Common Bees - Falls Creek Animal & Pest Control

Common Minnesota Bees

Bees play an important role in pollinating flowering plants, and are the major type of pollinator in eco-

systems that contain flowering plants. Bees either focus on gathering nectar or on gathering pollen

depending on demand, especially in social species. Bees gathering nectar may accomplish pollination,

but bees that are deliberately gathering pollen are more efficient pollinators. It is estimated that one third

of the human food supply depends on insect pollination, most of which is accomplished by bees,

especially the domesticated European honey bee. Contract pollination has overtaken the role of honey

production for beekeepers in many countries. Monoculture and the massive decline of many bee species

(both wild and domesticated) have increasingly caused honey bee keepers to become migratory so that

bees can be concentrated in seasonally-varying high-demand areas of pollination.

Despite the honey bee's painful sting and the stereotype of insects as pests, bees are generally held in high regard. This is most likely due to their usefulness as pollinators and as producers of honey, their social nature, and their reputation for diligence. Bees are one of the few insects regularly used on advertisements, being used to illustrate honey and foods made with honey .

In North America, yellowjackets and hornets, especially when encountered as flying pests, are often misidentified as bees, despite numerous differences between them. Although a bee sting can be deadly to those with allergies, virtually all bee species are non-aggressive if undisturbed and many cannot sting at all. In fact, humans will often be a greater danger to the bees, as bees are often affected or even harmed by encounters with toxic chemicals in the environment

Most bees are fuzzy and carry an electrostatic charge, which aids in the adherence of pollen. Female bees periodically stop foraging and groom themselves to pack the pollen into the scopa, which is on the legs in most bees, and on the ventral abdomen on others, and modified into specialized pollen baskets on the legs of honey bees and their relatives. Many bees are opportunistic foragers, and will gather pollen from a variety of plants, while others are oligolectic, gathering pollen from only one or a few types of plant. A small number of plants produce nutritious floral oils rather than pollen, which are gathered and used by oligolectic bees. One small subgroup of stingless bees, called "vulture bees," is specialized to feed on carrion, and these are the only bees that do not use plant products as food. Pollen and nectar are usually combined together to form a "provision mass", which is often soupy, but can be firm. It is formed into various shapes (typically spheroid), and stored in a small chamber (a "cell"), with the egg deposited on the mass. The cell is typically sealed after the egg is laid, and the adult and larva never interact directly (a system called "mass provisioning").

Yellowjackets and Bald-Faced Hornets

The term "hornet" is often used to refer to many of the wasps that build large papery nests. The most notable paper wasp is the baldfaced hornet, Dolichovespula maculata, and several species of yellowjackets (Vespula sp.), which are really wasps. In actuality the only true hornet found in the United States is the European hornet, Vespa crabro L.

Baldfaced hornets are large, black and white, heavy-bodied wasps about 3Š4 inch (20 mm) long. They typically build exposed, mottled grey nests in trees or shrubs. Occasionally, the wasps will build nests under roof overhangs, in attics, crawlspaces and wall voids, or under decks or porches. The nests are constructed of a paper-like martial formed from chewed wood. The nests are often described as "football shaped", but they may exceed a basketball in diameter.

Yellowjackets are house fly-sized wasps with distinct yellow and black markings and a few hairs. Yellowjacket nests are also constructed of paper, though they are tan in color, much smaller in size compared to the hornet nest and are usually found in an underground cavity. Common locations for nests are in lawns, particularly in sandy exposed areas, as well as at the base of trees or shrubs. Occasionally, yellowjackets will nest in attics or walls voids of houses or storage buildings.

An individual hornet or yellow jacket queen begins building a nest alone in the spring. Once a queen has produced enough workers to take over nest-building and foraging duties, she remains inside producing more offspring. The workers expand the nest, forage for food, feed the young and defend the nest. Like other predatory wasps, their diet consists mainly of other insects such as flies and bees. Bald-faced hornets will also feed on their yellowjacket relatives. They continue to enlarge the nest until fall when there may be 300-400 hornet, or 600-800 yellowjacket workers. Frequently, it is not until this time that the nest is noticed, although it has been there for many weeks, already. In the late summer, the colony produces reproductives--the insects that will mate. The mated female reproductives will serve as the next generation of queens in the following spring.The male's main purpose is mating and they cannot sting. Nests are abandoned by wintertime and the future queens seek shelter alone, in protected places under tree bark, in old stumps, or sometimes attics. The current year's nests are not reused the following spring.

Yellowjackets, in particular, may be late season pests around picnics, trash cans and hummingbird feeders as they scavenge. The only way to control this presence is to locate and destroy the nest, which is rarely possible. As an alternative, keep all outdoor food and drinks covered when possible. Trash cans should be kept covered or have a flap over the opening. Defensive behavior occurs in response to nest defense. If the nest is not in the immediate vicinity the likelihood of stings is greatly reduced.

If the nest is in a wall void or other inaccessible area in your home, you may consider hiring a pest control company to do the work for you. If the nest is in a wall, it may be desireable to remove it if convenient after spraying to avoid attracting carpet beetles that can invade the home and attack garments made wool, silk or fur. Yellowjacket traps (commercial or otherwise) have not shown to be of any value in reducing a yellowjacket problem.

Mining Bees:

Mining bees, or digger bees, (familys Andrenidae & Anthophoridae) nest in burrows in the ground. Unlike the honey bee, mining bees are "solitary" bees. They do not form long-lived colonies, nor do they live inside a single, well-defended nest controlled by one queen bee. Instead, each mining bee female usually digs her own individual burrow to rear her own young. Large numbers of these bees may nest near one another if soil conditions are suitable.

Mining bees are not aggressive and seldom, if ever, sting. The presence of numerous bees flying close to the ground, however, may constitute a nuisance for some people. Sometimes large numbers of males will fly about the same spot for several days in a mating display.

Mining bees range in size from about the size of honey bees to much smaller. The larger bees are furry and usually darker in color than honey bees. Some are brightly striped, while others are a shiny metallic green. Mining bee burrows may be located wherever there is exposed soil and good drainage. They are frequently found nesting in banks, such as along road cuts or any type of excavation, but may also be in level ground as well. The holes are about 6 mm (1/4 inch) or less in diameter. They are sometimes surrounded by a small mound of soil that the bee has brought up to the surface. Burrow structure varies according to species, but often there is a vertical tunnel with smaller side tunnels that terminate in a single cell.

The female mining bee stocks each cell with pollen and nectar she collects from flowers and then deposits an egg on the food mass. The larva hatches and consumes the stored pollen and nectar. When mature, it becomes a pupa, or resting stage, and finally becomes an adult bee. The adult bees overwinter below ground in the burrow site. During the next spring or early summer the adults emerge, mate, and the females begin burrow excavation. Mining bee populations can fluctuate dramatically from one season to the next.

Ground Nesting Wasps:

Many species of wasps are also solitary and nest in the ground. They have a life cycle similar to that of the mining bees. After preparing a burrow, the female wasp stocks it with provisions (which consist of insect or spider prey rather than pollen and nectar), lays one or more eggs in it, seals it and departs. Some species don't permanently seal the nest, but instead return repeatedly with additional prey as their larvae grow. These wasps range in size from extremely small forms to the large, fearsome looking "cicada killers."

Cicada Killers (Specius speciousus): Cicada killers resemble large yellowjackets. They are mostly black with pale yellow markings on the abdomen, and about 5 cm (2 inches) long. Despite their appearance, these insects are inoffensive and usually will not bother people even when provoked. Their sting is meant for paralyzing their prey and normally does not cause a reaction in humans. They are considered beneficial because they reduce cicada populations. However, they may cause lawn damage if there are large numbers of them nesting in close proximity to each other.

Another group of ground nesting wasps are the Scoliid (family: Scoliidae) or Tiphiid (family: Tiphiidae) wasps. Scoliid wasps are about 16 mm (5/8 inch) long and blue-black, with blackish-purple wings. They have a yellow stripe on each side of the abdomen. Their bodies are fairly hairy and the back part of the abdomen is covered with reddish hairs. Tiphiid wasps are black and somewhat hairy with short, spiny legs. Both wasps are generally seen flying over the lawn during the day, leaving in early evening. Scoliids and Tiphiids are beneficial wasps in that they parasitize grub populations. They are not aggressive and generally do not attack humans. Adults are often seen on golden rod flowers in the late summer.

It must be stressed that mining bees are extremely beneficial insects, of considerable importance in the pollination of many different types of plants. Their burrowing does not harm vegetation and may actually be of service in aerating the soil. Furthermore, the activity of these species is extremely brief, with adult bees flying for only two to four weeks. In some instances, the bees observed are males flying about their territory; males cannot sting, nor do they make burrows. We do not recommend using insecticides to control mining bees and ground nesting wasps; it is virtually impossible to eliminate the population in a single season.