Chemical imitation of yeast fermentation by the drosophilid-pollinated deceptive trap-flower Aristolochia baetica (Aristolochiaceae).

Deceptive flowers, unlike in mutualistic pollination systems, mislead their pollinators by advertising rewards which ultimately are not provided. Although our understanding of deceptive pollination systems increased in recent years, the attractive signals and deceptive strategies in the majority of species remain unknown. This is also true for the genus Aristolochia, famous for its deceptive and fly-pollinated trap flowers. Representatives of this genus were generally assumed to be oviposition-site mimics, imitating vertebrate carrion or mushrooms. However, recent studies found a broader spectrum of strategies, including kleptomyiophily and imitation of invertebrate carrion. A different deceptive strategy is presented here for the western Mediterranean Aristolochia baetica L. We found that this species is mostly pollinated by drosophilid flies (Drosophilidae, mostly Drosophila spp.), which typically feed on fermenting fruit infested by yeasts. The flowers of A. baetica emitted mostly typical yeast volatiles, predominantly the aliphatic compounds acetoin and 2,3-butandiol, and derived acetates, as well as the aromatic compound 2-phenylethanol. Analyses of the absolute configurations of the chiral volatiles revealed weakly (acetoin, 2,3-butanediol) to strongly (mono- and diacetates) biased stereoisomer-ratios. Electrophysiological (GC-EAD) experiments and lab bioassays demonstrated that most of the floral volatiles, although not all stereoisomers of chiral compounds, were physiologically active and attractive in drosophilid pollinators; a synthetic mixture thereof successfully attracted them in field and lab bioassays. We conclude that A. baetica chemically mimics yeast fermentation to deceive its pollinators. This deceptive strategy (scent chemistry, pollinators, trapping function) is also known from more distantly related plants, such as Arum palaestinum Boiss. (Araceae) and Ceropegia spp. (Apocynaceae), suggesting convergent evolution. In contrast to other studies working on floral scents in plants imitating breeding sites, the present study considered the absolute configuration of chiral compounds.

Catalogue of the Diptera (Insecta) of Morocco- an annotated checklist, with distributions and a bibliography.

The faunistic knowledge of the Diptera of Morocco recorded from 1787 to 2021 is summarized and updated in this first catalogue of Moroccan Diptera species. A total of 3057 species, classified into 948 genera and 93 families (21 Nematocera and 72 Brachycera), are listed. Taxa (superfamily, family, genus and species) have been updated according to current interpretations, based on reviews in the literature, the expertise of authors and contributors, and recently conducted fieldwork. Data to compile this catalogue were primarily gathered from the literature. In total, 1225 references were consulted and some information was also obtained from online databases. Each family was reviewed and the checklist updated by the respective taxon expert(s), including the number of species that can be expected for that family in Morocco. For each valid species, synonyms known to have been used for published records from Morocco are listed under the currently accepted name. Where available, distribution within Morocco is also included. One new combination is proposed: Assuaniamelanoleuca (Séguy, 1941), comb. nov. (Chloropidae).

On the identities of Neotropical Stegana species (Diptera, Drosophilidae). III. Four Costa Rican species described by J. R. Malloch

ABSTRACT The identities of the following four New World species of Stegana from Costa Rica, Stegana atrimana Malloch, 1924, Stegana nigrita Malloch, 1924, Stegana schildi Malloch, 1924, and Stegana tempifera Malloch, 1924, are clarified, and their redescriptions are provided. According to the original descriptions, the holotypes of the four species, deposited in the National Museum of Natural History (USNM), were males. However, upon dissection of their terminalia, we realized that all but one (S. tempifera) are females. Therefore, redescriptions of their external morphology (and/or terminalia) are mainly based on male paratypes, except for S. schildi, which is based on a male non-type specimen from Panama bearing Malloch's handwritten identification label. Photomicrographs of the habitus and terminalia, in addition to china ink drawings of the aedeagi and associated sclerites, are included.

On the identities of Neotropical Stegana species (Diptera, Drosophilidae). II. Stegana acutangula (Hendel) and Stegana triseta (Duda), with descriptions of three new closely related species

ABSTRACT Stegana (Orthostegana) acutangula (Hendel) from Bolivia and Stegana (Steganina) triseta (Duda) from Costa Rica are redescribed based on type specimens, and their identities clarified. A single syntype male of the first species (type species of the subgenus Orthostegana) is designated as a lectotype and one male out of the four Costa Rican syntypes (3 males, 1 female) of the latter species was selected as a lectotype of the Steganina subgenus. The other three (2 males, 1 female) specimens were designated as paralectotypes. All four males were dissected and their terminalia were photomicrographed. The two male Stegana triseta paralectotypes proved to belong to two unknown species closely related to Stegana acutangula, described here as Stegana dudai sp. nov. and Stegana turrialba sp. nov., and another male specimen, collected at Parque Nacional Yasuní, provinces of Napo/Orellana, Ecuador, is described as Stegana yasuni sp. nov. Additionally, we have included photomicrographs of the habitus of the type specimens as well as of some nontype specimens from Peru and Costa Rica. Based on the descriptions herein we not only clarified the status of these five species but also propose including all of them in the subgenus Orthostegana.

On the identities of Neotropical Stegana species (Diptera, Drosophilidae). I. Redescription of Stegana magnifica Hendel, 1913 and Stegana fumipennis (Enderlein, 1922)

Abstract Two conspicuous Steganinae species, Stegana (Steganina) magnifica Hendel, 1913 from Amazonian Peru and Stegana (Ceratostylus) fumipennis (Enderlein, 1922) from southern Brazil, are redescribed based on holotypes, and their identities are clarified. Both species are exclusive to the Neotropical Region and the first, with a body length of about 5.5 mm, is the largest species of Stegana described so far in this region, while the latter displays a peculiar antenna bearing an unusual, forward-projected, comma-shaped flagellomere 1. The photomicrographs of the habitus and terminalia of each specimen are also provided.

On the identities of Rhinoleucophenga pallida Hendel and Rhinoleucophenga obesa (Loew) (Diptera, Drosophilidae), with description of a new sibling species from Brazil

Abstract Rhinoleucophenga pallidaHendel, 1917 (type species of the genus) is redescribed based on its female holotype and a male from a nearby locality, and Rhinoleucophenga obesa (Loew, 1872) on its two syntypes, which are designated as the male lectotype and a female paralectotype. Both are valid species. A proposal is made to establish the genus Pseudophortica Sturtevant, 1918 (type species R. obesa), a junior synonym of Rhinoleucophenga, to subgenus rank and include all species of Rhinoleucophenga described or redescribed from males except R. pallida, which is unique in having a remarkable pedunculate surstylus, among other differences. The North American R. obesa is compared to its closest sibling, the South American species Rhinoleucophenga gigantea (Thomson, 1869). The occurrence of R. obesa in Brazil is also questioned, as suggested long ago by Marshall R. Wheeler. The specimens from Brazil previously identified as such most probably belong to the new species described in the present paper as Rhinoleucophenga (Pseudophortica) cantareira sp. nov. (type locality: Parque Estadual da Cantareira, City of São Paulo, State of São Paulo, Brazil). Numerous photomicrographs of their habitus and male terminalia taken with a Smartphone's rear camera and digitally stacked to create images with greater depth of focus are provided.

Oviposition Substrate of the Mountain Fly Drosophila nigrosparsa (Diptera: Drosophilidae).

The survival of insect larvae often depends on the mother's choice of oviposition substrate, and thus, this choice is an essential part of an insect species' ecology. Especially species with narrow substrate preferences may suffer from changes in substrate availability triggered by, for example, climate change. Recent climate warming is affecting species directly (e.g., physiology) but also indirectly (e.g., biological interactions) leading to mismatching phenologies and distributions. However, the preferred oviposition substrate is still unknown for many drosophilid species, especially for those at higher elevations. In this study, we investigated the oviposition-substrate preference of the montane-alpine fly Drosophila nigrosparsa in rearing and multiple-choice experiments using natural substrates in the laboratory. Insect emergence from field-collected substrates was tested. More than 650 insects were reared from natural substrates, among them 152 drosophilids but no individual of D. nigrosparsa. In the multiple-choice experiments, D. nigrosparsa preferred ovipositing on mushrooms (> 93% of eggs); additionally, a few eggs were laid on berries but none on other substrates such as cow faeces, rotten plant material, and soil. The flies laid 24 times more eggs per day when mushrooms were included in the substrates than when they were excluded. We infer that D. nigrosparsa is a mushroom breeder with some variation in oviposition choice. The flies favoured some mushrooms over others, but they were not specialised on a single fungal taxon. Although it is unclear if and how climate change will affect D. nigrosparsa, our results indicate that this species will not be threatened by oviposition-substrate limitations in the near future because of the broad altitudinal distribution of the mushrooms considered here, even if the flies will have to shift upwards to withstand increasing temperatures.

Fauna europaea: Diptera - brachycera.

Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding the Caucasus region). The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing taxonomic specialists throughout Europe and is a unique (standard) reference suitable for many user communities in science, government, industry, nature conservation and education. The Diptera-Brachycera is one of the 58 Fauna Europaea major taxonomic groups, and data have been compiled by a network of 55 specialists. Within the two-winged insects (Diptera), the Brachycera constitute a monophyletic group, which is generally given rank of suborder. The Brachycera may be classified into the probably paraphyletic 'lower brachyceran grade' and the monophyletic Eremoneura. The latter contains the Empidoidea, the Apystomyioidea with a single Nearctic species, and the Cyclorrhapha, which in turn is divided into the paraphyletic 'aschizan grade' and the monophyletic Schizophora. The latter is traditionally divided into the paraphyletic 'acalyptrate grade' and the monophyletic Calyptratae. Our knowledge of the European fauna of Diptera-Brachycera varies tremendously among families, from the reasonably well known hoverflies (Syrphidae) to the extremely poorly known scuttle flies (Phoridae). There has been a steady growth in our knowledge of European Diptera for the last two centuries, with no apparent slow down, but there is a shift towards a larger fraction of the new species being found among the families of the nematoceran grade (lower Diptera), which due to a larger number of small-sized species may be considered as taxonomically more challenging. Most of Europe is highly industrialised and has a high human population density, and the more fertile habitats are extensively cultivated. This has undoubtedly increased the extinction risk for numerous species of brachyceran flies, yet with the recent re-discovery of Thyreophoracynophila (Panzer), there are no known cases of extinction at a European level. However, few national Red Lists have extensive information on Diptera. For the Diptera-Brachycera, data from 96 families containing 11,751 species are included in this paper.