The results of a multi-year investigation into relationships between hoverflies (Syrphidae) of the Merodon constans species group and Galantheae host plants are summarized. The larvae of nine species of the M. constans group (within the M. albifrons evolutionary lineage), from the Black Sea and western Mediterranean regions were found to inhabit 13 species of snowdrops (Galanthus spp.) and a species of snowflake (Leucojum vernum). The relationship between Merodon analis Meigen, 1822 and Galanthus nivalis L. is confirmed. The natural-history unity of the M. constans group is confirmed by monophagy on Galantheae species. We describe and illustrate for the first time the methods used to investigate the life cycle of these elusive insects in the field. We show how phytophagous insects can be studied with minimal interference to plant populations, such as endangered snowdrop populations. We describe the distribution of all studied Merodon species and include an updated key to the species of the M. constans group. Two new species of this group, Merodon adjaricus Mishustin, Popov & Vujić, sp. nov. and Merodon resani Mishustin, Popov & Vujić, sp. nov., are described from Georgia. The insect-plant interactions, nature conservation issues and phytosanitary risks of these hoverfly species are also discussed.

Wild bees (Hymenoptera: Anthophila) and hoverflies (Diptera: Syrphidae), the two major groups of insect pollinators, are undergoing alarming declines worldwide, including Europe. The lack of accessible and verified spatial and temporal occurrence records currently challenges efforts to understand and mitigate this decline. Here, we compiled datasets from diverse sources, including taxonomists, national experts, public repositories, museum collections, published literature, verified open-access platforms, and aggregated datasets from previous European projects. The collected data were standardised, cleaned and validated by taxonomists and national experts. This collective effort resulted in two databases comprising more than 4.34 million and 1.04 million records for wild bees and hoverflies, respectively. The databases cover 97% of the European bee fauna (2,083 species out of 2,138 recorded in Europe) and 97% of the European hoverfly fauna (886 species out of 913 recorded in Europe). These standardised databases constitute essential resources for future assessments of status and trends, habitat associations, and other research and conservation initiatives to protect and understand wild pollinators on the European continent.

DNA barcoding offers a practical approach to species identification, especially in morphologically complex taxa such as Rhiniinae (Diptera, Calliphoridae). The most extensive COI barcode dataset for the subfamily to date was assembled, combining 216 newly generated sequences with more than 1,150 publicly available records from BOLD Systems and GenBank, with emphasis on Afrotropical taxa. Distance-based analyses, Neighbour-Joining (NJ) and Maximum Likelihood (ML) clustering, were evaluated, as well as automated barcode clustering approaches (ABGD and ASAP), for identifying morphospecies within this group. These analyses recognized 79 putative Afrotropical species, with most morphospecies forming well-supported barcode clusters congruent with morphological identifications. Several lineages, however, including species of Fainia, Rhinia, Cosmina, Stomorhina, and Rhyncomya, displayed low interspecific COI divergence, indicating that COI alone offers limited resolution. Yet, NJ and ML clustering helped highlight problematic taxa and identify previously unrecognized lineages. Public data on BOLD Systems comprised 957 BINs identified to subfamily level. Integrating ML, ABGD, ASAP, and voucher-based assessment allowed the assignment of 749 unnamed BINs to 11 species names, 193 BINs to eight genus names within 24 morphospecies, 12 BINs remain as Rhiniinae, and three represent non-Rhiniinae. The analyses also allowed linking 31 Afrotropical female morphotypes to their conspecific male morphotypes. This study establishes the first quality-controlled COI reference library for Afrotropical Rhiniinae and provides a framework for future taxonomic, ecological, and molecular investigations.

Two new species groups within the avidus-nigritarsis lineage of the hoverfly genus Merodon Meigen are here defined and assessed, i.e., the Merodon caudatus and Merodon ottomanus groups. Within the M. caudatus group, two species are recognised:Merodon caudatus Sack and a new species, Merodon crispotarsus sp. nov. Within the M. ottomanus group, an extensive examination of material from different collections revealed the presence of four new species, Merodon auriolus sp. nov., Merodon paeninsula sp. nov., Merodon projectus sp. nov., and Merodon rostrum sp. nov., apart from Merodon ottomanus Hurkmans. The genetic characterisation of species from the M. ottomanus group was performed through Maximum Parsimony (MP) and Maximum Likelihood (ML) analyses of the 5′ end of mitochondrial COI gene sequences, and the existence of the five above-mentioned independent taxa was supported. In addition, we confirmed the validity of M. auriolus sp. nov., M. paeninsula sp. nov., and M. ottomanus by using an integrative taxonomic approach including wing shape differences. Diagnoses, keys for both species groups, and the species they consist of, as well as distribution maps for all studied species, are provided.

The immature stages of hoverfly genus Merodon Meigen (Diptera: Syrphidae) are mostly understudied, with only about 6 % of species currently having published larva and/or puparium descriptions. The available information on breeding and oviposition sites and host-plants of these phytophagous larvae is also very limited. The aim of the present study is to expand upon this knowledge by introducing the first data on preimaginal stages of Merodon mishustini Popov, 2020 (belonging to the M. constans species group, M. albifrons lineage) reared from the bulbs of Galanthus spp. (Amaryllidaceae) in Turkey. The morphology of larvae and puparia is analyzed using stereomicroscope and scanning electron microscope and detailed illustrated descriptions of the main characters are presented. Variability within the species group and lineage, as well as the importance of the potential diagnostic characters as taxonomic tools for delimitation within the genus are discussed. The present study confirms the need for both more Merodon species and more specimens in different developmental stages to be examined and compared in order to arrive at better supported conclusions.

Hoverflies (Diptera: Syrphidae) are an integral part of biological control and pollination in both natural and agricultural ecosystems, yet their diversity in North Africa, particularly Hoverflies (Diptera: Syrphidae) are an integral part of biological control and pollination in both natural and agricultural ecosystems, yet their diversity in North Africa, particularly Algeria, remains understudied, with only 83 species documented. This study reports the first record of Ischiodon aegyptius (Wiedemann, 1830) in Algeria, expanding the known diversity of Syrphidae in the region. This paper presents the results of sampling conducted in a greenhouse at the University of Mostaganem. Hoverfly specimens were collected using standardised sweep nets and targeted collection from aphid-infested crops and surrounding vegetation. Thirteen species were identified, including both predatory and non-predatory species. This finding highlights the ecological versatility of I. aegyptius and the critical need for continued research to better understand the biodiversity, pest management and pollination roles of hoverflies, ultimately supporting the development of sustainable agricultural practices in Algeria.

The oriental latrine fly, Chrysomya megacephala (Fabricius, 1794), is a potential forensic indicator in Mediterranean countries due to its first report in southwestern Europe in 1998. It was first recorded in Alicante (southeastern Spain) and is expanding across the Iberian Peninsula. Until now, this synanthropic species of forensic importance had been captured in baited traps and on pig carcasses in Europe, but never on human corpses. After reviewing all cases studied at the Institute of Legal Medicine of Alicante and the National Institute of Toxicology and Forensic Sciences in Madrid, C. megacephala was recorded for the first time in seven Spanish cases. The identification of material collected during autopsies revealed its scarcity compared to other species in the sarcosaprophagous Diptera community. In all cases, C. megacephala larvae coexisted with thermophilous necrophagous blow fly Lucilia sericata. Other coexisting species included the calliphorids Calliphora vicina and Chrysomya albiceps, and the muscid Synthesiomyia nudiseta. Chrysomya megacephala was collected in various coastal localities in Spain, particularly along the southern and Mediterranean coasts. Most cases shared common characteristics, including the time of year (summer), domestic indoor habitats, and the decomposition stage (active decay). The relevance of these findings is discussed in relation to the importance of taxonomy in identifying this exotic species and its role as forensic entomological evidence in Europe. Given the impact of climate change, the species composition and biology of the sarcosaprophagous Diptera community, particularly in the Mediterranean basin, must be continuously studied and reviewed.

An overview of parasitoid species found on the black soldier fly is presented. The future significance of these natural enemies remains uncertain. However, a thorough assessment of their impact on black soldier fly farms worldwide is essential. The initial step involves the taxonomic identification and study of the life cycles of the species involved.

Merodon triangulum Vujić, Radenković & Hurkmans, 2020 is a European endemic hoverfly species belonging to Merodon constans species-group, inside albifrons -lineage. The distribution of this species is known to be mostly central Europe and Balkan peninsula and it has been categorized as Near Threatened in the European IUCN red list of hoverflies; this paper cites the species for the first time in Ukraine (western Ukraine, specifically). In the present study, the preimaginal stages of this species are described and figured using Scanning Electron Microscopy. The material used for the descriptions were larvae collected in Ukraine and Serbia feeding inside underground storage organs of the spring snowflake Leucojum vernum L., 1753. This morphological description constitutes the first one inside the constans species-group, and the sixth description of the albifrons -lineage, in which there is only one species-group left to have at least one species of the preimaginal stages described (i.e., ruficornis species-group). The descriptions were compared with the rest available of the genus, stating the diagnostical characters of the present species and the shared characters inside the lineage. The novel information provided on the trophic interaction between M. triangulum larvae and Leucojum bulbs is stated for the first time and further supports the association of the constans species-group with the underground storage organs of snowflakes and snowdrops (Galantheae) in their role as host plants.

Abstract Insects are part of the natural diet of fish and poultry species and to a lesser extent of pigs, dogs and cats. In traditional farming, poultry gather their food in a free roaming manner, and insects are part of the diet. Similarly, a large fraction of the diet of freshwater fish consists of aquatic insects. These features are exploited by farmers all over the world, as feed costs are high. For example, farmers lure termites to baskets filled with organic matter, and the insects are then fed to chickens. They also employ light sources above fishponds to attract insects for their fish. More sophisticated methods are, for example, attracting naturally occurring houseflies to containers filled with organic waste, e.g. manure. The captured maggots or pupae are then fed to poultry. We discuss the following insect groups as feeds for poultry, pigs, fish, dogs and cats: bees, caterpillars, cockroaches, flies, grasshoppers and termites. Feed for poultry can also consist of insect pests, which are then controlled at the same time, for example ducks to control rice pests. Moreover, leftovers from the silk industry can be used to feed chickens, pigs and fish. Insects are also commonly used as bait for fishing. The interest in a more industrial production of insects such as the black soldier fly and housefly as animal feed started in the 1970s. In the last 15 years, large-scale rearing of insects for animal feed has taken off, with the industry receiving more than 1.5 billion dollars in investment. The market is expanding, the legislation is becoming more conducive, while academic interest is increasing exponentially. The environmental, nutritional and functional benefits of insects as feed are becoming more and more recognized. Insects are poised to play an increasingly prominent role in shaping the future of animal feed production.

The Canary Islands are an excellent natural laboratory for understanding ecological and evolutionary processes such as biogeographical colonisation. The morphology of the larva, puparium and adult of the endemic Canarian copper fly, Calliphora splendens, is described, illustrated and contrasted with those of the other species of Calliphora that occur in Africa, the Iberian Peninsula and Macaronesia. Partial cytochrome oxidase I sequences show a connection between C. splendens, Calliphora vicina, Calliphora loewi and Calliphora croceipalpis, but more distant relationship with Calliphora vomitoria. Calliphora splendens produced unisexual offspring in captivity. This work confirms the relict character of the Canarian copper fly associated with the endemic laurel forest habitat.

The American hoverfly Eupeodes americanus (Wiedemann) (Diptera: Syrphidae) is an aphidophagous predator during its larval stage and is currently being evaluated for inclusion in biocontrol programs as a new biocontrol agent. However, little is known about its reproductive aptitudes. The objective of the present study was to determine the reproductive parameters of E. americanus and to compare them with those of a commercialized and widely used biological control agent for aphids, the aphid midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). The preoviposition period, oviposition period, adult longevity, lifetime and daily fecundity, egg hatching rate, and fertility were determined for E. americanus females and compared to those of A. aphidimyza. Trials were conducted under laboratory conditions in rearing cages on the broad bean plant Vicia faba L. (Fabaceae), infested with pea aphids Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). The results revealed that the preoviposition period, oviposition period, and adult longevity were significantly longer in E. americanus than in A. aphidimyza. The daily fecundity and egg-hatching rate were similar in both species. However, lifetime fecundity and fertility were considerably higher in E. americanus than in A. aphidimyza. This study demonstrates that the reproductive capacity of E. americanus is clearly superior to that of A. aphidimyza and therefore supports its inclusion in the aphid pest management program as a new biocontrol agent.

The genus Merodon Meigen (Diptera: Syrphidae) is one of the most species-rich hoverfly genera distributed across the Palaearctic and Afrotropical regions. In the Palaearctic, the genus Merodon boasts 195 described species, while its Afrotropical region pales in comparison, with a mere 17 species documented thus far. As a result of 8 years of fieldwork conducted in the Republic of South Africa, in this paper, we present the description of 11 new species for science with a description of immature stages for 2 species, which increases the diversity of this genus in the Afrotropical region by remarkable 39%. These revelations are based on integrating morphology, molecular analysis (COI gene and 28S rRNA) and geometric morphometry. All described species belong to the Merodon planifacies subgroup, the Merodon desuturinus lineage and, within that, to the Afrotropical Merodon melanocerus group. Additionally, we provide an illustrated key to 15 species belonging to the subgroup, a detailed discussion on relevant taxonomic characters, a morphological diagnosis, a distribution map and clarification of the association between M. capi complex and host plants from the genus Merwilla. Graphical Abstract

The main study objective was to build knowledge on the genus Eumerus in the Afrotropical region. The new species Eumerus rufotibialis Radenkovic et Vujic sp. nov. of the E. obliquus group is thus reported. Also presented are the preimaginal stages of the mentioned species and Eumerus compactus van Doesburg 1966 as well as Eumerus astropilops Hull 1964. The descriptions were elaborated using scanning electron microscopy and optical microscopy imaging; supporting images, diagnostical features and comparisons with available descriptions have been included, both for imago and preimaginal descriptions. The known host plant of the three species is indicated together with some biological notes that support their saprophagous feeding habits.