Exeristes Roborator Research Articles

Synoptic catalogue of insect parasitoids associated with Lixinae (Coleoptera: Curculionoidea: Curculionidae)

The first host-parasitoid catalogue for Lixinae is presented. This survey is based on literature search (~300 references) and followed by two parts, firstly one of the Lixinae, and secondly one of parasitoids with distinguishing numbers of their Lixine hosts. There are at least 221 species recorded as parasitoids on 108 lixine species. Records on 12 host-parasitoid associations seem to be questable or based on misidentifications. Most common hosts are species of two genera: Lixus (112 parasitoid species) and Larinus (43). All actually known parasitoids of Lixinae are dipterans (belonging to three families) and hymenopterans (15 families). The latter listed as parasitoids of no less than 102 lixine species (94.4%) and 22 hosts (19.4%) associated with Diptera. Six lixine species associated with dipterans only. Most common parasitoids are braconids. Four parasitoid species have the most extensive list of the hosts: Exeristes roborator (at least 29 host species), Cerceris tuberculata (12), Bracon urinator (11) and Zeuxia cinerea (10). Parasitoid complex of some hosts can include more than 10 (to 44!) species. Information contained in catalogue will be helpful for programs of effective biological control of economic important pests and weeds.

Determination of the parasitoids of the European sunflower moth and effectiveness in Ankara province

The European sunflower moth [Homoeosoma nebulellum (Denis&Schiffermüller)] (Lepidoptera: Pyralidae) is one of the most important sunflower pest in Turkey. Concerning the parasitoids of this pest, the only one study was conducted in Turkey. The aim of this study is the identification of the parasitoids of the European sunflower moth. Bracon hebetor (Say.), B. trucidator (Marshall), B. pectoralis (Wesmael) (Hymenoptera: Braconidae) and Exeristes roborator F. (Hymenoptera: Ichneumonidae) were found as natural enemies. Bracon pectoralis was determined for the first time on the European sunflower moth in the world. Moreover, it was found that B. hebetor was more common among the other parasites and the rate of parasitism was high. Parasitism rate was estimated 9-30% and 0-6.6% in 2013 and 2014, respectively.

The bagworm, Amicta quadrangularis (Christoph), and its natural enemies in Northern Egypt (Lepidoptera: Psychidae)

The bagworm, Amicta quadrangularis (Christoph) (Lepidoptera: Psychidae), was found infesting the white broom, Retana raetam (Frossk.) (Fabales: Fabaceae), a flowering wild plant native to northern Africa, in the desert area of Northern Egypt. This study sheds the light on some biological, morphological, and behavioral aspects of this insect species. A survey of the natural enemies associated with the larval stage revealed insectivorous birds (29–33%), a high percentage of parasitism by the ichneumonid, parasitoid species, Exeristes (Pimpla) roborator (Fab.) (Hymenoptera: Ichneumonidae) (8–11%), and the tachinid, Exorista (=Tachina) larvarum L. (Diptera: Tachinidae) (14–21%). The total percentage of attacking larvae by different natural enemies reached (51–65%) at the area of study.

Parasitoid and Inquiline Associations of Gall Inducing Insects on Rosa canina (L., 1758) and Prunus spinosa L., 1758: A Study in European Part of Turkey (Trakya University Arboretum, Edirne)

Gall specimens on leaves and branches of Rosa canina and Prunus spinosa were investigated. Field studies were conducted from February to June 2013 in European part of Turkey (Trakya University Arboretum, Edirne). In the study, from the galls collected from R. canina leaves and shoots, seven parasitoid and inquiline (Hymenoptera) species (Eupelmus urozonus, Exeristes roborator, Glyphomerus stigma, Orthopelma mediator, Pteromalus bedeguaris, Torymus bedeguaris, and Periclistus brandtii, belonging five families) associated with the three gall wasp (Hymenoptera) species (Diplolepis mayri, D. rosae, D. spinosissimae, belonging one family) were recorded. From the galls on P. spinosa leaves, one gall midge (Diptera) species (Putoniella pruni) was recorded. In addition, six species were determined as new records for the dipteran and hymenopteran fauna of Edirne province, European part of Turkey, and Turkey.

Exeristes roborator (Fabricius, 1793) (Hymenoptera: Ichneumonidae) in the parasitoid community of Diplolepis galls in the Carpathian Basin

Exeristes roborator (Fabricius, 1793) is usually known as the parasitoid of lepidopteran pupae, but was also recorded as the parasitoid of diff erent Cynipidae species in the southern parts of Europe and parts of Middle East. In samples of Diplolepis rosae (Linnaeus, 1758) and D. mayri (Schlechtendal, 1876) galls collected in the eastern Carpathian Basin after 2010 E. roborator appeared in large numbers compared to those collected before 2010, when the species was not present in the gall communities. Here we report the diff erential presence of Exeristes roborator in the two rose gall species, which points out the host shift of the ichneumonid parasitoid spreading towards north. With 3 figures.

Larval parasitoids and larval diseases of Malacosoma neustria L. (Lepidoptera: Lasiocampidae) detected in Erzurum Province, Turkey

The larval parasitoids and larval diseases of Malacosoma neustria (L.) (Lepidoptera: Lasiocampidae) in various host plants were investigated in Erzurum Province, Turkey, during 2004 and 2005. The larval parasitoids were reared in a laboratory, and a total of 29 parasitoid species were established in association with the larvae of M. neustria in the families Tachinidae (Diptera), Braconidae, Ichneumonidae, and Chalcidoidea (Hymenoptera). Of the 6 tachinid parasitoids, Pales pavida (Meigen) was the most prevalent species and accounted for 25% of the tachinid records. Among the tachinids, there were 2 new records for the Turkish fauna: Exorista amoena Mesnil and Palesisa nudioculata Villeneuve. Exorista amoena was reared from M. neustria for the first time. The braconid species Meteorus lionotus Thomson and Cotesia vanessa (Reinhard) were also reared from M. neustria for the first time. Among the 10 chalcidoid species reared, Monodontomerus aereus Walker and Brachymeria secundaria (Rusc.) were the most prevalent species. Five chalcidoid species, Asaphes suspensus (Nees), A. vulgaris Walker (Pteromalidae), Brachymeria secundaria (Ruschka) (Chalcididae), Eupelmus urozonus Dalman (Eupelmidae), and Eurytoma verticillata (F.) (Eurytomidae), were reared from M. neustria for the first time. Of the 10 species of ichneumonids reared, Exeristes roborator F. was the most abundant and accounted for 35% of the total ichneumonid records. The total parasitism rate of all parasitoids was 33.7%. As disease agents of M. neustria, the nuclear polyhedrosis virus and 4 pathogenic bacteria, Brevibacillus agri, Alcaligenes xylosoxydans xylosoxydans (Achromobacter xylosoxidans), Bacillus lentimorbus, and Serratia fonticola, were diagnosed. All of the bacteria from M. neustria were recorded for the first time. The percentage of diseased larvae was low, about 3%.

Natural History Studies for the Preliminary Evaluation of <I>Larinus filiformis</I> (Coleoptera: Curculionidae) as a Prospective Biological Control Agent of Yellow Starthistle

We studied the life history, geographic distribution, behavior, and ecology of Larinus filiformis Petri (Coleoptera: Curculionidae) in its native range to determine whether it is worthy of further evaluation as a classical biological control agent of yellow starthistle, Centaurea solstitialis (Asteraceae: Cardueae). Larinus filiformis occurs in Armenia, Azerbaijan, Turkey, and Bulgaria and has been reared only from C. solstitialis. At field sites in central and eastern Turkey, adults were well synchronized with the plant, being active from mid-May to late July and ovipositing in capitula (flowerheads) of C. solstitialis from mid-June to mid-July. Larvae destroy all the seeds in a capitulum. The insect is univoltine in Turkey, and adults hibernate from mid-September to mid-May. In the spring, before adults begin ovipositing, they feed on the immature flower buds of C. solstitialis, causing them to die. The weevil destroyed 25-75% of capitula at natural field sites, depending on the sample date. Preliminary host specificity experiments on adult feeding indicate that the weevil seems to be restricted to a relatively small number of plants within the Cardueae. Approximately 57% of larvae or pupae collected late in the summer were parasitized by hymenopterans [Bracon urinator, B. tshitsherini (Braconidae) and Exeristes roborator (Ichneumonidae), Aprostocetus sp. (Eulophidae), and unidentified species of Eurytomidae and Ormyridae]. This weevil may be a better choice than the other capitula insects already established in the United States, particularly in colder parts of the plant's range.

Note: Life history ofLixus bardanae on curly dock (Rumex crispus) in Turkey

The biology ofLixus bardanae (F.) (Coleoptera: Curculionidae) on curly dock (Rumex crispus L.) in northeastern Anatolia (Bayburt, Erzurum and Kars Provinces), Turkey, was studied during the years 2000 and 2001.L. bardanae completes one generation in a year, overwintering as an adult. It feeds on leaves of the host plant. Females lay eggs individually into stems and the young larvae create galleries in stems while feeding. Pupation occurs inside stems in cells fashioned from frass. In late September, adults move into soil and overwinter in an upright position around the roots of the host plant. Infestation levels were found to range between 34% and 84%. Two parasitoids,Exeristes roborator F. andEndromopoda phragmitidis Perve (Hymenoptera: Ichneumonidae), were reared fromL. bardanae.

First record of two ichneumonid wasps from Northeastern Turkey (Hymenoptera: Ichneumonidae)

Exeristes roborator (F.) and Xylophrurus ?nigricornis (Thomson) are for the first time recorded from Northeastern Turkey. E. roborator was reared from five species of the weevil genera Larinus Dej. and Rhinocyllus Germ, developing in flowerheads of Asterceae, and one species of the genus Lixus F., developing in the stem of Polygonacaeae. The single specimen of X. ?nigricornis emerged from the larva of Lixus ochraceus Boh. developing in the stem of a crucifer. All weevils belong to the weevil subfamily Lixinae (=Cleoninae) (Coleoptera, Curculionidae).

Effect of Prior Experience on the Response of Exeristes roborator (Hymenoptera: Ichneumonidae) to a Natural Host and Microhabitat in a Seminatural Environment

In a field cage, the responses of females of the polyphagous ichneumonid ectoparasitoid Exeristes roborator (F.) to a natural host and microhabitat were reduced by prior experience with the same host in an artificial microhabitat. Learning of the artificial microhabitat probably interfered with females' normal responses to the natural system. Parasitoids that had previously attacked hosts in the artificial microhabitat contacted the natural system in fewer numbers and performed host-seeking and host-attacking activities on it with lower intensity than control females. They also killed fewer host larvae than controls. Thus, rearing procedures that permit parasitoids produced for release as biological control agents to gain experience with nontarget hosts and microhabitats could impair these insects' effectiveness against target pests. Prior experience with the natural host and microhabitat did not increase females' responses to them. This result could reflect the way in which learning functions for E. roboratar . Learning might allow the parasitoid to use unusual or less preferred hosts when its normal hosts are rare but not to enhance its responses to hosts for which it has a strong innate preference. Learning may have caused E. roborator to respond almost exclusively to the natural host and microhabitat when it was familiar with them. Fidelity to a target system caused by prior exposure to it might enhance a biological control agents' performance over a longer term than was examined here.

Entomofauna of Centaurea sp. and their economic importance

The different species of Centaurea are host of numerous insects: among the most important some are pollinating (Apis melifica L.), the most of them are phytophagous (Larinus obtusus...,Agonopterix liturella Den. et Schiff., Chaetorellia jaceae R. D., Crophora quadrifasciata Meig.) and others are zoophagous (Exeristes roborator F. and Zeuxia cinerea Meig.). The plant root is harmed by the larvae of Pelochrista medulana Stgr., the stalk is mined by the caterpillars of Agonopterix liturella Den. et Schiff., and the flowers and seeds are destroyed by the larvae of Larinus obtusus Gyll., Eucosoma hohenwartina Den. et Schiff., E. aemulana Schlang., Chaetorellia jaceae R.D. and Urophora quadrifasciata Meig. Due to the population density and to the caused damages, the species Agonopterix liturella Den. et Schiff., Larinus obtusus Gyll., Chaetorellia jaceae R.D. and Urophora quadrifasciata Meig., are these who present a practical importance as agents of biological control of the knapweed species, especially Centaurea phrygia. On the whole, considering the seed losses caused only by the seed weevil (Larinus obtusus Gyll.) and by tephritids flies of the knapweed seeds (Chaetorellia sp. and Urophora sp.) these are estimated to 50-60 %.

Learning of host microhabitat colour by Exeristes roborator (F.) (Hymenoptera: Ichneumonidae)

Females of the polyphagous, ichneumonid ectoparasitoid, Exeristes roborator (F.), learned the colour (wavelength), but not the brightness (intensity), of light reflected by artificial host microhabitats in the laboratory. Females given hosts in a microhabitat of only one colour subsequently preferred to contact and perform host-seeking behaviour on it when offered a choice between it and a microhabitat of another colour. Control insects did not exhibit this preference. Colour learning influenced females' responses whether or not hosts were present in the microhabitats. However, it did not altogether prevent females from finding hosts in microhabitats of colours that they had not learned. In nature, learning of host microhabitat colour may allow E. roborator to identify plant material that experience has taught it is a profitable resource.

Learning of host microhabitat form byExeristes roborator (F.) (Hymenoptera: Ichneumonidae)

Females of the polyphagous, ichneumonid ectoparasitoid, Exeristes roborator(F.), learned the form of artificial host microhabitats in the laboratory. Females given hosts only in a microhabitat of one form subsequently concentrated their responses on this microhabitat when given a choice between it and a microhabitat of another form, neither of which contained hosts. Control females did not display similar preferences. The parasitoid did not appear to distinguish the form of a microhabitat until after it contacted it. When hosts were present in test microhabitats, learning of form was apparently overridden, possibly because the parasitoids detected the presence of hosts before they assessed form or because their responses were shaped by learning of host-related factors. Together with learning of other microhabitat characteristics, learning of form may contribute to recognition of plant structures that are likely to contain suitable hosts by E. roborator.

Maturation Feeding without Learning in Adult Exeristes roborator (Hymenoptera: Ichneumonidae)

Females of the polyphagous ichneumonid Exeristes roborator (F.) characteristically learn to respond to artificial host microhabitats in which they are fed either natural or factitious host larvae. In a laboratory experiment, they learned to associate a host with a glass pipette feeding device. However, they became reproductively mature without learning to respond to the feeding device when fed only hemolymph of coddled larvae of Galleria mellonella (L.). Thus, the adverse effects of learning by parasitoid females intended for inundative releases can be avoided by the appropriate prerelease feeding regime.

Learning of an olfactory stimulus associated with a host microhabitat by Exeristes roborator

AbstractFemales of the polyphagous, ectoparasitoid, Exeristes roborator (F.) (Hymenoptera: Ichneumonidae), learned an olfactory stimulus associated with an artificial host microhabitat in the laboratory. In a two‐choice olfactometer, females previously given hosts only in association with one stimulus showed a greater tendency to visit exclusively, and spend time in, chambers containing a source of that stimulus, than control females. Learning of olfactory cues could act in conjunction with learning of visual cues to allow the parasitoid to identify accurately microhabitats that experience has taught it contain hosts. It could also allow the parasitoid to identify these resources when visual cues are not available.RésuméL'apprentissage de l'odeur du microhabitat de l'hôte par Exeristes roboratorNous avons supposé que les femelles polyphages de l'ichneumonide ectoparasite, E. roborator (F.), pourraient apprendre les stimuli olfactifs liés au microhabitat artificiel dans lequel elles avaient attaqué leur hôte. 4 lots de femelles ont été placés dans des conditions différentes: le microhabitat des hôtes du premier lot était du Parafilm imprégné d'odeur de pomme; celui des hôtes du second était un Parafilm non traité. Les hôtes des lots témoins 3 et 4 étaient présentés respectivement avec les deux microhabitats et sans aucun micro‐habitat. Placées dans un olfactomètre statique contenant du Parafilm traité à la pomme et du Parafilm vierge, des femelles du lot 1 ont eu tendance à ne visiter que l'enceinte contenant du Parafilm traité à la pomme, elles ont passé environ 75% de leur temps dans cette enceinte. A l'opposé, les femelles des 3 autres lots ont eu tendance à ne visiter que l'enceinte sans odeur de pomme, et elles n'ont passé que 34 à 46% de leur temps dans l'enceinte traitée à la pomme. Les différences entre les réactions du lot 1 et des autres lots sont significatives, mais entre les lots 2, 3 et 4, elles ne le sont pas. Une expérience témoin confirme que les préférences des femelles du lot 1 ne sont pas innées; E. roborator a donc appris à reconnaitre les stimuli olfactifs du microhabitat sentant la pomme. L'apprentissage des signaux olfactifs liés au microhabitat de l'hôte pourrait s'effectuer seul ou en relation avec l'apprentissage de signaux visuels permettant au parasitoïde d'identifier avec précision les microhabitats d'un hôte convenable.

Detrimental effect of prior conditioning on host habitat location by Exeristes roborator

Detrimental effect of prior conditioning on host habitat location by Exeristes roborator

AGE-DEPENDENT ASSOCIATIVE LEARNING BY EXERISTES ROBORATOR (F.) (HYMENOPTERA: ICHNEUMONIDAE)

AbstractFemales of the polyphagous ichneumonid parasitoid, Exeristes roborator (F.), that were conditioned for 10 days to hosts in a specific habitat demonstrated associative learning by responding with ovipositor probes into the habitat alone. Females conditioned immediately after eclosion showed a higher participation rate, intensity, and duration (approximately 7 days) of learned behavior than those conditioned 5 or 10 days after eclosion, despite the fact that newly eclosed females did not probe for hosts with their ovipositors until 4 or 5 days after eclosion. The reduction in the learning ability of females within a short time after eclosion may impart a selective advantage to E. roborator by reducing the costs of learning. It could also reflect developmental constraints on the process of learning. The results suggest that carefully controlled associative learning could be exploited to improve the efficiency of host location by parasitoids released in biological-control programs.

New Rearing Device forExeristes roborator(F.) (Hymenoptera: Ichneumonidae)

A new rearing device for Exeristes roborator (F.) is described. The device is made of plexiglass, with top and bottom layers enclosing a multichambered layer in which the parasitoid larvae are individually reared on coddled host larvae. It reduces the cost and labor to rear the parasitoid by approximately 50%. The device is easy to work with and has the potential for use in mass production programs.

Exeristes, Itoplectis, Aphaereta, Brachymeria, and Hyposoter species: In vitro glyceride synthesis and regulation of fatty acid composition

Microsomes from two species of parasitic Hymenoptera, Exeristes roborator and Itoplectis conquisitor, exhibited little or no de novo glyceride synthesis but actively acylated endogenous mono- and diacylglycerides. It is suggested that this lack of de novo synthesis is related to the fact that the fatty acid composition of these parasitoid species closely resembles that of the hosts on which they are reared. Microsomes from three other species of parasitic Hymenoptera, Aphaereta pallipes, Brachymeria lasus, and Hyposoter exigua, whose fatty acid compositions are little influenced by the host species, exhibited active de novo glyceride synthesis as well as acylation of endogenous mono- and diacylglycerides. Radiotracer studies indicated that E. roborator microsomes and cytosol did not contain noncompetitive or uncompetitive inhibitors of glycerophosphate acyltransferase. E. roborator microsomes acylated exogenous phosphatidic acid but not dihydroxyacetone phosphate or glycerol. The maximum rate of glycerophosphate acylation was less than 0.1 nmole/min/mg microsomal protein after 15 min incubation. The incorporation was subject to rapid lipolysis on further incubation. The addition of bovine serum albumin (BSA) reduced the ability of E. roborator microsomes to acylate mono- and diacylglycerides with endogenous acyl groups. In the absence of BSA, palmitoyl-CoA was a more effective substrate than stearoyl-CoA for both mono- and diacylglyceride acyltransferases.

Exeristes roborator: Quantitative determination of in vitro larval growth rates in synthetic media with different glucose concentrations

Larval growth rates of the insect parasite, Exeristes roborator reared in vitro were calculated from egg hatching to the fourth instar. Dry weight gain and mean wet weight during feeding were considered. Dry weights of developing larvae were estimated as the sum of the total protein and lipid levels, eliminating the contribution of stored waste. Dry/wet weight ratios of larvae were found to decrease markedly during development. Growth rates of parasite larvae increased from approximately 1 μg/mg·day on carbohydrate-free media to 50 μg/mg·day on artifical diets containing 8% glucose.