Emerald cockroach wasp
Encyclopedia
The emerald cockroach wasp or jewel wasp (Ampulex compressa) is a solitary wasp
of the family
Ampulicidae
. It is known for its unusual reproductive behavior
, which involves stinging a cockroach
and using it as a host for its larva
e. It thus belongs to the entomophagous parasite
s.
, Africa
and the Pacific islands
. The flying wasps are more abundant in the warm seasons of the year.
A. compressa was introduced to Hawaii
by F.X. Williams in 1941 as a method of biocontrol
. This has been unsuccessful because of the territorial tendencies of the wasp, and the small scale on which they hunt.
.
demonstrated that the wasp stings precisely into specific ganglia
of the roach. It delivers an initial sting to a thoracic
ganglion and injects venom to mildly and reversibly paralyze
the front legs of its victim. The biochemical basis of this transient paralysis is discussed in a 2006 paper. Temporary loss of mobility in the roach facilitates the second venomous sting at a precise spot in the victims's head ganglia (brain
), in the section that controls the escape reflex
. As a result of this sting, the roach will first groom extensively, and then become sluggish and fail to show normal escape responses. In 2007 it was reported that the venom of the wasp blocks receptors for the neurotransmitter
octopamine
.
The wasp proceeds to chew off half of each of the roach's antenna
e. Researchers believe that the wasp chews off the antenna to replenish fluids or possibly to regulate the amount of venom because too much could kill and too little would let the victim recover before the larva has grown.
The wasp, which is too small to carry the roach, then leads the victim to the wasp's burrow
, by pulling one of the roach's antennae in a manner similar to a leash. Once they reach the burrow, the wasp lays a white egg, about 2 mm long, on the roach's abdomen
. It then exits and proceeds to fill in the burrow entrance with pebbles, more to keep other predators out than to keep the roach in.
With its escape reflex disabled, the stung roach will simply rest in the burrow as the wasp's egg hatches after about three days. The hatched larva lives and feeds for 4–5 days on the roach, then chews its way into its abdomen and proceeds to live as an endoparasitoid. Over a period of eight days, the wasp larva consumes the roach's internal organs
in an order which maximizes the likelihood that the roach will stay alive, at least until the larva enters the pupa
l stage and forms a cocoon inside the roach's body. Eventually the fully grown wasp emerges from the roach's body to begin its adult life. Development is faster in the warm season.
Adults live for several months. Mating takes about one minute, and only one mating is necessary for a female wasp to successfully parasitize several dozen roaches.
While a number of venomous animals paralyze prey as live food for their young, Ampulex compressa is different in that it initially leaves the roach mobile and modifies its behavior in a unique way.
Several other species of the genus Ampulex
show a similar behavior of preying on cockroaches. The wasp's predation appears only to affect the cockroach's escape responses. Research has shown that while a stung roach exhibits drastically reduced survival instincts (such as swimming, or avoiding pain) for approximately 72 hours, motor abilities like flight or flipping over are unimpaired.
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...
of the family
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...
Ampulicidae
Ampulicidae
The Ampulicidae, or Cockroach wasps, is a small , primarily tropical group of sphecoid wasps, all of which use various cockroaches as prey items for their larvae. They tend to have elongated jaws, a pronounced neck-like constriction behind the head, a strongly petiolate abdomen, and deep grooves on...
. It is known for its unusual reproductive behavior
Biological reproduction
Reproduction is the biological process by which new "offspring" individual organisms are produced from their "parents". Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction...
, which involves stinging a cockroach
Cockroach
Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...
and using it as a host for its 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. It thus belongs to the entomophagous parasite
Entomophagous parasite
Entomophagous parasites are insects that are parasitic on other insects. Nearly all insects are attacked by one or more insect parasites. This parasitic mode of life is most often confined to the larvae with the adults usually leading free lives...
s.
Distribution
The wasp is mostly found in the tropical regions of South AsiaSouth Asia
South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...
, Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
and the Pacific islands
Pacific Islands
The Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....
. The flying wasps are more abundant in the warm seasons of the year.
A. compressa was introduced to Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
by F.X. Williams in 1941 as a method of biocontrol
BioControl
BioControl is a peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of basic and applied research in biological control of invertebrate, vertebrate, and weed pests, and plant diseases. The journal was established in 1956 as Entomophaga and published by...
. This has been unsuccessful because of the territorial tendencies of the wasp, and the small scale on which they hunt.
Appearance
The wasp has a metallic blue-green body, with the thighs of the second and third pair of legs red. The female is about 22 mm long; the male is smaller and lacks a stingerStinger
-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:...
.
Reproductive behavior and life cycle
As early as the 1940s it was reported that female wasps of this species sting a roach (specifically a Periplaneta americana, Periplaneta australasiae or Nauphoeta rhombifolia) twice, delivering venom. A 2003 study using radioactive labelingRadioactive tracer
A radioactive tracer, also called a radioactive label, is a substance containing a radioisotope that is used to measure the speed of chemical processes and to track the movement of a substance through a natural system such as a cell or tissue...
demonstrated that the wasp stings precisely into specific ganglia
Ganglion
In anatomy, a ganglion is a biological tissue mass, most commonly a mass of nerve cell bodies. Cells found in a ganglion are called ganglion cells, though this term is also sometimes used to refer specifically to retinal ganglion cells....
of the roach. It delivers an initial sting to a thoracic
Thorax (insect anatomy)
The thorax is the mid section of the insect body. It holds the head, legs, wings and abdomen. It is also called mesosoma in other arthropods....
ganglion and injects venom to mildly and reversibly paralyze
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
the front legs of its victim. The biochemical basis of this transient paralysis is discussed in a 2006 paper. Temporary loss of mobility in the roach facilitates the second venomous sting at a precise spot in the victims's head ganglia (brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
), in the section that controls the escape reflex
Escape reflex
Escape reflex, a kind of escape response, is a simple reflectory reaction in response to stimuli indicative of danger, that initiates an escape motion of an animal....
. As a result of this sting, the roach will first groom extensively, and then become sluggish and fail to show normal escape responses. In 2007 it was reported that the venom of the wasp blocks receptors for the neurotransmitter
Neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...
octopamine
Octopamine
Octopamine is an endogenous biogenic amine that is closely related to norepinephrine, and has effects on the adrenergic and dopaminergic systems. It is also found naturally in numerous plants, including bitter orange. Biosynthesis of the D--enantiomer of octopamine is by β-hydroxylation of...
.
The wasp proceeds to chew off half of each of the roach's antenna
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
e. Researchers believe that the wasp chews off the antenna to replenish fluids or possibly to regulate the amount of venom because too much could kill and too little would let the victim recover before the larva has grown.
The wasp, which is too small to carry the roach, then leads the victim to the wasp's burrow
Burrow
A burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...
, by pulling one of the roach's antennae in a manner similar to a leash. Once they reach the burrow, the wasp lays a white egg, about 2 mm long, on the roach's abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
. It then exits and proceeds to fill in the burrow entrance with pebbles, more to keep other predators out than to keep the roach in.
With its escape reflex disabled, the stung roach will simply rest in the burrow as the wasp's egg hatches after about three days. The hatched larva lives and feeds for 4–5 days on the roach, then chews its way into its abdomen and proceeds to live as an endoparasitoid. Over a period of eight days, the wasp larva consumes the roach's internal organs
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
in an order which maximizes the likelihood that the roach will stay alive, at least until the larva enters the 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...
l stage and forms a cocoon inside the roach's body. Eventually the fully grown wasp emerges from the roach's body to begin its adult life. Development is faster in the warm season.
Adults live for several months. Mating takes about one minute, and only one mating is necessary for a female wasp to successfully parasitize several dozen roaches.
While a number of venomous animals paralyze prey as live food for their young, Ampulex compressa is different in that it initially leaves the roach mobile and modifies its behavior in a unique way.
Several other species of the genus Ampulex
Ampulex
Ampulex is a genus of wasps belonging to the family Ampulicidae.- Species :*Ampulex compressa Fabricius, 1781 – jewel wasp or emerald cockroach wasp)*Ampulex fasciata Jurine, 1807*Ampulex canaliculata Say, 1823...
show a similar behavior of preying on cockroaches. The wasp's predation appears only to affect the cockroach's escape responses. Research has shown that while a stung roach exhibits drastically reduced survival instincts (such as swimming, or avoiding pain) for approximately 72 hours, motor abilities like flight or flipping over are unimpaired.
See also
- GlyptapantelesGlyptapantelesGlyptapanteles is a genus of endoparasitoid wasp found in Central and North America. The larvae of the members of Glyptapanteles sp. are distinguished by their ability to manipulate their hosts into serving as bodyguards.-Reproduction:...
, a genus of wasp capable of inducing caterpillars to guard its pupae. - Hymenoepimecis argyraphagaHymenoepimecis argyraphagaHymenoepimecis argyraphaga is a Costa Rican parasitoid wasp whose host is the spider Plesiometa argyra. The wasp is unique in modifying the spider's web building behavior to make a web made of very strong lines designed to support the wasp's cocoon without breaking in the rain.-Reproduction:The...
, a species of wasp that affects the web-building behavior of spiders to its own ends. - Tarantula hawkTarantula hawkA tarantula hawk is a spider wasp which hunts tarantulas as food for its larvae. Tarantula hawks belong to any of the many species in the genera Pepsis and Hemipepsis in the family Pompilidae ....
External links
- Images of Emerald Cockroach Wasps, from MorphBank biological image database
- Video of An Emerald Wasp Enslaving A Cockroach, via EducatedEarth