Host preferences of aphidophagous hoverflies from field distribution of their larvae

The patterns of occurrences among aphid colonies of the larvae of two species of highly polyphagous predatory hoverflies, Episyrphus balteatus (de Geer) and Syrphus ribesii (L.) (Diptera: Syrphidae), were assessed in three areas (Nottingham, Cardiff (UK) and the Czech Republic); in the last two sites, larvae of other syrphid species were also identified. The two syrphid species showed considerable diet overlap, their larvae using many of the same aphids as food, but with significant exceptions. Together with information from the literature, even for these very generalist species there was a consistent pattern of preference among aphid species. Most other species showed restricted preferences. Larvae were more frequent on developed aphid colonies than on colonies that were younger or had almost disappeared

The early stages and life histories of three Eumerus and two Merodon species (Diptera: Syrphidae) from the Mediterranean region

This paper describes the early stages and life histories of the syrphids Eumerus obliquus (Fabricius, 1805), E. pulchellus Loew, 1848, E. pusillus Loew, 1848, Merodon constans (Rossi, 1794) and M. luteihumerus Marcos-Garcia, Vujic & Mengual, 2007 (Diptera, Syrphidae) from Spain and Morocco. E. pulchellus, E. pusillus and M. luteihumerus were found inside bulbs of Urginea maritima (L.) Baker and E. pulchellus additionally in tubers of Asphodelus aestivus Brot. These data are some ofthe few obtained of natural plant relationships in these speciesrich genera. E. obliquus was found in fruits and platyclades of Opuntia maxima Mill., both insect and host plant are introductions. M. constans was found in commercially grown bulbs of Muscari comosum (L.) Mill. The Eumerus larvae studied here appear to more saprophagous than phytophagous but M. luteihumerus at least, seems to be a strict phytophage

Neotropical Copestylum Macquart (Diptera: Syrphidae) Breeding in Fruits and Flowers, Including 7 New Species

Ten species of Copestylum (Diptera: Syrphidae) were reared from fruits and flowers in Costa Rica, Ecuador and Trinidad. Seven were new and in this paper, we describe them, their development sites and the third stage larva and/or the puparium of all ten species. One new synonym is proposed, Copestylum pinkusi (Curran) [= Copestylum cinctiventre (Curran)]. Similarities and differences between these new and other Copestylum species, suggest they separate into two groups, referred to as the Vagum and Cinctiventre species groups. Features characterising these groups for both adult and early stages are assessed. Each species was also distinguished using adult and early stage characters. Within the Vagum group, adults were more disparate morphologically than the larval stage; this was reversed in the Cinctiventre group. Adult colour patterns are probably cryptic in function and for disguise. Vagum species have disruptive marks, while the Cinctiventre species have reflective colours. Biologically, the groups are almost distinguished by larval development sites. Vagum species use predominantly fruits and have a larval stage that is relatively generalised in form and habit. Cinctiventre species are confined to developing in flowers and the larva is more specialised. A key to both adult and early stages of all ten species is provided.Fieldwork was funded by the AECID, Agencia Española de Cooperación Internacional para el Desarrollo, Ministerio de Asuntos Exteriores y de Cooperación (A/4426/05, A/6788/06, A/3415/05, A/020305/08 and A/019887/08; www.aecid.es). The taxonomic study was funded by the S.W. Williston Diptera Research Fund of the Smithsonian Institution (http://entomology.si.edu/) and the Pelham-Clinton Fellowship Fund of the National Museums Scotland (E.C. Pelham-Clinton Fellowship, reference NMS10/73; www.nms.ac.uk)

Rediscovery and reclassification of the dipteran taxon Nothomicrodon Wheeler, an exclusive endoparasitoid of gyne ant larvae

The myrmecophile larva of the dipteran taxon Nothomicrodon Wheeler is rediscovered, almost a century after its original description and unique report. The systematic position of this dipteran has remained enigmatic due to the absence of reared imagos to confirm indentity. We also failed to rear imagos, but we scrutinized entire nests of the Brazilian arboreal dolichoderine ant Azteca chartifex which, combined with morphological and molecular studies, enabled us to establish beyond doubt that Nothomicrodon belongs to the Phoridae (Insecta: Diptera), not the Syrphidae where it was first placed, and that the species we studied is an endoparasitoid of the larvae of A. chartifex, exclusively attacking sexual female (gyne) larvae. Northomicrodon parasitism can exert high fitness costs to a host colony. Our discovery adds one more case to the growing number of phorid taxa known to parasitize ant larvae and suggests that many others remain to be discovered. Our findings and literature review confirm that the Phoridae is the only taxon known that parasitizes both adults and the immature stages of different castes of ants, thus threatening ants on all fronts.Peer reviewe

Phenological shifts in hoverflies (Diptera: Syrphidae): linking measurement and mechanism

An understanding of ecological and evolutionary responses to global environmental change requires both a robust measurement of the change that is occurring and a mechanistic framework for understanding the drivers of that change. Such a requirement provides a challenge because biological monitoring is often ad hoc, and mechanistic experiments are often performed under highly simplified conditions. This study integrates multiple datasets to evaluate our current knowledge of the measurement and mechanism of phenological shifts in a key pollinator taxon: the hoverflies (Diptera: Syrphidae). First, two large, complementary and independent monitoring datasets are used to test for trends in phenology: an ad hoc national recording scheme containing >620,000 records, and standardised monitoring with consistent methods over 30 years. Results show that ad hoc and standardised recording data give quantitatively the same value for phenological advance in hoverflies (ca. 12 days°C-1 on average at the beginning of the flight period), supporting the value of biological recording for the measurement of global ecological change. While the end of the flight period appears static in ad hoc recording, the standardised dataset suggests a similar advance as in the beginning of the flight period. Second, an extensive traits dataset and a novel database of laboratory-derived developmental data on Syrphidae (153 published studies) are used to test for mechanistic patterns in phenological shifts. The only species trait that influenced phenology was voltinism, where species with more generations per year exhibit stronger phenological advances. We demonstrate considerable variation in the laboratory-derived sensitivity to temperature but this does not match field-derived measures of phenology. The results demonstrate that, as for many taxa, we have a strong understanding of the patterns of global ecological change but that we currently lack a detailed mechanistic understanding of those processes despite extensive research into 45 the fundamental biology of some taxonomic groups

Pollinator-flower interactions in gardens during the covid 19 pandemic lockdown of 2020

During the main COVID-19 global pandemic lockdown period of 2020 an impromptu set of pollination ecologists came together via social media and personal contacts to carry out standardised surveys of the flower visits and plants in gardens. The surveys involved 67 rural, suburban and urban gardens, of various sizes, ranging from 61.18° North in Norway to 37.96° South in Australia, resulting in a data set of 25,174 rows, with each row being a unique interaction record for that date/site/plant species, and comprising almost 47,000 visits to flowers, as well as records of flowers that were not visited by pollinators, for over 1,000 species and varieties belonging to more than 460 genera and 96 plant families. The more than 650 species of flower visitors belong to 12 orders of invertebrates and four of vertebrates. In this first publication from the project, we present a brief description of the data and make it freely available for any researchers to use in the future, the only restriction being that they cite this paper in the first instance. The data generated from these global surveys will provide scientific evidence to help us understand the role that private gardens (in urban, rural and suburban areas) can play in conserving insect pollinators and identify management actions to enhance their potential

Development sites, feeding modes and early stages of seven European Palloptera species (Diptera, Pallopteridae)

Two hundred and ninety-eight rearing records and 87 larvae and puparia were obtained of seven species of Palloptera Fallén (Diptera, Pallopteridae), mainly in Scotland during 2012–2013. The third stage larva and puparium of each species were assessed morphologically and development sites and feeding modes investigated by rearing, observation and feeding tests. Early stages appear to be distinguished by the swollen, apico-lateral margins of the prothorax which are coated in vestiture and a poorly developed anal lobe with few spicules. Individual pallopteran species are separated by features of the head skeleton, locomotory spicules and the posterior respiratory organs. Five species can be distinguished by unique character states. Observations and feeding tests suggest that the frequently cited attribute of zoophagy is accidental and that saprophagy is the primary larval feeding mode with autumn/winter as the main period of development. Food plants were confirmed for flowerhead and stem developing species and rain is important for maintaining biofilms on which larvae feed. Due to difficulties in capturing adults, especially males, the distribution and abundance of many pallopteran species is probably underestimated. Better informed estimates are possible if early stages are included in biodiversity assessments. To facilitate this for the species investigated, a key to the third stage larva and puparium along with details on finding them, is provided