Hidden Diversity—A New Speciose Gall Midge Genus (Diptera: Cecidomyiidae) Associated with Succulent Aizoaceae in South Africa

Aizoaceae (Caryophyllales) constitute one of the major floral components of the unique Greater Cape Floristic Region (GCFR), with more than 1700 species and 70% endemism. Within succulent Aizoaceae, the subfamily Ruschioideae is the most speciose and rapidly diversifying clade, offering potential niches for the diversification of specialized herbivorous insects. Nevertheless, insect diversity on these plants has not been studied to date, and knowledge of gall-inducing insects in the Afrotropics is generally scarce. Our recent observations indicate that succulent Aizoaceae in the GCFR support a rich and largely unstudied community of gall midges (Diptera: Cecidomyiidae). Here, we provide a first report of their diversity with a description of a new genus, Ruschiola Dorchin, and ten new species, based on morphological and molecular analyses of material collected during a three-year targeted survey across major GCFR vegetation types. A high degree of morphological uniformity in Ruschiola suggests recent diversification and necessitated the use of molecular data and laboratory rearing from host plants to verify species boundaries and host ranges.

Reclassification of Gall Midges (Diptera: Cecidomyiidae: Cecidomyiini) from Amaranthaceae, with Description of Ten New Species Based on an Integrative Taxonomic Study

The genus Halodiplosis includes 99 species restricted to host-plants of the Amaranthaceae, virtually all of which are from Central Asia. The discovery of numerous undescribed species putatively belonging to this genus in Israel instigated an exhaustive review of the original descriptions of all known species in this genus. This study revealed that the generic concept of Halodiplosis and some of the genera synonymized under it should be redefined based on morphological and life-history attributes, such that Halodiplosis is limited to only 13 species developing in plant tissues without obvious gall formation or as inquilines in galls of other cecidomyiids. Revised status were proposed for Asiodiplosis, Onodiplosis, and Desertomyia, all species of which are gall inducers. A detailed morphological study of the Israeli species combined with data on their life history and an analysis of mitochondrial COI and 16S gene sequences revealed nine gall-inducing species belonging to Asiodiplosis and one inquilinous species belonging to Halodiplosis. All ten species (Asiodiplosis admirabilis n.sp., A. bimoda n.sp., A. delicatula n.sp., A. largifica n.sp., A. mohicana n.sp., A. mucronata n.sp., A. paradoxa n.sp., A. pillosaeconspicua n.sp., A. stellata n.sp., and Halodiplosis fugax n.sp.) are described here as new to science, including the first descriptions of larvae and pupae for these genera.

An Integrative Study on Asphondylia spp. (Diptera: Cecidomyiidae), Causing Flower Galls on Lamiaceae, with Description, Phenology, and Associated Fungi of Two New Species

An integrative study on some species of Asphondylia was carried out. Two species of gall midges from Italy, Asphondylia rivelloi sp. nov. and Asphondylia micromeriae sp. nov. (Diptera: Cecidomyiidae), causing flower galls respectively on Clinopodium vulgare and Micromeria graeca (Lamiaceae), are described and illustrated. The characteristics of each developmental stage and induced galls are described, which allowed the discrimination of these new species in the complex of Asphondylia developing on Lamiaceae plants. Molecular data based on sequencing both nuclear (ITS2 and 28S-D2) and mitochondrial (COI) genes are also provided in support of this discrimination. Phylogeny based on nuclear markers is consistent with the new species, whereas COI phylogeny suggests introgression occurring between the two species. However, these species can also be easily identified using a morphological approach. Phenology of host plants and gall midges are described, and some peculiar characteristics allow the complete and confident discrimination and revision of the treated species. Gall-associated fungi were identified as Botryosphaeria dothidea,Alternaria spp., and Cladosporium spp.

A new species of the fossil genus Electrotrichia (Insecta: Trichoptera: Hydroptilidae) from Rovno amber (Zhytomyr region, Olevsk locality)

Recent discoveries of amber deposits have resulted in numerous new caddisfly species of Rovno amber described in a series of recent papers (Melnitsky & Ivanov, 2010, 2013, 2016a, b). The list of species previously known from Rovno amber included 42 species (Ivanov et al., 2016; Perkovsky, 2017). Our study is based on a collection of Trichoptera from a new Rovno amber locality near Olevsk in Zhytomyr region. Nine amber species have been reported from this region (Legalov et al., 2021; Radchenko et al., 2021), including new ant species, a new anthribid, two new genera, and four new species of gall midges (Fedotova & Perkovsky, 2015, 2017); additional new cicadellid genus and species is described from closely connected fauna of Perebrody (Dietrich et al., 2021). It total, the new collection includes 6 pieces of Rovno Amber with six specimens of Trichoptera, two of those are described below as a new species of Electrotrichia.

Taxonomic Description of Stenodiplosis tectori n. sp. (Diptera: Cecidomyiidae), a Seed Parasite of Cheatgrass, Anisantha tectorum, Based on Morphological and Mitochondrial DNA Data

Cheatgrass is an annual grass species from Eurasia that has become invasive in much of western North America. It has been implicated in recent increases in the frequency, size, and intensity of wildfires, contributing to severe economic, environmental, and social destruction. In order to reduce this damage, the USDA-ARS established a classical biological control program against cheatgrass. In 2018 and 2019, adult gall midges were collected emerging from cheatgrass seed heads collected at several sites in Bulgaria and Greece; this is the first gall midge ever recorded from cheatgrass. Morphological comparisons with related midge species recorded from other plant hosts revealed that this midge from cheatgrass is a new species, described here as Stenodiplosis tectori n. sp. This status was supported by sequence comparisons of a barcode region of the gene encoding the mitochondrial cytochrome c subunit I (CO1) protein in Stenodiplosis tectori n. sp. and three congeners. The present study is the first to report MT-CO1 data in the genus Stenodiplosis. The ingroup Stenodiplosis tectori n. sp. collected in the Balkans grouped in one phylogenetic supported clade, with an average K2P-distance from its closest related congener, S. sorghicola, of 7.73% (SD = 1.10). The findings indicated relatively high year-to-year within-population diversity. Implications for this gall midge’s utility as a biological control agent of cheatgrass are discussed.

First characterization of a taxonomically well‑resolved trophic network composed by host plants and gall midges (Diptera: Cecidomyiidae) in the Neotropical region

In the present study we described the structure of a trophic network composed by gall-midge species (Diptera: Cecidomyiidae) and their host plants in the Restinga of Barra de Maricá (Maricá, Rio de Janeiro, Brazil). Species data were retrieved from literature and different topological descriptors (links per species, connectance, and modularity of interactions) were used. All gall-midge species were monophages, with connectance of 2.8% of the 2,016 possible interactions. The network of host plants and gall midges had low number of links per species and high modularity, which indicates high specificity and specialization of plant-galling interactions in the area. This is the first characterization of a trophic network with good taxonomic resolution for the Neotropical gall midges.

A review of gall midges (Diptera: Cecidomyiidae) described from Mesozoic deposits

Twenty-four fossil gall midges (Cecidomyiidae) described from 1917–2020 from Mesozoic deposits, mostly ambers, are reviewed. Information from the original publications is used as the basis for reinterpretation, when such is regarded as appropriate here. As a result, the fossil record of cecidomyiids from the Mesozoic comprises representatives of the following subfamilies and tribes, all mycophagous (numbers in parentheses refer to species described): Catotrichinae (1); Micromyinae: Catochini (2), Amediini (1), Campylomyzini (1), Micromyini (2) and Aprionini (1); Winnertziinae: Heteropezini (2), Diallactiini (4) and Winnertziini (1); Porricondylinae: Dicerurini (1). Other Winnertziinae (3) and Micromyinae (5) cannot be classified to tribe because information on critical morphological structures is unavailable; they are thus considered incertae sedis. Members of the Lestremiinae sensu stricto are unrecorded from the Mesozoic, as are any Cecidomyiinae (the only subfamily containing phytophages and predators). Commonly occurring reasons for misinterpretation of amber fossils are the non-recognition of artefacts and the unfamiliarity with group-specific literature regarding prevailing taxonomic concepts and the morphological diversity found in Cecidomyiidae. These causes as well as obvious differences between neontological and paleontological taxonomic practices are discussed. Amediini trib. nov. Jaschhof, 2021 is introduced as a new tribe of the Micromyinae, to absorb the genera Amedia Jaschhof, 1997 (extant, North America, type genus), Amediella Jaschhof, 2003 (extant, New Zealand) and Eltxo Arillo & Nel, 2000 (extinct, Alava amber). A diagnosis of the new tribe is given. Krassiloviolini Fedotova & Perkovsky, 2017 is a new junior synonym of Heteropezini Schiner, 1868. Amediini Plakidas, 2017 and Zarqacecidomyius singularis Kaddumi, 2007 are nomina nuda.

Cecidomyiidae (Diptera, Insecta): richness of species and distribution in Brazil

Most Neotropical species of Cecidomyiidae (Diptera) have been described from Brazil, but a list of species with occurrence in the country has never been published. Little is known about their distribution and richness in the Brazilian phytogeographic domains. Additionally, a list of host plant species has never been gathered. The present study aims to fill these knowledge gaps and provides an overview of this family in Brazil. For this, data were obtained mainly from the literature, but also from the Cecidomyiidae collection of Museu Nacional and two herbaria (RB and R). Based on the site "Flora do Brasil 2020", botanical names were updated and plant species origin and distribution were verified. A total of 265 gall midge species have been recorded in Brazil, most from the Atlantic Forest (183), followed by Cerrado (60), and Amazon Forest (29). The other phytogeographic domains shelter from five to ten species. Phytophagous gall midges occur on 128 plant species of 52 families, almost all native, being 43 endemic to Brazil (21 endemic to Atlantic Forest, five to Cerrado, and one to Amazon). Although, the taxonomical knowledge is focused on the Atlantic Forest, each domain has its own fauna composition and these informations can be useful for environmental conservational purposes. About 58% of the Brazilian fauna are known only from the type-locality. In order to fill these gaps, it is necessary and important to collect in uninvestigated areas.