Thursday, April 9, 2015

The Buzz on Spring Household Pests

Carpenter Bees

Carpenter bee activity is increasing with the warmer temperatures. Although carpenter bees resemble bumble bees, the two can be readily distinguished from one another because carpenter bees have shiny bare abdomens, while bumble bees have yellowish hairs on their abdomens. The male bees are easy to identify because they have white spots in the center of their head (between their eyes) and they are typically seen hovering around prime real estate (from a carpenter bee's perspective) watching for the girl bee of their dreams and chasing off rival males at the same time. Males bees do not sting but their aggressive behavior can intimidate people.

After mating, the female bee goes hunting for a new place to build a nesting gallery. Choice locations include wooden porch rails and balusters, wooden planks and solid wood siding (even "repellent" woods such as cedar). The females handle the workload and excavate a nearly perfectly round hole and gallery that typically follows the wood grain. She then makes a ball of pollen, sticks it into the gallery and deposits an egg before constructing a partition of chewed wood debris and other materials. She then repeats this process until the gallery is furnished with each of her "children" having their own room (but no internet or cable TV). At that point, the females die and so for most of the summer, no activity is seen. The offspring will emerge in the late summer/fall and hang around before finding a sheltered location (like an abandoned gallery) where they pass the winter.

We still do not have any pesticides that provide long-term protection of wood for the duration of the bees' activity. It's also difficult economically and from a safety perspective to spray all of the exposed overhead wooden areas to protect them from the bees. We still recommend the tried and true method of dusting individual holes with a pesticide dust (some wettable powder formulations are labeled for this use, too) and then seal the holes (to keep out moisture).

We have additional information online at: http://insects.ncsu.edu/Urban/carpenterbees.htm

Paper Wasps

Overwintering paper wasps (Polistes spp.) queens are starting to become active. This is another situation where insects show up indoors and people think that they're entering their homes from outside. For the most part, the wasps have spent the winter in wall voids, attics, and crawlspaces. As a result, as the weather warms and they become active, some of the wasps accidentally stray indoors (instead of heading to the great outdoors) and people assume that there is an active nest in their wall, attic or crawlspace. The wasps are usually slow moving (you would be too if you had slept all winter!) and simply buzz about looking for a way outside but that creates this appearance of being aggressive. Although these wasps can sting, their main goal is finding:  a) food; and b) a place to build a nest. They are an easy target for a rolled-up newspaper!

The wasps that do make it to the outside (or were hiding out under bark, tarps, etc.) will often be seen hovering around the house exterior, particularly near chimneys and other vertical objects. This attraction to vertical objects often makes cell phone towers and similar structures the object of their attention which can be disconcerting to workers hundreds of feet up servicing these structures. Hereto, people assume that there is already an active nest and simply can't find it. Spraying broad areas of house siding, deck, etc. is not going to stop this activity.

The wasps are busy scoping out perspective nesting sites. If you have clients concerned about getting stung, wasps can be treated with a wasp & hornet spray that propels the chemical about 15-20 feet. Exercise caution as you spray overhead.

Also, remind people that despite their reputation for stinging, these wasps are actually beneficial and prey on caterpillars and other insects that would likely be chomping down on their flower or vegetable garden later in the year. So, focus on nests that may pose an imminent hazard. Trying to eradicate every wasp is neither practical or (more importantly) environmentally sound. For more info, please visit:

http://insects.ncsu.edu/Urban/paperwasp.htm