Different Distribution Patterns of Hoverflies (Diptera: Syrphidae) and Bees (Hymenoptera: Anthophila) Along Altitudinal Gradients in Dolomiti Bellunesi National Park (Italy).

Hoverflies (Diptera: Syrphidae) and bees (Hymenoptera: Anthophila) are two key taxa for plant pollination. In the present research, the altitudinal distribution of these taxa was studied along two gradients (elevation range: 780-2130 m) in the Dolomiti Bellunesi National Park (Northeastern Italy). Pan traps were used as a sampling device to collect both hoverflies and bees. Other than altitude, the effect of landscape complexity and plant diversity were considered as potential predictors of hoverfly and bee richness and abundance along the two gradients. A total of 68 species of hoverflies and 67 of bees were collected during one sampling year, confirming the efficacy of pan traps as a sampling device to study these taxa. Altitude was the main variable affecting both hoverfly and bee distribution. The two taxa show different distribution patterns: hoverflies have a unimodal distribution (richness and abundance) with peak at middle altitude (1500 m), while bees have a monotonic decline (richness and abundance) with increasing altitude. Both hoverfly and bee populations change with the increasing altitude, but the change in hoverflies is more pronounced than in bees. Species turnover dominates the ß-diversity both for hoverflies and bees; therefore, the hoverfly and bee communities at higher altitudes are not subsamples of species at lower altitude but are characterized by different species. This poses important conservation consequences. Some rare species, typical of an alpine habitat were recorded; the present research represents important baseline data to plan a monitoring scheme aimed at evaluating the effect of climate change on pollinators in these fragile habitats.

Possible Epigenetic Origin of a Recurrent Gynandromorph Pattern in Megachile Wild Bees.

Gynandromorphs, i.e., individuals with a mix of male and female traits, are common in the wild bees of the genus Megachile (Hymenoptera, Apoidea). We described new transverse gynandromorphs in Megachile pilidens Alfkeen, 1924 and analyze the spatial distribution of body parts with male vs. female phenotype hitherto recorded in the transverse gynandromorphs of the genus Megachile. We identified 10 different arrangements, nine of which are minor variants of a very general pattern, with a combination of male and female traits largely shared by the gynandromorphs recorded in 20 out of 21 Megachile species in our dataset. Based on the recurrence of the same gynandromorph pattern, the current knowledge on sex determination and sex differentiation in the honey bee, and the results of recent gene-knockdown experiments in these insects, we suggest that these composite phenotypes are possibly epigenetic, rather than genetic, mosaics, with individual body parts of either male or female phenotype according to the locally expressed product of the alternative splicing of sex-determining gene transcripts.

Catalog of the Diptera types described by Camillo Rondani.

This catalog lists all 1226 nominal species introduced by Rondani within Diptera (1174 available and 52 unavailable), providing for each available name data on the type locality, type material, current taxonomic status and with remarks on both the collectors and the specialists who have studied this material. The following new synonymies are proposed: Panops aeneus Philippi, 1865 [Acroceridae] under Lasia aenea Rondani, 1863, n. syn.; Panops nigripes Philippi, 1865 [Acroceridae] under Lasia cuprea Rondani, 1863, n. syn.; Tabanus brasiliensis Rondani, 1850 [Tabanidae] under Dichelacera fasciata Walker, 1850, n. syn.; Petagnia subpetiolata Rondani, 1859 [Tachinidae] under Petagnia occlusa Rondani, 1856, n. syn.; Tephritis siderata Rondani, 1868 [Tephritidae] under Hexacinia radiosa (Rondani, 1868), n. syn. Mallophora macquartii Rondani 1851 [Asilidae] is considered as a senior (but invalid) synonym of Mallophora scopipeda Rondani, 1863, n. syn. Paragus mundus Wollaston, 1858 [Syrphidae] is proposed as the valid name for Paragus coadunatus sensu Goeldlin de Tiefenau (1976); Paragus coadunatus Rondani, 1847 [Syrphidae] is reinstated as a junior synonym of Paragus haemorrhous Meigen 1822. Lectotypes are designated herein for the following nominal species: Domomyza anthracipes Rondani, 1875, Domomyza frontella Rondani, 1875 [both in Agromyzidae]; Chorthophila impudica Rondani, 1866 [Anthomyiidae]; Sephanilla sertulata Rondani, 1875 [Aulacigastridae]; Peratochetus lutescens Rondani, 1856 [Clusiidae]; Myopa punctum Rondani, 1857 [Conopidae]; Culex pulcritarsis Rondani, 1872 [Culicidae]; Ephydra ciligena Rondani, 1868 [Ephydridae]; Lonchea scutellaris Rondani, 1875 [Lonchaeidae]; Geomyza pictipennis Rondani, 1875 [Opomyzidae]; Megaglossa vegetationis Rondani, 1869 [Platystomatidae]; Eumerus tuberculatus Rondani, 1857, Merodon varius Rondani, 1845, Paragus mundus Wollaston, 1858, Pipizella neuphritica Rondani, 1868 [all in Syrphidae]; Exorista noctuicida Rondani, 1859, Phoricheta lacrimans Rondani, 1861 [both in Tachinidae]; Tephritis decipiens Rondani, 1871, Tephritis matutina Rondani, 1871, Urophora lejura Rondani, 1870, Urophora venabulata Rondani, 1870, Urophora veruata Rondani, 1870 [all in Tephritidae]. The following nominal species have lectotypes designated according to Article 74.5 of the I.C.Z.N. Code: Chortophila divergens Rondani, 1866, Chortophila incognita Rondani, 1866 [both in Anthomyiidae]; Habropogon doriae Rondani, 1873, Promacus taeniopus Rondani, 1873 [both in Asilidae]; Chelidomyia melbae Rondani, 1879, Myophthiria lygaeoides Rondani, 1878, Ornithomya gestroi Rondani, 1878, Ornithomya hatamensis Rondani, 1878 [all in Hippoboscidae]; Megaglossa corticarum Rondani, 1869 [Platystomatidae]; Elgiva lateritia Rondani, 1868, Tetanocera nigricosta Rondani, 1868, Tetanocera punctifrons Rondani, 1868 [all in Sciomyzidae]; Tabanus justorius Rondani, 1875 [Tabanidae]. The following lectotypes are designated by inference according to Article 74.6 of I.C.Z.N.: Diopsis aethiopica Rondani, 1873, Diopsis latimana Rondani, 1875, Teleopsis breviscopium Rondani, 1875, Teleopsis longiscopium Rondani, 1875 [all in Diopsidae]; Cyclopodia albertisii Rondani, 1878, Myophthiria reduvioides Rondani, 1875 [both in Hippoboscidae]; Myiodella brachialis Rondani, 1873, Senopterina zonalis Rondani, 1875 [all in Platystomatidae]; Stevenia florentina Rondani, 1861 [Rhinophoridae]; Miltogramma punctatella Rondani, 1868 [Sarcophagidae]; Sargus leoninus Rondani, 1875 [Stratiomyidae]; Chrysops alter Rondani, 1875, Chrysops unizonatus Rondani, 1875, Tabanus dives Rondani, 1875, Tabanus fulvissimus Rondani, 1875, Tabanus ignobilis Rondani, 1875 [all in Tabanidae]; Themara hirtipes Rondani, 1875 [Tephritidae]. The following names are new combinations: Diopsis latimana Rondani, 1875 [Diopsidae] is transferred to Teleopsis and kept as a junior synonym of Teleopsis dalmanni (Wiedemann, 1830), comb. nov.; Diopsis lativola Rondani, 1875 [Diopsidae] is transferred to Teleopsis and kept as a junior synonym of Teleopsis dalmanni (Wiedemann, 1830), comb. nov. The following names, previously deemed unavailable, are determined here to be available: Petagnia occlusa Rondani, 1856 [Tachinidae]; Tephritis siderata Rondani, 1868 [Tephritidae]. The following names, previous deemed available, are determined here to be unavailable: Porricondyla albitarsis Rondani, 1840 [Cecidomyiidae], Lucilia cyanicolor Rondani, 1850 [Calliphoridae]; Cephenemya stimulatrix Rondani, 1857 [Oestridae]; Cheilosia nigricornis Rondani, 1844, Cheilosia testacicornis Rondani, 1857, Pelecocera ruficornis Rondani, 1865 [all in Syrphidae]; Cylindrogaster sanguinea Rondani, 1861, Deximorpha cristata Rondani, 1862, Myostoma microcera Rondani, 1856 [all in Tachinidae]; Tripeta exacheta Rondani, 1870 [Tephritidae]. We consider Merodon italicus Rondani 1845 as an unnecessary substitute name for Merodon natans Fabricius, 1794 and confirm it as a junior synonym of Merodon natans Fabricius, 1794. Acting as First Revisers, the following are herein selected as correct original spellings: Trichophthalma philippii Rondani, 1863 [Nemestrinidae]; Sphiximorpha garibaldii Rondani, 1860 [Syrphidae]; Agelanius philippii Rondani, 1863 [Tabanidae]; Exorista achanthina Rondani, 1859, Platychyra brevicauda Rondani, 1865 [Tachinidae]. Species not previously treated in any recent Diptera catalog include the following: Chorthophila limbatella Rondani, 1877, Hylephila melitensis Rondani 1877 [both in Anthomyiidae]; Mya jonicroma Rondani, 1851, Mya versicolor Rondani, 1850, Somomya anulipes Rondani, 1863, Somomyia xanthomera Rondani, 1875 [all in Calliphoridae]; Madiza fabae Rondani, 1876 [Chloropidae]; Psilopus ducalis Rondani, 1850 [Dolichopodidae]; Gymnopa opaca Rondani, 1869 [Ephydridae]; Oedalea bracata Rondani, 1856 [Hybotidae]; Sapromyza albifrons Rondani, 1868, Sapromyza rectinervis Rondani, 1868 [both in Lauxaniidae]; Boletina parmensis Rondani, 1856, Bolithobia lateralis Rondani, 1856, Bolithomyza spinulina Rondani, 1856, Mycetomyza sciarina Rondani, 1856, Pachipalpus calceatus Rondani, 1856 [all in Mycetophilidae]; Lyoneura lugubris Rondani, 1856 [Psychodidae]; Volucella trizonata Rondani, 1875 [Syrphidae]; Echinomya apicalis Rondani, 1848, Echinomya ignobilis Rondani, 1863, Gonia ornata var. repudiata Rondani, 1859, Hyalomyia unicolor Rondani, 1868, Platychyra valida Rondani, 1865, Pyragrura uncinatus Rondani, 1861 [all in Tachinidae]. One species, Bertea subaptera Rondani, 1856, is returned to Diptera from Hymenoptera after examination of the type material.

An experimental approach to assessing the impact of ecosystem engineers on biodiversity and ecosystem functions.

Plants acting as ecosystem engineers create habitats and facilitate biodiversity maintenance within plant communities. Furthermore, biodiversity research has demonstrated that plant diversity enhances the productivity and functioning of ecosystems. However, these two fields of research developed in parallel and independent from one another, with the consequence that little is known about the role of ecosystem engineers in the relationship between biodiversity and ecosystem functioning across trophic levels. Here, we present an experimental framework to study this relationship. We combine facilitation by plants acting as ecosystem engineers with plant-insect interaction analysis and variance partitioning of biodiversity effects. We present a case-study experiment in which facilitation by a cushion-plant species and a dwarf-shrub species as ecosystem engineers increases positive effects of plant functional diversity (ecosystem engineers and associated plants) on ecosystem functioning (flower visitation rate). The experiment, conducted in the field during a single alpine flowering season, included the following treatments: (1) removal of plant species associated with ecosystem engineers, (2) exclusion (covering) of ecosystem engineer flowers, and (3) control, i.e., natural patches of ecosystem engineers and associated plant species. We found both positive and negative associational effects between plants depending on ecosystem engineer identity, indicating both pollination facilitation and interference. In both cases, patches supported by ecosystem engineers increased phylogenetic and functional diversity of flower visitors. Furthermore, complementarity effects between engineers and associated plants were positive for flower visitation rates. Our study reveals that plant facilitation can enhance the strength of biodiversity-ecosystem functioning relationships, with complementarity between plants for attracting more and diverse flower visitors being the likely driver. A potential mechanism is that synergy and complementarity between engineers and associated plants increase attractiveness for shared visitors and widen pollination niches. In synthesis, facilitation among plants can scale up to a full network, supporting ecosystem functioning both directly via microhabitat amelioration and indirectly via diversity effects.

Influence of Cover Crop Termination on Ground Dwelling Arthropods in Organic Vegetable Systems.

A key aspect in cover crop management is termination before the cash crop is planted. The aim of this study was to assess the effects of termination methods on ground-dwelling arthropods. The conventional mechanical termination method-i.e., green manuring by means of a disc harrow-was compared to flattening using a roller crimper. Two different crop systems were investigated for two growing seasons; cauliflower was grown in autumn after the termination of a mixture of cowpea, pearl millet, and radish, and tomato was cropped in spring and summer after the termination of a mixture of barley and vetch. Ground beetles (Coleoptera: Carabidae), rove beetles (Coleoptera: Staphylinidae), and spiders (Araneae) were sampled by means of standard pitfall traps throughout the growing season of both cash crops. The roller crimper increased the overall abundance of ground beetles in the first growing season of both cash crops, whereas in the second year, no significant effect could be detected. Rove beetles were more abundant in plots where the cover crops were terminated by the roller crimper. Finally, green manuring increased the abundance of spiders, especially on the first sampling date after cover crop termination. Albeit different taxa showed different responses, the termination of cover crops by a roller crimper generally increased the abundance of ground dwelling arthropods. Given that most of the sampled species were generalist predators, their increased abundance could possibly improve biological control.

Plant interactions shape pollination networks via nonadditive effects.

Plants grow in communities where they interact with other plants and with other living organisms such as pollinators. On the one hand, studies of plant-plant interactions rarely consider how plants interact with other trophic levels such as pollinators. On the other, studies of plant-animal interactions rarely deal with interactions within trophic levels such as plant-plant competition and facilitation. Thus, to what degree plant interactions affect biodiversity and ecological networks across trophic levels is poorly understood. We manipulated plant communities driven by foundation species facilitation and sampled plant-pollinator networks at fine spatial scale in a field experiment in Sierra Nevada, Spain. We found that plant-plant facilitation shaped pollinator diversity and structured pollination networks. Nonadditive effects of plant interactions on pollinator diversity and interaction diversity were synergistic in one foundation species networks while they were additive in another foundation species. Nonadditive effects of plant interactions were due to rewiring of pollination interactions. In addition, plant facilitation had negative effects on the structure of pollination networks likely due to increase in plant competition for pollination. Our results empirically demonstrate how different network types are coupled, revealing pervasive consequences of interaction chains in diverse communities.

The Influence of Vegetation and Landscape Structural Connectivity on Butterflies (Lepidoptera: Papilionoidea and Hesperiidae), Carabids (Coleoptera: Carabidae), Syrphids (Diptera: Syrphidae), and Sawflies (Hymenoptera: Symphyta) in Northern Italy Farmland.

Landscape structure as well as local vegetation influence biodiversity in agroecosystems. A study was performed to evaluate the effect of floristic diversity, vegetation patterns, and landscape structural connectivity on butterflies (Lepidoptera: Papilionoidea and Hesperiidae), carabids (Coleoptera: Carabidae), syrphids (Diptera: Syrphidae), and sawflies (Hymenoptera: Symphyta). Vegetation analysis and insect samplings were carried out in nine sites within an intensively farmed landscape in northern Italy. Plant species richness and the percentage of tree, shrub, and herb cover were determined by means of the phytosociological method of Braun-Blanquet. Landscape structural connectivity was measured as the total length of hedgerow network (LHN) in a radius of 500 m around the center of each sampling transect. Butterflies species richness and abundance were positively associated both to herb cover and to plant species richness, but responded negatively to tree and shrub cover. Shrub cover was strictly correlated to both species richness and activity density of carabids. The species richness of syrphids was positively influenced by herb cover and plant richness, whereas their abundance was dependent on ligneous vegetation and LHN. Rarefaction analysis revealed that sawfly sampling was not robust and no relationship could be drawn with either vegetation parameters or structural connectivity. The specific responses of each insect group to the environmental factors should be considered in order to refine and optimize landscape management interventions targeting specific conservation endpoints.

Gains to species diversity in organically farmed fields are not propagated at the farm level.

Organic farming is promoted to reduce environmental impacts of agriculture, but surprisingly little is known about its effects at the farm level, the primary unit of decision making. Here we report the effects of organic farming on species diversity at the field, farm and regional levels by sampling plants, earthworms, spiders and bees in 1470 fields of 205 randomly selected organic and nonorganic farms in twelve European and African regions. Species richness is, on average, 10.5% higher in organic than nonorganic production fields, with highest gains in intensive arable fields (around +45%). Gains to species richness are partly caused by higher organism abundance and are common in plants and bees but intermittent in earthworms and spiders. Average gains are marginal +4.6% at the farm and +3.1% at the regional level, even in intensive arable regions. Additional, targeted measures are therefore needed to fulfil the commitment of organic farming to benefit farmland biodiversity.