Summer picnic season is upon us, and that means it is time to grab the sunglasses, cooler and sunscreen, and head outdoors. But people are not the only ones who want to enjoy the warm weather. Flying, stinging insects like bees and wasps are abuzz, and make their presence known when collecting pollen and nectar as the weather warms.

“In the proper environment, bees, wasps and yellow jackets can be very beneficial,” says Ron Harrison, entomologist and Orkin technical services director. “In addition to pollinating flowers and plants, they eat grubs, flies and other harmful pests. It is when they are aggravated or feel threatened that they can be a bigger problem.”

There are more than 20,000 known bee species around the world. Their stings can be painful and may cause allergic reactions. About 2 million Americans are allergic to insect stings, according to the American College of Allergy, Asthma and Immunology, and many of them are at risk of life-threatening reactions.

Carpenter bees are fairly large and are often mistaken for bumble bees. They can cause significant damage to decks, siding, landscape timbers and even lawn furniture, but males – even though they are aggressive – do not have stingers, and the females rarely sting. Females bore holes in wood to deposit their eggs.

Yellow jackets can sting multiple times and aggressively protect their colonies, but otherwise, are not quick to sting. They commonly nest on or near the ground under porches or steps, in sidewalk cracks, around railroad ties, or at the base of trees. Yellow jackets are also scavengers, so they can be found near garbage cans and picnics.

Paper wasps look similar to yellow jackets in that they are narrow and dark brown with black wings and yellow markings. Paper wasp nests are made from small wood or plant fibers combined with saliva and appear to be made from paper. Their nests – frequently found in sheltered areas like tree branches and eaves of houses – include numerous compartments where they lay their eggs and rear their young.

Be sure to contact a pest professional like Orkin before attempting to address a bee infestation or hive. Harrison offers the following tips to help avoid flying and stinging pests:

* Use a weed trimmer to thin vegetation near your home, as thick vegetation provides a place for both bees and wasps to nest.

* Don’t leave food or drink containers uncovered for long periods of time. Pests are attracted to human food sources and stinging pests can often enter cans unseen, so it is best to pour your drink into a glass.

* Fit screens and tighten seals properly on doors and windows to prevent pests from entering into your home.

* For those at risk of an allergic reaction, apply an EPA-registered insect repellent on clothing and exposed skin to deter bites and stings.

Many people now tempt birds by placing nesting-boxes on their trees, and are delighted when the attention is appreciated. Birds, however, are not the only occupants of these shelters, at least they are not in a garden at Duffield, I am told. Last year three of the German boxes, usually the better type, had no avian inhabitants, but they were often used as day bedrooms by long-eared and other bats. This season an English-made box has two different sets of tenants. A great tit, now busily engaged in hastening forward the advent of seven little great tits, has its nest on the floor of the box, and an enterprising queen wasp suspended her cup-shaped nest from the ceiling, beneath the lid. Does her fellow-lodger object to her presence? Tits are accused of bee-eating, but this one has not sampled wasp. Wasps were plentiful last summer, and the nests seem to have produced an unusually large number of queens which survived the winter; wasps in moderation are useful, but too many useful things are often troublesome. A wasp killed now means one nest and many hundreds of individuals less in the summer. Many more of the delicate paper cups are constructed than ever develop into large colonies; in them the queen rears her first helpers, and they prepare the home for the ever-growing colony.

If you sense more wasps buzzing around your head, your patio and elsewhere outside your home this spring, you would be correct.

Exterminators and entomologists say record high temperatures late last month brought the creatures out in force after a winter that lacked the kinds of below-freezing temperatures to reduce the number of overwintering adults.

Dan Nyssen, owner of Valley Pest Control, said he was inundated with 100 calls for help immediately after the hot spell. And the calls are still coming.

“I’ve been doing this for 15 years. A lot of times, the wasps go in cycles. This is definitely one of those cycles,” he said in a brief interview in between stops.

While exterminators are busy, a local U.S. Department of Agriculture researcher is testing new chemical attractants to trap wasps.

Mike Bush, a Washington State University extension entomologist and tree-fruit agent, said he also has gotten calls.

His advice: Unless the wasp nests are in high-traffic areas that pose a stinging risk, homeowners should put up with the population. They are beneficial insects, especially if you are a home gardener.

“A lot of people call and are really worried about this,” according to Bush. “I try to tell people that yellow jackets and wasps are beneficial insects. They feed on other insects.”

Among their prey are caterpillars that feed on plants.

Bush and USDA researcher Peter Landolt, assigned to the Parker Heights Agricultural Research Service laboratory, say the majority of the wasps are paper wasps, a relatively new species in this area. The species is so called because adult females chew woody debris to create the one-layer nests in which eggs are laid.

Paper wasps resemble yellow jackets, but have a narrower waistline and longer legs. Another difference is that yellow jackets form a round-shaped, multi-layered nest with an opening at the bottom.

Unlike paper wasps that are more docile, yellow jackets can be aggressive.

“I tell people if you are dealing with yellow jackets, you don’t want to,” said Bush. “They will defend their hives and team up against you.”

All the wasps out now are females, Bush said, working to create nests for the queen to lay her eggs. Workers forage for food to feed the cream-colored grubs as they develop.

Males will emerge later in the summer to mate with the queen before she overwinters to start the process all over.

Landolt has used the opportunity of a larger wasp population to set out lures to test new chemical compounds that mimic food sources to attract wasps to traps.

A goal of the research center is to develop alternatives to pesticides.

Landolt said the larger population this year is a great chance to test the new compounds.

“At this time of year when they have no offspring, the wasps only have to worry about their own nutrition,” Landolt said.