Mutillidae
Encyclopedia
Mutillidae are a family
of more than 3,000 species of wasp
whose wingless female
s resemble ant
s. Their common name
velvet ant refers to their dense pile of hair which most often is bright scarlet or orange but may also be black, white, silver, or gold. Their bright colours serve as aposematic signals. They are known for their extremely painful sting
, facetiously said to be strong enough to kill a cow, hence the common name cow killer or cow ant is applied to some species. Unlike a real ant
, they do not have drones, workers, and queens. However, velvet ants do exhibit haplodiploid sex determination similar to other members of Vespoidea
(JH Hunt 1999).
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The exoskeleton of all velvet ants is unusually tough (to the point that some entomologists have reported difficulty piercing them with steel pins when attempting to mount them for display in cabinets). This characteristic allows them to successfully invade the nests of their prey and also helps them retain moisture. Like related families in the Vespoidea
, males have wings but females uniformly are wingless. They exhibit extreme sexual dimorphism
; the males and females are so different that it is almost impossible to associate the two sexes of a species unless they are captured while mating. In a few species the male is so much larger than the female that he carries her aloft while mating, which is also seen in the related family Tiphiidae
.
In mutillids, as in all Hymenoptera
, only the female is capable of inflicting a sting because the stinger itself is a modified female organ called an ovipositor
-- female mutillids have unusually long and maneuverable stingers. In both sexes a structure called a stridulitrum
on the metasoma
is used to produce a squeaking or chirping sound when alarmed. Both sexes of mutillids also bear hair-lined grooves on the side of the metasoma
called felt lines. Only one other vespoid family, the Bradynobaenidae
, has felt lines, but the females have a distinct pronotum and an elongated ant-like petiole
.
(1963) hypothesized that Mutillidae are generally stenothermic
and thermophilic; they may not avoid light but rather are active during temperatures which usually occur only after sunset.
The male locates a female on the wing and mates. The female then enters an insect nest, typically a ground-nesting bee such as a bumblebee or wasp nest, and deposits one egg near each larva
or pupa
. Her young then develop as idiobiont ectoparasitoids
, eventually killing their immobile larval/ pupal hosts within a matter of days.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of more than 3,000 species 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...
whose wingless female
Female
Female is the sex of an organism, or a part of an organism, which produces non-mobile ova .- Defining characteristics :The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male...
s resemble ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s. Their common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
velvet ant refers to their dense pile of hair which most often is bright scarlet or orange but may also be black, white, silver, or gold. Their bright colours serve as aposematic signals. They are known for their extremely painful sting
Stinger
-Biology:* Stinger, an organ or body part found in various animals that usually delivers some kind of venom.* Stinger , a minor neurological injury suffered by athletes.-Sports and entertainment:...
, facetiously said to be strong enough to kill a cow, hence the common name cow killer or cow ant is applied to some species. Unlike a real ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
, they do not have drones, workers, and queens. However, velvet ants do exhibit haplodiploid sex determination similar to other members of Vespoidea
Vespoidea
Vespoidea is a superfamily of order Hymenoptera of class Insecta, although older taxonomic schemes may vary in this categorization, particularly in their recognition of a now-obsolete superfamily Scolioidea...
(JH Hunt 1999).
Description
Vespoidea
Vespoidea is a superfamily of order Hymenoptera of class Insecta, although older taxonomic schemes may vary in this categorization, particularly in their recognition of a now-obsolete superfamily Scolioidea...
, males have wings but females uniformly are wingless. They exhibit extreme sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
; the males and females are so different that it is almost impossible to associate the two sexes of a species unless they are captured while mating. In a few species the male is so much larger than the female that he carries her aloft while mating, which is also seen in the related family Tiphiidae
Tiphiidae
Tiphiidae is a family of large solitary wasps whose larvae are almost universally parasitoids of various beetle larvae, especially those in the superfamily Scarabaeoidea....
.
In mutillids, as in all Hymenoptera
Hymenoptera
Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...
, only the female is capable of inflicting a sting because the stinger itself is a modified female organ called an ovipositor
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
-- female mutillids have unusually long and maneuverable stingers. In both sexes a structure called a stridulitrum
Stridulation
Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fishes, snakes and spiders...
on the 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...
is used to produce a squeaking or chirping sound when alarmed. Both sexes of mutillids also bear hair-lined grooves on the side of the 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...
called felt lines. Only one other vespoid family, the Bradynobaenidae
Bradynobaenidae
Bradynobaenidae is a family of wasps similar to the Mutillidae. These species are often found in arid regions.- Genera found in Europe :* Apterogyna Latreille, 1809* Gynecaptera Skorikov, 1935- Other genera :* Bradynobaenus Spinola, 1851...
, has felt lines, but the females have a distinct pronotum and an elongated ant-like petiole
Petiole (insect)
In entomology, the term petiole is most commonly used to refer to the constricted first metasomal segment of members of the Hymenopteran suborder Apocrita; it may be used to refer to other insects with similar body shapes, where the metasomal base is constricted...
.
Behavior
Mature mutillids feed on nectar. Although some species are strictly nocturnal, female mutillids are often active during the day. Females of Tricholabiodes thisbe are sometimes active up to two hours before sunset. Guido NonveillerGuido Nonveiller
Guido Nonveiller was a Croatian entomologist, FAO expert and professor at the University of Belgrade. He fought in the International Brigades and French Forces of the Interior during WW2. In 1989 he was inducted as a Commander of the l'Ordre des Palmes Académiques...
(1963) hypothesized that Mutillidae are generally stenothermic
Stenothermic
Stenothermic Adj. refers to a type of stenotherm; a species or living organism only capable of living or surviving within a narrow temperature range. See also Ecotope. Cf. Eurytherm....
and thermophilic; they may not avoid light but rather are active during temperatures which usually occur only after sunset.
Life cycle
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
or pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
. Her young then develop as idiobiont ectoparasitoids
Parasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...
, eventually killing their immobile larval/ pupal hosts within a matter of days.
Range
The 3,000-5,000 species of mutillidae occur worldwide, mainly in the dry tropics. They are especially common, however, in desert and sandy areas, with most of the over 400 North American species found in the southwestern United States and adjacent parts of Mexico, with others found in generally sandy regions throughout the United States and Canada.External links
- Velvet Ant (Cow Killer) Fact Sheet
- Cow Killer at the University of Nebraska-Lincoln Extension in Lancaster County, NebraskaLancaster County, Nebraska-Demographics:As of the census of 2000, there were 250,291 people, 99,187 households, and 60,702 families residing in the county. The population density was 298 people per square mile . There were 104,217 housing units at an average density of 124 per square mile...
- Mutillidae at BugGuide.Net
- Mutillidae at the University of FloridaUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
Institute of Food and Agricultural SciencesInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information... - Mutillidae at Texas A&M UniversityTexas A&M UniversityTexas A&M University is a coeducational public research university located in College Station, Texas . It is the flagship institution of the Texas A&M University System. The sixth-largest university in the United States, A&M's enrollment for Fall 2011 was over 50,000 for the first time in school...