Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-24T14:23:42.313Z Has data issue: false hasContentIssue false

STRUCTURE, SENSORY EQUIPMENT, AND SECRETIONS OF THE OVIPOSITOR IN A GIANT SPECIES OF HYMENOPTERA: MEGARHYSSA ATRATA F. (ICHNEUMONIDAE, PIMPLINAE)

Published online by Cambridge University Press:  31 May 2012

Jean-Pierre Nénon
Affiliation:
Laboratoire d' Écobio1ogie des Insectes Parasitoïdes, Campus de Beaulieu, Avenue du Général Leclerc, 35042 Rennes Cedex, France
Nabila Kacem
Affiliation:
Laboratoire d' Écobio1ogie des Insectes Parasitoïdes, Campus de Beaulieu, Avenue du Général Leclerc, 35042 Rennes Cedex, France
Joseph Le Lannic
Affiliation:
Centre Commun de Microscopie Électronique à Balayage, Campus de Beaulieu, Avenue du Général Leclerc, 35042 Rennes Cedex, France

Abstract

Megarhyssa atrata F., the largest hymenopteran parasitoid known, is found in the holarctic. The stylus of its ovipositor can reach a length of 142 mm, the longest of all known genitalia in Arthropoda. This pimpline parasitizes its host, Tremex columba L., at a great depth in wood. Valvulae 3, which are always shorter than the stylus, are characterized on their outer side by abundant trichoid sensilla of three different types, and on their inner side by a dense layer of cuticular spines probably used in cleaning and shielding the stylus while at rest. The joint region between stylus and abdominal segments is richly equipped with mechanoreceptive trichoid and campaniform sensilla. The ovipositor canal is located between the two valvulae 1 which are separate for their entire length and supported proximally by the two valvulae 2 which are joined to each other from the base. The distal end of the stylus, shaped like an indented lancet, has secretory pores, the first such to be observed in Hymenoptera, from which accessory gland secretions flow. These secretions reach the end of the stylus by intravalvular canals in valvulae 1 and 2. These substances, which may cause cell lysis and also act as lubricants, can accumulate among the tens of thousands of cuticular formations distributed along the stylus which are thought to be surface storage cavities for the secretions. The sensory equipment of the stylus consists of six rows of approximately 200 mechanoreceptive campaniform sensilla. The ovipositor of M. atrata is thus characterized by almost exclusively mechanoreceptive sensory equipment; chemical stimuli appear to be monitored by two types of trichoid sensilla on valvulae 3. The finding that secretory pores occupy exactly the same sites as chemoreceptors in Ichneumonidae, Chalcidoidea, and Proctotrupoidea demonstrates the importance of studying the ovipositor of this parasitoid adapted to withstanding extreme pressures as it penetrates deep into wood.

Résumé

Megarhyssa atrata F., le plus grand Hyménoptère parasitoïde connu, est une espèce holarctique. Le stylet de son ovipositeur peut atteindre 142 mm, ce qui en fait l’appareil génital le plus long qui prévale chez un arthropode. Ce pimpliné trouve son hôte, Tremex columba L., profondément enfoui dans le bois. Les valvules 3, toujours plus courtes que le stylet, comportent d’abondantes sensilles trichoïdes de trois types sur leur bordure externe, et leur bordure interne est ornée d’une couche dense d’épines cuticulaires qui servent probablement au nettoyage et à la protection du stylet au repos. La jonction entre le stylet et les segments abdominaux comporte de nombreuses sensilles trichoïdes et campaniformes mécanoréceptrices. Le canal de l’ovipositeur est situé entre les deux valvules 1 qui sont séparées sur toute leur longueur et supportées dans leur partie proximale par les deux valvules 2 qui, elles, sont soudées depuis la base. L’extrémité distale du stylet, en forme de lancette dentelée, comporte des pores sécréteurs, les premiers jamais observés chez un Hyménoptère, par lesquels s’écoulent les sécrétions des glandes accessoires. Les sécrétions atteignent l’extrémité du stylet par les canaux intravalvulaires des valvules 1 et 2; ces substances, qui peuvent causer des lyses cellulaires et servir de lubrifiants, s’ accumulent sur les dizaines de milliers de formations cuticulaires du stylet qui jouent probablement le rôle de cavités superficielles de réserve des sécrétions. L’appareil sensoriel du stylet est constitué de six rangées d’environ 200 sensilles campaniformes mécanoréceptrices. Les structures sensorielles de l’oviscapte de M. atrata sont donc presque exclusivement mécanoréceptrices; les stimulus chimiques semblent perçus par deux types de sensilles trichoïdes sur les valvules 3. La position de pores sécréteurs à l’endroit où se trouvent les chimiorécepteurs des Ichneumonidae, Chalcidoidea et Proctotrupoidea, démontre à quel point il est important d’étudier les mécanismes d’adaptation de l’oviscapte de ce parasitoïde capable de subir des pressions extrêmes au cours de sa pénétration dans le bois.

[Traduit par la Rédaction]

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abbot, C.E. 1934. How Megarhyssa deposits her egg. Journal of the NewYork Entomological Society 42: 127133.Google Scholar
Aubert, J.F. 1958. Biologie de quelques Ichneumonidae Pimplinae et d'une espèce trimorphique du groupe de Gelis corrupta Först, avec révision des travaux concernant la théorie de Dzierzon. Thèse Doctorat Sciences Naturelles, Université de Paris, Paris.144 pp.Google Scholar
Aubert, J.F. 1969. Les Ichneumonides ouest-paléarctiques et leurs hôtes. 1. Pimplinae, Xoridinae, Acaenitinae. Editions quatre feuilles: 1302.Google Scholar
Austin, A.D., and Browning, T.O.. 1981. A mechanism for movement of eggs along insect ovipositors. International Journal of Insect Morpholology and Embryology 10(2): 93108.CrossRefGoogle Scholar
Baumann, C. 1923. Über den Bau des Abdomens und die Funktion des Legeapparates von Thalessa leucographa Grav. Zoologischer Anzeiger 58: 149162.Google Scholar
Copland, M.J.W. 1971. The structure and possible function of the reproductive system in some Eulophidae and Tetracampidae. Entomologist 104: 428.Google Scholar
Copland, M.J.W. 1972. The structure of the female reproductive system in the Torymidae (Hymenoptera: Chalcidoïdea). Transactions of the Royal Entomological Society of London 124: 191212.CrossRefGoogle Scholar
Copland, M.J.W., and King, P.E.. 1971. The structure of the female reproductive system in the Chalcididae (Hymenoptera: Chalcidoïdea). Entomologist's Monthly Magazine 107: 230239.Google Scholar
Copland, M.J.W., King, P.E., and Hill, D.S.. 1973. The structure of the female reproductive system in the Agaonidae (Hymenoptera: Chalcidoidea). Journal of Entomology Series A Physiology & Behaviour 48: 2535.Google Scholar
Cushman, R.A. 1926. Some types of parasitism among the Ichneumonidae. Proceedings of the Entomological Society of Washington 28: 2551.Google Scholar
Fyles, , 1916. Observations upon some of the predaceous and parasitic Hymenoptera. Annual Report of the Entomological Society of Ontario 46: 5260.Google Scholar
Gardiner, L.M. 1966. A photographic record of oviposition by Rhyssa lineolata (Kirby) (Hymenoptera: Ichneumonidae). The Canadian Entomologist 98: 9597.CrossRefGoogle Scholar
Gustafson, J.F. 1950. The origin and evolution of the genitalia of the Insecta. Microentomology 15: 3567.Google Scholar
Heatwole, H., Davis, D.M., and Wenner, A.M.. 1962. The behaviour of Megarhyssa, a genus of parasitic hymenopterans (Ichneumonidae: Ephialtinae). Zeitschrift für Tierpsychologie 19: 652664.CrossRefGoogle Scholar
Le Ralec, A. 1991. Les Hyménoptères parasitoïdes: adaptations de I'appareil reproducteur femelle. Morphologie et ultrastructure de l'ovaire, de l'oeuf et de l'ovipositeur. Thèse de Doctorat, Université de Rennes 1, Rennes, France.117 pp.Google Scholar
Le Ralec, A., Rabasse, J.M., and Wajnberg, E.. 1996. Comparative morphology of the ovipositor of some parasitic Hymenoptera in relation to characteristics of their hosts. The Canadian Entomologist 128: 413433.CrossRefGoogle Scholar
Matsuda, R. 1958. On the origin of the external genitalia of insects. Annals of the Entomological Society of America 51: 8494.CrossRefGoogle Scholar
Matsuda, R. 1976. The Hymenoptera. pp. 373396in Pergamon Press (Ed.), Morphology and evolution of the insect abdomen. Pergamon Press, New York.CrossRefGoogle Scholar
Nénon, J.P. 1993. Les Megarhyssa (Hymenoptera: Ichneumonidae) dans le sud du Québec; clé simplifiée de détermination et période de vol. Fabreries Revue d'Entomologie du Québec 18(2): 4957.Google Scholar
Nénon, J.P. 1995. Bioécologie de Megarhyssa atrata (Hymenoptera: Ichneumonidae) ectoparasitoïde de Tremex columba (Hymenoptera: Siricidae) au Québec. Phytoprotection 76(3): 115122.CrossRefGoogle Scholar
Nénon, J.P., Le Lannic, J., Kacem, N., Barbier, R., and Allo, M.R.. 1995. Micromorphologie de l'ovipositeur des Hyménoptères et évolution des Symphytes phytophages aux Apocrites parasitoïdes. Comptes Rendus de l'Academie des Sciences de Paris, Série III, 318(10): 10451051.Google Scholar
Quicke, D.L.J. 1991. Ovipositor mechanics of the braconine wasp genus Zaglyptogastra and the ichneumonid genus Pristomerus. Journal of Natural History 25: 971977.CrossRefGoogle Scholar
Quicke, D.L.J., Fitton, M.G., and Ingram, S.. 1992. Phylogenetic implications of the structure and distribution of ovipositor valvilli in the Hymenoptera (Insecta). Journal of Natural History 26: 587608.CrossRefGoogle Scholar
Riley, C.V. 1888. The habits of Thalessa and of Tremex. Insect Life 1: 168179.Google Scholar
Rollard, C. 1987. La biocénose associée aux Aranéides en Landes armoricaines. Étude des relations Insectes-Araignées. Thèse de Doctorat Université Rennes 1, Rennes, France. 292 pp.Google Scholar
Scudder, G.G.E. 1961. The functional morphology and interpretation on the insect ovipositor. The Canadian Entomologist 93: 267272.CrossRefGoogle Scholar
Scudder, G.G.E. 1964. Further problems in the interpretation and homology of the insect ovipositor. The Canadian Entomologist 96: 405417.CrossRefGoogle Scholar
Smith, E.L. 1968. Biosystematics and morphology of Symphyta. I. Stem galling Euura of the California region and a new female genitalic nomenclature. Annals of the Entomological Society of America 61: 13891407.CrossRefGoogle Scholar
Smith, E.L. 1969. Evolutionary morphology of the external insect genitalia. I. Origins and relationships to other appendages. Annals of the Entomological Society of America 62: 10511079.CrossRefGoogle Scholar
Smith, E.L. 1970. Evolutionary morphology of the external insect genitalia. 2. Hymenoptera. Annals of the Entomological Society of America 1: 27.Google Scholar
Snodgrass, R.E. 1933. Morphology of the insect abdomen. II. The genital ducts and the ovipositor. Smithsonian Miscellaneous Collections 89: 148.Google Scholar
Snodgrass, R.E. 1935. Principles of Insect Morphology. McGraw-Hill, New-York. 667 pp.Google Scholar
Spradbery, P.H.B. 1970. Host finding by Rhyssa persuasoria (L.), an Ichneumon: a parasite of Siricid woodwasps. Animal Behaviour 18: 103114.CrossRefGoogle Scholar
Talbot, P.H.B. 1964. Taxonomy of the fungus associated with Sirex noctilio. Australian Journal of Botany 12: 4652.CrossRefGoogle Scholar
Townes, H., and Townes, M.. 1960. Ichneumon—flies of America north of Mexico: 2. Subfamilies Ephialtinae, Xorininae, Acaenitinae. U.S. National Museum Bulletin 216: 1676.Google Scholar