Ovipositor


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ovipositor

[′ō·və‚päz·əd·ər]
(invertebrate zoology)
A specialized structure in many insects for depositing eggs.
(vertebrate zoology)
A tubular extension of the genital orifice in most fishes.

Ovipositor

 

the external sexual organ in the females of many insects and some fish (for example, Rhodeus) by means of which eggs are laid. The ovipositors of insects are modified appendages to the eighth and ninth abdominal segments. They consist of three pairs of valves with the sexual orifice located between their bases. The valves of the ovipositor penetrate the substrate, and the eggs slide down between the valves during egg laying.

Because the eggs of Acrididae are placed into the soil in sacs that must be deposited at great depths, the ovipositor is strong and short and acts as a digging apparatus. The abdomen of the Acrididae can become elongated in order to push down the ovipositor. In dragonflies, true bugs, cicadas, and sawflies, the ovipositor places the eggs into plant tissue. Ichneumon flies and other hymenopterans have a long and sharp ovipositor that introduces eggs into the bodies of other insects, where the larvae live as parasites. The ovipositors of higher hymenopterans (honeybees, wasps, bumblebees) have become stingers—organs of protection and attack.

In fish the ovipositor is a modified urogenital papilla, which becomes elongated during spawning.

A. V. IVANOV

References in periodicals archive ?
Their ovipositors suggest that eggs may be buried in the ground (i.
Dissection and careful observation of the hind segments of the red palm weevil Rhynchophorus ferrugineus revealed the presence of two symmetrical glands in the ovipositor of the females, but absent in males.
The length of the ovipositor relative to the depth of the maggot within the fruit apparently limits the biocontrol agent's ability to successfully parasitize certain hosts, a problem that has been well documented for other fruit fly parasitoids (Sivinski et al.
Therefore, the present study has been carried out to observe various types of sensilla located on the antenna, maxillary palp, labial palp, tarsi and ovipositor of Ae.
In the first step of the oviposition, the female everted her ovipositor and placed its tip in contact with her chelicerae for up to 7 min.
The teeth catch into the wood so that with each oscillation, the ovipositor advances by a small step.
The female hovers over the water, dipping down repeatedly to break the water surface with her ovipositor.
She inserts her ovipositor into the ovary of the flowers and deposits her eggs, then walks up to the stigma of the flower and actively deposits a small amount of pollen.
Calling was recognized by the extrusion of the ovipositor beyond the tip of the abdomen, but females that showed obvious oviposition behavior (laying eggs) were excluded (Kamimura & Tatsuki 1993, 1994).
Males do not have the egg-laying ovipositor that doubles as a stinger on female insects.
The autapomorphies of the genus are a robust bifurcate process situated at the middle lobe of the pronotum and ah extremely short labium; a potential synapomorphy with Centromus Bergroth, 1910 is a strongly protruding, bill-shaped ovipositor.
House crickets are inexpensive, are easy to acquire and care for, and behave fairly normally in captivity The winged adults are also easily sexed; a female has a single, long, thin ovipositor at the end of her abdomen, and a male does not.