Removing symbiotic Wolbachia bacteria specifically inhibits oogenesis in a parasitic wasp

Wolbachia are bacteria that live in the cells of various invertebrate species to which they cause a wide range of effects on physiology and reproduction. We investigated the effect of Wolbachia infection in the parasitic wasp, Asobara tabida Nees (Hymenoptera, Braconidae). In the 13 populations tested, all individuals proved to be infected by Wolbachia. The removal of Wolbachia by antibiotic treatment had a totally unexpected effect—aposymbiotic female wasps were completely incapable of producing mature oocytes and therefore could not reproduce. In contrast, oogenesis was not affected in treated Asobara citri, a closely related species that does not harbor Wolbachia. No difference between natural symbiotic and cured individuals was found for other adult traits including male fertility, locomotor activity, and size, indicating that the effect on oogenesis is highly specific. We argue that indirect effects of the treatments used in our study (antibiotic toxicity or production of toxic agents) are very unlikely to explain the sterility of females, and we present results showing a direct relationship between oocyte production and Wolbachia density in females. We conclude that Wolbachia is necessary for oogenesis in these A. tabida strains, and this association would seem to be the first example of a transition from facultative to obligatory symbiosis in arthropod–Wolbachia associations.

Chemical and isotopic compositions of hydrothermal manifestations and minerals from the Broken Spur hydrothermal field

A representative collection of hydrothermal manifestations was sampled practically from all hydrothermal mounds of the Broken Spur hydrothermal vent field with use of the Mir manned submersibles during three cruises of R/V Akademik Mstislav Keldysh. Mineral associations characteristic for different morphological types of sulfide ores from hydrothermal pipes, plates, and diffusers are assessed. Particular attention is paid to distribution of minor elements and their distribution patterns determined by mineralogical zonation. Measured isotopic composition of sulfur in sulfide minerals varies from 0.4 to 5.2 per mil that indicates their similarity with ores from the Snake Pit vent field and is related to dilution of hot ore-bearing solutions by seawater and reduction of water sulfate ions to H2S with heavy isotopic composition.

The Comedies of Aristophanes /

Each play has special t.p.

Eight comedies of Aristophanes,

General introduction.--Chronological table.--Acharnians.--Knights.--Clouds.--Wasps.--Peace.--Birds.--Frogs.--Plutus.

Fauna insectorum Helvetiae. Hymenoptera. Fam. Diploptera Latr. (Vespida aut.)

Issued with Schweizerische entomologische Gesellschaft. Mittheilung, Bd. VII.

Grävsteklarnas liv.

Mode of access: Internet.

Bau und Entwicklung der Mundteile bei Vespa vulgaris,

Reprinted from Morphologisches Jahrbuch, Bd. 39, Heft 1.

Monographie der Gattung Synagris Latreille (Hymen.-Vespidae).

Also carries pagination of the original: p. [215]-333.

Cynipid galls of the Southwest (Hymenoptera, Cynipoidea); an aid to their identification.

Mode of access: Internet.

Australian hymenoptera chalcidoidea.

Caption title.

Etudes sur les fourmis, les guêpes et les abeilles.

Mode of access: Internet.

Zoocecidien vom Feldberg.

"Separatabdruck aus den 'Mitteilungen des Badischen botanischen Vereins.' 1903."

Gallen und gallentiere aus Argentinien.

Caption title.

Notes sur les fourmis et les guêpes,

22 numbered extracts from Comptes rendus des séances de l'Académie des sciences.

Los enemigos de los parásitos de las plantas : los Afelininos /

Includes index.