Catalogue of the Australian social wasps (Hymenoptera: Vespidae).

A catalogue of the social wasps occurring in Australia is presented. New synonymies include Vespa cohabitatrix Curtiss, 1938 (= Polistes olivaceus (DeGeer, 1773)) and Vespula vulgaris vetus Eck, 1999 (= Vespula vulgaris (Linnaeus, 1758)).

Catalogue of the Australian Eumeninae (Hymenoptera: Vespidae).

A catalogue of Eumeninae occurring in Australia is presented. The genus Lissodynerus Giordani Soika is synonymized with Pararrhynchium de Saussure. Species placed in the genus Pseudepipona de Saussure, by Giordani Soika and Borsato are transferred to Euodynerus Dalla Torre, and species placed in the genus Syneuodynerus Blüthgen, by Giordani Soika are transferred to Stenodyneriellus Giordani Soika. New combinations are Anterhynchium decoratum (de Saussure), A. tamarinum inviolatum (Giordani Soika), Australodynerus flavoniger (Giordani Soika), Deuterodiscoelius confusus (Giordani Soika), D. ephippium (de Saussure), D. insignis (de Saussure), D. spinosus (de Saussure), Euodynerus aborigenus (Borsato), E. alaris (de Saussure), E. angulatus alexandriae (Giordani Soika), E. angulatus angulatus (de Saussure), E. aspra (Giordani Soika), E. clypalaris (Giordani Soika), E. flavus (Giordani Soika), E. pallidus (Giordani Soika), E. succinctus purgatus(Giordani Soika), E. succinctus succinctus (de Saussure), Pararrhynchium desaussurei (Borsato), P. kurandensis (Giordani Soika), Pseudalastor aurantiacus (Borsato), P. pecularis (Borsato), Stenodyneriellus aurantiacus (Giordani Soika), S. aurantiopilosella (Giordani Soika), S. cylindrellus (Giordani Soika), S. longebispinosa (Giordani Soika) and S. occidentatus (Giordani Soika). Revised combinations are Australodynerus yanchepensis nigrithorax Giordani Soika and A. yanchepensis yanchepensis Giordani Soika, which are returned to that genus. Other new synonymies are Anterhynchium tamarinum septentrionale Giordani Soika = Anterhynchium tamarinum tamarinum (de Saussure), Ischnocoelia robusta analis Giordani Soika = I. robusta robusta (Meade-Waldo), Pseudabispa bicolor flavescentula (Giordani Soika) = P bicolor bicolor (de Saussure), Pseudalastor tridentatus septentrionalis Giordani Soika = P. tridentatus tridentatus Giordani Soika and Rhynchium australense Perkins = R. magnificum Smith.

Caught in the act: pollination of sexually deceptive trap-flowers by fungus gnats in Pterostylis (Orchidaceae).

BACKGROUND AND AIMS: Pterostylis is an Australasian terrestrial orchid genus of more than 400 species, most of which use a motile, touch-sensitive labellum to trap dipteran pollinators. Despite studies dating back to 1872, the mechanism of pollinator attraction has remained elusive. This study tested whether the fungus gnat-pollinated Pterostylis sanguinea secures pollination by sexual deception. METHODS: The literature was used to establish criteria for confirming sexual deception as a pollination strategy. Observations and video recordings allowed quantification of each step of the pollination process. Each floral visitor was sexed and DNA barcoding was used to evaluate the degree of pollinator specificity. Following observations that attraction to the flowers is by chemical cues, experimental dissection of flowers was used to determine the source of the sexual attractant and the effect of labellum orientation on sexual attraction. Fruit set was quantified for 19 populations to test for a relationship with plant density and population size. KEY RESULTS: A single species of male gnat (Mycetophilidae) visited and pollinated the rewardless flowers. The gnats often showed probing copulatory behaviour on the labellum, leading to its triggering and the temporary entrapment of the gnat in the flower. Pollen deposition and removal occurred as the gnat escaped from the flower via the reproductive structures. The labellum was the sole source of the chemical attractant. Gnats always alighted on the labellum facing upwards, but when it was rotated 180 ° they attempted copulation less frequently. Pollination rate showed no relationship with orchid population size or plant density. CONCLUSIONS: This study confirms for the first time that highly specific pollination by fungus gnats is achieved by sexual deception in Pterostylis. It is predicted that sexual deception will be widespread in the genus, although the diversity of floral forms suggests that other mechanisms may also operate.

Molecular genetic analysis and ecological evidence reveals multiple cryptic species among thynnine wasp pollinators of sexually deceptive orchids.

Sexually deceptive Chiloglottis orchids lure their male thynnine wasp pollinators to the flower by emitting semiochemicals that mimic the specific sex pheromone of the wasp. Sexual deception is possible because chemical rather than visual cues play the key role in wasp mate search, suggesting that cryptic wasp species may be frequent. We investigated this prospect among Neozeleboria wasp pollinators of Chiloglottis orchids, drawing on evidence from molecular phylogenetic analysis at three genes (CO1, rhodopsin and wingless), population genetic and statistical parsimony analysis at CO1, orchid associations and their semiochemicals, and geographic ranges. We found a compelling relationship between genetically defined wasp groups, orchid associations, semiochemicals and geographic range, despite a frequent lack of detectable morphological differences. Our findings reveal multiple cryptic species among orchid pollinators and indicate that chemical changes are important for wasp reproductive isolation and speciation. The diversity of Neozeleboria may have enabled, rather than constrained, pollinator-driven speciation in these orchids.