More Information

Additional Information

Anthrenus verbascivaried carpet beetle

By Deena Hauze

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. (Abdel-Dayem, et al., 2017; Bousquet, 1990; Majka, 2007; Robinson, 2005)

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. (Bousquet, 1990; Majka, 2007; Robinson, 2005)

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. (Bousquet, 1990; Majka, 2007; Robinson, 2005)

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. (Bousquet, 1990; Robinson, 2005; Shetlar, 2011)

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. (Bousquet, 1990; Robinson, 2005)

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. (Robinson, 2005; Shetlar, 2011)

  • Range length
    2 to 3 mm
    0.08 to 0.12 in

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. (Blake, 1961; Robinson, 2005)

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 ◦C with complete development in one year, while two diapause stages occur at 15 ◦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. (Miyazaki, et al., 2009; Robinson, 2005)

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. (Miyazaki, et al., 2009; Robinson, 2005)

Reproduction

Copulation can last from 1-9 minutes. Males and females take multiple mates. (Wojcik, 1969)

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. (Blake, 1958; Robinson, 2005)

  • Breeding interval
    Varied carpet beetles breed yearly.
  • Breeding season
    Varied carpet beetles breed in spring and early summer.
  • Range eggs per season
    50 (high)
  • Range gestation period
    4 to 35 days
  • Average gestation period
    18 days
  • Average time to independence
    0 minutes
  • Range age at sexual or reproductive maturity (female)
    1 to 2 years
  • Range age at sexual or reproductive maturity (male)
    1 to 2 years

No parental involvement occurs. (Robinson, 2005)

  • 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. (Blake, 1958; Robinson, 2005)

  • Range lifespan
    Status: wild
    2+ (high) years
  • Typical lifespan
    Status: wild
    1 to 2 years

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. (Robinson, 2005)

Communication and Perception

Varied carpet beetles use their sense of sight, touch, and chemical receptors to get information. They use pheromones to find mates. (Mayer, 2019; Wojcik, 1969)

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. (Majka, 2007; Robinson, 2005)

  • 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. (Robinson, 2005)

Adult wasps in the family Bethylidae are predators of varied carpet beetles. (Robinson, 2005)

  • Known Predators

Ecosystem Roles

Adult varied carpet beetles are pollinators of the species of plants they feed and mate on. Parasitic wasps (Bethylidae) have been recorded. (Robinson, 2005)

  • Ecosystem Impact
  • pollinates
Commensal/Parasitic Species

Economic Importance for Humans: Positive

Varied carpet beetles are a pollinator of flowering plants. (Robinson, 2005)

  • 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. (Bousquet, 1990; Robinson, 2005)

  • Negative Impacts
  • household pest

Conservation Status

Contributors

Deena Hauze (author), Animal Diversity Web Staff.

Glossary

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.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

agricultural

living in landscapes dominated by human agriculture.

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.

chemical

uses smells or other chemicals to communicate

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.

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.

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.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

internal fertilization

fertilization takes place within the female's body

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

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.

motile

having the capacity to move from one place to another.

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.

World Map

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

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.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

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.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

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.

Search

Navigation Links

Information
Classification

Classification