Stalking Stinging Insects

Accounts that involve bee and wasp control can be beneficial for PCOs…as long as they don’t get stung. hey say there are two sides to every story — and stinging insects are no exception. Bees and wasps may be man’s best friend among insects, yet these highly beneficial insects also cause problems that can be life threatening.

Take a good look at your dinner tonight. It’s a good bet that most of what you are eating is compliments of our friends, the bees. Bees and other insects pollinate many fruit and vegetable crops. Without them, our food would be pretty boring.

Bees and wasps are beneficial in other ways as well. They produce honey and beeswax, both of which provide hobbies for some people. Wasps also help control pests such as caterpillars, flies and spiders.

Of course, these insects are also beneficial for pest control operators. Many profitable dollars are derived from the bad side of the bee and wasp story. The bad side includes those unsightly mud and paper nests plastered on the sides of houses. But more important is the way bees and wasps defend themselves. Every year in the United States 50 to 100 people die from bee and wasp stings. In most cases, people will die within an hour if they have an allergic reaction to the venom. Fortunately, fewer than one in 100 people are allergic to bee and wasp venom.

Unfortunately, almost all bees and wasps we encounter, including all of the species mentioned here, are capable of stinging. The stinger is a modification of the insect’s egg-laying tube, or ovipositor. Now, if you think only females can sting, you are correct. But there’s no use wondering whether that bee or wasp is a stinger-equipped female or a harmless male. The fact is that almost 99% of wasps and bees that people come in contact with are female. Just assume that any wasp or bee can sting.

A SOCIAL LIFESTYLE? Among the many distinctive features of bees and wasps are their living arrangements. Some lead a solitary lifestyle while others live together in groups. We call those that live together "social" insects and this group includes ants, termites and some bees and wasps.

Knowing whether a particular wasp or bee is solitary or social is the key to understanding its behavior. For example, you are much more likely to be stung by a social bee or wasp rather than a solitary one because you are more likely to encounter a social wasp. These social insects are generally not as secretive and anti-social about where they build their nests. Also, social wasps sting not only to protect themselves, but also to protect an entire colony, including family members. That’s right — all of the wasps or bees in a colony are related. That is why these insects cooperate with one another.

Each individual in a wasp or bee colony belongs to a specific caste. Social insects are defined by the "Three Cs": colonies, cooperation and castes.

Yellowjackets are social wasps. Like other social wasps, they build nests of paper by chewing wood and mixing it with saliva. You get wasp calls in the fall because there are simply more yellowjackets late in the season. In addition, yellowjacket food supplies become scarce. The wasps typically forage for insects to feed their larvae. When these insects start dying from the cold or seek shelter in which to spend the winter, yellowjackets are forced to look for new food sources. In the fall there are more yellowjackets and that is the time of year that they’re more aggressively scavenging for food associated with humans.

WHAT’S IN SEASON? Now, let’s look at the whole season in a typical social wasp or bee colony. In spring, a queen locates a suitable nesting site and builds a nest. She lays eggs and does all the chores that the workers will do later. Those chores include enlarging, cleaning and repairing the nest, defending the colony and finding food. For wasps, that food is usually insects and spiders. For bees, it is nectar and pollen from flowers.

When the first workers emerge from their pupal cocoons, they break out of the familiar hexagonal cells and take over the queen’s colonial chores, all except laying eggs. Additional batches of workers are produced through the summer and the colony grows.

In most regions of the United States, all members of the colony will die as winter approaches, except a few females destined to become next year’s queens. These various females seek shelter and warmth when temperatures grow cold, often ending up in various cracks and crevices in buildings. The ones that spend the winter in buildings may emerge well before springtime due to the artificial heat in these structures. It is these new queens that you suddenly see in February around your window or crawling sluggishly across the floor.

The life cycle described above is typical of social bees and wasps, although the honey bee life cycle is different. First, honey bee colonies are perennial — they survive winter and continue on indefinitely. They can do this despite cold temperatures because of the way their colonies are constructed and by special behaviors that allow them to survive inside the nest. In addition, honey bee colonies produce drones and new queens in spring and mating occurs at the same time.

PREVENTION. As with many other pests, exclusion is probably the best control method for stinging insects. Sealing exterior cracks and crevices helps prevent honey bees and yellowjackets from nesting inside structures. Applications of long-lasting dusts to wall voids, soffits and attic voids can provide additional protection.

Perhaps less can be done to thwart species such as paper wasps, mud daubers and bald-faced hornets that build nests on structures. In spring, frequent inspections of the building’s exterior, along with attics and crawlspaces, can detect nests early before they grow and become more difficult to deal with. In the insects’ early stages, insecticide use is unnecessary because the nests can simply be removed. But, surface applications of liquid residuals to likely nest sites (e.g., eaves and soffits) can help prevent nesting.

CONTROL. When attempting control of bees and wasps, especially the social species, PCOs should take every precaution to avoid being stung. About 75% of people who are frequently stung become "immune" to stings, having little or no reaction to them. But some, about 2%, develop allergic reactions to stings that can be dangerous or even life threatening. So, it’s not a bad idea to have a bee sting kit handy. The kits are available by prescription and can prevent allergic reactions from becoming life threatening.

Allergies aside, another danger for the prospective bee and wasp specialist is the ladder used to reach the insects’ nests. Falling off ladders is one of the most common accidents in pest control. Needless to say, the odds of injuries increase when you’re perched on a ladder concentrating on not being stung by dozens of angry bees!

Another often overlooked but highly valuable precaution is the bee suit, which can prevent stings altogether. The suits can be purchased for around $100. At this price, can anyone serious about bee and wasp control afford NOT to have one?

Control of solitary bees and wasps, as well as social wasps, can be accomplished simply by removal of the nest or by application of residual insecticides directly to the nest.

Removal of bald-faced hornets’ nests can also be effective, although survivors may rebuild them. If immediate removal isn’t practical, punch a duster tip into the nest and apply dust to the interior and the entrance hole. A quick knockdown aerosol (e.g., those containing pyrethrins) can be used when first approaching the nest to avoid being stung by the sentries.

Quick knockdown is also recommended when working with yellowjacket nests, such as those in attics and crawlspaces. Again, once the guard workers are subdued with aerosol, dust can be applied into the nest.

Where bees or wasps are nesting in structural voids and entering the structure through exterior holes, cracks or crevices, dust or residual liquids should be applied into the openings. This alone may not be sufficient for complete control, as the nest may be several feet from the hole. A pressure duster or Actisol-type unit can be used to achieve greater penetration. It may also be necessary to drill and treat voids in walls, soffits and other areas.

Finally, there is the all-too-common problem of scavenging yellowjackets around food and trash at food processing plants and outdoor gatherings, such as picnics. Often nests cannot be located, as yellowjackets will forage up to 1,000 yards from the nest. Insecticide applications have generally not been useful in these situations. Fans and air doors, used to "blow away" the yellowjackets, are often impractical. Keeping trash cans and dumpsters tightly closed and regularly cleaned and emptied can help. Mass trapping has been employed with mixed results.

One problem with trapping has been finding a bait that attracts yellowjackets consistently. Recently, however, the USDA may have discovered a "universal" yellow-jacket bait, a byproduct of sugar consumption produced by bacteria and fungi. It is said to be highly attractive to many types of yellow-jackets, hornets and even some paper wasps.

CONCLUSION. As you can see, there’s a solution for even the most difficult wasp and bee problems. Like so many other pests, control of stinging insects often depends on correctly identifying the insect and the problem, then employing the appropriate controls. Once again, the key to success is knowledge of the various wasp and bee species, of their identifying characteristics and behaviors, and of control methods. Wasp and bee control doesn’t have to be difficult or dangerous. It can be a valuable part of any pest control business — for those who have the knowledge to make it so.