Vespula pensylvanica
Encyclopedia
Vespula pensylvanica is a species
of wasp
in the genus
Vespula
.
s) and this has great potential for negative impact on the native fauna in insular habitat
s. In its genus, it is one of the few species that also has a scavenging
habit
as opposed to a strictly predatory habit and is thus considered a major pest to humankind. Along with two other species — the "common wasp" or "yellowjacket" (Vespula vulgaris) and the "German wasp" or "European wasp" (Vespula germanica) — V. pensylvanica is part of the "Vespula vulgaris species group
" which together are the most abundant and bothersome of eusocial
wasps species. With a predilection for scavenging carrion that attracts it to the human food and garbage, V. pensylvanica is the most significant pest yellowjacket in western North America
.
Vespula pensylvanica shares its basic yellow and black pattern with other species of wasp in genus Vespula and its sister genus Dolichovespula
which are collectively known in North America
by the common name "yellowjacket
." V. pensylvanica, however, is the only member of its species group
that has a complete yellow eye ring around each compound eye. This eye ring is also visible in queen wasps
of this species.
Occasionally, the eye loop is entirely absent in males; it can be broadly interrupted in both sexes but rarely so in females. Males without a yellow eye loop can be distinguished from V. germanica by more subtle morphological
differences, viz, "the deeply emarginate or spotted subantennal mark on the frons
, the slender preapical portion of the aedeagus
, and the much more densely pubescent apical margin of tergum
". The majority of females of Vespula squamosa also have a narrow eye loop but this species shows a radically different metasoma
l pattern.
The length of this species's fore wing is 8.5–10.5 mm in workers, 12.5–14.5 mm in queens, and 12.5–14.0 mm in males.
across the western half of North America, in temperate zone climates . More precisely, individuals have been identified in Canada
from Manitoba
to British Columbia
. The easternmost record for V. pensylvanica is a single record from Ontario
but it is apparently not established in that province as a species. In the United States
the eastern edge of its range is in Wisconsin
, Nebraska
, Colorado
, and Texas
. In Mexico
it is known from Baja California Norte, México
, and Michoacán
.
and other areas V. pensylvanica has been recorded as an introduced species
. Attempts to eradicate this species from Hawaii
using the toxicant
bendiocarb
began almost as soon as a population was discovered there in 1977. A 1988 paper revealed that V. pensylvanica was successfully attracted to canned Figaro brand tuna
cat food
laced with micro-encapsulated
diazinon
as well as, to a lesser extent, the same cat food laced with amidino-hydrazone
. The color of the dispensers from which the bait was offered proved critical; translucent white dispensers were most effective.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Vespula
Vespula
Vespula is a small genus of social wasps, widely distributed in the Northern Hemisphere. Along with members of their sister genus Dolichovespula, they are collectively known by the common name yellowjackets in North America...
.
Description
V. pensylvanica is a predatory species that feeds on a wide range of invertebrate taxa (and occasionally even on slugSlug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
s) and this has great potential for negative impact on the native fauna in insular habitat
Insularity
Insularity reflects a wide range of physical and emotional meanings in accordance with a person or place:* For a place, it relates to an island or any physically isolated place distant and inaccessible without sufficient means of transport...
s. In its genus, it is one of the few species that also has a scavenging
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
habit
Habit (biology)
Habit, when used in the context of biology, refers to the instinctive actions of animals and the natural tendencies of plants.In zoology, this term most often refers to specific behavioral characteristics, even when directly related to physiology...
as opposed to a strictly predatory habit and is thus considered a major pest to humankind. Along with two other species — the "common wasp" or "yellowjacket" (Vespula vulgaris) and the "German wasp" or "European wasp" (Vespula germanica) — V. pensylvanica is part of the "Vespula vulgaris species group
Species group
A species group is an informal taxonomic rank into which an assemblage of closely related species within a genus are grouped because of their morphological similarities and their identity as a biological unit with a single monophyletic origin.-Use:...
" which together are the most abundant and bothersome of eusocial
Eusociality
Eusociality is a term used for the highest level of social organization in a hierarchical classification....
wasps species. With a predilection for scavenging carrion that attracts it to the human food and garbage, V. pensylvanica is the most significant pest yellowjacket in western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Vespula pensylvanica shares its basic yellow and black pattern with other species of wasp in genus Vespula and its sister genus Dolichovespula
Dolichovespula
Dolichovespula is a small genus of social wasps distributed widely throughout the Northern Hemisphere. The yellow and black members of the genus are known by the common name yellowjackets in North America along with members of their sister genus Vespula...
which are collectively known in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
by the common name "yellowjacket
Yellowjacket
Yellowjacket is the common name in North America for predatory wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as "wasps" in other English-speaking countries...
." V. pensylvanica, however, is the only member of its species group
Species group
A species group is an informal taxonomic rank into which an assemblage of closely related species within a genus are grouped because of their morphological similarities and their identity as a biological unit with a single monophyletic origin.-Use:...
that has a complete yellow eye ring around each compound eye. This eye ring is also visible in queen wasps
Eusociality
Eusociality is a term used for the highest level of social organization in a hierarchical classification....
of this species.
Occasionally, the eye loop is entirely absent in males; it can be broadly interrupted in both sexes but rarely so in females. Males without a yellow eye loop can be distinguished from V. germanica by more subtle morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
differences, viz, "the deeply emarginate or spotted subantennal mark on the frons
Frons
Frons is the term used to describe the frontal area of an insect's head. It covers the upper part of the face above the clypeus and below and between the antennae. It supports the pharyngeal dilator muscles and usually bears an ocellus . The term itself is derived from the Latin frons "forehead"....
, the slender preapical portion of the aedeagus
Aedeagus
An aedeagus is a reproductive organ of male insects through which they secrete sperm from the testes during copulation with a female insect...
, and the much more densely pubescent apical margin of tergum
Tergum
A tergum is the dorsal portion of an arthropod segment other than the head. The anterior edge is called the base and posterior edge is called the apex or margin. A given tergum may be divided into hardened plates or sclerites commonly referred to as tergites...
". The majority of females of Vespula squamosa also have a narrow eye loop but this species shows a radically different metasoma
Metasoma
The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. In insects, it contains most of the digestive tract, respiratory system, and circulatory system, and the apical segments are typically...
l pattern.
The length of this species's fore wing is 8.5–10.5 mm in workers, 12.5–14.5 mm in queens, and 12.5–14.0 mm in males.
Range
Even though the specific name given it by Henri Louis Frederic de Saussure is "pensylvanica", this species is actually nativeIndigenous (ecology)
In biogeography, a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism has its own natural range of distribution in which it is regarded as native...
across the western half of North America, in temperate zone climates . More precisely, individuals have been identified in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
from Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
to British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
. The easternmost record for V. pensylvanica is a single record from Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
but it is apparently not established in that province as a species. In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
the eastern edge of its range is in Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
, Nebraska
Nebraska
Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....
, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. In Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
it is known from Baja California Norte, México
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and Michoacán
Michoacán
Michoacán officially Estado Libre y Soberano de Michoacán de Ocampo is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 113 municipalities and its capital city is Morelia...
.
Invasiveness
In the Hawaiian IslandsHawaiian Islands
The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...
and other areas V. pensylvanica has been recorded as an introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
. Attempts to eradicate this species from Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
using the toxicant
Toxicant
A toxicant is a chemical compound that has an effect on organisms.A distinction can be drawn between "toxic" and toxin, with the latter being a subcategory of the former....
bendiocarb
Bendiocarb
Bendiocarb is an acutely toxic carbamate insecticide used in public health and agriculture and is effective against a wide range of nuisance and disease vector insects...
began almost as soon as a population was discovered there in 1977. A 1988 paper revealed that V. pensylvanica was successfully attracted to canned Figaro brand tuna
Tuna
Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...
cat food
Cat food
Cat food is food intended for consumption by cats.As with all species, cats have requirements for specific dietary nutrients, rather than ingredients. Certain nutrients, including many vitamins and amino acids, are degraded by the temperatures, pressures and chemical treatments used during...
laced with micro-encapsulated
Micro-encapsulation
Micro-encapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules many useful properties. In a relatively simplistic form, a microcapsule is a small sphere with a uniform wall around it...
diazinon
Diazinon
Diazinon , a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company...
as well as, to a lesser extent, the same cat food laced with amidino-hydrazone
Hydrazine
Hydrazine is an inorganic compound with the formula N2H4. It is a colourless flammable liquid with an ammonia-like odor. Hydrazine is highly toxic and dangerously unstable unless handled in solution. Approximately 260,000 tons are manufactured annually...
. The color of the dispensers from which the bait was offered proved critical; translucent white dispensers were most effective.