José A. Quartau

Ranking protected areas in the Azores using standardised sampling of soil epigean arthropods

Nineteen areas in seven of the nine Azorean islands were evaluated for species diversity and rarity based on soil epigean arthropods. Fifteen out of the 19 study areas are managed as Natural Forest Reserves and the remaining four were included due to their importance as indigenous forest cover. Four of the 19 areas are not included in the European Conservation network, NATURA 2000. Two sampling replicates were run per study area, and a total of 191 species were collected; 43 of those species (23%) are endemic to the archipelago and 12 have yet to be described. To produce an unbiased multiple-criteria index (importance value for conservation, IV-C) incorporating diversity and rarity based indices, an iterative partial multiple regression analysis was performed. In addition, an irreplaceability index and the complementarity method (using both optimisation and heuristic methods) were used for priority-reserves analyses. It was concluded that at least one well-managed reserve per island is absolutely necessary to have a good fraction of the endemic arthropods preserved. We found that for presence/absence data the suboptimal complementarity algorithm provides solutions as good as the optimal algorithm. For abundance data, optimal solutions indicate that most reserves are needed if we want that at least 50% of endemic arthropod populations are represented in a minimum set of reserves. Consistently, two of the four areas not included in the NATURA 2000 framework were considered of high priority, indicating that vascular plants and bird species used to determine NATURA 2000 sites are not good surrogates of arthropod diversity in the Azores. The most irreplaceable reserves are those located in older islands, which indicates that geological history plays an important role in explaining faunal diversity of arthropods in the Azores. Based both on the uniqueness of species composition and high species richness, conservation efforts should be focused on the unmanaged Pico Alto region in the archipelago’s oldest island, Santa Maria.

Transmission of the pine wood nematode Bursaphelenchus xylophilus through feeding activity of Monochamus galloprovincialis (Col., Cerambycidae)

Abstract:  Transmission of the pinewood nematode (PWN) Bursaphelenchus xylophilus (Steiner & Bührer) Nickle to Pinus pinaster Aiton branches through feeding wounds of its vector in Portugal, Monochamus galloprovincialis Olivier, was studied under laboratory conditions. All the B. xylophilus‐infected beetles transmitted nematodes to branches they fed. The transmission was more frequent during the first 6 weeks after emergence, with transmission peaks during the second and the sixth week. The adult M. galloprovincialis transmitted nematodes for a mean of 5 weeks, independently of the beetles sex or longevity. No relation was found between beetle feeding intensity and effective transmission of B. xylophilus to the branches. The nematode transmission ceased after the ninth week, even in insects which still had B. xylophilus on their bodies. The longevity of the nematode‐free insects (control group) was slightly higher than the B. xylophilus‐infected beetles, although with no significant difference. The results emphasize the necessity to control the immature stages of M. galloprovincialis prior to emergence and develop efficient strategies to capture and eliminate the recently emerged beetles, as majority of the nematode infection of healthy pine trees occurs during a short period of few weeks after beetle emergence.

Reproductive traits of Monochamus galloprovincialis (Coleoptera: Cerambycidae) under laboratory conditions.

The pine sawyer Monochamus galloprovincialis (Olivier) is the vector of the introduced pine wood nematode Bursaphelenchus xylophilus (Steiner & Bührer) Nickle in Portugal, and until recently was considered a secondary forest insect. Under laboratory conditions, a study of biological and reproductive traits of 37 insect pairs was conducted. The longevity of both sexes was similar, being 61.2+/-6.5 days for males and 64.0+/-6.3 days for females (mean+/-SE). Sixteen small-sized insects (22% of the population) died within 20 days and before starting to reproduce. The sexual maturation period (without egg laying) was 20.4+/-0.7 days (mean+/-SE), while the oviposition period lasted 54.0+/-4.2 days (mean+/-SE). The oviposition rate increased very quickly during the first weeks of life, peaking to almost two eggs per day during days 30-44, and gradually dropping in the following weeks. The females laid an average of 67.0+/-5.96 (mean+/-SE) eggs through their lives. The hatch rate was 92.6+/-1.0% (mean+/-SE). There were large individual variations in longevity and fecundity parameters, and principal component analysis based on 16 morphological and biological parameters separated the breeding insects into four distinct groups. Almost half of the reproducing beetles were large-sized insects, with high longevity and fecundity traits. Overall, the reproductive potential of the Portuguese population of M. galloprovincialis seems to be smaller than that described for other Monochamus vectors of the pine wood nematode both in North America and Japan.

Ranking the Azorean Natural Forest Reserves for conservation using their endemic arthropods

Endemic arthropods were used to evaluate the conservation value of the 16 Natural Forest Reserves (NFRs) of the Azores (Macaronesia). For each of the 280 known Azorean endemic species of arthropods, a rarity index was calculated, using distribution and abundance data obtained from the literature. In addition, several scoring indices were used to rank the 16 NFRs. Frequency distributions of the rarity index indicated that there was a tendency for a greater proportion of the commonest species being represented in the NFRs in contrast with a lower representation of the rarest species. About 60% of the endemic arthropod species that were recorded from the NFRs are ‘single NFR endemics’, that is, are known from only one of the 16 NFRs. Species richness was considered to be a very good surrogate measure of the conservation value of the 16 NFRs under study. The fact that the six highest ranked NFRs (using a composite multi-criteria index) are located in different islands has some important conservation management implications; to preserve a large proportion of the Azorean arthropod biodiversity there is a need to protect sites in all islands. If the five highest ranked NFRs are correctly managed in terms of conservation, then at least 80% of the endemic arthropods known from the NFRs could be protected. Most of the tested taxa (Acari-Oribatei; Lepidoptera; Diptera; Coleoptera) are good surrogates of the overall total set of species present in the 16 NFRs when using a species richness index.

Feeding and oviposition preferences of Monochamus galloprovincialis for certain conifers under laboratory conditions

Feeding and oviposition preferences of Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae: Monochamini), the vector of the pine wilt nematode (PWN), Bursaphelenchus xylophilus (Steiner and Bührer) Nickle (Nematoda: Aphelenchoididae), in Portugal, was studied in three laboratory experiments: an adult feeding preference trial between branches of five pines, a no‐choice oviposition experiment on seven conifer bolts, and an oviposition choice trial between maritime pine, Pinus pinaster Aiton, and four other pines, P. pinea L., P. sylvestris L., P. halepensis Miller, or P. radiata D. Don. Scots pine (P. sylvestris) was the pine with the largest bark feeding area, while P. radiata was the least chosen to feed upon. Female M. galloprovincialis laid eggs on P. sylvestris, P. halepensis, P. pinaster, P. radiata, P. pinea, and Pseudotsuga menziesii (Mirbel) Franco, but larvae successfully completed development only on the first four pines. Beetles emerging from maritime pine bolts were slightly bigger than the others. No preference for oviposition was detected when beetles were given the choice between P. pinaster and P. sylvestris or P. halepensis. Inversely, greater oviposition occurred on P. pinaster when compared with P. pinea and P. radiata. Although PWN currently affects only P. pinaster in Portugal, the results on host suitability for M. galloprovincialis suggest that P. sylvestris and P. halepensis are adequate hosts for the insects feeding and oviposition, and thus may also be PWN hosts in Europe. The systematically high feeding and oviposition attraction for P. sylvestris exhibited by the beetles means that the eventual spread of the PWN to areas where both M. galloprovincialis and P. sylvestris occur may have a significant impact on this widespread and economically important pine, considered to be highly susceptible to B. xylophilus.

Cicadas from Portugal: revised list of species with eco-ethological data (Hemiptera: Cicadidae)

The cicada fauna from Portugal is reviewed, as a result of a joint Portuguese-French project. Thirteen species are reported (Lyristes plebejus, Cicada orni, Cicada barbara lusitanica, Tibicina tomentosa, Tibicina quadrisignata, Tibicina garricola, Melampsalta varipes, Tympanistalna gastrica, Euryphara contentei, Tettigetta argentata, Tettigetta estrellae, Tettigetta josei, Tettigetta mariae), while five taxa which were previously referred to in the literature, have not been found (Tibicina corsica fairmairei, Tibicina haematodes, Tibicina nigronervosa, Cicadetta flaveola, Cicadivetta tibialis). Based on morphological and acoustic features, the following synonymies are established: Tettigetta argentata (Olivier, 1790) = Tettigetta atra (Gomez-Menor, 1957) n. syn. and Tettigetta estrellae Boulard, 1982 = Tettigetta septempulsata Boulard & Quartau, 1991 n. syn. Data on time of emergence, geographical distribution, habitat occupation and acoustic calling behaviour are given for each species.

Molecular phylogeny and DNA barcoding in the meadow-spittlebug Philaenus spumarius (Hemiptera, Cercopidae) and its related species

Philaenus spumarius, widely studied for its colour/pattern polymorphism, is a widespread species across the Holartic. The patterns of haplotype divergence at the mitochondrial gene cytochrome oxidase I (COI) found in this study suggest a postglacial western Europe (Iberian and Italian peninsulas to Britain) and a eastern (from Near East to Finland) south-to-north colonization. The haplotypes found in North America are most likely derived from the British haplotypes. The barcode fragment used here allowed the distinction of the species within genus Philaenus and questioned some taxonomic identifications of sequences present in Genbank.

Winter dormancy of the pine sawyer Monochamus galloprovincialis (Col., Cerambycidae) in Portugal

Abstract:  The pine sawyer Monochamus galloprovincialis is the vector of the introduced pine wood nematode Bursaphelenchus xylophilus in Portugal and has a fixed univoltine life cycle, overwintering as larvae inside the wood. We investigated the possibility of the existence of a phase of winter dormancy affecting the larvae, its induction and termination under controlled conditions and its incidence and termination in the field. In the laboratory, the majority of the newly hatched larvae which were maintained at a constant temperature of 23°C and different photoperiods became dormant in <70 days. Part of the population completed dormancy and reassumed development until adult emergence at the constant temperature, without the need for a chilling period. Although no critical photoperiod for dormancy maintenance or termination could be determined, dormancy termination was more frequent for larvae experiencing changes on daylength duration. In the field, dormancy incidence grew progressively from a minimum of 26% in October to a maximum of 100% in April, and dormancy appeared to be completed only during late winter. The results suggest that M. galloprovincialis larvae underwent an obligatory dormancy associated with the last larval instar, which conforms to the general definition of diapause, although presenting some affinities with oligopause. The role of this dormancy on the regulation of the pine sawyer’s seasonal development and the number of generations is discussed.

Conflicting patterns of DNA barcoding and taxonomy in the cicada genus Tettigettalna from southern Europe (Hemiptera: Cicadidae)

DNA barcodes have great potential to assist in species identification, especially when high taxonomical expertise is required. We investigated the utility of the 5′ mitochondrial cytochrome c oxidase I (COI) region to discriminate between 13 European cicada species. These included all nine species currently recognized under the genus Tettigettalna, from which seven are endemic to the southern Iberian Peninsula. These cicadas have species‐specific male calling songs but are morphologically very similar. Mean COI divergence between congeners ranged from 0.4% to 10.6%, but this gene was proven insufficient to determine species limits within genus Tettigettalna because a barcoding gap was absent for several of its species, that is, the highest intraspecific distance exceeded the lowest interspecific distance. The genetic data conflicted with current taxonomic classification for T. argentata and T. mariae. Neighbour‐joining and Bayesian analyses revealed that T. argentata is geographically structured (clades North and South) and might constitute a species complex together with T. aneabi and T. mariae. The latter diverges very little from the southern clade of T. argentata and shares with it its most common haplotype. T. mariae is often in sympatry with T. argentata but it remains unclear whether introgression or incomplete lineage sorting may be responsible for the sharing of haplotypes. T. helianthemi and T. defauti also show high intraspecific variation that might signal hidden cryptic diversity. These taxonomic conflicts must be re‐evaluated with further studies using additional genes and extensive morphological and acoustic analyses.

Patterns of acoustic variation in Cicada barbara Stål (Hemiptera, Cicadoidea) from the Iberian Peninsula and Morocco

Field recordings of the calling song and of an amplitude modulated signal produced by males of Cicada barbara from North Africa and the Iberian Peninsula were analysed in order to assess the geographical acoustic variation and the potential usefulness of acoustic data in the discrimination of subspecies and populations. Sound recordings were digitized and the frequency and temporal properties of the calls of each cicada were analysed. In all regions studied, peak frequency, quartiles 25, 50 and 75% and syllable rate showed low coefficients of variation suggesting inherent static properties. All frequency variables were correlated with the latitude, decreasing from south to north. In addition, most acoustic variables of the calling song showed significant differences between regions, and PCA and DFA analyses supported a partitioning within this species between Iberian Peninsula+Ceuta and Morocco, corroborating mtDNA data on the same species. Therefore, the subspecific division of C. barbara into C. barbara barbara from Morocco and C. barbara lusitanica from Portugal, Spain and Ceuta finds support from the present acoustic analyses, a result which is also reinforced by molecular markers.