Julia Stigenberg

Phylogeny of the parasitic wasp subfamily Euphorinae (Braconidae) and evolution of its host preferences

The braconid subfamily Euphorinae is a large, cosmopolitan group of endoparasitoid wasps. The majority of species attack adult hosts, a strategy that is rare among parasitic wasps, but there are also many species that attack nymphs and larval stages. Euphorine hosts may belong to a variety of insect orders (Coleoptera, Hemiptera, Hymenoptera, Neuroptera, Psocoptera, Orthoptera and Lepidoptera) although most euphorine tribes are confined to Coleoptera. Here we investigate the phylogenetic relationships of the Euphorinae based on molecular data (3 kb of nucleotide data from four markers: 18S, 28S, CAD and COI) and propose a higher‐level classification based upon the resulting phylogeny. We also infer the evolution of host associations and discuss the diversification of the Euphorinae. Results from both Bayesian inference and maximum‐likelihood analysis show that the subfamily, as previously circumscribed, is paraphyletic. We propose that the subfamily be expanded to include the tribes Meteorini and Planitorini (Mannokeraia + Planitorus), so that it corresponds to a clade that is strongly supported as monophyletic in our analyses. Based on our results, a revised higher classification of the Euphorinae is proposed, in which 52 extant genera and 14 tribes are recognized. We reinstate the genus Microctonus belonging to the tribe Perilitini, and synonymize Ussuraridelus with Holdawayella, Sinuatophorus with Eucosmophorus. Furthermore, we propose the following tribal rearrangements: Spathicopis and Stenothremma are transferred to Perilitini; Tuberidelus, Eucosmophorus and Plynops to Cosmophorini; Ecclitura to Dinocampini; Chrysopophthorus, Holdawayella and Wesmaelia to Helorimorphini; Proclithroporus and Heia to Townesilitini. The monotypic tribe Cryptoxilonini is synonymized with Cosmophorini. The genera Pygostolus and Litostolus are placed in a separate tribe, Pygostolini, previously recognized as a subtribe among the Centistini. Parsimony‐based ancestral state reconstructions suggest that the ancestor of Euphorinae was a parasitoid of lepidopteran larvae, and that a host shift to larval Coleoptera occurred only in one clade of the Meteorini, some members of which secondarily shifted back to larval lepidopteran hosts. In the remainder of the subfamily, there was an initial shift from larval to adult coleopterans, followed by subsequent shifts to adults or larvae of Hemiptera, Hymenoptera, Neuroptera, Orthoptera and Psocoptera.

Meteorus acerbiavorus sp. nov. (Hymenoptera, Braconidae), a gregarious parasitoid of Acerbia alpina (Quensel) (Lepidoptera, Arctiidae) in North Finland

The new gregarious parasitoid Meteorus acerbiavorus sp. nov. (Hymenoptera, Braconidae) was reared from the cocoons of Acerbia alpina (Quensel) (Lepidoptera, Arctiidae) in north-western Finnish Lapland. This species belongs to Meteorus rubens (Nees) species group and differs from the most related M. rubens in the following features: the eyes densely setose; the median lobe of the mesoscutum, scutellum, mesopleuron, and the hind coxa entirely or at least partly rugulose-granulate or rugose-areolate and sometimes with granulation; the ovipositor subapically with distinct dorsal node; the ventral borders of the first metasomal tergum weakly separated by narrow space in its basal half; the colour of the body and legs mostly or entirely dark; the fore wing more or less darkened. Phylogenetic relationships among several Meteorus species close to M. rubens including new M. acerbiavorus were investigated based on DNA sequence fragments of the mitochondrial COI and the nuclear 28S rDNA genes. The discussions on the species groups of Meteorus, on distribution of Acerbia alpina in the Holarctic and on its known parasitoids are presented.

Multilocus phylogeny of the parasitic wasps in the tribe Euphorini (Hymenoptera: Braconidae) with revised generic classifications

Background Parasitic wasps in the family Braconidae are important regulators of insect pests, particularly in forest and agroecosystems. Within Braconidae, wasps in the tribe Euphorini (Euphorinae) attack economically damaging plant bugs (Miridae) that are major pests of field and vegetable crops. However, the evolutionary relationships of this tribe have been historically problematic. Most generic concepts have been based on ambiguous morphological characters which often leads to misidentification, complicating their use in biological control. Methods Using a combination of three genes (COI, 28S, and CAD) and 80 taxa collected worldwide, we conducted Bayesian inference using MrBayes, and maximum likelihood analyses using RAxML and IQ-Tree on individual gene trees as well as the concatenated dataset. Results The monophyly of the tribe Euphorini and the two genera Peristenus and Leiophron were confirmed using maximum likelihood and Bayesian inference. The subgeneric classifications of Leiophron sensu lato were not supported, and the monotypic genus Mama was also not supported. Discussion Euphoriella, Euphoriana, Euphorus, and Mama syn. n, have been synonymized under Leiophron. Mama mariae syn. n was placed as a junior synonym of Leiophron reclinator. The generic concepts of Peristenus and Leiophron were refined to reflect the updated phylogeny. Further we discuss the need for revising Euphorini given the number of undescribed species within the tribe.

Review of the Palaearctic (and Oriental) Allurus (Braconidae, Euphorinae) based on material from Sweden

Abstract Background The tribe Centistini includes three genera, Allurus, Centistes and Centistoides (Stigenberg et al. 2015). They are solitary endoparasitoids of adults and final instar larvae of beetles from the family Curculionidae (Jackson 1920, Aeschlimann 1980, Tobias 1986) New information In this paper we present a key, molecular data (standard DNA barcode, CO1) and images of the two species of Allurus occurring in the Western Palaearctic. A third Oriental species described from China (Taiwan) is also included in the key. Allurus is a Holarctic genus with three known species (A. choui, A. lituratus, A. muricatus). Our sequence data confirms that A. muricatus and A. lituratus are two distinct and separate species and this paper points out good and easy characters to separate them.