Bees, Wasps and Hornets

A Wasp

Introduction

Where species of Bees, Hornets, and Wasps can inflict stings to humans, their benefits include being pollinators of flowering and fruit plants, reducing several species of pest insects by preying on them, etc. Some humans may have sever alergic reactions to the stings. Some of these sting capable insects live in social or solitary lifestyle. In Social living struture there are casts of insects which are assigned specific roles in the social community sharing one big nest or hive. There are workers, quuen(s), males, etc.

An example of solitary insects is carpenter bees and spide wasps whereas Yellowjackes, Paper Wasps, Hornets and Honey Bees are considered Social Insects.

Recognition
Body with base of abdomen constricted, sometimes stalked. Wings 4 in number, with front wings a little longer than hind wings; wings with relatively few veins. Antennae moderately long, females 12-segmented and males 13-segmented. Tarsi 5-segmented. Mouthparts chewing but sometimes with a modified tonguelike sucking structure. Females with a well-developed ovipositor modified into a stinger.

In addition, thorax contains as 4th segment, the propodeum, which is actually the basal abdominal segment fused to the thorax; wings without an accessory vein (extra vein behind anal vein) and hind wing with 2 or fewer basal cells.

Identification

Biology

Bees, hornets, and wasps have complete metamorphosis: egg, larva, pupa, and adult. Those which are social have a caste system composed of workers, queen(s), and males (drones). Although the workers are sterile females, they occasionally lay eggs or can sometimes assume reproductive functions if the queen dies. Except for the paper wasps, colonies contain only the founding queen until mid-summer when many queens and males are produced; but honey bees have only one functional queen at a time. With the onset of cold weather, workers, noninseminated queens, and males die off leaving the inseminated queens to overwinter and start new colonies in the spring. Honey bees are the exception where the entire colony including immatures, workers, and the queen overwinters. In the solitary bees and wasps, only the inseminated queen overwinters.

Adults of social species feed on nectar, honeydew, sap, fruit juices, etc. Protein for larvae comes from pollen for the bees but for the wasps and hornets, it consists of insects and spiders if the adults are predators, or meat if they are scavengers. Workers get some protein but mostly carbohydrates from the trophallactic fluid exuded by the larvae when fed. The larvae of solitary species get all their food from the paralyzed prey or pollen ball upon which their egg was laid and which is then usually sealed in a cell.

Control

Since bees, hornets, and wasps are beneficial, control should only be done where there is an immediate threat to people or their pets, or when peace-of-mind is required. If control/elimination is required, then use an appropriately labeled pesticide. Dust and aerosol formulations work best in most situations, and carbamates and pyrethroids are especially effective.

For social species, locate the nest entrance for each colony to be controlled during the day. Pesticide application should be done at night when most of the adults are on/in the nest. Only background lighting should be used and a bee veil should be worn. For solitary species, their nest(s) should be treated during daylight but be sure to wear a bee veil and other appropriate protective gear/clothing. See the individual treatments for more specific directions.


Paper wasps

Introduction

Paper wasps get their common name from the paperlike material of which they construct their nests; true also of the other vespids. It has been suggested that they be called umbrella wasps based on the shape of their nests. In the urban situation, these usually unaggressive wasps are a nuisance pest. Various species are found throughout the United States.

Recognition

Adults about 5/8-3/4" (16-20 mm) long. Color brownish with yellow markings, a few species with reddish markings. Head with clypeus (upper lip) usually pointed at appex. Pronotum in lateral view almost triangular, extending to tegulae (structure at base of front wing) or nearly so. Long-legged, middle tibia with 2 apical spurs. Hind wing with small jugal lobe (lobe on rear near body). 1st abdominal segment conical, not stalklike.

Similar groups

(1) Yellowjackets and hornets (subfamily Vespinae) with clypeus (upper lip) broadly truncate and slightly notched at apex, hind wing lacks jugal lobe (lobe on rear near body). (2) Potter and mason wasps (subfamily Eumeninae) have middle tibia with 1 apical spur. (3) Spider wasps (Pompilidae) have mesopleura (side of mesothorax) with a transverse suture (impressed line), hind wing with a jugal lobe.

Representative species

Golden paper wasp, Polistes fuscatus aurifer Saussure. Length about 5/8-3/4" (16-20 mm); black with face and most of abdomen bright yellow; thorax with 6 narrow yellow stripes, legs mostly yellow; found in British Columbia, Washington, Oregan, California, Nevada, Idaho and Montana

Polistes annularis (Linnaeus). Length about 3/4" (18 mm); blackish brown with bright yellow margin on 1st abdominal segment; found in Connecticut, New York, New Jersey, Maryland, Delaware, southeastern U.S., Texas, and South Dakota.

Polistes apachus Saussure. Length about 3/4" (20 mm); golden brown with yellow markings, pronotum bordered with thin yellow stripe, mesonotum with 2 transverse stipes (anterior narrow, posterior broad), abdomen with alternating stripes of golden brown and yellow; found in southern California and in Texas and adjacent regions.

Polistes dorsalis dorsalis (Fabricius). Length about 3/4" (17-18 mm); reddish brown with 1st abdominal segment narrowly outlined with yellow, tarsi yellow; found in southeastern U.S., Missouri, Kansas, Colorado, Oklahoma, Texas, and New Mexico.

Biology

Paper wasps are semi-social, existing in small colonies but without a worker caste. Overwintering inseminated queens begin building nests in the spring. These founding queens are often joined by other inseminated queens which assist in nest building and maintenance. Such secondary queens become functional workers and relegate egg laying to the founding queen. However, should the founding/dominant queen die, one of the secondaries can assume egg laying and assure that the nest will survive.

Nests consist of a single layer of paperlike comb with the cells opening downward. This comb is supported/suspended from a branch, twig, or horizontal surface by a single long pedicel; this single, long pedicel apparently aids in the defense of the nest by predators such as ants. This comb is never enclosed by an envelope, but remains naked. A single egg is laid in each cell and the developing larva is fed primarily protein from insect prey through the open cell. The cell is capped when the larva is ready to pupate. Nests are small to moderate in size containing up to about 150-250 cells; largest contained 320 cells and was 6x8" (15x20 cm) in size.

Habits

Paper wasps hang their comb nests from twigs and branches of trees and shrubs which can cause concern when ornamental shrubs and hedges are trimmed or fruit is being picked from trees. If a nest is contacted, there is high probability that person doing the trimming or fruit picking will get stung. Paper wasps also like to hang their comb nests from porch ceilings, the top member of window and door frames, soffits, eaves, attic rafters, deck floor joists and railings, etc., almost any protected place imaginable.

Control

Paper wasps are beneficial insects, helping to control many insect pests. If their nest is located near human activity, control is warranted. It is essential that the adults be contacted and killed or they will quickly rebuild. For adults, use an appropriately labeled pesticide such as aerosol pyrethrins or a pyrethroid and do the application early in the morning or at night when most of the wasps will be on the nest. Then remove the nest.

Before trimming shrubs or hedges or picking fruit, check the plant for paper wasp nests and treat and remove any found before proceeding. Be careful that the pesticide used will not harm the plant involved.


Yellowjackets

Introduction

Yellowjackets receive their common name from their typical black and yellow color pattern. They are worldwide in distribution with about 16 species occurring in the United States.

Recognition

Adult workers about 3/8-5/8" (10-16 mm) long depending on the species, with their respective queens about 25% longer. Abdomen usually banded with yellow and black, several species with white and black, and 2 northern species also marked with red. Wings folded longitudinally at fest. ln addition, pronotum in lateral view almost triangular, extending to tegula (structure at base of front wing) or nearly so; front wing 1st discoidal cell about half wing lef1gth; hind wing lacks jugal lobe (lobe on rear margin near body); clypeus (front lip) broadly truncate and slightly notched; middle tibiae with 2 apical spurs. The worker abdominal color pattern is usually distinctive for each species but because it does vary, a series of specimens may be required for identification.

Similar groups

(1) Baldfaced hornets (D. maculata) mostly black with yellowish-white markings on face, thorax, and end of abdomen. (2) European hornets (Vespa crabro) very large (up to 1 3/8"/35 mm long), brownish with orange stripes. (3) Honey bees (Apidae) with hairy eyes, hind tarsal1st segment enlarged and flattened, hind wing with jugal lobe (lobe on rear margin near body), abdomen not banded with yellow and black. (4) Some clear-wing moths (Lepidoptera: Sesi1dae) which resemble yellowjackets, with siphoning mouthparts.

Biology

Yellowjackets are social insects and live in nests or colonies. The adults are represented by workers which are sterile females, queens, and males which come from unfertilized eggs and usually appear in late summer.

Typically, only inseminated queens overwinter and do so in sheltered places. ln the spring, she uses chewed-up cellulose material to build up a paper carton nest of a few cells which will eventually consist of 30 to 55 cells covered by a paper envelope. One egg is laid in each cell and the queen feeds the developing larvae arthropod protein material and nectar. After about 30 days, the first 5 to 7 workers emerge and shortly thereafter take over ail the work except egg laying. The nest will eventually consist of a number of rounded paper combs which are open ventrally and attached one below another, and are usually covered with a many-Iayered paper envelope. Nest size varies from 300 to 120,000 cells, averaging 2,000 to 6,000 cells, and usually contains 1,000 to 4,000 workers at its peak. Later in the season, larger reproductive cells are built in which queens will be reared; males are usually reared in old worker cells. The colony is then entering the declining phase. The newly emerged queens and males leave the nest and mate. Only the inseminated queens hibernate and survive the winter. The founding queen, the workers, and the males ail die.

Habits


Depending on the species, the overwintered queen will usually select either a subterranean or aerial nesting site. Most of the pest species are ground nesting. However, the German yellowjacket usually nests in buildings in the United States, the western yellowjacket occasionally nests in buildings, and the aerial yellowjacket commonly attaches its nest to shrubs, bushes, houses, garages, sheds, etc.

Those nesting in the ground typically select areas bare of vegetation or else clear an area around the entrance. There are nest entrance guards to protect the colony. Yellowjackets are very slow to sting unless the nest entrance is approached and then they are quite aggressive. Each can sting a number of times, inflicting much pain. Some people become hypersensitive to their stings and future stings can become life threatening. Those nesting in or on buildings are only a problem when the nest or nest entrance is located near human activity. Overwintering queens may enter the living space during the winter seeking warmth, or in the spring when they are looking for a nest site or just trying to get back outside.

Control


Yellowjackets are considered beneficial insects because their food consists mostly of various arthropods, often pest species. However, if their nest is located close to occupied buildings, recreational areas, or within structures, then control is warranted. During the day, locate where the nest entrance is for each colony to be controlled. Control should be done at night when most of the yellowjackets are in the nest. Only background lighting should be used and a bee veil should be worn. If it is a ground nest, then dust an area for 6" (15 cm) around the entrance hole with an appropriately labeled pesticide dust. If the nest is located in a wall void, then either dust the void via the entrance ho le or apply an appropriately labeled aerosol pyrethroid and close the entrance hole. ln a day or so, the wall void nest area should be treated with a long-lasting, highly repellent material or else should be opened up and cleaned out to prevent future dermestid beetle, spider beetle, and/or psocid problems. If it is an aerial nest, then an appropriately labeled aerosol works well.

In situations where pesticide application is not desirable, the use of baited traps can help reduce the number of adults. For German and eastern yellowjackets, grenadine has been found to be a very attractive bait. The traps should be placed 3-8 ft (1.8-2.4 m) above the ground, between the area to be protected and the nesting area, such that they are protected from passers by and the wind, and placed about 5 ft (1.5 m) apart at the height of the season. They should be checked daily, and cleaned and rebaited as required.


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