''Reclinervellus nielseni'' is one of the spider-ectoparasitoids belonging to the ''Polysphincta'' genus-group (

Hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typi ...

Ichneumonidae The Ichneumonidae, also known as ichneumon wasps, ichneumonid wasps, ichneumonids, or Darwin wasps, are a family of parasitoid wasps of the insect order Hymenoptera. They are one of the most diverse groups within the Hymenoptera with roughly 25 ...

Pimplinae Pimplinae are a worldwide subfamily of the parasitic wasp family Ichneumonidae. Pimplinae are parasitoids of Holometabola, often the pupae of Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects whi ...

) and utilizes exclusively ''

Cyclosa ''Cyclosa'', also called trashline orbweavers, is a genus of orb-weaver spiders first described by Anton Menge in 1866. Widely distributed worldwide, spiders of the genus ''Cyclosa'' build relatively small orb webs with a web decoration. The w ...

'' spiders (

Araneae Spiders ( order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

Araneidae Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name ...

) as hosts. The species is distributed from Britain to Japan but is rather sparse.

Behavior

''Reclinervellus nielseni'' is known to manipulate web-building behavior of the host spider to modify an original fragile orb-web into a simple and durable web with conspicuous web decorations. The host spider species is different in accordance with the region, that is '' Cyclosa conica'' in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

whereas '' Cyclosa argenteoalba'' in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. The modified web is derived from a pre-programmed resting web constructed before spiders' molting, verified by the conformity of web shape and the presence of specific web decoration. The web decorations are thought to serve as a web-advertiser toward flying potential web destroyers (birds and insects). The web is conspicuous under ultraviolet light, and stronger than the typical resting web. Although the molting web structure usually only the two days the spider takes to molt, the larvae remain within their spider-cocoon for up to ten days before hatching.

References

Pimplinae Insects described in 1923 Mind-altering parasites {{Ichneumonidae-stub