Native Delaware: UD expert releases list of top five bad bugs of summer

May 7, 2013 under CANR News, Cooperative Extension

Summer is right around the corner and along with the good (long days, holiday weekends and lush, green landscapes) comes the bad (humidity, beach traffic and bugs).

Admittedly, there are plenty of beneficial insects that pollinate flowers or gobble pests, and plenty of insects that just hang around, doing neither bad nor good.

In fact, beneficial insects far outnumber pests, according to Brian Kunkel, an entomologist with University of Delaware Cooperative Extension. “More than 97 percent of arthropods typically seen in the home landscape are either beneficial or innocuous,” he says.

But it’s the other three percent that can drive us crazy, wreaking havoc with our prized rose bushes, tomato plants or elm trees. Or, in the case of biting insects, leaving itchy welts all over us.

Kunkel has pulled together a list of the worst pests – what he’s dubbed the “top five bad bugs of summer.”

“Another entomologist might come up with a very different ranking – pest conditions change from year to year and from location to location. I’ve had people call me about a stink bug outbreak in one neighborhood and the next neighborhood only had mild issues,” notes Kunkel. “But these ‘top five bad bugs’ are the ones that Extension gets the most calls about; the ones that inflict the most damage in area gardens, nurseries, and neighborhoods.”

Here’s Kunkel’s list of the top five bad bugs of summer 2013:

1. Scale pests

2. Wasps

3. Bagworms

4. Japanese beetles

5. Stink bugs

You might be wondering why cicadas didn’t top this list – after all, it’s been all over the news about the millions of cicadas ready to emerge in the Mid-Atlantic after a 17-year slumber.

While plenty of cicadas will be flying around southeastern Pennsylvania, southern New Jersey and Maryland this summer, Delaware will see only the occasional cicada crossing the state line. That’s because Delaware’s brood – called Brood X – is still burrowed under ground and isn’t due to emerge until 2021.

Bagworms are a pest in DelawareFar more worrisome than big, fat cicadas are teeny tiny scale pests, notes Kunkel. In fact, scale pest are the single biggest threat to Delaware home landscapes virtually every growing season, he says.

These insidious pests are easy to overlook because of their diminutive size and inconspicuous color. Oystershell scales are about one-eighth of an inch long and dark brown, blending right into the tree branches that they latch onto. It usually isn’t until the branch is dying that the homeowner realizes that these bumps are actually insects sucking sap from the tree.

While oystershell scales prefer certain trees – willows, lilacs, dogwoods and poplars here, as well as aspens and cotoneasters out West – they aren’t picky. They’ve been found on 130 different species of plants. And oystershell is just one of 8,000-plus different scale insects; almost every plant is vulnerable to some type of scale insect.

Kunkel rates wasps as the number two bad guy, not because of damage they do to the landscape but because of the damage they can do to people.

Only the female wasp stings but when she does, you’re going to know it. Even a normal, non-allergic reaction usually results in pain, swelling and redness around the sting site. A localized reaction can bring swelling to an entire limb. Allergic reactions, of course, require immediate medical attention.

Next up on the bad bug list are bagworms. Kunkel says there is variability from year to year in the size of Delaware’s bagworm population. “Some years are a lot worse than others,” he says.

Like scale pests, bagworms start out very small and aren’t likely to be noticed by the homeowner. They are generalists in their eating habits – they are known to eat about 100 different species of plants, including cherries, pines, junipers, arborvitae and birch.

Japanese beetles makes Kunkel’s list primarily because of Sussex County outbreaks in recent years “The population of Japanese beetles in Sussex is much higher than in Kent and New Castle counties,” says Kunkel. “Georgetown has some decent-sized populations but throughout Sussex they can be an issue.”

The last pest to make it onto the bad guy list – the stink bug – is the one everyone loves to hate. The brown marmorated stink bug made serious inroads into Delaware in 2011, particularly in New Castle County. Last summer, the population was considerably lower.

Farmers and homeowners in other states have seen considerable damage to their plants. Fruit orchards have been particularly hard hit.

“Thus far, brown marmorated stink bug has been more of a nuisance than a pest in the home landscape in Delaware,” says Kunkel. “However, some of our farmers have experienced issues. We have a number of UD research projects underway so we can work to control this pest.” 

Help for what’s bugging you

Got a pest problem in your yard or garden? Call Cooperative Extension’s free garden help line. In New Castle, call 831-8862; in Kent call 730-4000; in Sussex call 856-2585, ext. 535.

Article by Margo McDonough

Photo by Brian Kunkel

This article can also be viewed on UDaily.

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UD researcher offers the buzz on why bees, wasps are busy in autumn

October 9, 2012 under CANR News, Cooperative Extension

You buy a cider doughnut at the apple orchard and they quickly find you. Your kid opens a sports drink at the soccer field and they show up. You dine on the deck on a warm afternoon and sure enough, there they are.

This time of year, bees and wasps seem to be everywhere. Why won’t they buzz off?

University of Delaware bee researcher Debbie Delaney can’t clear the bees and wasps from your backyard barbecue but she can shed some light on why these insects are busy in autumn. Given how beneficial these species are to humans (yes, wasps, too) she hopes people will become more tolerant of their activity this time of year.

“Bees aren’t trying to sting you or ruin your outdoor fun,” says Delaney, assistant professor of entomology and wildlife ecology in the College of Agriculture and Natural Resources. “It’s just that autumn is a particularly important time for honeybees and native bees as they get ready for winter.”

In late summer and fall, worker bees labor long hours, collecting enough nectar to feed and maintain the colony throughout the winter. Bees visit flowers to obtain carbohydrates (nectar) and protein (found in the pollen).  Late-blooming flowers that feed the bees include asters, chrysanthemums, goldenrod and Russian sage.

“As the days shorten, the bees know it’s time to go into this food-gathering mode,” says Delaney. “If supplies run low during the winter, beekeepers can feed bees various sugary concoctions — for example, sugar syrup, corn syrup or granulated sugar in the form of sugar boards. But wild bees are out of luck in this regard. Their colonies may not survive if they didn’t make adequate preparations.”

For the most part, bees hunker down and stay in the hives all winter. On unseasonably warm winter days, they will come out to remove waste from their abdomens and the hive, clean themselves, and forage. Of course, there isn’t much to forage in the dead of winter so provisions gathered in fall are critical to the success of the hive.

While bees are busy getting ready for the season ahead, wasps are taking advantage of a brief, well-deserved retirement.

“In late summer and fall, when the queen wasp stops laying eggs, the worker wasps change their food-gathering strategy,” says Delaney. “Earlier in the season, the wasps were busy collecting insects – a protein source – for the colony’s young. But now they’re intent on getting sweets and carbohydrates for their own consumption.”

Adult wasps have just a few weeks to binge on carbohydrates before they die off at the first hard frost. They deserve some fun, considering the good that they do.

“I don’t think many people realize that wasps are beneficial insects,” says Delaney. “But they are true carnivores and engage in a lot of insect collecting earlier in the season. They are predators of a number of pest insects, including mosquitoes, flies and beetle larvae.”

Wasps that do enjoy a longer lifespan are the newly mated gynes (aka, queens). They over winter alone, awaiting the first signs of spring, which signals them to start the creation of their own nest.

Compared to wasps, there’s much more awareness of the critical role that bees play to human life. If honeybees disappeared, food would be scarce, as colonies stopped pollinating fruit, nut and vegetable crops. And if all 20,000-plus species of bees in the world were to disappear, the results could be catastrophic.

Here in Delaware, residents can thank honeybees and native bees for pollinating a cornucopia of crops, including apples, asparagus, blueberries, broccoli, cabbage, carrots, cantaloupe, cucumber, eggplant, peaches, pears, peppers, pumpkins, strawberries, tomatoes, watermelon and more, notes Delaney.

Plus, the honeybees share their honey with us, too. Delaney and her students pulled honey from the UD Apiary in late July and August and it’s now for sale for at the UDairy Creamery. This is the second season that UD honey has been available to the public.

Branded with the moniker “Dare to Bee,” the first harvest was golden in color and had a light taste, which reflects the fact that the bees obtained a lot of pollen and nectar from a stand of black locust trees near the apiary. The second harvest is darker in color and has a caramel flavor representing a blend of late season native and introduced species such as asters and knotweeds.

“Dare to Bee” honey sold out fast last autumn. If you’d like to try it, buzz on over to the UDairy Creamery soon. It’s located behind Townsend Hall on the university’s Newark campus. For store hours and more info, go to the website.

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily.

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