Search Results - Cleptes

Chrysidids are distributed in all the zoogeographic Regions, except for the Antarctica. Cleptids of the genus Cleptes are perhaps the most primitive and ancient group among chrysididae, because of their hosts diets (they parasite primitive wasps like Sawflies, linked to plants of the temperate climates). Those species are nearly exclusive of the northern hemisphere (Holarctic Region), absent - or nearly - from the tropical regions. Also the Amiseginae seem to have developed in the northern hemisphere and then migrated to the Oriental and to the Neotropical Regions during the Quaternary and extincted elsewhere perhaps during the glaciations. Same thing for the Chrysidinae, currently dominant in the Palearctic and in the Neotropical Regions. The Chrysidinae of the other Regions are derived in subsequent successive times.

The chrysidid fauna of the Australian Region is considerably poorer than that of the other Regions and shows in-common taxa with the Oriental fauna. It is reasonable that Chrysidids have seen a remarkable evolutionary differentiation, as testified by the absence of affinity between the faunas of the regions splitted off from the "One Continent" (Gondwana) and by the endemism of many Genera.

The human activity is responsible of the current wide distribution for some species, through the exchange of vegetals hosting larvas and adults: wood, plants, canes, etc. Some examples of widespread species: Stilbum cyanurum, Omalus aeneus, Pseudomalus auratus.

For citation purposes

Once prepared, the specimen can be parked in an entomological box, with the similar ones, but one last component it still lacking: the identification label. Such label is written by its identifier, the entomologist who recognizes it on the basis of its diagnostic characters and assigns it to a known species. Therefore, the last pinned label should report the following info: Genus species Author, sex, identifier and year, i.e. Chrysis ignita L., ♀, C.Darwin det., 1980). When more determination cards are present on the same spacimen it means that the specimen has been examined and revised by many specialists, each one leaving his own taxonomic opinion. Generally, the last temporal diagnosis is the most reliable, reported on the lowest label.

The procedure of identification of a specimen is executed by a specialist who receives the material by a collector. After some time, he returns the material and keeps some specimens for his own collection, as an "honorarium" for his performance. The identification is performed using a stereoscopic microscope and through a critical comparison between what is seen and what is written in the determination keys.

Móczár (1997) wrote: « Most species of Cleptes [but this could be extended to the whole Chrysididae] are rare and their colour and sculpture show a great variety even within populations. The main reasons behind it are the cleptoparasitic lifestyle and the microclimatic circumstances which influence individual development. Thus, their classification is sometimes uncertain. »

The main determination keys for Chrysididae have been supplied by the following Authors: W. Linsenmaier, L. Móczár, L.S. Kimsey and R. Bohart (see the Literature page).

Chrysis.net offers a

For citation purposes

The fundamental morphologic features which distinguish chrysidids from the other wasps are:

• reduction of the number of the visible abdominal segments to 5 or less
• an internal ovipositor or genital tube, constituted by the remaining abdominal segments
• 11 antennal articles (flagellomeres), plus pedicel and scape
• labial palps with 3 articles and maxillar palps with 5 articles
• fore wings with 5 closed cells, or less, and
• hind wings without closed cells.

According to the Zoological Record, Chrysidids are ranked in the taxonomic hierarchy as Aculeate Wasps, wasps equipped by a stinging apparatus. But, according to the present-day classifications, the traditional sections (infraorders) 'Terebrantia' ('Parasitica') and 'Aculeata' of the Suborder 'Apocrita' have been abandoned in the direction of taxonomy based on Superfamilies.

The Family Chrysididae comprises 5 Subfamilies and 83 Genuses. Their taxonomy down to the Genus level is as follows:

* the asterisk indicates the presence of the Genus in Europe.

For citation purposes

With some exceptions, Chrysidids are generally colored and their structural coloration is due to light interference, and it varies with the viewing angle.

Many species are characterized by colors with metallic glares, green, blue, copper, gold, etc., and some colorations seem to be typical of precise geographic regions.

The Loboscelidiini and the Allocoeliini lack any metallic coloration; their colors are brown, black, reddish and, in the some cases, white.

The Amisegini are generally from brown to black, with little metallic glares from green to blue on face and thorax; the abdomen is generally non-metallic (metallic in Duckeia).

The coloration of the Cleptini is very variable. Some species are completely non-metallic black. Cleptes species are generally metallic on head and thorax, the abdomen being non-metallic. Typical of almost all the European Cleptes is the metallic color of the head and of the thorax (mainly red in females and green-blue in males), with a non- or not completely metallic abdomen.

The Chrysidini and the Elampini are always colored with metallic colors. In Europe the commonest colors are the green-blue on head and thorax, with a copper or golden abdomen. The species of southern Spain, N Africa and Middle East tend to be completely copper- or brass-colored. In tropical Asia we observe the diffusion of a pattern with green body and a copper-colored spot on both sides of the second abdominal tergite in species belonging to even distant Genera (the reason is unknown), while in the Philippines Chrysidids are purple with a red-shining head. Some Hedychridium show a reddish non-metallic abdomen.

In Parnopes a clean chromatic distinction based on the geographic distribution is observed. The African and American species tend to be colored of uniform blue, green, purple. In the palearctic species, instead, the abdomen is often different from the rest of the body and generally non-metallic.

White colorations are generally reduced to spots and stripes on mandibles, antennal articles, tegulae, legs, abdominal tergites; in the species of the Loboscelidiini and the Elampini they are not observed.

From: Kimsey L.S. & Bohart R.M., 1991 – The Chrysidid wasps of the World. Oxford University Press, ix-652.

Observations:

• color can be altered from the chemicals used in order to kill, to preserve or to rehydrate specimens.
• color has a diagnostic value in many cases, but not always, because each species shows a variability both chromatic and morphologic.
• does an environmental relation between color of the adult and the physical parameters (humidity, temperature) at the time of the development exists?
• melanism is rarely observed.

Image galleries

For citation purposes

Chrysidids are parasites of other insects, or more parasitoids, which means that their activity - in most cases - brings death to their hosts; some species are also cleptoparasites, which means that they use the food carried on by the host as resources for their larvas.

Chrysidid females own a long telescopic ovipositor that acts as an instrument to place the egg inside the nest of the host wasp. Such ovipositor derives from the evolutive reduction of a vulnerant apparatus (sting) to an introflected apparatus (segments inside the abdomen).

Ovipositor: TN = gastral terga; SN = gastral sterna (from Morgan (1984)).

For some Chrysidid species, the specialization in the choice of the host is high and determines a strong host/parasite association. For other species, instead, the choice of the host seems to be determined by the type of nest constructed by the host and for which the Chrysidid "is trained". The nature of the primary food source is a feature which distinguishes the subfamilies: Amiseginae and Loboscelidiinae feed on Phasmid eggs; Chrysidinae (except for the genus Praestochrysis, host of Lepidoptera) and Parnopinaefeed on larvas of other Hymenoptera (Eumenids, Sphecids, Apoids, Vespoids, Tenthredinids).

Cleptinae prey on prepupal Tenthredinoidea. Thanks to the studies of Clausen (1940), Gauss (1964) and Dahlsten (1961 and 1967) we can make some generalizations. Adult Cleptes search for their hosts' cocoons in the soil or in the ground; once the cocoon is localized, the female Cleptes open a hole in the wall with their jaws, then they insert their long ovipositor and put their egg on the host larva. Once the ovideposition has taken place, they close the hole with a mucillaginous material; the Chrysidid larva, after having consumed the host, will secrete its own cocoon inside the host's cocoon.

Identical modalities are observed in Chrysidinae of the Genus Praestochrysis. Piel (1933) studied the biology of Praestochrysis shanghaiensis, parasite of the nocturnal butterfly Monema flavescens Walker (Lepidoptera Limacodidae). The Chrysidid attacks the silky cocoon of the caterpillar as soon as it has been hardened; with some bites, it produces a hole wide enough to let the ovipositor enter inside. Once this operation is completed, the chrysidid female abrades the material around the cocoon and pastes it back with her saliva in order to close the hole. It has been experimentally observed that if the hole fails to be closed, the entire content of the cocoon is destroyed by molds.

The female Chrysidinae generally penetrate the nest of the host during its construction and place their egg in a hidden spot of the cell. Some Chrysidids, like Stilbum cyanurum, seem to be specialized in preying on different species that construct their nests with mud (like Sceliphron sphecids). Other species of Chrysidids are more taxa-specific and prey only on certain Genera or just on single species.

There are two basic strategies in parasitizing hosts. The first one wants that the Chrysidid starts with eating the host egg or the young host larva and then eats the food resources present in the nest (cleptoparasitism); the second one wants that the Chrysidid waits for the development of the host larva to its prepupal stadium, and then the Chrysidid kills it after cleaning the nest. This second way generally happens when the host belongs to those apoids who accumulate pollen and other sweets in the nest, impossible to be synthetized by Chrysidids. When the supplies accumulated by the the mother wasp for her larva are enough to feed also the parasite larva, it is possible to assist to the development of both the larvae without any trace of parasitism. In some cases, it is possible to see more than one Chrysidid specimen from a single cell, rather than a single Chrysidid from the single cell as it generally happens. These facts, underlined by Kimsey & Bohart (1990), could be explained as a behaviour of parsimony and of optimization of the available resources, when sufficient, avoiding the energy-expensive parasitism.

The Chrysidids parasitoids of potentially vulnerant wasps (sting, jaws) show a morphologic-functional adaptation of defensive nature: the abdominal segments - strongly sclerotized on the external surface and concave in the ventral surface - allow the lodging of antennas and legs when the Chrysidid closes itself into a defensive sphere. Such a behaviour prevents the host from mutilating or from stinging the Chrysidid.

Móczár (1961) has reported some observations on the Stilbum cyanurum species, which parasites the mud nests of the Sceliphron destillatorium (Illiger) sphecid wasp. The female wets a point of the dry mud of the nest with a drop coming from her mouth parts and then touches it with her ovipositor. The operation, repeated a few times, brings to the penetration of the muddy wall and to the deposition of an egg into the cocoon of the Sceliphron. The Chrysidid ovipositor is very strong and indented, so it can be used to work like a knife. After the ovideposition and the extraction of the ovipositor, the wet mud is used to close the hole, leaving a visible depression on the cell wall. Berland & Bernard (1938) have listed many hosts for Stilbum cyanurum: Sceliphron, Eumenes, Chalicodoma and Megachile, all producers of mud nests.

Carrillo & Caltagirone (1970) have made detailed observations on the host-parasite relations between two sphecid species, Solierella peckhami (Ashmead) and S. plenoculoides Fox, and the Chrysidid Pseudolopyga carrilloi. Thanks to their studies, carried out in California and in laboratory, it turns out that the female Chrysidid places the egg on the living larva of the first or of the second stage of a Hemipteran bug of the Genus Nysius (Hemiptera Lygaeidae, two species being involved: N. raphanus and N. tenellus). The two species of Solierella use paralized Nysius larvas in order to provision the nest, 4-10 larvas per cell. In such a complicated way the Chrysidid is able to make its egg enter the nest of the host without being seen and without the risk of the adult host noticing its presence and destroying its egg. It is noticeable that the egg will develop only in the case that the larva that carries it is captured and paralyzed by the Solierella. That's one is the only known case of a Chrysidid linking its egg just on a free host, which will be used in a second time as a prey by a sphecid. An interesting case of competition against the Pseudolopyga comes from a sympatric species, Hedychridium solierellae, which parasites the same species of Solierella and the Pseudolopyga itself. This Chrysidid directly places its egg in the Solierella cell and its larva feeds on the host larva, on its supplies and also on the egg or on the larva of Pseudolopyga, when present.

Chrysidid larva (from Morgan (1984)).

For citation purposes