Geographic Range
Anthrenus verbasci
, commonly known as varied carpet beetles, are an introduced Palearctic species. A
cosmopolitan species, they are nearly worldwide in distribution, including the Nearctic,
Palearctic, Oriental, and Neotropical regions. They have also been found in South
America. Varied carpet beetles were introduced in North America around 1850.
- Biogeographic Regions
- nearctic
- palearctic
- oriental
- neotropical
- Other Geographic Terms
- cosmopolitan
Habitat
Varied carpet beetles are found in temperate regions. Adult
Anthrenus verbasci
from outdoor populations can be found on flowering plants, especially those in the
genus of
meadowsweets
. Varied carpet beetles occupy nests of birds, such as sparrows and swallows, and
bat roosts. Primarily a household pest, indoor populations are found in stored food
materials, plant materials (dried fruit and nuts), and animal materials (wool, fur,
skins). They are commonly found in dried-milk factories, and less frequently in flour
mills and various warehouses. They occur in wasp nests in attics and under the siding
of homes.
Eggs and larvae are found on animal materials, such as wool, skin, or fur, or in the
nests of birds, such as
sparrows
,
starlings
,
corvids
,
swifts
, and in
bat
roosts. Larvae are known to be on dried insect collections and
silkworm moth
cocoons.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- forest
- Other Habitat Features
- urban
- suburban
- agricultural
Physical Description
Adult varied carpet beetles range in length from 2-3 mm. The body is rounded with
an irregular pattern of color. The dorsal surface is covered in fine scales of brownish-yellow,
white, and black color. The white scales form patterns that partly merge to form three
wavy transverse bands. The underside has scales of greyish-yellow color. Adult varied
carpet beetles have wings.
Varied carpet beetles are distinct from other beetles in their genus (
Anthrenus
) in having 11-segmented antenna and in having body scales more than twice as long
as wide. They can be differentiated from the 11-segmented antennae
common carpet beetles
by the width and length of the scales.
Full-grown larval beetles range in length from 4-5 mm and present tufts of setae.
Larvae have elongated bodies with a narrow front and broad rear. The setae form light-
and dark-brown transverse stripes across the body. Dense setae cover each side of
the posterior end.
- Other Physical Features
- ectothermic
- bilateral symmetry
Development
Eggs are laid individually or in batches. Hatching times are dependent on temperature,
lasting 30–35 days at 18 ◦C and decreasing to 10–12 days at 29 ◦C. Larval development
is affected by temperature, relative humidity, and food quality; typically taking
222-323 days at a temperature between 15–25 ◦C. The last larval skin serves as the
pupal case for pupation; adults remain inactive for 1-8 days before emerging from
the case. The pupal period lasts 17–19 days at 18 ◦C and decreases with increasing
temperature to 7–8 days at 29 ◦C. Adults live and reproduce 20-60 days after emerging
from pupation.
Pupation occurs in a circannual rhythm. The periodicity of pupation is dependent on
the temperature and environment. Diapause depends on temperature; one diapause occurs
at 25 â—¦C with complete development in one year, while two diapause stages occur at
15 â—¦C with a life cycle of 2 years. Household varied carpet beetles produce adults
in the fall, while outdoor populations produce adults in the spring.
Metamorphosis happens around the same time each year. The specific time it happens
depends on the temperature and environment. Household adult carpet beetles produce
adults in the fall. Field populations produce adults in the spring.
- Development - Life Cycle
- metamorphosis
- diapause
Reproduction
Copulation can last from 1-9 minutes. Males and females take multiple mates.
- Mating System
- polygynandrous (promiscuous)
Varied carpet beetles live and reproduce for 20-60 days after emerging from pupation
in spring to early summer. Adult varied carpet beetles from outdoor populations have
an attraction to light and mate on the plants they feed on. Those from indoor populations
have a positive attraction to light only near the end of their oviposition period.
Adult beetles do not require food or water to reproduce. The fecundity of beetles
is around 100 eggs. Eggs are laid individually or in batches.
- Key Reproductive Features
- semelparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- oviparous
No parental involvement occurs.
- Parental Investment
- no parental involvement
Lifespan/Longevity
The life cycle of varied carpet beetles ranges from 1-2 years depending on temperatures.
Low temperatures extend the length of the larval development cycle and pupation. Similarly,
high temperatures shorten the time spent in development. Outdoor populations tend
towards longer lifespans due to the impact of winter temperatures on their rate of
development.
Behavior
Varied carpet beetles live in colonies. Indoor colonies can get into stores of food.
Adults can fly, but they like to stay close to their homes.
Communication and Perception
Varied carpet beetles use their sense of sight, touch, and chemical receptors to get
information. They use pheromones to find mates.
- Communication Channels
- chemical
- Other Communication Modes
- pheromones
Food Habits
Indoor populations feed on stored food materials, such as wheat, maize, oats, rice,
biscuits, cakes, seeds, cayenne pepper, cacao, and dried cheese. They also feed on
wool, fur, skins, and are known to feed on insect collections and
silkworm
cocoons. Outdoor populations of adult varied carpet beetles feed primarily on pollen
and nectar from the
meadowsweet
genus, but also from the
hogweed
,
chervil
,
ground elder
,
umbellifer
,
yarrow
,
chamomile
genera, and the
daisy
family.
- Animal Foods
- insects
- Plant Foods
- seeds, grains, and nuts
- fruit
- pollen
- flowers
Predation
Adult parasitoid wasps in the family
Bethylidae
are predators of varied carpet beetles.
Adult wasps in the family
Bethylidae
are predators of varied carpet beetles.
Ecosystem Roles
Adult varied carpet beetles are pollinators of the species of plants they feed and
mate on. Parasitic wasps (
Bethylidae
) have been recorded.
- Ecosystem Impact
- pollinates
- Parasitic wasps in the Bethylidae family
Economic Importance for Humans: Positive
Varied carpet beetles are a pollinator of flowering plants.
- Positive Impacts
- pollinates crops
Economic Importance for Humans: Negative
Varied carpet beetles are a well-known household pest. They are known to infest factories,
museums, and warehouses. Often feeding on dried food stores and animal products,
they destroy household goods.
- Negative Impacts
- household pest
Conservation Status
Additional Links
Contributors
Deena Hauze (author), Animal Diversity Web Staff.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- Palearctic
-
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- oriental
-
found in the oriental region of the world. In other words, India and southeast Asia.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- cosmopolitan
-
having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- urban
-
living in cities and large towns, landscapes dominated by human structures and activity.
- suburban
-
living in residential areas on the outskirts of large cities or towns.
- agricultural
-
living in landscapes dominated by human agriculture.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- metamorphosis
-
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
- diapause
-
a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- semelparous
-
offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- internal fertilization
-
fertilization takes place within the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- colonial
-
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
- chemical
-
uses smells or other chemicals to communicate
- pheromones
-
chemicals released into air or water that are detected by and responded to by other animals of the same species
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- herbivore
-
An animal that eats mainly plants or parts of plants.
- folivore
-
an animal that mainly eats leaves.
References
Abdel-Dayem, M., H. Fad, A. El-Torkey, A. Elgharbawy, Y. Aldryhim, B. Kondratieff, A. Al Ansi, H. Aldhafer. 2017. The beetle fauna (Insecta, Coleoptera) of the Rawdhat Khorim National Park, Central Saudi Arabia. ZooKeys , 653: 1-78. Accessed April 26, 2020 at https://zookeys.pensoft.net/article/10252/list/9/ .
Blake, G. 1958. Diapause and the Regulation of Development in Anthrenus verbasci (L.) (Col., Dermestidae). Bulletin of Entomological Research , 49(4): 751-775.
Blake, G. 1961. Length of life, fecundity and the oviposition cycle in Anthrenus verbasci (L.) (Col., Dermestidae) as affected by adult diet.. Bulletin of Entomological Research , 52(3): 459-472.
Bousquet, Y. 1990. Beetles Associated with Stored Products in Canada: An identification guide . Ottawa: Research Branch Agriculture Canada, Publication 1837.
Majka, C. 2007. The Derodontidae, Dermestidae, Bostrichidae, and Anobiidae of the Maritime Provinces of Canada (Coleoptera: Bostrichiformia). Zootaxa , 1573: 1-38. Accessed April 26, 2020 at https://www.researchgate.net/publication/228385936_The_Derodontidae_Dermestidae_Bostrichidae_and_Anobiidae_of_the_Maritime_Provinces_of_Canada_Coleoptera_Bostrichiformia .
Mayer, M. 2019. Handbook of Insect Pheromones and Sex Attractants . Boca Raton: CRC Press.
Miyazaki, Y., T. Nisimura, H. Numata. 2009. A circadian system is involved in photoperiodic entrainment of the circannual rhythm of Anthrenus verbasci. Journal of Insect Physiology , 55 (4): 494-498. Accessed April 26, 2020 at https://doi.org/10.1016/j.jinsphys.2008.12.003 .
Robinson, W. 2005. Urban Insects and Arachnids: A Handbook of Urban Entomology . Cambridge: Cambridge University Press. Accessed April 24, 2020 at http://www.bio-nica.info/biblioteca/Robinson2005UrbanInsects.pdf .
Shetlar, D. 2011. "Carpet Beetles" (On-line). Ohioline. Accessed April 24, 2020 at https://ohioline.osu.edu/factsheet/HYG-2103-10 .
Wojcik, D. 1969. Mating Behavior of 8 Stored-Product Beetles (Coleoptera: Dermestidae, Tenebrionidae, Cucujidae, and Curculionidae). Florida Entomologist , 52(3): 174-176. Accessed April 29, 2020 at https://journals.flvc.org/flaent/article/view/56506/54185 .