Strange loves: a remarkable case of aberrant copulation in beetles (Coleoptera: Meloidae, Chrysomelidae)

A case of copulation between two mimic and repellent beetle species (a male of Timarcha fracassii, and a female of Meloe autumnalis), belonging to distinct families (Chrysomelidae, Meloidae), is recorded

Larval features of the Italian endemic Pyrochroa serraticornis kiesenwetteri Fairmaire, 1849 (Coleoptera: Pyrochroidae: Pyrochroinae) solve taxonomic uncertainties

Recent findings rearranged the taxonomy of the European species of the genus Pyrochroa Geoffroy (Coleoptera: Pyrochroidae), and to date three species are recognized: P. bifoveata Molfini et al., 2022 and P. coccinea (Linnaeus, 1761) with cryptic adults and distinctive larvae, and the polytypic P. serraticornis (Scopoli, 1763), including the subspecies kiesenwetteri Fairmaire, 1849. Incongruences between molecular and morphological analyses questioned the recognition of P. s. serraticornis and P. s. kiesenwetteri as taxa of the same species. In the present paper, observations of larval characters of P. s. kiesenwetteri confirm this taxon as a subspecies of P. serraticornis. Moreover, new characters of P. s. serraticornis larvae are offered by analysing specimens from a new European locality

Phylogeny of European Pyrochroa (Coleoptera, Pyrochroidae) reveals cryptic taxa and different glacial histories

Only three saproxylic species of Pyrochroinae (Coleoptera: Pyrochroidae) are distributed in Europe, two of which belonging to Pyrochroa: P. coccinea and P. serraticornis. However, P. serraticornis is polytypic, for the presence of the endemic subspecies P. s. kiesenwetteri in southern Italy. Using both molecular and morphological data, we explored the phylogeny of the European Pyrochroa species. A multilocus (COI, CAD, 28S) phylogenetic analysis helped highlight different evolutionary histories for the two examined species. First, P. coccinea, distributed throughout Europe, showed a high differentiation among Italian and European populations. Furthermore, three different taxonomic entities were identified within P. serraticornis, among which the cryptic species Pyrochroa bifoveata sp. n. from central Europe is described and illustrated. A comprehensive identification key to the European Pyrochroinae is also provided. Our results also suggested an historical survival of P. coccinea and P. s. kiesenwetteri in glacial refugia in Italy, and a subsequent post-glacial spread of the former species throughout the Peninsula. In contrast, the current distribution of P. s. serraticornis likely originated from a post-glacial colonization of western European relict populations, while the survival of P. bifoveata plausibly occurred in more eastern glacial refugia (e.g. Carpathian or Balkan regions). Similarly, the European populations of P. coccinea could have originated from relict populations in glacial refugia out from the Italian Peninsula. More comprehensive data on the taxonomy, ecology and biogeography of Pyrochroa are needed to learn more about these species and to help preserve the European saproxylic fauna

Strange loves: a remarkable case of aberrant copulation in beetles (Coleoptera: Meloidae, Chrysomelidae)

A case of copulation between two mimic and repellent beetle species (a male of Timarcha fracassii, and a female of Meloe autumnalis), belonging to distinct families (Chrysomelidae, Meloidae), is recorded

New Evidence of Canthariphily: Tilloidea transversalis (Coleoptera: Cleridae) Sequestering Cantharidin From Lydus trimaculatus (Coleoptera: Meloidae)

Cantharidin (CTD) is a defensive compound autogenously and exclusively produced by two phylogenetically related beetle families: Meloidae and Oedemeridae. Although this molecule usually acts as a strong deterrent against potential predators and parasites, some arthropod species, collectively named ‘canthariphilous species’, are attracted to CTD. Some species can sequester CTD from the CTD-producing species, using it as a chemical defense against enemies. The present paper focuses on the first-ever description of canthariphilous interactions between a checkered beetle species (Coleoptera: Cleridae) and a CTD -producing species. Field observations revealed individuals of the phytophagous beetle Tilloidea transversalis (Charpentier, 1825) (Coleoptera: Cleridae) biting individuals of the blister beetle Lydus trimaculatus (Fabricius, 1775) (Coleoptera: Meloidae). Laboratory behavioral experiments followed to verify if this peculiar behavior of T. transversalis also occurs on other co-occurring species. Moreover, chemical analyses were performed to assess whether T. transversalis can sequester CTD. Our results show that T. transversalis only attacks CTD-producing species. However, while chemical analyses prove that T. transversalis can sequester CTD from the hemolymph of L. trimaculatus, some clues (based on a CTD-baited traps sampling) suggest that this beetle, contrarily to other canthariphilous species, does not appear to show a high attraction to pure synthetic CTD. Thus, other unknown signals, alone or in combination with CTD, could be implicated in triggering the canthariphilous behaviors of T. transversalis

Unraveling the role of male reproductive tract and haemolymph in cantharidinexuding Lydus trimaculatus and Mylabris variabilis (Coleoptera: Meloidae): a comparative transcriptomics approach

Abstract Background: Meloidae (blister beetles) are known to synthetize cantharidin (CA), a toxic and defensive terpene mainly stored in male accessory glands (MAG) and emitted outward through reflex-bleeding. Recent progresses in understanding CA biosynthesis and production organ(s) in Meloidae have been made, but the way in which selfprotection is achieved from the hazardous accumulation and release of CA in blister beetles has been experimentally neglected. To provide hints on this pending question, a comparative de novo assembly transcriptomic approach was performed by targeting two tissues where CA is largely accumulated and regularly circulates in Meloidae: the male reproductive tract (MRT) and the haemolymph. Differential gene expression profiles in these tissues were examined in two blister beetle species, Lydus trimaculatus (Fabricius, 1775) (tribe Lyttini) and Mylabris variabilis (Pallas, 1781) (tribe Mylabrini). Upregulated transcripts were compared between the two species to identify conserved genes possibly involved in CA detoxification and transport. Results: Based on our results, we hypothesize that, to avoid auto-intoxication, ABC, MFS or other solute transporters might sequester purported glycosylated CA precursors into MAG, and lipocalins could bind CA and mitigate its reactivity when released into the haemolymph during the autohaemorrhaging response. We also found an overrepresentation in haemolymph of protein-domains related to coagulation and integument repairing mechanisms that likely reflects the need to limit fluid loss during reflex-bleeding.Conclusions: The de novo assembled transcriptomes of L. trimaculatus and M. variabilis here provided represent valuable genetic resources to further explore the mechanisms employed to cope with toxicity of CA in blister beetle tissues. These, if revealed, might help conceiving safe and effective drug-delivery approaches to enhance the use of CA in medicine

Genetic variability and conservation of longhorn beetle Rosalia alpina in Italy in the frame of EU-LIFE MIPP Project.

Rosalia alpina (Linnaeus, 1758) is one of the most attractive saproxylic longhorn beetle in Europe, ranked as a priority species and listed the Annexes II and IV of the European Habitats Directive 92/43EEC. The distribution range of R. alpina extends from central-southern Europe to northern Turkey and Caucasic Region (Sama G. 2002). In Italy, this species is widespread and mainly associated to ancient deciduous beech forests. In the frame of EU-LIFE Project MIPP (Monitoring Insects with Public Participation, LIFE11 NAT/IT/000252) - aimed to standardize methods for monitoring R. alpina in Europe - ecological data on population size and habitat preferences of this species were collected in two National Parks in Italy (PNFC: Parco Nazionale Foreste Casentinesi; PNALM: Parco Nazionale Abruzzo, Lazio and Molise). These ecological surveys were integrated by the analysis of genetic polymorphism at 6 microsatellite loci (Drag et al. 2013) in a sub-sample of 89 individuals of R. alpina from both PNFC and PNALM (years: 2014-2015) to assess levels of heterozygosity, population structuring and gene flow. Our analysis suggests similar levels of genetic diversity among examined sub-populations (with only slight differences in allelic richness), also comparable to those already observed in South-East Europe (Drag et al. 2015). Inferences about inbreeding, kin relationships and extent of gene flow among Italian R. alpina populations are presented. Finally, the significance of integrating ecological and genetic data to set efficient conservation planning for endangered saproxylic beetles are remarked