This article, in memoriam, provides details of the professional life of Michael Charles Day, researcher at the Natural History Museum, London and specialist in the taxonomy of aculeate Hymenoptera especially Pompilidae. It also includes a short account of his lifelong interest in caving.

Factors affecting the ecology of a large population of Pacific cicada killers (Sphecius convallis) occupying a field of mine tailings in Ruby, AZ, were examined. Burrows were quite dense in certain areas around the periphery of the mine tailings, but were dispersed randomly within these areas. Approximately 1600 females (based on burrow counts) and 2500 males (based on mark-recapture) were recorded

Island ecosystems are particularly vulnerable to the introduction of exotic species that can have an impact on local fauna and flora. Here, the carpenter bee Xylocopa pubescens is reported in Gran Canaria (Canary Islands, Spain) for the first time. This species is native to North Africa and the Near East and shows a rapid dispersion across the city of Las Palmas de Gran Canaria, together with a single

This study investigates the nesting habits of Epicharis picta in a nest aggregation located in a fragment of the Atlantic forest in Southeastern Brazil. Ten emergence-traps were set up in this nest aggregation to standardize data collection of phenology, natural enemies, and sex ratio. Epicharis picta nests were in an area of 160 m² with a density of 41 nests/m². Nest and cell architecture are described

The large and distinctive chalcidoid wasp Leptoomus janzeni Gibson, 2008, originally described from late Eocene Baltic amber, is newly recorded from coeval Rovno amber (Ukraine) based on a single well-preserved female specimen. Only 66 species of Rovno hymenopterans (49%) are also known from Baltic amber. High resolution photomicrographs and measurements of the specimen are given. Some character states

Japanese species of the muscaeforme-group, charon-group, and floridanum-group of Gryon have been revised. Among the species of the muscaeforme-group, G. fulvicoxasp. nov. is newly described. Gryon misha Kozlov & Kononova, syn. nov. is considered a junior synonym of G. japonicum (Ashmead). Gryon maruzzae Mineo, syn. nov. and G. sugonjaevi Kozlov & Kononova, syn. nov. are considered junior synonyms of

Aprostocetus smilax Gates & Zhang, sp. nov., is described from stem and leaf galls on Smilax havanensis Jacq. in southern Florida, USA. It is the third species of Aprostocetus Westwood known to induce plant galls. Two parasitoids of A. smilax are also described: Phylloxeroxenus smilax Gates & Zhang sp. nov. and Sycophila smilax Gates & Zhang, sp. nov. We conclude that A. smilax is the true gall inducer

Surveys with sentinel eggs of Bagrada hilaris (Hemiptera: Pentatomidae) in southern California retrieved two parasitoids that were not previously known to be associated with this stink bug, Trissolcus hullensis and T. utahensis (Hymenoptera: Scelionidae). Molecular and morphological analysis of these specimens is used to modify the concept of T. utahensis and assess the factors that contribute to intraspecific

The status of the genus Neorthostigma Belokobylskij, 1998 is re-established as a result of additional morphological studies. A new species, N. braetisp. nov., from Papua New Guinea is described and illustrated. Aspilota brachyclypeataFischer 1978 is transferred to Neorthostigma, hence N. brachyclypeata (Fischer, 1978), comb. nov. A new synonym is suggested, Aspilota macrops Stelfox & Graham, 1951 =

Only two species (Syzeuctus coreanus and S. sambonis) of the genus Syzeuctus were known to inhabit South Korea. In the present study, four species of this genus are newly recorded from South Korea. Among them, two species, S. albopictus Kang & Lee, sp. nov. and S. flavofacialis Kang & Lee, sp. nov., are described as new. Of the other species, the male of S. takaozanus was hitherto unknown and is described

Ecosystems under ecological restoration should be monitored in order to investigate if the ecosystem is being functionally recovered, especially in highly vulnerable biodiversity hotspots like Andean forests. Here we sampled Hymenoptera families in four Andean forest reserves above 1800 masl from Southern Ecuador, in three conservation levels in each forest: low (degraded), medium (10–15 years of recovery)

The Palaearctic species of the digger wasps genus Hoplisoides Gribodo, 1884 (Hymenoptera: Crabronidae: Bembicinae) are reviewed, and a key to both sexes is given. Two new species are described and illustrated: Hoplisoides flavescens Mokrousov, sp. nov. (Azerbaijan) and H. leleji Mokrousov, sp. nov. (Turkmenistan). New synonymy is proposed for Hoplisoides craverii (A. Costa), 1867 = Gorytes merceti

The wasp genus Psenulus is the most diverse genus of the family Psenidae in the superfamily Apoidea, with its diversity peaking in the Oriental realm. Six species of the genus are here recorded for the first time from the Hong Kong SAR. Three of these, Psenulus ephippiussp. nov., Psenulus gibbussp. nov. and Psenulus pallenssp. nov. are described as new to science. An identification key, figures for

The introduction and establishment of the North American mud-dauber wasp Sceliphron caementarium (Drury, 1773) is reported for the first time from the Maltese Islands. A check-list of the Maltese Sphecidae is provided.

Continuing prior studies on Chinese Sphecodes, we here report further records of twelve rarely collected and little known species from mountainous regions of Southern and South-Western China (Xizang, Sichuan, Yunnan). Forty two species are currently known from China, yet until now only two species were known from Southern and South-Western China. We report six entirely new records for China, including

Low-light adapted bees are substantially understudied components of the bee fauna, particularly in Australia. Whilst several species in Australia are thought to be adapted to low-light conditions, explicit records of these taxa actually foraging at twilight or night are absent from the scientific literature. We present the first observations of Australian bees foraging in low-light conditions as well

The yellow-legged, or Asian hornet, Vespa velutina, has invaded large parts of South-Western Europe and now starts spreading further north. Recently, it has been reported from Hamburg, Northern Germany. Yet, the origin of this new invasion is not clear as the founders may have come either from Southern Europe or from Asia. We here use COI sequences to test these alternatives and find that the specimens

New additions to the knowledge of the subfamily Eumeninae in Russia are provided. Stenodynerus rossicus Fateryga & Kochetkov, sp. nov. is described from Amurskaya Province and Altai Republic. Three species of eumenine wasps are reported from Russia for the first time: Onychopterocheilus kiritshenkoi (Kostylev, 1940), Pterocheilus quaesitus (Morawitz, 1895), and Stenodynerus chitgarensis Giordani Soika

The fossil species of Thaumatodryinus from Dominican amber are studied, and the first revision is presented with a key to the known taxa. We recognize three species, T. miocenicus Olmi, 1995, T. priscus (Olmi, 1998), comb. nov. and T. fuscescenssp. nov. The current classification of the genus and relationships between fossil and living species are discussed. Comments on the host records for Thaumatodryinus

A brief review of the proctotrupoid genus Vanhornia Crawford is given. A new species, Vanhornia yuriisp. nov. from Primorskiy Territory, Russia, is described and illustrated. Photographic illustrations of Vanhornia eucnemidarum Crawford, 1909 (specimens from USA), V. leileri Hedqvist, 1976 (specimens from the Russian Far East) and V. quizhouensis (He & Chu, 1990) (holotype) are given. An identification

Eucharissa (Hymenoptera: Eucharitidae) is an enigmatic genus within Chalcidoidea. Adults have at least 16 antennal segments, which is shared only by the closely related genus, Saccharissa, with some species of Eucharissa having as many as 22 antennal segments. At most, other Chalcidoidea have up to 14 segments. Phylogenetic analyses place Eucharissa within the poneromorph-ant attacking clade, but until

A new fossil species of Eulophidae, Kressleinius celans, gen. et sp. nov., is described from Eocene Baltic amber. It does not place into any extant genera within Eulophidae due to a lack of distinctive synapomorphies. The results of a morphology-based phylogenetic analysis placed K. celans in Tetrastichinae because of features shared with several genera, including having 6 flagellomeres past the anelli

A new species of Microgastrinae (Hymenoptera: Braconidae) parasitoid wasp, Microgaster godzilla Fernandez-Triana & Kamino, is described from Japan. From a biological and morphological perspective this is a very unusual species. It represents only the third known microgastrine to be aquatic, and the first one to be found entering the water. The female wasp searches for its hosts, aquatic larvae of Elophila

In Trinidad, West Indies the social wasps Angiopolybia pallens and Polybia rejecta come to foam nests of the frog Engystomops pustulosus, where they prey on eggs and tadpoles. Frog offspring in early-stage foam nests appear to be almost immune to predation by the wasps, but they become more vulnerable as the nests age and lose definition.

Phoretic copulation, a form of phoresy in which a male physically transports a female by flight and/or foot from their initial site of contact before mating, is newly recorded in the Nearctic velvet ant Sphaeropthalma pensylvanica (Lepeletier, 1845) (Hymenoptera: Mutillidae). Further, this is the first record of the behavior in the species-rich subfamily Sphaeropthalminae. A description of the S. pensylvanica

Exotic ants are a growing component of urban and disturbed habitats worldwide. Sampling in two Iberian Mediterranean localities revealed several exotic species. The tree-nesting, black acrobat ant Crematogaster inermis Mayr, 1862, has been detected nesting outdoors on a Robinia pseudoacacia tree in a public garden in Valencia (Spain) and represents a new addition to the continental European fauna.

Doryctobracon areolatus (Szépligeti), a solitary endoparasitoid native to the Neotropics, attacks eggs and early instar larvae of Anastrepha fruit flies, and can enter diapause under tropical and subtropical conditions. We aimed to test if biological attributes, such as size, flight ability, starvation resistance, longevity and fecundity of diapausing individuals differ from those of non-diapausing

Idiococcobius Hayat, syn. nov., is synonymised with Coccobius Ratzeburg, based on morphological and molecular data from a new species of Coccobius from Malaysian Borneo. The new species is sufficiently similar morphologically to the type species of Idiococcobius to place it unambiguously within that genus, but molecular data from the new species, and a reassessment of the morphology of Idiococcobius

Parasitoid hymenopterans are a highly diverse group of insects; therefore, the choice of an adequate sampling method becomes important to achieve a representative species richness of a site. The aim of this work is to evaluate the size and diversity of parasitoids in relation to the height of the Malaise trap placement above the ground of a low deciduous forest from Yucatan, Mexico. Parasitoids were

We report the presence of two Asian species of larval parasitoids of spotted wing Drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), in northwestern North America. Leptopilina japonica Novkovic & Kimura and Ganaspis brasiliensis (Ihering) (Hymenoptera: Figitidae) were found foraging near and emerging from fruits infested by D. suzukii at several locations across coastal British Columbia

Chartocerus azizaesp. nov. is described as the first known fossil from the family Signiphoridae, based on two inclusions in the same piece of Eocene Baltic amber (36.7–48.5 million years ago). Implications of the morphology of C. azizae are discussed, indicating that it should be placed in Chartocerus.

Sampling of crapemyrtle trees (Lagerstroemia L.) in central Texas yielded the discovery of an invasive scale pest, Lopholeucaspis japonica Cockerell, and its parasitoid natural enemy, Marlattiella prima Howard. These discoveries expand the known range of both the scale insect and the parasitoid wasp in the United States. Marlattiella prima was not recovered in the absence of L. japonica. Of the two

A new species of Ctenopelmatinae, Rhinotorus nigrus Sheng, Li & Sun, sp. nov. reared from cocoons of Pristiphora erichsonii (Hartig) in Jilin Province, China, is described and illustrated. A key to Eastern Palaearctic species of Rhinotorus is provided.

Halyomorpha halys is a severe invasive Asian pest worldwide and classical biological control is foreseen as the most promising control method. Egg parasitoids appear to be the most important natural enemies of this pest, especially the Asian hymenopteran Trissolcus japonicus. In the invaded areas, only a few egg parasitoid species have been able to adopt H. halys as a host. Anastatus bifasciatus is

We report the solitary parasitism by Colastomion formosanum (Watanabe) (Hymenoptera, Braconidae, Rogadinae) on the larva of Nevrina procopia (Stoll) (Lepidoptera, Crambidae) feeding on Turpinia ternata Nakai (Staphyleaceae) in Amami Ôshima Is., Japan. This is the first host record for the genus Colastomion Baker outside of Papua New Guinea. We have also inferred the phylogenetic relationships of Colastomion

Here we describe two new Ephedrus species from the Biologiezentrum Linz´s collection: Ephedrus antennalissp. nov., which possesses 12-segmented antennae, a unique character within the genus Ephedrus; and E. carinatussp. nov., which represents an additional member of the root aphid parasitoid group within the genus Ephedrus.

Two new Costa Rican species of the braconid parasitoid wasp subfamily Cardiochilinae, Heteropteron kidonoi Dabek & Whitfield and Heteropteron hasegawai Dabek & Whitfield, are described and illustrated from dry forest in the Area de Conservacion Guanacastae, along with data on rearing from their hosts. Heteropteron kidonoi is a solitary endoparasitoid of Stenoma cathosiota (Lepidoptera: Depressariidae)

Taxonomy of the potter wasps of the genus Labus from Vietnam is reviewed, with six species recorded. Of them, one species previously identified as L. clypeatus van der Vecht, 1935 is described as new, namely L. angulus, sp. nov. Another new species, Labus obtusussp. nov., is also described. In addition, a key to all species of the genus occurring in Vietnam is given.

In this study, Halysituberosus Dong & Wang, 2017 is treated as a synonym of Allorhynchium van der Vecht, 1963 (syn. nov.). Halysituberosus yingjiangensis Dong & Wang, 2017 is a new synonym of Allorhynchium lugubrinum (Cameron, 1900) (syn. nov.) and Halysituberosus menglianensis Dong & Wang, 2017 is transferred to Allorhynchium as a new combination (comb. nov.). Based on additional COI gene sequencing

Bees require suitably close foraging and nesting sites to minimize travel time and energy expenditure for brood provisioning. Knowing foraging distances in persistent (‘healthy’) populations is therefore crucial for assessing harmful levels of habitat fragmentation. For small bees, such distances are poorly known because of the difficulty of individual tagging and problems with mark-recapture approaches

A new species of Andrena Fabricius, 1775, subgenus Trachandrena Robertson, 1902 is described and illustrated, A. hadfieldisp. nov., from Arizona, United States. The new species, presently known only from the female holotype, was collected in a Malaise trap in 1994, and remained unstudied until recently. In addition, Trachandrena is compared to similar subgenera in North America to assist in recognizing

Checklists provide information about the species found in a defined region and serve as baselines for detecting species range expansions, contractions, or introductions. Bees are a diverse and important group of insect pollinators. Although some bee populations are declining, these patterns are difficult to document and generalize due to a lack of long-term studies for most localities. Documenting