Fall invader bugs: summertime friends and autumn foes

Word is it’s going to be a cold winter this year, despite the screwy hot and cold weather we experienced last week.

Mother Nature’s latest tricks remind me of the morning of October 20, 2003, which was one of the coldest October mornings we’d had in a while. There was some scattered frost, but the time of the season hit me particularly hard when I went to pick some faded flowers off a potted mum and the flower was frozen solid. The next day, however, the temperature was back around 70 degrees.

I don’t know if it was a coincidence or if the sudden swing in temperatures was the trigger, but suddenly on the warmer of the two days, my office and the entire building was swarming with Asian ladybird beetles. The season of the autumn invaders was officially in full swing and guess what? They’re back.

These beetles are not the only fall home invaders of the six-legged type. In fact, each region of the country seems to have four or five bugs that just can’t wait for the cooling of the fall to come on in and join us.

These are all insects that quietly and inconspicuously go about their business, outdoors in our gardens in the summer, yet when the weather gets cold, they seek overwintering shelter in our protected sites. None of them bite or sting but their sheer numbers, rude behavior and some distinguishable odors make them unwanted visitors.

In most years (and yes these invaders can vary from year to year) the most prevalent of these visitors is the Asian ladybird beetle. It is a dull orange color and has anywhere from zero to 19 black spots on its wing covers. They are very effective predators and feed on such landscape and garden pests as aphids, scales and a few other insects.

However, in late summer and early fall they congregate in large numbers, often in the thousands, and seek shelter. They tend to be attracted to homes whose exteriors are light in color with southerly exposures and somewhat exposed, but they are equal opportunity shelter seekers.

Tightly-sealed windows and well-maintained exterior house trim helps a great deal in keeping these insects outdoors. And if you have a large number making it into your living spaces, you can assume that the cold winter winds can do the same thing.

Some caution needs to be exercised, however, when trying to get rid of them as they can exude an orange colored liquid when annoyed, swatted, swept or crushed and the liquid can leave stains on fabrics. The best and easiest way to collect and get rid of the Asian ladybird beetle is to use a vacuum cleaner. Contrary to current rumors, these beetles do not bite.

The western conifer seed bug is another relative newcomer to the East End. It also invades homes in the fall, but usually in much smaller numbers than the ladybugs. This bug is about three quarters of an inch long, has gray and brown coloration and greatly resembles a squash vine bug.

Its size and slow movements can be quite alarming to some but they are relatively harmless. However, when handled or crushed, they also exude a foul-smelling odor.

The birch catkin bug usually becomes noticed prior to all the other invaders that we’ll look at. Immatures of this lygaeid hemiptera often develop in the seed capsules of azalea, rhododendron and Japanese andromeda. They will congregate in large numbers in birch trees (especially the white-barked birches) in August and September. From there they may move to the sides of buildings.

These insects are rather small and may not actively seek to be in homes. They seem to hitch rides on the clothing of people that pass by them or on household pets that walk near them. And yes, again, these bugs can exude a foul-smelling odor when crushed.

The boxelder bug spends the summer using its piercing/sucking mouth to feed on seeds, especially those of the boxelder tree, acer negundo. This half-inch-long black bug with orange markings will congregate in large numbers on the sides of homes and seek entry.

The boxelder bug’s presence is often quite alarming and unwanted, which in some instances leads homeowners to finally remove the host female boxelder tree that’s just outside. Of course, when it’s your neighbor’s tree, then there’s a bit of a problem.

Unlike the Asian ladybird beetle, which seems to be an annual occurrence, the boxelder bug seems to run on a longer cycle. It may not be a problem for years, then appears en masse.

According to Dan Gilrein, extension entomologist at the Cornell Cooperative Extension research facility in Riverhead, there is a fifth unwanted bug, similar to the conifer seed bug, on its way to the East End and looking for winter quarters.

“A related pest is the brown marmorated stink bug,” he told me. “It is moving in from southeastern New York from 
Pennsylvania and New Jersey and it’s recently been spotted in Manhattan and Long Island.”

Most homeowners quickly lose the unique feeling of curiosity that these insects usually impart and their emotions soon turn to dread and frustration if only from the sheer number of insects that may come in without the courtesy of even knocking. There are a few commonsense approaches that homeowners can take as precautions against these and the other unwanted house guests.

All doors, windows and attic vents should be inspected every summer for small openings and holes in screens. Caulking around trim and crevices should be checked for shrinkage and damage.

Once discovered, the problems should immediately be tended to since 
pests like the beetles will seek out these holes for potential overwintering sites, then on the first sunny and warm winter day, they often awaken and continue the invasion.

Once any of these insects make their way into the home, they should be vacuumed up. Then, the vacuum bag should be removed and placed in a tightly-sealed plastic bag and moved to an outdoor location.

Never, ever use insecticides indoors to kill or control these insects. There is, however, an Ortho product that can be applied to the outside of doors and windows that seems to be an effective and long-lasting repellent.

In the case of the ladybugs, some gardeners may want to vacuum up the offenders and store them in the vacuum bag in a cold garage or shed until spring arrives. The bugs can then be released back into the garden where they’ll become friends again instead of invaders.

Keep growing.

Andrew Messinger has been a professional horticulturist for more than 30 years. He divides his time between homes and gardens in Southampton, Westchester and the Catskills. E-mail him at: Andrew@hamptongardener.com. The Hampton Gardener is a registered trademark.