Dr. Peter Duelli

1. Windthrow disturbance is an important driver of arthropod diversity in forests. In the past, studies have mainly focused on the first years after disturbance, and there are hardly any data on arthropod trajectories in windthrows and on salvage logging effects over decades.
2. We sampled arthropods of different functional groups on 16 permanent plots following two windstorms (Vivian and Lothar) in coniferous and broadleaf forests at different elevations in Central Europe over two decades. Flight interception and pitfall traps were operated during the entire growing seasons in three habitat types per site: unsalvaged windthrow, salvaged windthrow and control forest.
3. In total, 524,115 individuals from 1666 arthropod species were identified, of which more than 90% occurred in windthrows, including 40%–53% species exclusively found in windthros. Over the two decades, saproxylics, herbivores, pollinators, predators and endangered species showed significantly higher species numbers and abundances in windthrows than in control forests, where only 6% exclusive species occurred.
4. Arthropod communities in windthrows showed distinct dynamics during the two decades. Their species numbers and abundances peaked in the first 3 years, coined by saproxylic species, such as bark beetles, and by pollinating hoverflies. While abundances declined rapidly, species numbers remained elevated for two decades. Arthropod similarity between windthrows and forests (indicating resilience) increased with time but depended on elevation and forest type. After 20 years, it reached an average of 50% in lowland broadleaf forests, but only 30% in high-elevation spruce forests, indicating lower resilience.
5. Salvage logging had no significant effect on overall species numbers but altered species composition. More than 10% exclusive species were found in salvaged and up to 20% in unsalvaged windthrows, with the latter supporting more endangered species, particularly towards the second decade.
6. Synthesis and applications. Our study shows that windthrow causes an initial boost of arthropod diversity. While abundances thereafter rapidly decline, species numbers remain at relatively high levels during at least two decades. Unsalvaged windthrows are an indispensable resource for endangered species, particularly in later wood decay stages.

Further data on the lacewing fauna of the Cape Verde Islands (Neuroptera: Chrysopidae, Hemerobiidae). Chrysoperla lucasina (Lacroix 1912), and Wesmaelius navasi (Andréu, 1911) are recorded for the first time for the Cape Verde Archipelago. Additional faunistic and phenological data complement the report of Aistleitner & Hölzel (2012).

Als Erstnachweise für den Kapverdischen Archipel werden Chrysoperla lucasina (Lacroix 1912) und Wesmaelius navasi (Andréu, 1911) angegeben. Vorliegende weitere faunistische und phänologische Daten ergänzen die Arbeit von Aistleitner & Hölzel (2012).

A checklist of the Neuropterida (Raphidioptera, Megaloptera, and Neuroptera) of Switzerland is provided. The inventory presently contains only extant species. Fossil neuropterids have recently been discovered in southern Switzerland, but are not yet described. The faunal records are divided into the 26 political cantons of Switzerland. A short description of the alpine geography and the glacial past of Switzerland is given. The main contributors to the knowledge of Swiss Neuropterida are discussed.

Most insects were dead when they were named by taxonomists, and predominantly morphological criteria have been used for more than two centuries. But in nature there are populations with individuals looking identical, that turn out to represent two or more different species, and others that look different but are single biological species. Coastal and several continental populations of the green lacewing Chrysoperla mediterranea (Hölzel 1972) had been considered to be one species, based on identical precopulatory "song patterns" (Henry et al. 1999) and viable hybrid production. More than 20 years later, Canard & Thierry (2020) described Chrysoperla europaea Canard and Thierry, 2020 as a new species, based on continental specimens, which they decided were morphologically different enough from the coastal morph of C. mediterranea. Here, we test in free choice experiments whether virgin males and females of coastal and continental populations can detect a difference between sexual partners of their own population versus members of the other morph. No reproductive separation between three populations were found, although they show significant morphological differences in claw shape and size. We conclude that all three tested populations from Southern France, Southern Switzerland, and Central Switzerland are the same biological species, and that C. europaea is therefore a junior synonym of C. mediterranea. We suggest the future use of behavioral tests in closely related allopatric species to see whether they are in fact the same species.

1. While many studies on insect diversity report declines, others show stable, fluctuating or increasing trends. For a thorough understanding of insect trends and their effects on ecosystem functioning, it is important to simultaneously assess insect richness, abundance and biomass, and to report trends for multiple taxa.
2. We analysed insect richness, abundance and biomass data for all insects and for eight insect taxa (Buprestidae, Cerambycidae, Carabidae, other Coleoptera, Aculeata, other Hymenoptera, Heteroptera and Lepidoptera) from 42 sites across Switzerland from 2000 to 2007, representing three major habitat types in Switzerland (agricultural, unmanaged [open and forested] and managed forest habitats). As potential drivers of temporal patterns, we evaluated weather- and land-use-related factors. As predictors, we included temperature and precipitation as well as the vegetation index and the habitat type, respectively.
3. We found a consistent pattern of stable or increasing trends for richness, abundance and biomass of insects in total and the eight taxa over 8 years. Both overall patterns and six out of eight taxa (except for Cerambycidae and Lepidotpera) showed the highest values in agricultural habitats. However, when accounting for elevation, there was no difference in open habitats regardless of whether they were used agriculturally.
4. Habitat types were the most important predictors, followed by weather- and vegetation-related factors. Modelled responses to mean temperature were unimodal, whereas the standard deviation of temperature showed positive and precipitation negative effects. Longer time series are needed to draw robust inferences and to investigate potential negative effects of future warming.

The rare green lacewing species Chrysoperla renoni (Lacroix, 1933) was recorded in the Esperstedter Ried, Thuringia, for the first time in Germany. So far, the species had been found in wetlands and marshy sites at distances of more than 700 km in France, Hungary and Romania. Due to its rareness and the geographic isolation the population in Thuringia has to be treated as a ‘Verantwortungsart’ in the sense of the German Red List of Endangered Species. The survival of the population depends on the preservation and development of the currently populated area. However, the groundwater level of Esperstedter Ried was lowered by reduced winter precipitation as well as by technical groundwater abstraction in the last years.

Die seltene Florfliegenart Chrysoperla renoni (Lacroix, 1933) wurde in Esperstedter Ried bei Bad Frankenhausen (Thüringen) erstmals in Deutschland nachgewiesen. Die wenigen bisherigen Nachweise erfolgten in feuchten Habitaten im Küstenbereich und in den Auen an Flüssen und Seen in Frankreich, Ungarn und Rumänien, mehr als 700 km entfernt. Aufgrund ihrer Seltenheit und des isolierten Vorkommens in Thüringen ist Ch. renoni als Rote-Liste Verantwortungsart anzusehen. Die langfristige Sicherung dieser Population wird maßgeblich von der Erhaltung und Entwicklung der besiedelten Lebensraumtypen abhängen. Geringe Winterniederschläge und die technische Grundwasserabsenkung führten in den letzten Jahren zu deutlichen Veränderungen des Habitats.

We report the first records of Nineta inpunctata (Reuter, 1894) and Chrysopa gibeauxi (Leraut, 1989) for the federal state of Vorarlberg (Austria), and the first records of Chrysopa gibeauxi (Leraut, 1989) and Chrysoperla mediterranea (Hölzel, 1972) for the Principality of Liechtenstein. Chrysopa pallens (Rambur, 1838) has to be deleted from the faunal list of Vorarlberg, since all presently available specimens turned out to be Chrysopa gibeauxi. A revised checklist of the chrysopids (green lacewings) of Vorarlberg and Liechtenstein is presented.

Recent studies reporting widespread declines in arthropod biomass, abundance and species diversity raised wide concerns in research and conservation. However, repeated arthropod surveys over long periods are rare, even though they are key for assessing the causes of the decline and for developing measures to halt the losses. We repeatedly sampled arthropod fauna in a representative Swiss agricultural landscape over 32 years (1987, 1997, 2019). Sampling included eight study sites in four different semi-natural and agricultural habitat types and different trap types (pitfall, window, yellow bucket) over an annual period of 10 weeks to capture flying and ground dwelling arthropod taxa. In total, we analyzed 58,448 individuals from 1343 different species. Mean arthropod biomass, abundance and species richness per trap was significantly higher in 2019 than in the prior years. Also, species diversity of the study area was highest in 2019. Three main factors likely have contributed to the observed positive or at least stable development. First, the implementation of agri-environmental schemes has improved habitat quality since 1993, 6 years after the first sampling. Second, landscape composition remained stable, and pesticide and fertilizer was constant over the study period. Third, climate warming might have favored the immigration and increase of warm adapted species. Our results support the idea that changes in arthropod communities over time is highly context-dependent and complex.

All nine presently known European species of the Apertochrysa prasina group (formerly the Pseudomallada prasinus group) are diagnosed. Separate keys for the identification of living and preserved specimens of each sex are presented. For males, the "furwing" trait (increased numbers of setae on costal crossveins) is often crucial for identification, especially in preserved specimens. In some cases, females of the newly recognized prasinoid species (Ap1, Ap2, Ap3) are impossible to distinguish without live coloration. This is largely why the three "new" species are difficult to assign to one of the many old (often female) type specimens of former prasinoid species or varieties, which had been synonymized with Chrysopa prasina in the past.

Apertochrysa Tjeder, 1966, is identified as a new senior subjective synonym of the large, subcosmopolitan, green lacewing genus currently known under the name Pseudomallada Tsukaguchi, 1995. Apertochrysa is rediagnosed and the taxonomic consequences of the new synonymy are reviewed. New combinations are created in Apertochrysa for 165 species formerly placed in Pseudomallada and for two species formerly placed in Mallada; three species are transferred from Pseudomallada back to previously-established combinations in Apertochrysa; and 13 additional species are retained in Apertochrysa from previous placements. This brings the total number of Apertochrysa species to 183.

Two of the most intriguing yet poorly understood taxa in the Chrysoperla carnea-group of green lacewings are the European species (alternatively, forms or ecotypes) known as Chrysoperla renoni and C. ankylopteryformis. These two rare taxa have been variously combined and separated by systematists over the years, but their taxonomic status remains controversial, partly because the two have very unusual characteristics, and partly because they are simply difficult to find in nature. Here, we introduce new observations and experimental results, gathered from living individuals collected at new localities in Hungary (C. renoni) and Spain (C. ankylopteryformis). These data encompass duetting song phenotype, mate choice and species recognition, body colour, pretarsal claw dimensions, wing setal length, and predominant habitat associations. The inheritance of several of these traits is also explored, by hybridising each of the two focal taxa with their abundant, co-occurring relative in the carnea-group, C. pallida. Our findings support recognition of C. renoni and C. ankylopteryformis each as valid, independent species, thereby also raising the latter species from its current synonymy with C. renoni (formally, Chrysoperla ankylopteryformis Monserrat & Díaz-Aranda, 1989 stat. rev.). We propose an evolutionary hypothesis to explain the reproductive isolation of these species from one another, as well as from C. pallida.
https://www.zoobank.org/urn:lsid:zoobank.org:pub:7800468B-0E79-4634-B523-FDF18BC3EC95

Three species of green lacewings (Neuroptera, Chrysopidae) are new faunistic records for Vorarlberg (Austria) and one also for the Principality of Liechtenstein: Cunctochrysa cosmia (Navas, 1918), Chrysopa dorsalis Burmeister, 1839, Chrysopa commata Kis & Újhelyi, 1965. Chrysopa nigricostata Brauer, 1850 has to be eliminated from the faunal list of Liechtenstein. In addition, corrections are made concerning Hemerobius schedli Hölzel, 1970 reported in AISTLEITNER & GRUPPE (2009). Some new observations of Libelloides coccajus (Denis & Schiffermüller, 1775), a protected species in Liechtenstein, are given.

Climates around the world are rapidly turning warmer and often drier. Agricultural approaches must change accordingly. One important global practice is commercial use of cryptic species of the Chrysoperla carnea-group of green lacewings to control arthropod pests. Recently, one highly drought-tolerant species, originally present only in the Old World, is suspected of expanding its range to some of the driest habitats in the New World. Here we examine putative specimens of this species, Chrysoperla zastrowi (Esben-Petersen, 1928), collected in the desert southwest of the United States, the parched northwest of Mexico, and Guatemala. Using species-specific vibrational duetting-song phenotypes, subtle morphological character states, and mitochondrial DNA sequences, we confirm that C. zastrowi is now a naturalized part of the lacewing fauna of the Americas, making it the only species of the carnea-group to have a truly global range. As such, we encourage its broader commercial use for pest control on irrigated agricultural systems in the hotter, drier regions of the world to which it is best adapted and within which it now appears to be fully naturalized. We briefly consider future range expansion of both subspecies of C. zastrowi, C. z. zastrowi, and C. z. sillemi, in response to continued global warming.

Le selve castanili e i vecchi castagni da frutto rappresentano ambienti potenzialmente interessanti per gli invertebrati del bosco e, in particolare per le specie legate al legno (xilobionti). Abbiamo testato questa ipotesi attraverso il campionamento degli invertebrati di 18 castagni secolari di grosse dimensioni nella selva Mont Grand a Soazza (GR): 9 castagni in ambienti aperti e in buono stato (definiti come "castagni gestiti") e 9 in stato precario di salute nel bosco non più gestito ("castagni abbandonati"). In ogni albero, abbiamo campionato gli invertebrati in tre habitat principali: la "chioma e il tronco esterno", l'"interno delle cavità del tronco" e "le cavità alla base del tronco". Con 39’572 individui appartenenti a 645 specie di 8 ordini diversi, la diversità biologica dei 18 castagni investigati nella selva Mont Grand a Soazza è da considerare alta. Gli habitat più ricchi di specie sono stati "chioma e il tronco esterno" e "le cavità alla base del tronco". I coleotteri sono l’ordine più ricco di specie campionate (309 specie di cui 176 legate al legno). Di queste, 49 specie sono considerate rilevanti dal profilo della conservazione, poiché minacciate o sono specie relitte di foreste primarie oppure specie forestali carismatiche della Svizzera. Nessuna differenza, per contro, è stata rilevata nel numero di specie e di individui tra castagni gestiti e castagni abbandonati, mentre la composizione delle comunità è risultata diversa, con ben il 47% delle specie campionate unicamente in una delle due tipologie di gestione. Questo sottolinea l’urgenza di recuperare i castagni abbandonati attraverso interventi mirati basati sulle potenzialità di ciascun castagno al fine di conservarli il più a lungo possibile.

Chestnut orchards and old chestnut trees are potentially interesting habitat for forest dwelling invertebrates and, in particular, for those that depend on wood (xylobionts). We tested this hypothesis by sampling invertebrates in 18 large, old chestnut trees in the Mont Grand chestnut orchard in Soazza (GR): 9 trees were in open habitats and in good condition (we termed them «managed chestnut trees») and 9 were in no longer managed forest and in a precarious state («abandoned chestnut trees»). On each tree, we sampled invertebrates in three main habitats: «crown and outer stem», «inner stem cavities» and «cavities at the stem bottom». With 39'572 individuals belonging to 645 species of 8 different orders, the biological diversity of the 18 chestnut trees investigated in the Mont Grand forest in Soazza is to be considered high. The most species-rich habitats were «crown and outer stem» and «cavities at the stem bottom». Beetles were the most species-rich order (309 species of which 176 xylobiont species). Of these, 49 species are considered to be of conservation concern, because they are either threatened or relict species of primary forests, or charismatic forest species in Switzerland. On the other hand, no difference was found in the number of species and individuals between managed and abandoned chestnut trees. However, the composition of their communities was different, with as many as 47% species sampled only in one of the two management types. Our results underline the urgency of recovering abandoned chestnut trees through targeted interventions based on the potential of single chestnut trees in order to conserve them in the long term.

Les châtaigneraies à fruits sont des milieux créés et entretenus par l’homme depuis leur introduction il y a quelque 2000 ans. Sans entretien régulier, elles sont vouées à disparaître, ce qui aurait des effets négatifs sur le paysage et la biodiversité. Afin de mieux comprendre ces processus, des études comparatives sur les chauves-souris, les oiseaux, les lichens et les arthropodes ont été réalisées dans des châtaigneraies entretenues et abandonnées. Tous les taxons et tout particulièrement les espèces rares et menacées profitent de l’entretien des châtaigneraies. La restauration de ces dernières est donc indispensable pour la conservation à long terme d’un paysage agro-forestier comportant des arbres-habitats séculaires de grande valeur écologique.

A new species and a new genus of Rhachiberothidae, Rhachiella malawica gen. nov., spec. nov., are described from Malawi. The new species is characterized by a flat vertex, a long penisfilum in the male, and by a bifurcate pseudohypocauda in the female. This combination of characters requires the description of a new genus, which is the sister taxon of Mucroberotha Tjeder, 1959. This is the first record of Rhachiberothidae in Malawi.
 The distributions of all 14 species of Rhachiberothidae so far known are shown in three maps.

It has recently been determined that Pseudomallada prasinus (Burmeister, 1839) is part of a complex of prasinoid species (Duelli & Obrist, 2019). Apart from P. prasinus s.s. and P. abdominalis s.s., each at the opposite end of the prasinoid spectrum, some populations in Switzerland and surrounding countries show consistently differing morphological and biological traits, while nevertheless living in the same habitats. To test whether they constitute reproductively isolated species, seven strains of three morphologically distinctive prasinoid morphs (Pp1, Pp2, Pp3) were reared and the virgin offspring (F₁) paired with single partners of each of the six other strains. The four strains of morph Pp3 were unable to produce any viable offspring when paired with the two other morphs, suggesting that Pp3 is a distinct species. The Mediterranean morph Pp1 produced some offspring with the two strains of morph Pp2, but the crossed offspring (F₂) of the hybrids yielded less than 2% viable larvae. Furthermore, in a cage experiment with free choice of partners between Pp1 and Pp2, all females produced offspring of their own morph; there were no hybrids. We conclude that north and south of the Alps there are at least three reproductively isolated prasinoid species in addition to P. prasinus and P. abdominalis. Their distinctiveness is principally based on live color traits, but also on the presence or absence of the "furwing" phenotype in males (double number of setae on wing veins). Therefore, many old museum specimens, especially females, cannot be identified with confidence. Because most of the dozens of synonymized type specimens of prasinoid species and varieties in museums are females, and all have lost their color, it is presently not possible to assign valid names to the three "new" species. We call them Pseudomallada prasinoid 1 (Pp1), P. prasinoid 2 (Pp2), and P. prasinoid 3 (Pp3). Using the distinctive traits given here, most specimens that have retained their original colors (live, recently pinned, or deep frozen) can be identified.

Recent discovery of Cunctochrysa cosmia (Navás, 1918) in Switzerland (Neuroptera, Chrysopidae). - With the recent discovery of Cunctochrysa cosmia, all three European species of Cunctochrysa have now been documented for Switzerland. In addition, we report two further records for the Mediterranean species C. baetica, so far only known from one site at Follatères, Valais. The third species, C. albolineata, is rather common in Switzerland. Noteworthy is the fact that all three species were collected in the same place at the same light trap on a warm evening in July 2019.

Durch den Neufund von Cunctochrysa cosmia (Navás, 1918) sind nun alle drei europäischen Cunctochrysa-Arten für die Schweiz belegt. Auch die in der Schweiz bisher nur von den Follatères im Wallis bekannte mediterrane C. baetica wurde an zwei Standorten im Mittelwallis bestätigt. Die dritte Art, C. albolineata, kommt in der Schweiz verbreitet vor. Bemerkenswert ist die Tatsache, dass alle drei Arten an einem warmen Juliabend 2019 an derselben Stelle oberhalb Visp (VS) ans Licht flogen.

Three sympatric morphs of Pseudomallada prasinus were hybridized in search of reproductively separated species.

The mid-term impact of forest fires and windthrows on species compositions in the insect orders Neuroptera, Raphidioptera, and Mecoptera was assessed in Swiss forests using standardized flight interception traps. For 50 species the abundances in intact control plots were compared to those in moderately or strongly disturbed forest stands. The catches were combined over four forest disturbance projects, ranging from windthrows in alpine spruce forests and lowland deciduous forests to winter forest fires in Southern Switzerland and a large summer fire in southwestern Switzerland. As a result, 82% of the 50 species benefited from the disturbance and became more abundant in the years after the fire or windthrow. More species (19) had their maximum abundance in intermediately disturbed plots than in heavily disturbed forests (17). Only 11 species, mainly Hemerobiidae and Coniopterygidae, peaked in the undisturbed forest stands. The species are listed per impact and ranked as winners (more than 66% specimens per treatment collected in disturbed forest plots), losers (more than 66% specimens per treatment in undisturbed forest plots), and indifferent species. An additional 29 species that were too scarce for an assessment are listed in Appendix 1. We conclude that for Neuropterida and Mecoptera catastrophic incidences are natural ecological events which create new habitats and by this foster their occurrence and abundance.