Spider wasp
Encyclopedia
Wasps in the family Pompilidae are commonly called spider wasps (in South America
, species may be referred to colloquially as marabunta or marimbondo, though these names can be generally applied to any very large stinging wasps). The family is cosmopolitan
, with some 5,000 species in 6 subfamilies. All species are solitary, and most capture and paralyze prey, though members of the subfamily Ceropalinae are cleptoparasites of other pompilids, or ectoparasitoids
of living spiders.
Pompilids typically have a slender body with long, spiny legs and the hind femur is often long enough to reach past the tip of the abdomen. The tibiae of the rear legs usually have a conspicuous spine at their distal end. The first two segments of the abdomen being narrowed characterize the slender look of their body. The Pompilid body is typically dark (black or blue, sometimes with metallic reflections), but many brightly colored species exist. From a lateral view, its pronotum looks rectangular and it extends back to the tegulae, near the base of the wings. Most species are macropterous (having long wings), but a few brachypterous (short-winged) and apterous (no wings) are known.
Spider wasps are best distinguished from other vespoid wasp
s in having (in most species) a transverse groove dividing the mesopleuron
(the mesepisternal sclerite, a region on the side of middle segment of the thorax above the point where the legs join) into halves. Like other Vespoidea they have antennae with 10 flagellomeres in the female and 11 in the male. Most Pompilidae have the inner margin of the eye straight. The hind wings do not have a distinct claval lobe but they have a distinctive jugal lobe. The hind leg has a tibial spur with a tuft or row of fine hairs. The legs are long and slender with the tips of the tibia (metatibia) long enough to extend beyond the tip of the abdomen (metasoma). Sexual dimorphism is not marked although females are often larger than the males, with coloring and wing appearance varying greatly among the many species, though black is the most common color, with contrasting aposematic markings of orange, red, yellow, or white also being fairly common. Larva
e can also be identified by physical examination.
Spider wasps are long-legged, solitary wasps that use a single spider as a host for feeding their larva
e. They paralyze the spider with a venomous stinger
. Once paralyzed, the spider is dragged to where a nest will be built some wasps having already made a nest.
A single egg is laid on the abdomen of the spider, and the nest or burrow is closed.
The size of the host can influence whether the wasp will lay an egg that will develop as a male, or an egg that will develop into a female larger prey yielding the (larger) females.Spider predators and parasites. Iziko Museums of Cape Town. www.museums.org.za. Retrieved 28 November 2006. A complex set of adult behavior can then occur, such as spreading dirt or inspecting the area, leaving the nest site inconspicuous. When the wasp larva hatches it begins to feed on the still-living spider. After consuming the edible parts of the spider, the larva spins a silk cocoon and pupa
tes usually emerging as an adult the next summer. Some ceropalines lay the egg on a still-active spider, where it feeds externally on hemolymph
. In time, that spider will die, and the mature wasp larva will then pupate.
As mentioned above, Pompilidae gets its common name, “Spider Wasps,” from the their notable behavior of hunting and killing spiders, often larger than themselves, as food for their larvae. They provide each of their larvae with a single prey item/ host, which must be large enough to serve as its food source throughout its development. It has been shown in Pepsis thisbe of the southwestern United States that there is a direct correlation between adult wasp body length and the weight of its host spider, Aphonopelma echina. Because the size of a P. thisbe adult is determined by the size of the host that was provided for it by its mother, it is implied that the seasonal frequency of host sizes will determine the size variation in adult wasps.
Because of the large body size of their prey, pompilids usually will either construct burrows near the site of attack or use the host’s own burrow or tunnel. The paralyzed spider is concealed in a burrow so that the pompilid larva can develop without disruption by other parasites or scavengers. Some pompilids only temporarily paralyze their host, which regains activity before being killed by the maturing wasp larva.
In another study on Pepsis thisbe, it was shown that chemosensory cues are used to detect its specific host. This study concluded that specific chemosensory cues attract the wasp to its prey, Aphonopelma echina, despite other host spiders of the same size and frequency being present.
In studies on Pepsis formosa , a pompilid of the southwestern United States, it was shown that the wasps had behavioral plasticity. Their hunting behavior concerning their host Rhechostica echina improved with experience. The time required completing all behavioral components decreased with each spider killed.
Concerning mating behavior, males acquire perch territories to scan for incoming receptive females. In studies on the tarantula wasp Hemipepsis ustulata, it was shown that larger males are more likely to acquire perch territories and that territorial males appear to increase their chances of mating because receptive females fly to perch sites held by said males.
and then enclose the spider in the burrow. The egg will hatch and the larva will feed on the spider, breaking through the integument with its mandibles. The larva has 5 instar
stages before it pupates, where there are no major morphological differences between the first 4 instars, with the exception of size. At the conclusion of the final instar, the larva will spin a silky cocoon where it will emerge as an adult either later in the same summer season or will overwinter, depending on the species and the time of year the larva pupates.
Adult Pompilidae are nectar-feeding insects and feed on a variety of plants. The female wasps search for a variety of spiders for their larva to feed on, including wolf spiders (Lycosidae), huntsman spiders (Sparassidae), and baboon spiders (Harpactirinae). As the larva feeds on its host, it saves the vital organs, such as the heart and central nervous system, for last. By waiting until the final larva instar, it ensures that the spider will not decompose before the larva has fully developed.
. This index runs from 0 to 4, where a 0 is given to a sting from an insect that can not break through human skin, a 2 is given for intermediate pain, and a 4 is given for intense pain. The scale rates stings from 78 different species in 42 different genera. Spider Wasps of the genera Pepsis, also known as Tarantula Hawks, have a sting rating of 4.0. The sting is described as "blinding, fierce, shockingly electric. A running hair drier has been dropped into your bubble bath" Only the bite of the Bullet Ant, Paraponera clavata, is ranked higher, with a 4.0+ rating.
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, species may be referred to colloquially as marabunta or marimbondo, though these names can be generally applied to any very large stinging wasps). The family is cosmopolitan
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
, with some 5,000 species in 6 subfamilies. All species are solitary, and most capture and paralyze prey, though members of the subfamily Ceropalinae are cleptoparasites of other pompilids, or 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...
of living spiders.
Morphology
Like other strong fliers, the thorax of Pompilidae is modified for efficient flight. The mesothorax is solidly fused to the pronotum and metathorax; Moreover, the prothorax is best developed in families such as Pompilidae and Scoliidae because they use their forelegs to dig.Pompilids typically have a slender body with long, spiny legs and the hind femur is often long enough to reach past the tip of the abdomen. The tibiae of the rear legs usually have a conspicuous spine at their distal end. The first two segments of the abdomen being narrowed characterize the slender look of their body. The Pompilid body is typically dark (black or blue, sometimes with metallic reflections), but many brightly colored species exist. From a lateral view, its pronotum looks rectangular and it extends back to the tegulae, near the base of the wings. Most species are macropterous (having long wings), but a few brachypterous (short-winged) and apterous (no wings) are known.
Spider wasps are best distinguished from other vespoid 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...
s in having (in most species) a transverse groove dividing the mesopleuron
Pleuron (insect)
The pleuron is a lateral sclerite of thoracic segment of an insect between the tergum and the sternum. The terms pro-, meso- and metapleuron are used respectively for the pleura of the first, second and third thoracic segments....
(the mesepisternal sclerite, a region on the side of middle segment of the thorax above the point where the legs join) into halves. Like other Vespoidea they have antennae with 10 flagellomeres in the female and 11 in the male. Most Pompilidae have the inner margin of the eye straight. The hind wings do not have a distinct claval lobe but they have a distinctive jugal lobe. The hind leg has a tibial spur with a tuft or row of fine hairs. The legs are long and slender with the tips of the tibia (metatibia) long enough to extend beyond the tip of the abdomen (metasoma). Sexual dimorphism is not marked although females are often larger than the males, with coloring and wing appearance varying greatly among the many species, though black is the most common color, with contrasting aposematic markings of orange, red, yellow, or white also being fairly common. Larva
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...
e can also be identified by physical examination.
Spider wasps are long-legged, solitary wasps that use a single spider as a host for feeding their larva
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...
e. They paralyze the spider with a venomous stinger
Stinger (organ)
A sting, sometimes called a stinger in the US, is a sharp organ or body part found in various animals that delivers some kind of venom . A true sting differs from other piercing structures in that it pierces by its own action and injects venom, as opposed to teeth, which pierce by the force of...
. Once paralyzed, the spider is dragged to where a nest will be built some wasps having already made a nest.
The size of the host can influence whether the wasp will lay an egg that will develop as a male, or an egg that will develop into a female larger prey yielding the (larger) females.Spider predators and parasites. Iziko Museums of Cape Town. www.museums.org.za. Retrieved 28 November 2006. A complex set of adult behavior can then occur, such as spreading dirt or inspecting the area, leaving the nest site inconspicuous. When the wasp larva hatches it begins to feed on the still-living spider. After consuming the edible parts of the spider, the larva spins a silk cocoon and 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...
tes usually emerging as an adult the next summer. Some ceropalines lay the egg on a still-active spider, where it feeds externally on hemolymph
Hemolymph
Hemolymph, or haemolymph, is a fluid in the circulatory system of some arthropods and is analogous to the fluids and cells making up both blood and interstitial fluid in vertebrates such as birds and mammals...
. In time, that spider will die, and the mature wasp larva will then pupate.
Ecology & Behavior
Currently, Pompilidae is split unequally into six subfamilies throughout most of the world. Ceropalinae and Notocyphinae contain two genera each and occur in Central and South America and the Oriental region. Epipompilinae contains a single genus and occurs in the Neotropics, the Australasian region, and the Afrotropical region. Ctenocerinae contains two genera in the Neotropics, four in Australia and 11 in Africa. Pepsinae and Pompilinae are the most diverse and the remaining genera are split between them.As mentioned above, Pompilidae gets its common name, “Spider Wasps,” from the their notable behavior of hunting and killing spiders, often larger than themselves, as food for their larvae. They provide each of their larvae with a single prey item/ host, which must be large enough to serve as its food source throughout its development. It has been shown in Pepsis thisbe of the southwestern United States that there is a direct correlation between adult wasp body length and the weight of its host spider, Aphonopelma echina. Because the size of a P. thisbe adult is determined by the size of the host that was provided for it by its mother, it is implied that the seasonal frequency of host sizes will determine the size variation in adult wasps.
Because of the large body size of their prey, pompilids usually will either construct burrows near the site of attack or use the host’s own burrow or tunnel. The paralyzed spider is concealed in a burrow so that the pompilid larva can develop without disruption by other parasites or scavengers. Some pompilids only temporarily paralyze their host, which regains activity before being killed by the maturing wasp larva.
In another study on Pepsis thisbe, it was shown that chemosensory cues are used to detect its specific host. This study concluded that specific chemosensory cues attract the wasp to its prey, Aphonopelma echina, despite other host spiders of the same size and frequency being present.
In studies on Pepsis formosa , a pompilid of the southwestern United States, it was shown that the wasps had behavioral plasticity. Their hunting behavior concerning their host Rhechostica echina improved with experience. The time required completing all behavioral components decreased with each spider killed.
Concerning mating behavior, males acquire perch territories to scan for incoming receptive females. In studies on the tarantula wasp Hemipepsis ustulata, it was shown that larger males are more likely to acquire perch territories and that territorial males appear to increase their chances of mating because receptive females fly to perch sites held by said males.
Life Cycle & Diet
Unlike many other families in the order Hymenoptera, wasps in this family are solitary and nest alone. A female wasp will search the ground and tree trunks for a spider and upon finding the spider will sting it, paralyzing the spider. Once the spider is paralyzed, the female wasp will make a burrow or take the spider to a previously made burrow. The female wasp will lay one single egg on the abdomen of the spider using its ovipositorOvipositor
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...
and then enclose the spider in the burrow. The egg will hatch and the larva will feed on the spider, breaking through the integument with its mandibles. The larva has 5 instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
stages before it pupates, where there are no major morphological differences between the first 4 instars, with the exception of size. At the conclusion of the final instar, the larva will spin a silky cocoon where it will emerge as an adult either later in the same summer season or will overwinter, depending on the species and the time of year the larva pupates.
Adult Pompilidae are nectar-feeding insects and feed on a variety of plants. The female wasps search for a variety of spiders for their larva to feed on, including wolf spiders (Lycosidae), huntsman spiders (Sparassidae), and baboon spiders (Harpactirinae). As the larva feeds on its host, it saves the vital organs, such as the heart and central nervous system, for last. By waiting until the final larva instar, it ensures that the spider will not decompose before the larva has fully developed.
Schmidt Pain Index
In 1984, Joseph O. Schmidt, a researcher from Arizona, developed a Hymenopteran sting pain scale; what is now known as the Schmidt Sting Pain IndexSchmidt Sting Pain Index
The Schmidt Sting Pain Index is a pain scale rating the relative pain caused by different Hymenopteran stings. It is mainly the work of Justin O. Schmidt, an entomologist at the Carl Hayden Bee Research Center in Arizona...
. This index runs from 0 to 4, where a 0 is given to a sting from an insect that can not break through human skin, a 2 is given for intermediate pain, and a 4 is given for intense pain. The scale rates stings from 78 different species in 42 different genera. Spider Wasps of the genera Pepsis, also known as Tarantula Hawks, have a sting rating of 4.0. The sting is described as "blinding, fierce, shockingly electric. A running hair drier has been dropped into your bubble bath" Only the bite of the Bullet Ant, Paraponera clavata, is ranked higher, with a 4.0+ rating.