bacteria. A lot of illnesses caused by ticks can be treated by antibiotics if detected early on.

Hot spots: Last year, Kalamazoo was home to 53 confirmed human cases of Lyme disease—the highest in the state. MDHHS says since infected blacklegged ticks were detected in West Michigan in 2002 “the tick and the bacterium have been invading northward along the Lake Michigan coast.”

In 2019, human cases of Lyme disease were reported in every county in our viewing area except Montcalm, Newaygo and Lake counties.

(A map provided by the Michigan Department of Health and Human Services shows the number of human cases of Lyme disease in 2019 by county. )

What you can do: Avoid long grass and shaded brushy areas which are havens for humidity-loving ticks. Remove leaf litter from your yard and keep your grass trimmed.

Wear repellent. Permethrin, which kills ticks on contact, can also be sprayed on clothing. Check your body and clothing for ticks each day you have been outside.

If you find a tick on your body, use tweezers to remove the insect gently to prevent its mouth parts from detaching in your skin. Clean the bite area and your hands and send the tick to the state for identification and testing.

generic tick_1559598228708.jpg.jpg
(An image shows ticks collected for testing and identification.)



(An undated photo gives a front view of the Asian giant hornet, dubbed the murder hornet. Photo courtesy: Washington state Department of Agriculture/Bugwood.org)

Status: Not yet been reported in Michigan but found in Washington state. The Asian giant hornet’s life cycle starts in April when the queens emerge from hibernation to feed on sap and fruit and look for a place to build their underground nest. This invasive insect is most destructive in late summer and early fall.

Why they’re trouble: Dubbed the “murder hornet,” Asian giants have a painful sting that contains a neurotoxin powerful enough to kill a provoking human if stung multiple times. However, the bigger threat is to honeybees, which farmers rely on to pollinate their crops. Murder hornets attack honeybee hives, killing the adults and feasting on the larva and eggs.

(An undated photo gives a laterview of an Asian giant worker hornet. Photo courtesy: Allan Smith-Pardo/USDA APHIS PPQ/Bugwood.org)

Hot spots: The world’s largest hornet, this 2-inch killer from Asia was discovered in Washington state last December. Workers with that state’s department of agriculture began trapping the queens in spring to try to prevent its spread.

In this April 23, 2020, photo provided by the Washington State Department of Agriculture, dead Asian giant hornets sit on a researcher’s field notebook in Blaine, Wash. (Karla Salp/Washington State Department of Agriculture via AP)

An insect researcher told News 8 because Lake Michigan provides insulation from the harshest winter temperatures, the murder hornet may survive in West Michigan.

What you can do: Remain vigilant and report any possible murder hornets, which are 2-inches long with an orange head, golden colored wings, black thorax and orange and black striped abdomen.

However, do not confuse them with the cicada killer, which entomologists say has happened.

Russell says the best way to deal with the murder hornet is to track it and stop it in the Pacific Northwest before it has a chance to travel.

“Hopefully, it won’t show up here for quite a while,” he added.


(Adult spotted lanternflies are identifiable by their bright body and wing colors. Photo courtesy: Pennsylvania Department of Agriculture/Bugwood.org.)

Status: While the spotted lanternfly hasn’t been detected in our state, the Michigan Department of Natural Resources is asking people to keep an eye out for this destructive bug.

Why they’re trouble: The spotted lanternfly could damage or kill more than 70 types of crops and plants including Michigan’s grapes, apples, hops and hardwood trees. This invasive insect sucks sap from host plants and secretes large amounts of sugary, sticky liquid called honeydew, which MDNR says can lead to mold that’s deadly to crops. The honeydew liquid also attracts other pests including hornets, wasps and ants, which can lead to harvesting challenges and bad encounters for campers and hikers.

(Adult spotted lanternfly’s bright wing coloration is hidden when wings are closed. Photo courtesy: Robert Gardner/Bugwood.org.)

Hot spots: Since it was discovered in southeastern Pennsylvania in 2014, the spotted lanternfly has been rapidly spreading, with confirmed infestations in Delaware, Virginia, New Jersey, Maryland and West Virginia. Russell says right now, it’s not a question of if the invasive species will show up in Michigan, but when.

“Unless our luck changes, it’s going to show up here eventually,” he told News 8.

What you can do: Monitor outdoor surfaces for spotted lanternfly egg masses, which have a gray, waxy, putty-like coating resembling old chewing gum.

(An undated photo shows spotted lanternfly egg masses on a picnic table. Photo courtesy: Emilie Swackhammer/Penn State University/Bugwood.org.)

“Prevention and early detection are vital to limiting the spread of spotted lanternfly,” said Robert Miller with the Michigan Department of Agriculture and Rural Development. “Spotted lanternfly cannot fly long distances, but they lay eggs on nearly any surface, including cars, trailers, firewood and outdoor furniture. Before leaving an area where a quarantine is present, check vehicles, firewood and outdoor equipment for unwanted hitchhikers.”

Spotted lanternfly eggs look like brownish seeds and the nymphs are wingless and beetle-like with black and white spots. The nymphs develop red patches as they grow into adults, which are roughly an inch long. Adult spotted lanternflies have two sets of spotted wings and red and a yellow and black abdomen.

The life cycle of a spotted lanternfly, courtesy Penn State University College of Agricultural Sciences.

If you find a spotted lanternfly eggs, nymphs or adults, send photos and the date, time and location of your sighting to MDA-Info@Michigan.gov. MDARD encourages people to collect a specimen in a container for state officials verify.

Copyright 2020 Nexstar Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Know something newsworthy? Report It!

News 8 Links