mojo
21st September 2015, 22:42
In the last week my home has had at least 6 conenose inside and over 20 found over a few days on the outside on screens and windows. They are attracted to light at night and can squees through tiny cracks. I was getting painful bites at night while sleeping and realize now what the culprit is. I informed my neighbor whom was clueless of this critter and most people I meet aren't familiar with it.
31245
What is a Conenose Bug?
Conenose bugs are members of the family Reduviidae which are commonly called
assassin bugs. Most members of this insect family are predators of other insects, but
the conenose bugs in the genus Triatoma are blood-sucking parasites of a wide variety
of wild and domestic animals and humans. Of the 15 species of Triatoma that are found
in the U.S., Triatoma protracta is the most widespread and medically important species
found in California. Adults are ½ to ¾ inch long, a uniform dark brown to black in color,
with an elongate, cone-shaped head possessing a three-segmented beak which folds
beneath it when not feeding. Wings are folded flat over the back when not in flight.
Nymphs are similar in appearance to adults except that they do not have wings and are
smaller. Other common names for conenose bugs include kissing bug, steelpin bug,
diamond-back bug, and Wallapi tiger.
Where are conenose bugs found?
In California, conenose bugs are prevalent in the foothill areas surrounding the Central
Valley and in the foothills and desert areas of Southern California. Triatoma protracta
frequently lives in or near the nests of wood rats (Neotoma spp.), or pack rats as they
are commonly called, which are its preferred host. By laying eggs in the nest of a
rodent, a source of blood is provided for the immature bugs when they hatch. After eggs
hatch in the summer, development proceeds through 5 nymphal stages in the nest
environment, with the last nymphal stage molting to an adult the following spring. The
Triatoma life cycle from egg to adult is typically completed in one year with each
nymphal stage and adult requiring a blood meal to complete development. Dispersal
flights of adult conenose bugs occur throughout the summer during warm evening
hours. During these flights, conenose bugs may be attracted to and aggregate around
lights and gain entrance into the home environment where they may feed on humans or
pets. Another common assassin bug, the western corsair (Rasahus thoracicus), will also
aggregate towards lights around homes and may be mistaken for a conenose bug. The
adult western corsair is usually larger than a conenose bug and has an orange and
black body with an orange spot on each wing. This Reduviid feeds on other insects and
does not seek out warm-blooded hosts for a blood meal. The western corsair can inflict
a very painful bite when antagonized.
What is the medical importance of conenose bugs?
As blood-sucking insects, conenose bugs pose a public health risk through their
incidental feeding on humans. Conenose bugs are night-time feeders with most bites
occurring in the house while the victim is asleep. Normally the bite is painless due to the
conenose’s anesthetic saliva and the bite may result in a localized reaction. Nonsensitized
individuals may not even be aware that they have been fed upon. The most
common reaction to a conenose bite is redness of the skin and the development of
intensely itching welts. Bite reactions usually dissipate in 24-48 hours, but may persist
1
STATE OF CALIFORNIA—HEALTH AND HUMAN SERVICES AGENCY California Department of Public Health
Division of Communicable Disease Control
for a week or more. In a person who has been sensitized by previous bites the injected
saliva may cause a severe allergic reaction. Anaphylactic reactions may occur with
weakness, sweating, shortness of breath, nausea, abdominal cramping, and vascular
collapse. Anaphylactic reactions require immediate medical treatment and sensitive
individuals may be advised by a physician to keep a kit containing epinephrine and
antihistamines in their bedroom.
Some species of conenose bugs, primarily Triatoma infestans (not found in California),
are vectors of Chagas’ disease in Latin America. This debilitating, sometimes fatal
disease is caused by a flagellate protozoan, Trypanosoma cruzi, and is transmitted
through the excreted feces of the conenose bug rather than the bite. Transmission
occurs when T. cruzi infected feces are inadvertently scratched into the bite or
transferred to mucous membranes. As a precaution, any recognized or suspect
conenose bites should be cleaned with soap and water and disinfected. Symptoms of
Chagas’ disease include swelling of the face and eyelids, high fever, nervous system
disorders, and potential destruction of cardiac and skeletal muscles. Though T. cruzi
protozoan have been found naturally infecting both conenose bugs and vertebrate hosts
in North America, behavioral feeding differences in North American Triatoma probably
account for the rare occurrence of locally acquired human infections of Chagas’ disease
in the US. California, Texas, and Tennessee have reported locally acquired cases in
humans and pet dogs.
What can be done to prevent conenose bites?
Where conenose bugs are a nuisance around residences, management of this pest
relies on removing likely harborages and sealing points of entry. Rodent harborage
around the home can be reduced by removing piles of lumber, firewood, and debris.
Vegetation management in close proximity to structures should be maintained.
Structural problems or damaged vents that may allow rodents entry to attics, indoor
spaces, or crawl spaces under the home should be fixed through screening or by other
means. Chimney caps and all outdoor vents should be appropriately screened. Screens
on windows, sliders, and exterior doorways should fit tightly and be in good repair. Pet
doors should be insect proof. Use weather stripping, silicone sealants, or caulk to repair
cracks or seal openings around doors or windows where insects may enter. Because
conenose bugs are attracted to lights at night, minimize outdoor lighting and draw
curtains in lighted rooms during spring and summer months when adult Triatoma
dispersal flights typically occur. Inspect bedroom spaces and bedding before retiring for
the presence of conenose bugs. Bed frames and bedding should not contact walls,
furniture, or other objects which may provide crawling, host seeking conenose bugs
access to the bed. A bed net, tucked in, is the best exclusionary item to use for those
sensitized to conenose bites and at risk for anaphylactic shock.
31245
What is a Conenose Bug?
Conenose bugs are members of the family Reduviidae which are commonly called
assassin bugs. Most members of this insect family are predators of other insects, but
the conenose bugs in the genus Triatoma are blood-sucking parasites of a wide variety
of wild and domestic animals and humans. Of the 15 species of Triatoma that are found
in the U.S., Triatoma protracta is the most widespread and medically important species
found in California. Adults are ½ to ¾ inch long, a uniform dark brown to black in color,
with an elongate, cone-shaped head possessing a three-segmented beak which folds
beneath it when not feeding. Wings are folded flat over the back when not in flight.
Nymphs are similar in appearance to adults except that they do not have wings and are
smaller. Other common names for conenose bugs include kissing bug, steelpin bug,
diamond-back bug, and Wallapi tiger.
Where are conenose bugs found?
In California, conenose bugs are prevalent in the foothill areas surrounding the Central
Valley and in the foothills and desert areas of Southern California. Triatoma protracta
frequently lives in or near the nests of wood rats (Neotoma spp.), or pack rats as they
are commonly called, which are its preferred host. By laying eggs in the nest of a
rodent, a source of blood is provided for the immature bugs when they hatch. After eggs
hatch in the summer, development proceeds through 5 nymphal stages in the nest
environment, with the last nymphal stage molting to an adult the following spring. The
Triatoma life cycle from egg to adult is typically completed in one year with each
nymphal stage and adult requiring a blood meal to complete development. Dispersal
flights of adult conenose bugs occur throughout the summer during warm evening
hours. During these flights, conenose bugs may be attracted to and aggregate around
lights and gain entrance into the home environment where they may feed on humans or
pets. Another common assassin bug, the western corsair (Rasahus thoracicus), will also
aggregate towards lights around homes and may be mistaken for a conenose bug. The
adult western corsair is usually larger than a conenose bug and has an orange and
black body with an orange spot on each wing. This Reduviid feeds on other insects and
does not seek out warm-blooded hosts for a blood meal. The western corsair can inflict
a very painful bite when antagonized.
What is the medical importance of conenose bugs?
As blood-sucking insects, conenose bugs pose a public health risk through their
incidental feeding on humans. Conenose bugs are night-time feeders with most bites
occurring in the house while the victim is asleep. Normally the bite is painless due to the
conenose’s anesthetic saliva and the bite may result in a localized reaction. Nonsensitized
individuals may not even be aware that they have been fed upon. The most
common reaction to a conenose bite is redness of the skin and the development of
intensely itching welts. Bite reactions usually dissipate in 24-48 hours, but may persist
1
STATE OF CALIFORNIA—HEALTH AND HUMAN SERVICES AGENCY California Department of Public Health
Division of Communicable Disease Control
for a week or more. In a person who has been sensitized by previous bites the injected
saliva may cause a severe allergic reaction. Anaphylactic reactions may occur with
weakness, sweating, shortness of breath, nausea, abdominal cramping, and vascular
collapse. Anaphylactic reactions require immediate medical treatment and sensitive
individuals may be advised by a physician to keep a kit containing epinephrine and
antihistamines in their bedroom.
Some species of conenose bugs, primarily Triatoma infestans (not found in California),
are vectors of Chagas’ disease in Latin America. This debilitating, sometimes fatal
disease is caused by a flagellate protozoan, Trypanosoma cruzi, and is transmitted
through the excreted feces of the conenose bug rather than the bite. Transmission
occurs when T. cruzi infected feces are inadvertently scratched into the bite or
transferred to mucous membranes. As a precaution, any recognized or suspect
conenose bites should be cleaned with soap and water and disinfected. Symptoms of
Chagas’ disease include swelling of the face and eyelids, high fever, nervous system
disorders, and potential destruction of cardiac and skeletal muscles. Though T. cruzi
protozoan have been found naturally infecting both conenose bugs and vertebrate hosts
in North America, behavioral feeding differences in North American Triatoma probably
account for the rare occurrence of locally acquired human infections of Chagas’ disease
in the US. California, Texas, and Tennessee have reported locally acquired cases in
humans and pet dogs.
What can be done to prevent conenose bites?
Where conenose bugs are a nuisance around residences, management of this pest
relies on removing likely harborages and sealing points of entry. Rodent harborage
around the home can be reduced by removing piles of lumber, firewood, and debris.
Vegetation management in close proximity to structures should be maintained.
Structural problems or damaged vents that may allow rodents entry to attics, indoor
spaces, or crawl spaces under the home should be fixed through screening or by other
means. Chimney caps and all outdoor vents should be appropriately screened. Screens
on windows, sliders, and exterior doorways should fit tightly and be in good repair. Pet
doors should be insect proof. Use weather stripping, silicone sealants, or caulk to repair
cracks or seal openings around doors or windows where insects may enter. Because
conenose bugs are attracted to lights at night, minimize outdoor lighting and draw
curtains in lighted rooms during spring and summer months when adult Triatoma
dispersal flights typically occur. Inspect bedroom spaces and bedding before retiring for
the presence of conenose bugs. Bed frames and bedding should not contact walls,
furniture, or other objects which may provide crawling, host seeking conenose bugs
access to the bed. A bed net, tucked in, is the best exclusionary item to use for those
sensitized to conenose bites and at risk for anaphylactic shock.