Abstract Insect declines are a global issue with significant ecological and economic ramifications. Yet, we have a poor understanding of the genomic impact these losses can have. Genome‐wide data from historical specimens have the potential to provide baselines of population genetic measures to study population change, with natural history collections representing large repositories of such specimens. However, an initial challenge in conducting historical DNA data analyses is to understand how molecular preservation varies between specimens. Here, we highlight how Next‐Generation Sequencing methods developed for studying archaeological samples can be applied to determine DNA preservation from only a single leg taken from entomological museum specimens, some of which are more than a century old. An analysis of genome‐wide data from a set of 113 red‐tailed bumblebee Bombus lapidarius specimens, from five British museum collections, was used to quantify DNA preservation over time. Additionally, to improve our analysis and further enable future research, we generated a novel assembly of the red‐tailed bumblebee genome. Our approach shows that museum entomological specimens are comprised of short DNA fragments with mean lengths below 100 base pairs (BP), suggesting a rapid and large‐scale post‐mortem reduction in DNA fragment size. After this initial decline, however, we find a relatively consistent rate of DNA decay in our dataset, and estimate a mean reduction in fragment length of 1.9 bp per decade. The proportion of quality filtered reads mapping to our assembled reference genome was around 50%, and decreased by 1.1% per decade. We demonstrate that historical insects have significant potential to act as sources of DNA to create valuable genetic baselines. The relatively consistent rate of DNA degradation, both across collections and through time, mean that population‐level analyses—for example for conservation or evolutionary studies—are entirely feasible, as long as the degraded nature of DNA is accounted for.

Determining when animal populations have experienced stress in the past is fundamental to understanding how risk factors drive contemporary and future species' responses to environmental change. For insects, quantifying stress and associating it with environmental factors has been challenging due to a paucity of time-series data and because detectable population-level responses can show varying lag effects. One solution is to leverage historic entomological specimens to detect morphological proxies of stress experienced at the time stressors emerged, allowing us to more accurately determine population responses. Here we studied specimens of four bumblebee species, an invaluable group of insect pollinators, from five museums collected across Britain over the 20th century. We calculated the degree of fluctuating asymmetry (FA; random deviations from bilateral symmetry) between the right and left forewings as a potential proxy of developmental stress. We: (a) investigated whether baseline FA levels vary between species, and how this compares between the first and second half of the century; (b) determined the extent of FA change over the century in the four bumblebee species, and whether this followed a linear or nonlinear trend; (c) tested which annual climatic conditions correlated with increased FA in bumblebees. Species differed in their baseline FA, with FA being higher in the two species that have recently expanded their ranges in Britain. Overall, FA significantly increased over the century but followed a nonlinear trend, with the increase starting c. 1925. We found relatively warm and wet years were associated with higher FA. Collectively our findings show that FA in bumblebees increased over the 20th century and under weather conditions that will likely increase in frequency with climate change. By plotting FA trends and quantifying the contribution of annual climate conditions on past populations, we provide an important step towards improving our understanding of how environmental factors could impact future populations of wild beneficial insects.

During May 2012 Diptera were sampled in the Serro do Courel area of Lugo Province, Galicia, northwest Spain. The authors of this paper, members of the Malloch Society (see website) are active in attempting to understand the detailed ecology of flies. Much of this work is through targeting larval stages often with an emphasis on saproxylic situations. By rearing adults from larvae direct relationships between them and their detailed habitat requirements are established. The list of nematocerous Diptera that were sampled includes 36 species two of them new to science and records of six others new to the Iberian peninsula are provided. We describe Lipsothrix galiciensis Hancock & Hewitt sp. nov., and Prionolabis pjotri Hancock sp. nov. of the family Limoniidae and provide a key to adults of European Lipsothrix species. Such results from this brief opportunity indicate the potential of the area for further field work in these and other families of Diptera.

The syrphids (Syrphidae) of Serra do Courel, a mountainous locality of just over 20,000ha at the west end of the Cantabrian Mountains, northern Spain are poorly known. The Scottish based, Malloch Society visited the locality in May 2012 and collected a total of 462 specimens of 98 syrphid species and 36 genera. These represent the first syrphid records from Serra do Courel. The area has many meadows and small woodlands or 'soutos' and these habitats combined were the most productive, 69 spp. recorded. Cheilosia lucense Ricarte sp. nov. is described from Courel and compared with other species of the alpina group. Six other syrphid species were new to the Iberian Peninsula, three of which belong to the saproxylic genus, Brachyopa. In common with studies elsewhere in the Cantabrian Mountains, Cheilosia was the most diverse genus and 21 species were recorded. The syrphid fauna of the Cantabrian Mountains includes 203 species of which 24 are here added and a species checklist provided.

The results of the hoverfly (Syrphidae) collection by the ‘Malloch Society’ on the Greek island of Lesvos are presented.Fieldwork took place from February to March 2006 and from May to June 2010. An account of 66 species from 28 generais provided including two species new to science, five species new to Greece and data for several rarely recorded species.We describe Eumerus armatus Ricarte and Rotheray sp. nov., a medium size species with red abdomen. We also describeSphiximorpha hiemalis Ricarte, Nedeljković and Hancock sp. nov., a hairy species with distinctive colour and pollinositypatterns and abdomen shape. The female of Eumerus claripennis Coe, 1957 is described and the male genitalia are figured.The majority of species encountered belonged to the typically Mediterranean genera Eumerus (8 spp.), Merodon (16 spp.)and Paragus (6 spp.). Approximately 71% of the recorded species also occur in Turkey. This supports the idea that West Mediterranean and Anatolian faunas overlap in Lesvos.

Recent ecological surveys have resulted in rearing examples of the five British members of the genus Lipsothrix (Diptera, Limoniidae). These have provided samples for investigating the morphology of their thoracic spiracular gill by the use of scanning electron microscopy. This reveals unique characteristics for the five species available. The differing structures may relate to varying larval habitats. A species identification key for pupae is based on features of the plastron. Information from the juvenile stages supports the placing of Lipsothrix in the Limoniinae.