The superfamily Platygastroidea (Hymenoptera: Proctotrupomorpha) is a diverse group of parasitoid wasps that are parasitoids of nine orders of insects as well as spiders. They appear to show a clear pattern of host group specificity among genera. A robust phylogeny is essential for devising a stable and informative classification and understanding the pattern of the shifts to parasitize new host groups. We conducted phylogenetic analyses of Platygastroidea based on four molecular markers (18S, 28S, COI and wingless) and 119 morphological characters, and a phylogenomic analysis of a subset of taxa based on 4371 single-copy, protein-coding genes. The four-gene analyses, both with and without morphological data, robustly recovered some well-established groups, e.g., Platygastridae (in its traditional sense), Scelionini, Teleasinae and Telenominae, as well as some novel patterns of relationship. The ground-plan host for the superfamily are the eggs of Orthoptera, with multiple shifts to attack new host groups. The phylogenomic analysis of a subset of taxa recovered a clear pattern of relationships for the backbone of the superfamily with maximal bootstrap support. Based on the combination of these two approaches, we present a revised classification for Platygastroidea and recognize the following eight families: Geoscelionidae stat.rev., Janzenellidae fam.nov., Neuroscelionidae fam.nov., Nixoniidae stat.rev., Platygastridae stat.rev., Proterosceliopsidae †, Scelionidae stat.rev. and Sparasionidae stat.rev.
Accessions PI 126449 and PI 134417 of wild tomato, Lycopersicon hirsutum f. glabratum C.H. Mull, were assessed for resistance to the pink potato aphid, Macrosiphum euphorbiae (Thomas). Aphid populations under field and greenhouse conditions were significantly lower on the L. hirsutum f. glabratum plants compared to L. esculentum. Removal of trichome glands and exudates by wiping the leaf surface resulted in a dramatic decrease in aphid mortality. Compared to L. esculentum, aphid behavior on the L. hirsutum f. glabratum plants was characterized by 40 to 52% abandonment, delay in time for first probe, reduction of number and duration of probes and decrease in the total proportion of time probing. Removal of the trichomes reduced the percentage of abandonment and increased the total proportion of time probing. Density and type of glandular trichomes varied among plant lines and on adaxial and abaxial leaf surfaces within a line, particularly for the L. hirsutum f. glabratum plants. PI 134417 was, in general, more resistant to the aphids than PI 126449.
Five genera in the tribe Sparasionini are described and keyed. Electroteleia Brues (Baltic amber), Sceliomorpha Ashmead (Neotropics) and Sparasion Latreille (Nearctic, Palearctic, Oriental, and Afrotropical regions) are redescribed. Listron Musetti and Johnson, new genus is described from Chile with two species, L. politum Musetti and Johnson, new species (type species of the genus), and L. bilaminatum Masner, new species. Mexon Masner and Johnson, new genus, is described from Mexico, with two new species, M. adelphos Masner and Johnson, new species (type species of the genus), and M. consors Masner and Johnson, new species. The synonymy of Aliofreniger Szabó with Sceliomorpha and of Prosparasion Kieffer with Sparasion are confirmed. Transfer of the type species of Prosparasion, P. coeruleum Kieffer, 1913 into the genus Sparasion makes it a secondary junior homonym of Sparasion coeruleus Kieffer, 1905. The replacement name Sparasion lividus Johnson, Masner, and Musetti is proposed for the junior name to resolve this homonymy. The gender of the name Sparasion is discussed, and we propose that it should be treated as a masculine noun. The authorship of the family-group name Sparasionini is credited to Dahlbom (1858).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.