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There are 50
mosquito species found in Massachusetts; some are common, and others are
found less frequently. Each species has it's own unique combination of
characteristics. The presence of a particular mosquito species is dependent
on the type of nearby wetland or habitat. Examples of different habitats that
produce different mosquito species include permanent swamps, temporary woodland
pools, river flood plains, cattail swamps or artificial containers. The last
item can be almost any container which can hold stagnant water for at least a
week in the summer, including roadside highway drains, old rimless tires,
unused swimming pools, uncovered empty trash cans, and bird baths.
The species of
mosquito found at any one time in an area is dependent on temperature and
season; there are early spring, late spring, summer, and mid-summer species.
Some mosquito species have several generations each summer, so their
populations increase as the summer goes along. Most mosquito species are
active primarily during dusk and dawn or during cloudy warm days. However,
one local species is active all night and some species will bite during hot
sunny days. Three of our local mosquito species will enter protected shelters
such as houses, and it is usually one of these three species that annoy
people while they are trying to sleep.
While some
mosquitoes are indiscriminate about what they bite, most are selective. Some
of our mosquito species feed primarily on humans and other mammals, while
others mostly bite birds, and still others feed on amphibians (such as frogs)
or reptiles (such as snakes). Some species are very aggressive and
persistent, while others are very shy. Finally, some deliver a more annoying
bite that results in more itching.
The chance of
acquiring a mosquito-borne disease in Massachusetts is extremely rare.
However, the species which are believed to transmit Eastern Equine
Encephalitis include some of the most numerous species, which on given nights
can be caught on any suburban or rural property in eastern or central
Massachusetts. West Nile Virus has been introduced into our area in the year
2000, and continued research is showing many species of mosquito, including
human biters, adept at carrying and possibly transmitting this disease.
Mosquitoes also transmit animal diseases, and the probability of a pet dog or
cat acquiring heartworm is not so remote. It is recommended that a veterinarian
monitor your pet and administer the proper preventative medication.
Please note:
the sub-genus Ochlerotatus has been elevated to genus, thus affecting
most of the Aedes classifications.
- Aedes albopictus - Aedes albopictus was first collected
in the United States at a tire dump near Houston, TX in 1985. The
species spread rapidly through the southern United States and has been
documented in over 25 states over the last decade. The first record of
this species in Mass. was documented in 2000. Aedes albopictus is
a multi-voltine species and should have a seasonal distribution similar
to that of Ochlerotatus triseriatus. Ae. albopictus is an
opportunistic container breeder that is capable of utilizing natural as
well as artificial container habitats. Although the mosquito is most
often associated with discarded tires in this country, it has the
ability to adapt to an exceptionally wide range of confined water
sources. The mosquito is known for its ability to survive in very small
collections of water, requiring only 1/4" of depth to complete its
life cycle.
- Aedes cinereus - Common late spring and early summer
mosquito pest of humans and other mammals. Larvae are found in late
April and May in tussock and leather-leaf marshes.
- Aedes vexans - Very common summer mosquito. This pest of
humans and other mammals can have several generations each season, so
the population may increase during the summer. Larvae are found in a
wide variety of temporary pools and wetlands. This mosquito is a suspect
in the transmission of EEE from birds to humans. After significant rain
events, this mosquito can be quite numerous and is considered a major
pest of man. West Nile Virus has been isolated from this species in
2000.
- Anopheles punctipennis - Found occasionally in the spring and
summer. This pest of humans and other mammals has a mildly annoying
bite. The larvae are found in a wide variety of wetlands including
permanent swamps and along the edges of ponds and slow moving streams.
West Nile Virus has been isolated from this species in 2000.
- Anopheles quadrimaculatus - Common Summer mosquito. A pest of humans
and other mammals that readily enters houses and has a mildly annoying
bite. The population increases during the summer. The larvae are found
in clear water amongst low vegetation or floating debris, in permanent
swamps, and along the edges of ponds and slow moving streams.
- Coquillettidia perturbans - Very common mid-June to mid-August
mosquito. An indiscriminate pest of birds, humans and other mammals that
is known to be a vicious biter, and will readily enter homes. The larvae
are unusual in that they are found attached to the submerged roots of
cattails and a few other aquatic plants. This trait makes this species
impervious to control using pesticides that are effective against larvae
of other species. This mosquito is suspected in the transmission of EEE
from birds to humans.
- Culex pipiens - Very common year round mosquito which
primarily feeds on birds. It will readily enter a house, but is
considered shy. It will typically only bite people when they are
motionless, usually while they are sleeping. The larvae are found in
water holding containers and in polluted waters. Culex pipiens
are considered the primary vector of West Nile Virus. West Nile Virus
has been isolated from this species in 1999 and 2000.
- Culex restuans - Culex restuans has a distribution
that ranges from central Canada south into Mexico. The mosquito is very
common in the eastern and central United States. Culex restuans undergoes
a life cycle that is typical for domestic Culex. Inseminated
adult females enter hibernation in fall and pass the winter in a period
of quiescence. Culex restuans utilizes an exceptionally wide
range of larval habitats. The water used by this species can vary from
nearly clear to grossly polluted. Culex restuans regularly
colonizes temporary ground pools that remain flooded after they have
produced broods of floodwater Ochlerotatus. Culex restuans
is also the first species to utilize water that collects in discarded
tires. The species can often be found in tire water that is absolutely
clear and devoid of leaf litter.
- Culex salinarius - Common summer mosquito. A fierce biting pest
of birds, humans and other mammals which can have several generations in
a summer, so the population may increase during the season. This
mosquito is active all night. Larvae are found in both fresh and
polluted grassy hummock areas of permanent water swamps. West Nile Virus
has been isolated from this species in 2000.
- Culex territans - Culex territans is quite common
throughout most of eastern Europe and is even found in parts of Africa.
In North America, Cx. territans extends from Alaska and Canada south
through most of the United States. Culex territans has a life
cycle that is typical for most Culex species. In late fall,
inseminated adult females feed on carbohydrates and hibernate in
subterranean enclosures where they pass the winter in a state of torpor.
The mosquitoes emerge in very early spring, obtain a blood meal and lay
the first egg rafts of the season. Culex territans is a frog
feeder and it is not uncommon to see this species feeding on Spring
Peepers. Egg hatch, however, may be delayed because of the mosquito's
unique oviposition habits. Unlike most Culex, Cx. territans
females rarely deposit their egg rafts directly on the surface of the
water. This mosquito normally positions the raft up on the bank and
relies on rainfall or rising water levels to flush the eggs onto the
water's surface. Culex territans shares habitat with many of the
univoltine Ochlerotatus in early spring, a variety of Anopheles
sp. later in the summer and Uranotaenia sapphirina very late
in the season. The species is occasionally found in containers but
cannot tolerate even moderate levels of pollution. Culex territans
is common in farm ponds, swamps and bogs and roadside ditches. Culex
territans is one of the few species that can be collected from
streams. It is not uncommon to find larvae within the grassy margins of
slow moving streams and specimens are sometimes found in rock pool
habitats normally associated with Ochlerotatus atropalpus.
- Culiseta melanura - Common spring and summer mosquito. A bird-
feeding mosquito that can have several generations per year, so the
population may increase towards the end of the summer. Larvae are found
in holes in the root structures of white cedar and red maple trees in
swamps. This is an important mosquito species because it is believed to
spread EEE virus through the bird population. This mosquito does not
bite humans.
- Culiseta morsitans - Culiseta morsitans is a mosquito of
the northern United States with a distribution that extends through
Canadian Yukon Territory into Alaska. The mosquito is fairly common in
New England and upper New York state. Records from the Atlantic coast
region indicate that the species has been collected as far south as
Delaware. Culiseta morsitans has a life cycle similar to that of
the northern Ochlerotatus group of mosquitoes. The species is
considered univoltine but females are long lived and frequently appear
in light trap collections well into the summer. Unlike most members of
the Genus Culiseta, the egg rafts are deposited on damp earth,
probably deep within the Carex tussocks that are so common in
their breeding habitat. Mature stands of red maple that grow in
12-18" of early spring ground water provide typical habitat.
Uprooted trees are common in many of the swamps that support this
species and tussocks of Carex serve as indicators of the
semi-permanent nature of the habitat
- Ochlerotatus abserratus - Very common early spring to early summer
mosquito pest of humans and other mammals. Larvae are found in temporary
spring pools and margins of permanent waters in April. Readily bites in
shaded areas during the day.
- Ochlerotatus atropalpus - Uncommon mosquito in Massachusetts, but can
be a pest of man as our data has shown. This species is known as the
"rockpool" mosquito, which describes it's preferred habitat,
but data from New Jersey has shown that it has become well adapted to
artificial containers such used tire casings.
- Ochlerotatus aurifer - Found occasionally in the spring and early
summer. Vicious biting pest of humans and other mammals. Larvae are
found in the spring in open marshes.
- Ochlerotatus canadensis - Common late spring and summer mosquito.
Fierce biting pest of humans and other mammals. Larvae are abundant in
late spring and found occasionally during the summer in woodland pools,
swamp borders and grassy hummock areas. This long-lived mosquito is the
primary suspect in the transmission of heartworm to dogs and a possible
suspect in the transmission of EEE from birds to humans.
- Ochlerotatus cantator - A mosquito more common in salt marsh areas,
but has been collected in the Central Massachusetts area. Larvae can be
found in freshwater habitat that received runoff from streets and highways
that receive salt during the winter. Is considered a pest of man, but
not considered common in this area. when adult samples are found, it is
likely that they developed elsewhere.
- Ochlerotatus communis - Ochlerotatus communis is a true
snowpool species, common throughout the northern United States and
Canada into Alaska. Throughout its range, the species is associated with
heavily forested areas at high elevations. Ochlerotatus communis
larvae are most common in deep snowpools filled with dark colored water
in forested areas above elevations of 1500 ft. In most cases, Oc.
communis is the only large mosquito in the pools although in some
years, small numbers of another northern species, Ochlerotatus
provocans, may be intermixed.
- Ochlerotatus dorsalis - Ochlerotatus dorsalis has
distribution that extends over the greater portion of North American
northern Europe and into Asia. In the United States, the mosquito
reaches greatest abundance from the plains states to the Pacific coast.
In the east, it has been reported in lesser numbers across the Great
Lakes states to the east coast states of Massachusetts, Connecticut and
New Jersey. Ochlerotatus dorsalis overwinters in the egg stage
and the eggs hatch after flooding during the first warm weather in the
spring. Oc. dorsalis is well known for its capacity to migrate
long distances. The adults are strong fliers and have been traced for 22
miles in Utah and more than 30 miles in California. As a result, the
mosquito has been recognized as a chance migrant in some areas of its
range. Ochlerotatus dorsalis larvae occur in a variety of
habitats including both brackish and freshwater. They are found in large
numbers on tidal marshes of the Pacific coast. The species is also
common along the margins of the Great Salt Lake in Utah. Ochlerotatus
dorsalis can be found in a variety of freshwater habitats including
marshes, temporary pools formed by precipitation, natural springs and
irrigation water. The larvae Oc. dorsalis have been found in
association with numerous other mosquito species. In Utah, the species
has been found breeding with 18 other species of mosquitoes including Ochlerotatus
vexans, Culex tarsalis and Culiseta inornata . In New York, under
saline conditions, the larvae have been found with Ochlerotatus
sollicitans.
- Ochlerotatus excrucians - Very common mid spring and early summer
mosquito pest of humans and other mammals. Larvae are found in a wide
range of wetland habitats. This mosquito is a suspect in the
transmission of heartworm to dogs. Isolated specimens have been found
throughout the summer months.
- Ochlerotatus fitchii - Oc. fitchii is a mosquito of the
northern United States and Southern portion of Canada. Its range extends
from Maine to New Jersey on the eastern seaboard, west to northern
Nevada and north into British Columbia. Oc. fitchii is a
univoltine species with a typical northern Ochlerotatus life
cycle. In Massachusetts, the single generation of eggs hatch in April
and the larvae reach 4th instar during the early part of May. Egg hatch
may be staggered during the early season and a variety of instars can be
collected from different habitats in the same geographic area. Adults
are on the wing in May, blood feed and deposit their eggs which do not
hatch until the following spring. Oc. fitchii has been reported
from a wide variety of habitats but the species is most common in
semi-permanent bodies of water in open areas that support emergent
vegetation.
- Ochlerotatus grossbecki - Oc. grossbecki is recognized as a
mosquito of the southeastern United States, but the species is found in
Massachusetts on occasion. The mosquito occurs at low levels throughout
the more southern areas of the state. Oc. grossbecki is one of
the earliest mosquitoes to hatch from overwintering eggs. Development is
rapid, considering the cold water that is present in the early Spring. Oc.
grossbecki is on the wing before most mosquito control agencies put
out their surveillance traps, however, the species persists until early
summer and can be represented in low numbers in trap collections during
May and June. The larvae of Ae. grossbecki are most common
in flooded woodlands where mature Red Maple and Beech are the dominant
trees. Decomposing leaves add tannins to the aquatic habitat and in most
cases, habitat water is so dark that a white dipper submerged more than
2 ft below the surface cannot be clearly detected.
- Ochlerotatus japonicus japonicus - New species found in Mass. in 2000. This
species was first found in New York & New Jersey in 1998, then
Connecticut in 1999. This mosquito is native to Japan, Korea, Taiwan,
and southern China. It's preferred habitat is artificial containers and
discarded tire casings. It is not believed at this time to be a
voracious biter of man, however research done by CMMCP has shown it can
be a pest. West Nile Virus has been isolated from this species in 2000.
- Ochlerotatus sollicitans - Very common summer mosquito found primarily
along the coast. This aggressive mosquito will bite on a hot sunny day
and is known to fly long distances, so it occasionally turns up in our
district. Larvae are found on the edges of salt marshes.
- Ochlerotatus stimulans - Spring mosquito that has been shown by data
collection to be found well into the summer months. Has a singe generation
like all spring mosquitoes, and is not considered a vector of disease at
this time. Readily bites mammals, and can be a common pest in the
spring.
- Ochlerotatus taeniorhynchus - The black salt marsh mosquito is a severe
biter of man and livestock along the southern coasts from North Carolina
to Florida and in the Caribbean. Unchecked populations can have a major
economic impact. While capable of transmitting eastern equine
encephalitis and St. Louis encephalitis in the laboratory, it is not a major
vector of these diseases in nature. It is, however, an important natural
vector of dog heartworm and Venezuelan equine encephalitis. The black
salt marsh mosquito is found on the coastal plains from Massachusetts to
Texas, in California along the Pacific Coast and in the Caribbean. It is
more abundant in the south. This mosquito breeds in the upper regions of
grass salt marshes where it is generally associated with spike grass (Distichlis
spicata) and salt meadow hay (Spartina patens). In the south,
production also occurs in the high marsh associated with mangroves,
saltwort (Batis maritima) and glassworts (Salicornia
species). It also breeds on dredge disposal islands along the Atlantic
Intracoastal Waterway. During the mosquito season, a portion of each egg
clutch will hatch when flooded. Productive salt marsh sites are flooded
at irregular intervals by wind or lunar tides, or heavy rainfall.
Bacteria and other microorganisms provide an abundant food supply. in
the field, hundreds to thousands of mature larvae often form tightly
clustered "balls" which are thought to be associated with
feeding, Under optimal conditions, emergence of adults can occur in as
little as six days following egg hatch. Host seeking occurs in the
evening and to a lesser extent in the morning. Females do not seek hosts
to any great extent during darkness. In daytime, hosts that move near
resting females may be attacked. The black salt marsh mosquito will feed
on birds as well as mammals. All populations in Florida exhibit some autogeny
which refers to an ability of females to develop eggs without taking a
bloodmeal. At northern latitudes, eggs enter diapause in response to
decreasing day length and water temperature; breeding can occur year
round in the extreme south.
- Ochlerotatus triseriatus - Common summer mosquito. A pest of humans
and other mammals. Most of these larvae actually are found in old
rimless tires, although some are found in other shaded artificial
containers and in tree holes. When this mosquito is a pest, it's breeding
source is usually close by. West Nile Virus has been isolated from this
species in 2000.
- Ochlerotatus trivittatus - Common summer mosquito. Larvae are found in
floodwater pools in both swamps and marshes. This pest is a persistent
biter, and will even bite during the day.
- Psorophora columbiae - Psorophora columbiae,
formerly known as Ps. confinnis, is a widespread pest from
Florida, where it is known as the 'glades mosquito," to New York. Scattered
populations exist in Massachusetts and across the United States westward
to California. The species is found in Mexico, Central America, the
Caribbean and South America to Argentina. Psorophora columbiae
reaches its greatest abundance in the rice growing areas of the
southwestern U. S. where astronomical numbers, similar in magnitude to
the production of saltmarsh mosquitoes, may occur. Eggs are deposited on
moist soil which is subject to flooding by water from rainfall or
irrigation. The incubation period is about 3-5 days in the rice growing
areas of Arkansas. The larvae mature rapidly during the hot summer,
often developing from first instar to pupae in as few as 3.5 days. The
larvae develop in temporary shallow freshwater pools and puddles where
there is vegetation. The larvae may occasionally be found in slightly
brackish water. Ideal sites for Production of larvae are ricefields,
grassy roadside ditches, and grassy swales. The normal flight range of
this mosquito is at least 6-8 miles; however, much longer distances have
been recorded. The mosquito is readily attracted to light, and the New
Jersey light trap is commonly used to monitor populations. The females
are furious biters in day or night. Hosts include any warm blooded
animal; however bovine blood seems to be preferred.
- Toxorhynchities rutilus septentrionalis - Predatory mosquitoes in the genus Toxorhynchites
are the most common arthropods which have been used for control of
"container-breeding" mosquitoes. The combination of
carnivorous larvae and innocuous adults is very attractive in biological
control. Successful biological control has been reported using Toxorhynchites
species from Japan, Southeast Asia, the Caribbean and the United States.
Most of the 71 species of Toxorhynchites are found in forested
tropical regions throughout the world. At least one, Toxorhynchites
rutilus, has a subspecies (septentrionalis) that is found
as far north as 40 degrees N latitude in Connecticut and southern New
York. Limited collections have been made in the CMMCP area in Millbury
and Worcester. The other subspecies of Toxorhynchites rutilus
found in mainland United States, Tr. rutilus, has been reported
only from Florida, Georgia and Louisiana. Toxorhynchites are
unusually large mosquitoes; the wingspan may exceed 12 mm; the body
length may exceed 7 mm. Adults are frequently covered with iridescent
scales and the proboscis has a pronounced 90 degree downward curve.
Fourth instar larvae may be more than 2 cm in length. Adults feed on plant
nectars. A few species are precocious and do not need nectar to initiate
oviposition. Protein used in reproduction is apparently entirely derived
from larval feeding, although some nectars may provide modest amounts of
some amino acids. Cumbersome in flight, they are most frequently seen
resting near treeholes or engaging in their characteristic elliptical
oviposition flight patterns at the mouth of natural and man-made
containers. They are not known to oviposit in small ponds or other open
water such as ground pools. Larvae feed on the living macroinvertebrates
inhabiting flooded treeholes, bromeliads and man-made containers. They
are dependent on movement for prey location. Although they are more
successful in feeding on mosquitoes, eating as many as 400 larvae during
their larval development periods, they can successfully complete larval
development with artificial protein sources such as water fleas (Daphnia)
or brine shrimp. Cannibalism is not uncommon, especially in small
containers, but containers such as tires with ample food supplies may
support half a dozen or more similarly sized larvae. Larval behavior is
especially intriguing with feeding dependent on prey size and
availability. Wanton killing of prey without feeding has been reported.
All known species are multivoltine. In the United States, Toxorhynchites
generally overwinter as late larval instars. Diapause is controlled by
day length, rather than temperature. Although the use of Toxorhynchites
alone is unlikely to reduce pest or vector species below operational
thresholds, they can be a valuable tool in areas where containers and
treeholes contribute substantially to the standing crop of mosquitoes.
However, they are highly susceptible to insecticides, and care has to be
exercised in the timing of release of Toxorhynchites and
application of insecticide sprays. Their large size and docile
appearance create the opportunity for them to serve as focal points for
public awareness campaigns aimed at the cleanup of man-made containers
that are used as breeding sites by pest mosquitoes.
- Uranotaenia sapphirina - Uranotaenia sapphirina is found from
southeastern Canada to Florida along the eastern seaboard of the United
States. Its range extends into the central states west to North Dakota and
south into Mexico. Uranotaenia sapphirina has a life cycle
that is similar to many of the Culex species. The adult females
enter hibernation after they have been inseminated in the fall, pass the
winter in a state of torpor and emerge in late spring to initiate a
multivoltine breeding season. The species lays unique egg rafts that
float partially submerged on the water's surface. Larvae are rarely
evident until July, but peak sharply during the month of August. Larvae
persist in prime breeding habitat into the month of September but
decline sharply with the onset of cool weather. The brightly ornamented
adults do not fly far from their breeding site but are readily attracted
to artificial light. Light traps that are placed near suitable breeding
habitat frequently give an overestimation of this species' population
density during the summer months. Uranotaenia sapphirina is a
mosquito that is almost always associated with permanent and
semipermanent ponds that support rich stands of emergent and floating vegetation.
In many areas of Massachusetts, Duckweed (Lemna sp.) appears to
be an indicator plant. The larvae often congregate in large numbers
among the tiny leaves and trailing roots of this floating aquatic plant.
Water depth can vary from a few inches to several feet in the swampland
utilized by this species. Uranotaenia sapphirina larvae usually
avoid shade and are usually found in greatest abundance in sunlit areas
of the breeding habitat.
- Wyeomyis smithii - Wyeomyia smithii belongs to the
tribe Sabethini, a group of 12 mosquito genera that share more
biological than taxonomic characteristics. The tribe is well represented
in the New World tropics. Wyeomyia is the only sabethine genus
that occurs in North America. Wyeomyia smithii has a distribution
that extends from Newfoundland south to Delaware, west to northern
Illinois and northwest into Saskatchewan. The mosquito's distribution
corresponds to the range of the northern pitcher plant, Sarracenia
purpurea gibbosa. Another pitcher plant mosquito, Wyeomyia
haynei, is found in the southern pitcher plant, Sarracenia
purpurea venosa, from Maryland to South Carolina. The range of the
two pitcher plant mosquitoes does not appear to overlap. Wyeomyia
smithii is a multivoltine mosquito that completes its entire
life cycle in the immediate vicinity of its predacious host plant. The
females deposit their eggs directly on the water within the plant or
just above the waterline in older leaves. The larvae live in the liquid
of the plant and feed on the carcasses of insects and spiders being
digested by the plant enzymes. Multiple generations take place from
spring through fall. Late in the season, the females attach eggs to
young leaves, before they become filled with water. The species
overwinters as a larva frozen in a block of ice within the plant. The
overwintering larvae pupate during the month of May and are usually on
the wing by June. Wyeomyia smithii is an obligate inhabitant of
the predacious pitcher plant and has never been reported from any other
larval habitat.
Additional
species descriptions will be added in the near future. Please check back
soon.
Credit must
be given for the information complied here to Dave Henley at the East
Middlesex Mosquito Control Project, Dr. Wayne Crans at Rutgers University,
Tim Deschamps and Curtis Best at the Central Massachusetts Mosquito Control
Project, as well as the Massachusetts Entomologist group.
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