Genus Eurytoma Research Articles

First record of the occurrence of parasitoids of genus Eurytoma and Eupelmus (Hymenoptera: Calcidoidae) associated to the seeds of Cassia leptophylla in Brazil

The presence of parasitoids, predators, and pathogens that utilize the biological control of pest is important to agriculture and forestry is imperative as a dynamic equilibrium factor in agroecosystems. The insects of the order Hymenoptera possess a great diversity of habitats and are a species of insectivores predominate in population, frequencies, and effectiveness, in which they attack pest. The knowledge of the species that forms an ecosystem is one of the basic assumptions within a program of integrated pest management. This study objective identifies the parasitoid species of Cydia tonosticha and Pygiopachymerus lineola obtained from fruits of Cassia leptophylla (Fabaceae: Caesalpinoideae) collected from trees in an urban area of the municipal of Santa Maria, Rio Grande do Sul, and sent to the Entomology Laboratory of the Department of Plant Defense at the Federal University of Santa Maria (UFSM). The species found were identified as genus Eurytoma (Eurytomidae) and Eupelmus (Eupelmidae), and found as the first record of these parasitoids associated with the gold medallion tree (C. leptophylla).

Species composition of the parasitoid genus Eurytoma (Hymenoptera: Eurytomidae) varies at a local scale in Diplolepis variabilis (Hymenoptera: Cynipidae) galls

Abstract We evaluated the diversity and spatiotemporal emergence patterns of parasitoid wasp species in the genus Eurytoma Illiger (Hymenoptera: Eurytomidae) associated with leaf galls induced by Diplolepis variabilis Bassett (Hymenoptera: Cynipidae) throughout the Okanagan Valley, British Columbia, Canada. We collected D. variabilis galls throughout the region, recorded adult Eurytoma emergence times, extracted mitochondria DNA from a subset of the emergents, and used cytochrome c oxidase 1 and cytochrome b amplificons to assign sampled individuals to species. We also assayed for the bacterial endosymbiont Wolbachia to evaluate the incidence of thelytoky in Eurytoma. Eurytoma showed an extended emergence period and a significant right skew in male emergence. We recorded six Eurytoma species, one of which appears to be previously undescribed. The greatest diversity of Eurytoma species occurs in the north of the sampled area. Five of the six species showed Wolbachia infection in at least some individuals, and the most abundant and widespread species, Eurytoma imminuta Bugbee, showed high Wolbachia infection levels and an all-female population, which strongly indicates endosymbiont-induced thelytoky. Our results demonstrate that gall communities are locally variable, and we suggest that future studies be undertaken to quantify variation in community composition at more local scales than has been past practice.

A Review of the Palaearctic Species of the Genus Eurytoma Ill. of the robusta Group, with Description of a New Species from Uzbekistan (Hymenoptera, Chalcidoidea: Eurytomidae)

A morpho-biological review and analysis of the Palaearctic species of the robusta group of the genus Eurytoma is presented. The differences between the species of the robusta group and the other species-groups of the genus Eurytoma are described. The hosts of the species of the robusta group and their geographical distribution are listed. A key to 62 Palaearctic species of the robusta group is compiled. A new species, Eurytoma uzbekistanica sp. n. belonging to the robusta species-group and morphologically closest to Eu. nochurae Zerova is described from Uzbekistan. Photographs of the types of Eu. uzbekistanica sp. n., Eu. herbaria Zerova, Eu. ibaraca Zerova, Eu. paramygdali Zerova et Fursov, Eu. armenica Zerova et Fursov, and Eu. nagoya Zerova, and also of the non-type specimens of Eu. dentata Mayr, Eu. robusta Mayr, and Eu. pyrrhidii Erdos are given. The holotype of the new species and material of the other species discussed are deposited in the collection of I.I. Schmalhausen Institute of Zoology of the National Academy of Sciences of Ukraine (Kyiv).

New records of three Eurytomidae (Hymenoptera: Chalcidoidea) associated with Stipa arabica Trin. & Rupr. (Poaceae) in Iran

ABSTRACT Despite the valuable scientific contributions of professional workers and amateur naturalists our knowledge of galls is still poorly known in Iran. In this study three species of the genus Eurytoma Illiger, viz Eurytoma collaris Walker, 1832, Eurytoma differta Zerova, 1977 and Eurytoma stepposa Zerova, 1980 reared from Stipa arabica Trin. & Rupr. (Poaceae) were reported for the first time for the fauna of Iran, collected from Kerman province in 2000. Diagnostic characters, short taxonomic comments and geographical distribution of these species are briefly mentioned.

Complex of Natural Enemies Associated With Scale Insects (Hemiptera: Coccomorpha) on Sugarcane in Brazil

A survey of the natural enemies of Aclerda takahashii (Kuwana, 1932) (Hemiptera: Aclerdidae) and Saccharicoccus sacchari (Cockerell, 1895) (Hemiptera: Pseudococcidae) was carried out in the state of São Paulo, Brazil. A total of ten associations were recorded, six parasitoid-host and four predator-prey, which three are new: parasitoids of the genus Eurytoma (Hymenoptera: Eurytomidae) and Hambletonia (Hymenoptera: Encyrtidae) associated with A. takahashii and S. sacchari, respectively; and the predator of the genus Diadiplosis (Diptera: Cecidomyiidae) with a S. sacchari. Anagyrus saccharicola Timberlake, 1932 and Mariola flava Noyes, 1980 (Hymenoptera: Encyrtidae) are reported for the first time in Brazil.

Two New Species of the Chalcid Genus Eurytoma Ill. (Hymenoptera, Chalcidoidea: Eurytomidae) from Israel and Spain

Two new species of the genus Eurytoma: Eu. vatrjapitzini Zerova et Klymenko, sp. n. and Eu. lirae Zerova et Klymenko, sp. n. are described. The first belongs to the robusta group, the second to the compressa group. Eurytoma vatrjapitzini sp. n. was collected using a Malaise trap in Israel; Eu. lirae sp. n. was reared from galls on stems of Artemisia campestris L. (Asteraceae) in Spain. The holotypes and all the paratypes of the new species are deposited in the collection of the Institute of Zoology, National Academy of Science of Ukraine (Kyiv).

New species of parasitoid wasps of the family Eurytomidae (Hymenoptera, Chalcidoidea) from the United Arab Emirates

Two new species of the genus Eurytoma, Eu. emirata Zerova, sp. n. and Eu. cornutella Zerova, sp. n., and two new species of the genus Nikanoria, N. globosa Zerova, sp. n. and N. cuspidata Zerova, sp. n., are described from the United Arab Emirates. This is the first record of genera and species of Eurytomidae from the United Arab Emirates. Holotypes and paratypes of the new species are deposited in the collection of Institute of Zoology, the National Academy of Sciences of Ukraine (Kiev).

Comparative morphology and biology of terminalinstar larvae of someEurytoma(Hymenoptera, Eurytomidae) species parasitoids of gall wasps (Hymenoptera, Cynipidae) in western Europe

Gómez J. F., Nieves-Aldrey J. L., Hernández Nieves M. & Stone G. N. 2011. — Comparative morphology and biology of terminal-instar larvae of some Eurytoma (Hymenoptera, Eurytomidae) species parasitoids of gall wasps (Hymenoptera, Cynipidae) in western Europe. Zoosystema 33 (3): 287-323.We present a taxonomic and biological study of the genus Eurytoma Illiger, 1807 (Hymenoptera, Eurytomidae), based on the morphology and biology of the terminal-instar larvae of 13 species living as parasitoids in the galls of European species of cynipid gall wasps. We provide the first detailed descriptions of the terminal-instar larvae of the studied species, illustrating diagnostic characters for the family and the studied genera with SEM pictures. We also provide a species key for the identification of Eurytoma larvae associated with cynipid galls, based on particular characters associated with the head, mouthparts and mandibles. Although we find only limited informative variation in body shape, the head and mandibles provide many characters of potential taxonomic and phylogenetic value. We summarise the larval biology of the 13 Eurytoma species inhabiting cynipid galls. Eurytoma larvae are usually solitary idiobiont ectoparasitoids of the host larva or of larvae of cynipid inquilines that also often feed on gall tissue.

New Species of the Genus Eurytoma (Hymenoptera, Eurytomadae) from Ukraine and Israel

New Species of the Genus Eurytoma (Hymenoptera, Eurytomadae) from Ukraine and Israel Two new species: Eurytoma kuslitzkyi Zerova, sp. n. from Israel and Eurytoma cornuta Zerova, sp. n. from Ukraine are described. The first species belongs to the robusta species group, and differs from other species of this group by the structure of the mesosternal shelf with two projections. The second species belongs to the compessa species group and differs from all other species of this group by the sharp corn on mesopleura.

Phylogenetic analysis of Eurytominae (Chalcidoidea: Eurytomidae) based on morphological characters

A phylogenetic study of the Eurytominae (Hymenoptera: Chalcidoidea) treating 178 taxa and based on 150 morphological characters is given. Several cladograms using the complete species sample, but obtained with different weightings, are presented. Local studies were also carried out to provide possible alternate topologies. The deep nodes of the trees were unstable and were never supported, but most of the superficial nodes were stable and robust. The results therefore provide support for a generic classification of the subfamily. The large genus Eurytoma - which includes about half of the described species of the subfamily - proved to be polyphyletic, and is redefined in a narrowed sense using putative synapomorphies. Bruchophagus and Prodecatoma were similarly redefined. The genera Philolema and Aximopsis are reconsidered and defined in a broader concept. A number of the species presently included in Eurytoma were transferred to these genera. Finally, 22 new generic synonymies are proposed and 33 species are transferred. The study also demonstrates that the Eurytomidae are polyphyletic. The results strongly sup-port a sister-group relationship between the Heimbrinae and the Chalcididae. The Rileyinae consist of two groups of unrelated taxa. A redefinition of the subfamily in a more restricted sense is supported by our results. The remaining group, consisting of the traditional Rileyinae, is included in the subfamily Buresiinae. Considered in this way they comprise the genera Buresium and Macrorileya, the latter being a senior synonym of Archirileya. The Buresiinae appear as the sister group of the Eurytominae. We propose to restrict the family Eurytomidae to these two taxa. This sister-group relationship provides evidence to polarize the biological habits within Eurytominae. The common ancestor of Buresiinae is presumed to parasitize insects (mostly at the egg stage) living in grass stems. (Resume d'auteur)

Destruction of Floral Buds in the bromeliad Vriesea friburgensis by the Phytophagous Larvae of the Wasp Eurytoma sp in southern Brazil (Hymenoptera: Eurytomidae)

In the terrestrial bromeliad Vriesea friburgensis Mez var paludosa (L B Smith) L B Smith 1952 of Southern Brazil it was observed that several flower buds did not open. The reproductive tissue at the base of the buds was destroyed by a phytophagous insect larva. The emerging adults were determined as eurytomid wasps, probably of a yet undescribed species of the genus Eurytoma Illiger 1807. In the laboratory, the course of its preadult development was studied, revealing a specific interorganismic relation between this parasitic hymenopteran and the bromeliad host.

A review of the Palaearctic species of the genus Eurytoma, belonging to the E. robusta species-group (Hymenoptera, Eurytomidae), with description of two new species

A review of Palaearctic species of the Eurytoma robusta group is given. This group includes 46 species. A key to these species is provided. Two new species, Eurytoma ibaraca Zerova, sp. n. from Japan and E. clarissae Zerova, sp. n. from Israel, are described. E. ibaraca is close to E. armenica Zer., but differs from it in the longer metasoma of the female, longer funicular segments, longer postmarginal vein, and sharp prominence on the fore coxa. E. clarissae is similar to E. asiatica Zer., but differs from it in the bulging fore coxa and longer postmarginal vein. The type material is deposited in the collection of the Shmalhausen Zoological Institute, National Ukrainian Academy of Sciences (Kiev).

Superparasitism by Torymus cyanimus (Hymenoptera: Torymidae) in the Volga-Kama region

On the basis of a twenty-year investigation, the life-cycle of Torymus cyanimus Boheman (Hymenoptera: Torymidae), a hyperparasitoid of a gall-forming fly in the Volga-Kama region is described. This parasitoid is the top-consumer in a food chain on Cirsium setosum (Willdenow) Iljin, in which the herbivore is Urophora cardui L. (Diptera: Tephritidae) and the primary parasitoids belong to the genus Eurytoma (Hymenoptera: Eurytomidae). Mating and oviposition behaviour were studied, and the superparasitism and larval cannibalism investigated in the second parasitoid generation. The superparasitism in T. cyanimus evolved in connection with the ovipositor elongation, leading to eggs being laid later when the fly host has already been completely consumed by larvae of Eurytoma serratulae F. Hyperparasitism and larval cannibalism in the second generation of T. cyanimus might account for the evolution of hyperparasitism in this species.

Bottom-Up and Top-Down Influences in the Trophic System of a Willow, a Galling Sawfly, Parasitoids and Inquilines

Strong bottom-up effects dominated the trophic system of the host plant, Salix pentandra, the specialist galling sawfly ; Euura amerinae, inquilines in the genus Eurytoma and the most common parasitoid attacking both genera of herbivores, Pteromalus. capreae. A young willow population provided the basic resources for the second and third trophic levels, and the inquilines and parasitoid species showed strong positive, but density-independent, responses to food supply. Colonized trees ranged from 3 to 7 years old in 1989, and the Euura population had increased by 1991, declined significantly by 1992, and went almost extinct in 1994. The sex ratio declined steadily from 1989 to 1992. Populations of Eurytoma and Pteromalus tracked their resources closely, without influencing the major aspects of Euura population change dictated by availability of young trees and the rapid development of host resistance correlated with tree age. Trees continuously colonized by Euura from before 1989 to 1992 were much more favorable to both higher trophic levels than trees colonized for the first time between 1989 and 1992, indicating the importance of host heterogeneity in the system. Overall, effects from the host plant up the trophic system were very much stronger than the effects of carnivores down the food web.

The Palaearctic species of Eurytoma (Hymenoptera: Eurytomidae) developing in stone fruits (Rosaceae: Prunoideae)

AbstractSpecies of the chalcidoid genus Eurytoma associated with stone fruits are studied for the Palaearctic region. The eight species known to have such an association are: E. amygdali Enderlein, E. maslovskii Nikol'skaya, E. padi Veresh-chagin, E. samsonowi Vasiljev, E. schreineri Schreiner, E. turkestanica sp. n., E. paramygdali sp. n. and E. armenica sp. n. The first six species are phytophagous, developing in the stones, and the last two are entomophytophages, starting their development as parasitoids of a phytophagous species and completing development feeding on plant tissue. Four species, E. amygdali, E. schreineri, E. samsonowi, and E. maslovskii are of economic importance. Information is given on the economic importance, biology, distribution and taxonomy of these species, and includes several new records for hosts and distribution. A key is given to distinguish the species.

Revision of Chalcid Wasps of Genus Eurytoma in America North of Mexico

Revision of Chalcid Wasps of Genus Eurytoma in America North of Mexico

A Revision of the Genus Eurytomocharis Ashmead in North America. (Hymenoptera: Eurytomidae.)

The genus Eurytomocharis was described by Ashmead in 1888, without any included species. E. minuta, described by Ashmead in 1894, was designated the genotype. Peck in 1951 placed Eurytomo- charis as a synonym of Eurytoma, and then resurrected it again in 1963. The present revision redefines the genus and describes the following new species from North America: Eurytomocharis armillata, E. sporoboli, E. glyceriae, E. pascuorum, and E. planitiae. All of the species, where known, are phytophagous in the stems of grasses. Examination of cotype specimens in the U. S. National Museum collection from beyond the boundaries of continental North America have resulted in transferring Eurytomocharis minima Ashm. from St. Vincent, West Indies, to the genus Eurytoma and Isosoma heteromera Ashm., also from St. Vincent, to Eurytomocharis. The genus Eurytomocharis has had a varied history. It was listed by Ashmead in 1888 in a paper containing a key to the genera of the Eurytominae, without any included species. In 1894 Ashmead described Eurytomocharis minuta from Jacksonville, Florida, and designated it as the genotype. In 1896 L. 0. Howard described two additional species of the genus, E. eragrostidis, from stems of Eragrostis poaeoides from Lafayette, Indiana, and E. triodiae, from dry stems of Triodia cuprea collected near Washington, D. C. The genus has never been formally described except by a brief mention of characteristics used in keys in the papers by Ashmead, 1888 and 1904.

BIOLOGICAL OBSERVATIONS ON SOME EURYTOMID (HYMENOPTERA: CHALCIDOIDEA) PARASITES ASSOCIATED WITH COMPOSITAE, AND SOME TAXONOMIC IMPLICATIONS

NATURALISTS for many years have collected plant galls and reared from them large and miscellaneous collections of insects, including many parasitic Hymenoptera. As early as the end of the eighteenth century, Fabricius (1798) described his Ichneumon serratulae (now in the genus Eurytoma) from specimens reared from galls on stems of Serratula arvensis L. (now in the genus Cirsium), the common creeping thistle. Some of the most popular plants with such workers have been the various Composite species, which are attacked by a wide variety of gall-forming insects. Although much rearing work has been carried out, it has usually been limited to collecting the parts of the plants concerned a t a suitable season and awaiting the emergence of the insects. I n this way a large collection can be obtained, but little is learnt of the true habits of the species concerned. The interrelationships of hosts and parasites are uncertain and the separation of phytophagous from entomophagous forms may be very difficult. Furthermore, collecting often tends to be indiscriminate so that mixed collections of galls may be kept unwittingly and any resulting host records will be doubtful. With little extra labour the same original plant material could be made to yield detailed information on such matters. If the galls, stems, or whatever the plant material may be, are opened a t a stage when the larvae within are fully fed (this will often be the whole period of the winter months), they can be removed together with cast skins, egg-shells, host remains, etc., and isolated in small gelatin capsules. Here they will usually pupate and emerge successfully. In this way can be built up a fairly detailed picture of the life histories concerned. Such methods were first effectively employed by Varley (1947) in his work on the parasites of the knapweed gall-fly, Uroplwra jaceana (Hering). I have used similar techniques with a wide diversity of galland stem-living insects and it is the purpose of this paper to describe the interrelationships of four species of Eurytorm which parasitise gallformers on various Composites in Britain, and to discuss briefly some of the taxonomic implications of such studies. None of the names here used for Eurytorna species will be found in Kloet and Hincks (1945).

A Note on Eurytoma calycis Bugbee (Hymenoptera: Eurytomidae) Occurring in Shoots of Jack Pine (Pinus banksiana (Lamb.))

Members of the genus Eurytoma Illiger show a great diversity of feeding habits. There are approximately 90 species or subspecies listed in the synoptic catalogue of the Hymenoptera (Muesebeck et al., 1951) and the first supplement to this catalogue (Krombein et al., 1958), and about 40 per cent of these have been listed with entomophagous hosts. The habitats of another 28 species are listed as galls and the lack of information on their hosts is made clear by Bugbee (1951) who states, “It should be clearly understood that where hosts are given in this paper, all that is indicated is that the parasites were bred or emerged from that particular host gall.” Seven species are listed as phytophagous on seeds and berries and the remainder have no specified hosts.

A New Species of the Genus Eurytoma (Hymenoptera: Eurytomidae) Phytophagous in the Buds of Jack Pine (Pinus banksiana)

In the spring of 1959, Dr. O. Peck of the Entomology Research Institute, Department of Agriculture, Ottawa, Canada, sent to me a long series of Eurytoma specimens for determination. Dr. J. B. Thomas reared the series from buds of jack pine (Pinus banksiana) and is ready to publish on the biology of the species. This new species has been included in a projected revision of the genus Eurytoma in North America, north of Mexico, but due to the uncertainty as to just when it will be ready for publication, it seems best to publish the description concurrently with the paper by Dr. Thomas, so as not to hold up 'his valuable contribution to the biology of the species.