Traumatic insemination
Traumatic insemination, also known as hypodermic insemination, is the mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...

 practice in some species of invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s in which the male pierces the female's 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...

 with his penis and injects his sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...

 through the wound into her abdominal cavity (hemocoel). The sperm diffuse through the female's 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...

, reaching the ovaries and resulting in fertilization. The process is detrimental to the female's health. It creates an open wound which impairs the female until it heals, and is susceptible to infection. The injection of sperm and ejaculatory fluids
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...

 into the hemocoel can also trigger an immune reaction in the female. Bed bugs, which reproduce solely by traumatic insemination, have evolved a pair of sperm-receptacles, known as the spermalege
The spermalege is a special-purpose organ found in bed bugs that appears to have evolved to mitigate the effects of traumatic insemination. The spermalege has two embryologically distinct parts, known as the ectospermalege and mesospermalege...

. The spermalege reduce the damage to the female bed bug during traumatic insemination.

The evolutionary origins of traumatic insemination are disputed. Although it evolved independently
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...

 in many invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

 species, traumatic insemination is most highly adapted and thoroughly studied in bed bugs, particularly Cimex lectularius. Traumatic insemination is not limited to male-female couplings, or even couplings of the same species. Both homosexual and inter-species traumatic inseminations have been observed.


In humans and other complex life forms, blood and lymph
Lymph is considered a part of the interstitial fluid, the fluid which lies in the interstices of all body tissues. Interstitial fluid becomes lymph when it enters a lymph capillary...

 circulate in two different systems, the circulatory system
Circulatory system
The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...

 and lymphatic system
Lymphatic system
The lymphoid system is the part of the immune system comprising a network of conduits called lymphatic vessels that carry a clear fluid called lymph unidirectionally toward the heart. Lymphoid tissue is found in many organs, particularly the lymph nodes, and in the lymphoid follicles associated...

, which are enclosed by systems of capillaries
Capillaries are the smallest of a body's blood vessels and are parts of the microcirculation. They are only 1 cell thick. These microvessels, measuring 5-10 μm in diameter, connect arterioles and venules, and enable the exchange of water, oxygen, carbon dioxide, and many other nutrient and waste...

, vein
In the circulatory system, veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart...

s, arteries
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....

, and nodes
Lymph node
A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...

. This is known as a closed circulatory system. Insects, however, have an open circulatory system in which blood and lymph circulate unenclosed, and mix to form a substance called 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...

. All organs of the insect are bathed in hemolymph, which provides oxygen and nutrients to all of the insect's organs.

Following traumatic insemination, sperm can migrate through the hemolymph to the female's ovaries, resulting in fertilization. The exact mechanics vary from taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

 to taxon. In some orders of insects, the male genitalia (paramere
Parameres are part of the external reproductive organs of male insects and the term was first used by Verhoeff in 1893 for the lateral genital lobes in Coleoptera. The primary phallic lobes which appear in the nymph or larval stages may become a pair of penes in the Ephemeroptera or a simple...

) enters the female's genital tract, and a spine at its tip pierces the wall of the female's bursa copularix. In others, the male penetrates the outer body wall. In either case, following penetration, the male ejaculates
Ejaculation is the ejecting of semen from the male reproductory tract, and is usually accompanied by orgasm. It is usually the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. In rare cases ejaculation occurs because of prostatic disease...

 into the female. The sperm and ejaculatory fluids diffuse through the female's hemolymph. The insemination is successful if the sperm reach the ovaries and fertilize an ovum.

Female resistance to traumatic insemination varies from one species to another. Females from some genera, including Cimex, are passive prior to and during traumatic insemination. Females in other genera resist mating and attempt to escape. This resistance may not be an aversion to pain caused by the insemination, as observational evidence suggests that insects do not feel pain.

Research into the paternity of offspring produced by traumatic insemination has found "significant" last-sperm precedence. That is, the last male to traumatically inseminate a female tends to sire most of the offspring from that female.

Evolutionary adaptation

Many reasons for the evolutionary adaptation of traumatic insemination as a mating strategy have been suggested. One is that traumatic insemination is an adaptation to the development of the mating plug
Mating plug
right|thumbnail|A mating plug in a female [[Richardson's ground squirrel]] A mating plug, also known as a copulation plug, sperm plug, vaginal plug, or sphragis, is gelatinous secretion used in the mating of some species. It is deposited by a male into a female genital tract and later hardens into...

, a reproductive mechanism used by many species. Once a male finishes copulating, he injects a glutinous secretion into the female's reproductive tract, thereby "literally glu[ing] her genital tract closed". Traumatic insemination allows subsequent males to bypass the female's plugged genital tract, and inject sperm directly into her circulatory system.

Others have argued that the practice of traumatic insemination may have been an adaptation for males to circumvent female resistance to mating
Sexual conflict
Sexual conflict occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly the mode and frequency of mating, leading to an evolutionary arms race between males and females. The conflict encompasses the actions and behaviors of both sexes to influence...

 to eliminate courtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...

 time, allowing one male to inseminate many mates when contact between them is brief; or that it evolved as a new development in the sperm competition
Sperm competition
Sperm competition is a term used to refer to the competitive process between spermatozoa of two different males to fertilize an egg of a lone female. Competition occurs whenever females engage in promiscuous mating to increase their chances in producing more viable offspring...

 as a means to deposit sperm as close to the ovaries as possible.

This bizarre method of insemination probably evolved as male bed bugs competed with each other to place their sperm closer and closer to the mother lode of eggs, the ovaries. Some male insects evolved long penises with which they enter the vagina but bypass the female's storage pouch and deposit their sperm further upstream close to the ovaries. A few males, notably among bed bugs, evolved traumatic insemination instead, and eventually this strange procedure became the norm among these insects.

It has recently been discovered that members of the plant bug genus Coridromius (Miridae
The large and diverse insect family Miridae contains the plant bugs, leaf bugs, and grass bugs, and may also be known as capsid bugs. It is the largest family of true bugs belonging to the suborder Heteroptera, with over 10,000 known species and new ones constantly being described...

) also practice traumatic insemination. In these bugs, the male intromittent organ is formed by the coupling of the aedeagus with the left paramere, as in bed bugs. Females also exhibit paragenital modifications at the site of intromission, which include grooves and invaginated copulatory tubes to guide the male paramere. The evolution of traumatic insemination in Coridromius represents a third independent emergence of this form of mating within the true bugs.

Health repercussions

While advantageous to the reproductive success of the individual male, traumatic insemination imposes a cost on females: reduced lifespan and decreased reproductive output. "These [costs] include (i) repair of the wound, (ii) leakage of blood, (iii) increased risk of infection through the puncture wound, and (iv) immune defence against sperm or accessory gland fluids that are introduced directly into the blood."

The male bed bug penis has been shown to carry five (human) pathogenic microbes, and the exoskeleton of female bed bugs nine, including Penicillium chrysogenum
Penicillium chrysogenum
Penicillium chrysogenum is common in temperate and subtropical regions and can be found on salted food products, but it is mostly found in indoor environments, especially in damp or waterdamaged buildings. It was previously known as Penicillium notatum. It has rarely been reported as a cause of...

, Staphylococcus saprophyticus
Staphylococcus saprophyticus
Staphylococcus saprophyticus is a coagulase-negative species of Staphylococcus bacteria. S. saprophyticus is often implicated in urinary tract infections. S. saprophyticus is resistant to the antibiotic novobiocin, a characteristic that is used in laboratory identification to distinguish it from S...

, Stenotrophomonas maltophilia
Stenotrophomonas maltophilia
Stenotrophomonas maltophilia is an aerobic, nonfermentative, Gram-negative bacterium. It is an uncommon bacterium and human infection is difficult to treat. Initially classified as Pseudomonas maltophilia, S. maltophilia was also grouped in the genus Xanthomonas before eventually becoming the type...

, Bacillus licheniformis
Bacillus licheniformis
Bacillus licheniformis is a bacterium commonly found in the soil. It is found on bird feathers, especially chest and back plumage, and most often in ground-dwelling birds and aquatic species ....

, and Micrococcus luteus
Micrococcus luteus
Micrococcus luteus is a Gram-positive, spherical, saprotrophic bacterium that belongs to the family Micrococcaceae. An obligate aerobe, M. luteus is found in soil, dust, water and air, and as part of the normal flora of the mammalian skin...

. Tests with blood agar
Agar or agar-agar is a gelatinous substance derived from a polysaccharide that accumulates in the cell walls of agarophyte red algae. Throughout history into modern times, agar has been chiefly used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture medium...

 have shown some of these species can survive in vivo. This suggests infections from these species may contribute to the increased mortality rate in bed bugs due to traumatic insemination.

The successive woundings each require energy to heal, leaving less energy available for other activities. Also, the wounds provide a possible point of infection which can reduce the female's lifespan. Once in the hemolymph, the sperm and ejaculatory fluids may act as antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

s, triggering an immune reaction.

There is a tendency for dense colonies of bed bugs kept in laboratories to go extinct, starting with adult females. In such an environment, where mating occurs frequently, this high rate of adult female mortality suggests traumatic insemination is very detrimental to the female's health. The damage done, and the (unnecessarily) high mating rate of captive bed bugs, have been shown to cause a 25% higher-than-necessary mortality rate for females.

Bed bug adaptation

The effects of traumatic insemination are deleterious to the female. Female bed bugs have evolved a pair of specialized reproductive organs ("paragenitalia") at the site of penetration. Known as the ectospermalege and mesospermalege (referred to collectively as spermalege
The spermalege is a special-purpose organ found in bed bugs that appears to have evolved to mitigate the effects of traumatic insemination. The spermalege has two embryologically distinct parts, known as the ectospermalege and mesospermalege...

), these organs serve as sperm-receptacles from which sperm can migrate to the ovaries. All bed bug reproduction occurs via traumatic insemination and the spermalege
The spermalege is a special-purpose organ found in bed bugs that appears to have evolved to mitigate the effects of traumatic insemination. The spermalege has two embryologically distinct parts, known as the ectospermalege and mesospermalege...

. The genital tract, though functional, is used only for laying fertilized eggs.

The ectospermalege is a swelling in the abdomen, often folded, filled with hemocyte
A hemocyte is a cell that plays a role in the immune system of invertebrates. It is found within the hemolymph.Hemocytes are phagocytes of invertebrates....

s. The ectospermalege is visible externally in most bed bug species, giving the male a target through which to impale the female with the paramere. In species without an externally visible ectospermalege, traumatic insemination takes place over a wide range of the body surface.

Exactly why males 'comply' with this aspect of female control over the site of mating is unclear, especially as male P. cavernis appear to be able to penetrate the abdomen at a number of points independent of the presence of an ectospermalege. One possibility is that mating outside the ectospermalege reduces female fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...

 to such an extent that the mating male's paternity is significantly reduced ... The ectospermalege appears to act as a mating guide, directing the male's copulatory interest, and therefore damage, to a restricted area of the female's abdomen.

The mesospermalege is a sac attached to the inner abdomen, under the ectospermalege. Sperm is injected through the male's penis into the mesospermalege. In some species, the ectospermalege directly connects to the ovaries—thus, sperm and ejaculate never enters the hemolymph and thus never trigger an immune reaction. (The exact characteristics of the spermalege vary widely across different species of bed bugs.) The spermalege are generally found only in females. However, males in the Afrocimex genus possess an ectospermalege. Sperm remains in the spermalege for approximately four hours; after two days, none remains.

Male bed bugs have evolved chemoreceptors on their penises. After impaling a female, the male can "taste" if a female has been recently mated. If he does, he will not copulate as long and will ejaculate less fluid into the female.

Use in the animal kingdom

Although traumatic insemination is most widely practiced among heteroptera
Heteroptera is a group of about 40,000 species of insects in the Hemiptera. Sometimes called "true bugs", that name more commonly refers to Hemiptera as a whole, and "typical bugs" might be used as a more unequivocal alternative since among the Hemiptera the heteropterans are most consistently and...

ns (typical bugs), the phenomenon has been observed across a wide variety of other invertebrate taxa
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

. These include:
  • Oxyurida
    Oxyurida is an order of nematode worms of the class Secernentea. It consists of four families, one of which contains the human pinworm ....

    (nematodes) – Traumatic insemination has been observed in pinworm genera including Auchenacantha, Citellina
    Citellina is a worm genus within the Oxyuridae family. Species of this genus typically parasitise marmots and ground squirrels of holarctic distribution...

    , Passalurus, and "probably" Austroxyris
  • Acanthocephala
    Acanthocephala is a phylum of parasitic worms known as acanthocephales, thorny-headed worms, or spiny-headed worms, characterized by the presence of an evertable proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host...

    (parasitic, thorny-headed worms) – The presence of mating plug
    Mating plug
    right|thumbnail|A mating plug in a female [[Richardson's ground squirrel]] A mating plug, also known as a copulation plug, sperm plug, vaginal plug, or sphragis, is gelatinous secretion used in the mating of some species. It is deposited by a male into a female genital tract and later hardens into...

    s on the sides of Pomphorhynchus bulbocolli suggests traumatic insemination occurs in this species. Because these parasites cannot move after anchoring themselves to a host's intestine, traumatic insemination may have evolved to compensate for their immobility.
  • Rotifera (wheel animalcules) – In the Brachionus
    Brachionus is a genus of planktonic rotifers occurring in freshwater, alkaline and brackish water.-Species:e.g. Brachionus calyciflorus,Brachionus plicatilis s.s.,Brachionus ibericus,Brachionus rotundiformis,...

    genus, the male pierces the syncytial
    In biology, a syncytium is a large cell-like structure; filled with cytoplasm and containing many nuclei. Most cells in eukaryotic organisms have a single nucleus; syncytia are specialized forms used by various organisms.The term may also refer to cells that are connected by specialized membrane...

     integument (equivalent to skin) and injects sperm; in Asplanchna brightwelli the male secretes an enzyme which breaks down the female integument and injects sperm through the hole.
  • Turbellaria
    The Turbellaria are one of the traditional sub-divisions of the phylum Platyhelminthes , and include all the sub-groups that are not exclusively parasitic. There are about 4,500 species, which range from to in length...

    (free living flatworms) – Hermaphroditic
    In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...

     flatworms reproduce by "penis fencing
    Penis fencing
    Penis fencing is a mating behavior engaged in by certain species of flatworm, such as Pseudobiceros hancockanus. Species which engage in the practice are hermaphroditic; each individual has both egg-producing ovaries and sperm-producing testes....

    ". Individuals "fence" with penises, attempting to use their penis to pierce the skin of the other and inject sperm. The 'loser' is the flatworm which is inseminated and must bear the energy costs of reproduction. One study of Pseudoceros bifurcus found "Most inseminations were unilateral. Even when reciprocal penis insertion could be achieved by the second partner, the first to inseminate obtained a longer injection time than the second."
  • Gastropod snail
    Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

  • Strepsiptera
    The Strepsiptera are an order of insects with ten families making up about 600 species...

    (twisted-winged parasites) – In Xenos vesparum, fertilization can occur either via extragenital ducts, or by traumatic insemination into the hemocoel.
  • Drosophila
    Drosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...

    (flies) – Ejaculates are injected through the body wall into the genital tract, not the abdomen.
  • Opisthobranchia
    Opisthobranchs are a large and diverse group of specialized complex marine gastropods previously united under Opisthobranchia within the Heterobranchia, but no longer considered to represent a monophyletic grouping...

    (sea slugs) – Characterized by "repeated small injections into the dorsal surface of the partner, interrupted by synchronised circling movements", culminating in a standard genital insemination.
  • Harpactea
    Harpactea is a genus of spiders from the family Dysderidae, with more than 150 described species.Harpactea species are non-web building predators that forage on the ground and on tree trunks at night, mainly in xerothermic forests...

    (spiders) – The male of the spider species Harpactea sadistica
    Harpactea sadistica
    Harpactea sadistica is a species of dysderine spider, found only in Israel. It was first described in 2008.-Description:Both sexes have the same body characteristics. The length of the pale yellow-brown, smooth carapace ranges from 1.1 to 1.7 mm. The legs are pale yellow, with the first two...

    pierces the female's body cavity and inseminates her ovaries directly.

Homosexual traumatic insemination

Traumatic insemination is not limited to male–female couplings. Male homosexual traumatic inseminations have been observed in Xylocoris maculipennis and the Afrocimex genus.

In the genus Afrocimex, both species have well developed ectospermalege (but only females have a mesospermalege). The male ectospermalege is slightly different from that found in females, and amazingly enough, Carayon (1966) found that male Afrocimex bugs suffer actual homosexual traumatic inseminations. He found the male ectospermalege often showed characteristic mating scars, and histological studies showed "foreign" sperm were widely dispersed in the bodies of these homosexually mated males. Sperm cells of other males were, however, never found in or near the male reproductive tract. It therefore seems unlikely that sperm from other males could be inseminated when a male that has himself suffered traumatic insemination mates with a females. The costs and benefits, if any, of homosexual traumatic insemination in Afrocimex remain unknown.

Klaus Reinhardt of the University of Sheffield and colleagues observed two morphologically different kinds of spermalege in Afrocimex constrictus
Afrocimex constrictus
Afrocimex constrictus, also called the African bat bug, is an insect parasite of Egyptian fruit bats in bat caves in East Africa. Population sizes can comprise millions of individuals and there can be one to 15 bugs per bat...

, a species in which both male and females are traumatically inseminated. They found females use sexual mimicry
Sexual mimicry
Sexual mimicry is where one sex takes the characteristics of the other within a species. Examples of sexual mimicry in animals are the spotted hyena, bonobo chimp, spider monkey, lemur, european mole and some insects...

 as a way to avoid traumatic insemination. In particular, they observed males, and females who had male spermalege structures, were inseminated less often than females with female spermalege structures.

In Xylocoris maculipennis, a flower bug, after a male traumatically inseminates another male, the injected sperm migrate to the testes. (The seminal fluid and most of the sperm are digested, giving the inseminated male a nutrient-rich meal.) It has been suggested, although there is no evidence, that when the inseminated male ejaculates into a female, the female receives both males' sperm.

Interspecies traumatic insemination

Cases of traumatic insemination between animals of different species will sometimes provoke a possibly lethal immune reaction. A female Cimex lectularius traumatically inseminated by a male C. hemipterus will swell up at the site of insemination as the immune system responds to male ejaculates. In the process, the female's lifespan is reduced. In some cases, this immune reaction can be so massive as to be almost immediately fatal. A female Hesperocimex sonorensis will swell up, blacken, and die within 24–48 hours after being traumatically inseminated by a male H. cochimiensis.

Similar mating practices

In the animal kingdom, traumatic insemination is not unique as a form of coercive sex. Research suggests, in the Acilius genus
Acilius (genus)
Acilius is a holarctic genus of diving beetles. It contains the following species:*Acilius abbreviatus*Acilius athabascae*Acilius brevis*Acilius canaliculatus*Acilius confusus*Acilius duvergeri*Acilius fasciatus...

 of water beetle
Water beetle
A water beetle is a beetle adapted to living in water. Water beetles rise to the water surface and take atmospheric air into their tracheal systems. There are approximately 2000 species of water beetles. The rest marine species tend to live in the intertidal zone...

s, there is no courtship system between males and females. "It's a system of rape. But the females don't take things quietly. They evolve counter-weapons." Cited mating behaviors include males suffocating females underwater till exhausted, and allowing only occasional access to the surface to breathe for up to six hours (to prevent them breeding with other males), and females which have a variety of body shapes (to prevent males from gaining a grip). Foreplay is "limited to the female desperately trying to dislodge the male by swimming frantically around".

"Rape behavior" has been observed in a number of duck species. In the blue-winged teal
Blue-winged Teal
The Blue-winged Teal is a small dabbling duck from North America.-Description:The Blue-winged Teal is long, with a wingspan of , and a weight of . The adult male has a greyish blue head with a white facial crescent, a light brown body with a white patch near the rear and a black tail. The adult...

, "rape attempts by paired males may occur at any time during the breeding season." Cited reasons for this being beneficial to the paired males include successful reproduction, and chasing away intruders from their territory. Bachelor herd
Bachelor herd
A bachelor herd is a gathering of juvenile male animals who are still sexually immature, or of 'harem'-forming animals who have been thrown out of their parent groups but not yet formed a new family group....

s of bottlenose dolphin
Bottlenose Dolphin
Bottlenose dolphins, the genus Tursiops, are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. Recent molecular studies show the genus contains two species, the common bottlenose dolphin and the Indo-Pacific bottlenose dolphin , instead of one...

s will sometimes gang up on a female and coerce her to have sex with them, by swimming near her, chasing her if she attempts to escape, and making vocalized or physical threats. In the insect world, male water strider
Water strider
Gerridae is a family of true bugs in the order Hemiptera, commonly known as water striders, water bugs, magic bugs, pond skaters, skaters, skimmers, water scooters, water skaters, water skeeters, water skimmers, water skippers, water spiders, or Jesus bugs...

s unable to penetrate her genital shield, will draw predators to a female until she copulates.

External links

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