Gloria Antonini

DNA Fingerprinting to Improve Data Collection Efficiency and Yield in an Open-Field Host-Specificity Test of a Weed Biological Control Candidate

Abstract An open-field test was conducted in southern France to assess the host-specificity of Ceratapion basicorne (Illiger), a candidate for biological control of yellow starthistle. Test plants were infested by naturally occurring populations of C. basicorne but were also exposed to sympatric herbivore species, including other Ceratapion spp. Insects from the test plants were collected directly into tubes of ethanol and were subsequently identified to species according to DNA sequence similarity with morphologically identified reference specimens. This integrated, morphological and molecular identification method was used in an effort to maximize the amount of data gained in the field bioassay and to minimize the number of taxonomist–hours necessary to complete the study. The results obtained showed that the French C. basicorne population only attacked yellow starthistle and cornflower, another known host of C. basicorne. Molecular phylogenetic analysis of the insects collected from all other nonhost plants rejected the possibility that any were C. basicorne. Nomenclature: Cornflower, Centaurea cyanus L. CENCY; yellow starthistle, Centaurea solstitialis L. CENSO; Ceratapion basicorne (Illiger)

Molecular and morphological evidence of a new sibling species of Calobius (Coleoptera: Hydraenidae) of the C. quadricollis complex from peninsular Italy

A molecular and morphological analysis was performed to clarify the taxonomic status of Italian members of the Calobius quadricollis complex (Coleoptera, Hydraenidae, Ochthebiinae), including species strictly associated with hypersaline marine rock pools along the Mediterranean and Macaronesian coasts. The analysis was mainly focused on the specific distinction and formal description of a new species, Calobius urbanelliae n. sp., from peninsular Italy. This species is of difficult morphological distinction, but, on the basis of the mitochondrial DNA marker cytochrome c oxidase subunit I, it is highly differentiated from C. quadricollis Mulsant, 1844 (NW Mediterranean) and C. steinbuehleri Baudi, 1864 (NE Mediterranean), which are partially sympatric with it along part of the western and eastern coasts of peninsular Italy. One possible palaeogeographical scenario underlying the specific differentiation of the three species is briefly discussed.

Testing the performance of a fragment of the COI gene to identify western Palaearctic stag beetle species (Coleoptera, Lucanidae).

Abstract The taxonomy of stag beetles (Coleoptera: Lucanidae) remains challenging, mainly due to the sexual dimorphism and the strong allometry in males. Such conjecture confounds taxonomic based conservation efforts that are urgently needed due to numerous threats to stag beetle biodiversity. Molecular tools could help solve the problem of identification of the different recognized taxa in the “Lucanus cervus complex” and in some related Palaearctic species. We investigated the potential use of a 670 bp region at the 3’ end of the mitochondrial cytochrome c oxidase subunit I gene (COI) for barcoding purposes (different from the standard COI barcoding region). Well resolved species and subspecies were L. tetraodon, L. cervusakbesianus, L. c. laticornis, as well as the two eastern Asian outgroup taxa L. formosanus and L. hermani. Conversely, certain taxa could not be distinguished from each other based on K2P-distances and tree topologies: L. c. fabiani / L. (P.) barbarossa, L. c. judaicus / an unknown Lucanus species, L. c. cervus / L. c. turcicus / L. c. pentaphyllus / L. (P.) macrophyllus / L. ibericus. The relative roles of phenotypic plasticity, recurrent hybridisation and incomplete lineage sorting underlying taxonomic and phylogenetic discordances are discussed.

Redescription and natural history of Meligethes longulus Schilsky, 1894, and provisional revision of the M. coracinus species‐complex (Coleoptera, Nitidulidae, Meligethinae)

Abstract The taxonomic identification and a re‐description of the problematic Meligethes longulus Schilsky, 1894 from eastern Turkey are presented. This species, belonging to the M. coracinus complex and known so far on the basis of a single immature holo‐type, was repeatedly confused in the past with other closely related taxa, thus introducing considerable instability in the nomenclature and taxonomy of the whole group, involving several distinct biological species throughout southern Europe and western Asia. The recent re‐discovery of this species in eastern Turkey allowed M. longulus to be definitely identified as being an extremely rare and localized species, with larval stages strictly associated with the host‐plant Matthiola odoratissima (Bieb.) R.Br. (Brassicaceae), in dry exposed terrigenous and sandy hill slopes of eastern Turkey. An updated key to the identification of both described and un‐described members of the M. coracinus complex is also presented, and a rather isolated species of the M. coracinus complex from southern Turkey, M. cristofaroi n. sp., is described as new. A preliminary evolutionary scenario of the whole species‐complex, based also on results from a companion molecular research, is finally discussed.

Specific distinction by allozymic data of sympatric sibling species of the pollen-beetle genus Meligethes (Coleoptera, Nitidulidae)

Abstract An allozyme analysis was performed, combined with field data on insect/host‐plant associations, in order to clarify taxonomic relationships within the W‐Palaearctic Meligethes coracinus complex (Coleoptera, Nitidulidae, Meligethinae). The analysis was focused on the specific distinction of M. coracinus, M. matronalis and M. subaeneus, with special regard to the last two species occurring in sympatry. Alternative fixed and unique alleles were scored at several loci. The genetic distances between M. matronalis, M. subaeneus and M. coracinus (0.198–0.572) were in the range of values usually scored between closely related insect species. Genetic data and ecological evidence clearly show that M. matronalis and M. subaeneus, erroneously synonymized in a recent paper, are distinct biological species that frequently occur in syntopy in central and southern Europe, on different larval host plants, although they rarely show synchronous phenology. Their specific differentiation likely occurred during the palaeoclimatic changes of the Plio‐Pleistocene ice cycles in southern Europe.

A new exceptional Meligethes of the M. aeneus species-group from Western Alps and an updated key to identification of M. aeneus and allied species (Coleoptera: Nitidulidae: Meligethinae)

A new Meligethes from Italian Maritime Alps (Piedmont, Cuneo province), member of the M. aeneus species-group, is described as M. salvan sp. n. The new taxon, despite sharing a few important morphological features with members of the M. aeneus species-complex, is very distinct due to a peculiar combination of characters. The systematic position of Meligethes salvan sp. n. is rather problematic, this new species probably representing a true “palaeoendemic relict” of Tertiary origin, as a few other well-known isolated species of different taxonomic groups, endemic to the crystalline Ercinian massifs of the SW Maritime Alps. The new synonymy Meligethes asperrimus Guillebeau, 1897 = Meligethes flavimanus Stephens, 1830 is introduced, while Meligethes gracilis C. Brisout de Barneville, 1863, recently erroneously synonymyzed with M. aeneus (Fabricius, 1775) by a Russian author, is resurrected at a specific rank. A provisional key to the identification of Meligethes aeneus and allied Holarctic species is finally presented.

Computer-aided photographic identification of Rosalia alpina (Coleoptera: Cerambycidae) applied to a mark-recapture study

Assessing the conservation status of protected species needs quantitative population data, generally obtained using Capture‐Mark‐Recapture methods (CMR). The exploitation of natural marking (e.g. individual morphological traits) offers an interesting alternative, based on image analyses, which may result in a less manipulation of protected species compared to the typical artificial marking method. In our 2‐year CMR study, we tested for the first time in the natural setting the feasibility and the application of the computer‐aided photographic identification method of Rosalia alpina using the individual elytral spots as the natural marking. The I3SC software was used for the photographic analysis. Data were collected from populations of two National Parks of central Italy during July–August in 2014 and 2015. We developed a standard procedure in order to optimise the image acquisition in the field and to acquire clear and comparable images, facilitating the I3SC screening process. The results demonstrated that the computer‐aided photographic identification of natural markings can be implemented in a CMR population study of R. alpina. Our image processing approach showed that using only the elytral central spot contours made the tracing contour process less time‐consuming obtaining reliable results. Furthermore, I3SC output scores were used to identify a threshold value for the identification of new individuals or recaptures, facilitating the final identification proposed by operators. Finally, we assessed the possibility of performing the methodology using a Citizen Science approach.

Molecular ecology and phylogenetics of the water beetle genus Ochthebius revealed multiple independent shifts to marine rockpools lifestyle

Marine rockpools represent a dynamic ecosystem where inhabiting species usually suffer changeable conditions, with consequent phenomena of local populations’ size expansions and reductions. Nevertheless, a few specialized insect groups are known to live in marine rockpools, and among them, several species belong to the water beetle family Hydraenidae. Three groups of Ochthebius sensu lato (s.l.) live in fact in marine rockpools: the putative subgenus Calobius, the former subgenus Cobalius (both mostly Mediterranean–Macaronesian) and two species of the O. capicola group from South Africa. In this work, we performed a molecular phylogeny of Ochthebius s.l., running molecular clocks, aiming to address the following questions: Are these three groups related? Which is their position within Ochthebius s.l.? How many different times and in how many lineages of Ochthebius s.l. a shift from inland waters to marine rockpools environments happened? Is the current taxonomic status of these three groups supported by genetics? We found that Calobius, Cobalius and the O. capicola group represent three distinct groups, with no sister relationships, suggesting that a shift from fresh/brackish waters to marine rockpools happened independently at least three different times along the diversification of the genus. Cobalius represents an effective separate subgenus, whereas such a rank is not supported by molecular data for Calobius, which represents a monophyletic clade within the nominal subgenus Ochthebius sensu stricto (s.str.). However, as Calobius is monophyletic and characterized by strongly peculiar and distinguishing morphology, we suggest referring to this group as the ‘Calobius’ lineage. Three Mediterranean taxa within this lineage represent likely valid new species, to be described soon. In the same way, the taxonomy of Cobalius should be revised, with two previously formally recognized species found to be paraphyletic, and the possible presence of two additional cryptic species.

Genetic variability in Italian populations of Drosophila suzukii

BackgroundDrosophila suzukii is a highly destructive pest species, causing substantial economic losses in soft fruit production. To better understand migration patterns, gene flow and adaptation in invaded regions, we studied the genetic structure of D. suzukii collected across Italy, where it was first observed in 2008. In particular, we analysed 15 previously characterised Simple Sequence Repeat (SSR) markers to estimate genetic differentiation across the genome of 278 flies collected from nine populations.ResultsThe nine populations showed high allelic diversity, mainly due to very high heterozygosity. The high Polymorphism Information Content (PIC) index values (ranging from 0.68 to 0.84) indicated good discrimination power for the markers. Negative fixation index (FIS) values in seven of the populations indicated a low level of inbreeding, as suggested by the high number of alleles. STRUCTURE, Principal Coordinate and Neighbour Joining analysis also revealed that the Sicilian population was fairly divergent compared to other Italian populations. Moreover, migration was present across all populations, with the exception of the Sicilian one, confirming its isolation relative to the mainland.ConclusionsThis is the first study characterising the genetic structure of the invasive species D. suzukii in Italy. Our analysis showed extensive genetic homogeneity among D. suzukii collected in Italy. The relatively isolated Sicilian population suggests a largely human-mediated migration pattern, while the warm climate in this region allows the production of soft fruit, and the associated D. suzukii reproductive season occurring much earlier than on the rest of the peninsula.

Revision of the Southern African Pollen Beetle Genus Anthystrix (Coleoptera: Nitidulidae: Meligethinae)

ABSTRACT The pollen beetle genus Anthystrix Kirejtshuk, 1981 previously included six South African species characterized by unusual dimorphic development of male antennal characters. The genus is revised and three new species are described from South Africa, including Anthystrix endroedyi new species, Anthystrix flabellicornis new species, and Anthystrix megalocera new species. Anthystrix luculenta Kirejtshuk & Easton 1988, Anthystrix rotundiclava Kirejtshuk & Easton 1988, and Anthystrix martini (Grouvelle, 1899) need to be transferred to two new undescribed genera. These new genera will globally include ≈20 species, most of which remain undescribed or previously attributed to the unrelated genus Meligethinus Grouvelle, 1906. One new synonymy is proposed: Meligethinus uhligi Kirejtshuk & Easton, 1988, = Pria martini Grouvelle, 1899, syn. nov. Larval host plants of Anthystrix species are reported as dioecious Asteraceae trees within the tribe Tarchonantheae (Tarchonanthus). An identification key to all Anthystrix species is provided.