Barking up the right tree for the eyed elater, Alaus oculatus

 

Guess which one is a maniacal predator ravaging prey in the stygian world beneath the bark of fallen trees.

 

As we settle into the coldest weeks of the winter, the search for insects outdoors becomes a little trickier than in summertime. Many insects here in the DMV have migrated to warmer lands or hunkered down in hibernal refuges to survive winter’s chill. One reliable place to find fascinating insects any season of the year is beneath the bark of fallen trees. So, on a 24-degree morning last week I combed the banks of the Patuxent River in search of recently downed oak trees, those in an early stage of decomposition with bark still clinging to underlying wood. Beneath the bark, nutrient rich tissues are home to myriad wood decaying fungi and scores of insects that consume not only decomposing wood but luxuriant fungal hyphae and fruiting bodies. In this realm of decomposers, voracious predators prowl in search of the tender flesh of other insects.

A mating pair of eyed elaters greet a predator or camera with four spooky eyes.

The first two oaks I encountered yielded a few tiny fly larvae but nothing more. Under the bark of a third fallen oak, an almost fully-grown larva of the eyed elater rested in a state of winter torpor. These fierce predators hunt other insects such as the larvae of flies, caterpillars, and other beetles living in the dark voids beneath bark. Powerful jaws of the eyed elater larva capture and dismember prey. After consuming a full complement of victims and completing its juvenile development, the larva transforms into the magnificent eyed elater, also known as the eyed click beetle.  One look at this big beauty (up to 1 ½ inches long) provides instant understanding of how “eyed” became part of its name. As you stare at the beetle, two large and impressive eyes stare back at you. But these are not true eyes. The real compound eyes are rather small and located on the head of the click beetle near the base of the antennae. The markings on the back of the beetle are false eyespots like those we have seen on other guests of Bug of the Week, like the Polyphemus moth, swallowtail butterfly larva, and owl butterfly. The beetle’s strange and ghostly eyespots are thought to startle or confuse predators such as birds or other reptiles that might want to make a meal of a large, tasty beetle.

Beneath the bark of recently fallen trees thrives a rich ecosystem of fungi, insects, and microbial decomposers of wood. Larvae of the eyed elater are ferocious invertebrate predators high in the food web of these hidden realms. Bringing a chilly eyed elater larva indoors for a brief warm-up allows one to see the powerful jaws of this awesome predator.

The peg on the underside of the click beetle is part of the remarkable system which propels the beetle into the air with an audible click.

That explains the business about the “eyed”, but what about the “click”? To understand the click, you must be lucky enough to find and capture a click beetle. When grasped by a geeky entomologist, the eyed click beetle produces an unnerving snap of its body. When placed on its back on the ground, this snap propels the beetle into the air. The acceleration of this flip can exceed 2,000 meters per second squared and shoot the beetle several inches into the air. How do they do this? Click beetles have a remarkable peg latch on the under-surface of their body between the front and middle legs. The beetle flexes its body creating tension that, when released, causes the front end of the beetle to snap backward, propelling the insect into the air with an audible click. The beetle often lands right side up, but if it doesn't, the click-and-flip process may be repeated until the beetle finally rights itself. Although the full reason for the beetle flipping-out is not fully known, we can speculate that this forceful snapping and flipping might help the beetle escape the grasp of a tormenting predator or nosy entomologist.

Listen for the audible ‘click’ as the eyed elater flexes up and down. With a powerful snap of its body, the eyed elater jumps several inches, often righting itself. An unsuspecting vertebrate predator or bug geek might have an unnerving surprise when encountering this lively insect.

One last etymological note regarding this interesting beetle has to do with the name “elater”, coined from the ancient Greek word for “that which drives away”, a fitting name for this clever beetle. Smaller, less dramatic click beetles are frequent visitors to our porch lamps in spring and summer. Click beetles are great fun to capture and most entertaining, but please put them back unharmed where you found them when you are done.

Acknowledgements

This remarkable video by Dr. Adrian Smith of the North Carolina State University provided great insight into the mechanics of propulsion used by click beetles. Watch his amazing video at this link: https://www.google.com/search?q=how+does+the+click+beetle+flip+up&oq=&aqs=chrome.2.69i59i450l8.697805522j0j15&sourceid=chrome&ie=UTF-8#kpvalbx=_HdLxYYrqCYCqptQP7OaeiAg15  

The bible for identifying insect larvae and nymphs, “Immature Insects” by Frederick W. Stehr, was used to identify the larva of the eyed elater.

Velvet Photomorphs | Catalogue of Organisms

The velvet ants of the family Mutillidae are a diverse but relatively little-studied group of insects. As well as their often retiring habits, studies of this family are hindered by the difficulty of associating sexes. Females are wingless and superficially resemble hairy ants. Males are usually winged and resemble more typical wasps (there is a small handful of species in which both sexes are flightless). What we do know of velvet ant diversity suggests a high level of endemicity with different regions each having their own distinct assemblages of genera and species. In North America, one of the most diverse recognised genera is Photomorphus.

Female Photomorphus banksi, copyright Cotinis.

Species of Photomorphus are found across much of the United States and Mexico, being most diverse in the arid regions of the south-west (Brabant et al. 2010). The genus is currently divided between three subgenera, each originally described from males. Males have round, slightly protruding eyes, a more or less petiolate metasoma with a distinct constriction between the first and second segments, and a pair of ridges on the mesosternum behind the procoxae. The genus is currently divided between three subgenera: Photomorphus, Photomorphina and Xenomorphus. Males of subgenus Photomorphus have a distinct space between the mesocoxae and bidentate mandibles whereas Photomorphina males have the mesocoxae closely placed and tridentate mandibles (Manley & Pitts 2002). Females of Photomorphus have dense, silver setae on the mesosoma whereas females of Photomorphina have a less hairy mesosoma and typically have a band of plumose setae along the dorsal hind margin of the second metasomal segment (Brabant et al. 2010). The third subgenus, Xenomorphus, is known from a single Mexican species only and its female remains unidentified.

Male Photomorphus paulus, copyright J. C. Jones.

Photomorphus is part of a lineage of nocturnal mutillids common in arid regions of North America. Velvet ants develop as nest parasites of other wasps and bees; Photomorphus species are presumably no exception but their hosts are as yet unknown. A phylogenetic analysis of the North American nocturnal mutillids by Pitts et al. (2010) supported recognition of the group as a single clade but identified Photomorphus itself as polyphyletic. A clade corresponding to the subgenus Photomorphus was recovered but Photomorphina species were divided between multiple separate clades. This included the species P. myrmicoides which Brabant et al. (2010) had suggested should be moved from Photomorphina to subgenus Photomorphus. Females of P. myrmicoides have hair like that of subgenus Photomorphus but differs in the structure of the pygidial plate, a hairless area at the end of the metasoma. In the strict subgenus Photomorphus, this plate is completely smooth and shiny; in Photomorphina and P. myrmicoides, it is rough or marked by ridges. Clearly a reclassification of Photomorphus is on the cards but we are yet to see when we have the confidence to enact it.

REFERENCES

Brabant, C. M., K. A. Williams & J. P. Pitts. 2010. True females of the subgenus Photomorphina Schuster (Hymenoptera: Mutillidae). Zootaxa 2559: 58–68.

Manley, D. G., & J. P. Pitts. 2002. A key to genera and subgenera of Mutillidae (Hymenoptera) in America north of Mexico with description of a new genus. Journal of Hymenoptera Research 11 (1): 72–100.

Pitts, J. P., J. S. Wilson & C. D. von Dohlen. 2010. Evolution of the nocturnal Nearctic Sphaerophthalminae velvet ants (Hymenoptera: Mutillidae) driven by Neogene orogeny and Pleistocene glaciation. Molecular Phylogenetics and Evolution 56: 134–145.

Lichen Darklings | Catalogue of Organisms

The beetles of the family Tenebrionidae, often referred to as the darkling beetles, are a diverse bunch. Members of this family have adapted to a wide range of lifestyles, coming in a variety of body types. Among the more obscure representatives of the tenebrionids are the members of the Southern Hemisphere tribe Titaenini.

Titaena sp., copyright Martin Lagerwey.

Members of the Titaenini have a typical Gondwanan distribution, being known from southern and eastern Australia, New Zealand, New Caledonia and southern South America (Matthews & Bouchard 2008). They grow up to about a centimetre and a half in length with an elongate, parallel-sided body shape that is more or less cylindrical. The prothorax is relatively short, allowing the head to be held vertically in the Australian genus Titaena. Antennae are short with fairly simple segments not forming a club at the end. Legs have similarly simple tarsi. The tribe is distinguished from other, similar darkling beetles by the epipleura (the flattened underside of the elytral margins) which are shortened, not reaching the elytral apex. Members of the Titaenini have large repugnatorial glands opening near the end of the abdomen. In the Australian genus Titaena, at least, species are usually metallic blue or green in coloration.

The habits of the Titaenini are poorly known. As far as we do know, their larvae are specialised feeders on lichen. Adults probably pursue a similar diet. This is an exposed lifestyle, one in which you could easily come to the attention of predators, and the bright coloration of Titaena probably functions to warn off any such unwelcome interest.

REFERENCE

Matthews, E. G., & P. Bouchard. 2008. Tenebrionid Beetles of Australia: Descriptions of tribes, keys to genera, catalogue of species. Australian Biological Resources Study: Canberra.

A Spider for Christmas | Catalogue of Organisms

Hasselt's spiny spider Macracantha hasselti, copyright Patrick Randall.

In many warmer parts of the Old World, the spiny orb-weavers of the subfamily Gasteracanthinae are among the most eye-catching of all spiders. As well as constructing complex, easily seen webs in the manner of other orb-weavers, these spiders draw attention by their bright colours and ornate structure, often with prominent arrangements of spines on the abdomen. Here in Australia, their dramatic appearance has lead to their often being referred to as "Christmas spiders". The exact reason for this drama is uncertain. The spines are generally presumed to be for defence but the coloration has been subject to multiple proposals from an aposematic warning to functioning as a lure for flying insects.

Variants of Gasteracantha kuhli, from Macharoenboon et al. (2021).

The taxonomic history of the Christmas spiders is a complicated one, going back to the early years of arachnology. Not surprisingly for such distinctive animals, a large number of species were described by early authors. However, species of spiny orb-weavers are often very variable, leading to a significant number being described as new on more than one occasion. As with other orb-weavers, males are much smaller than females, and the spines on the abdomen tend to be more poorly developed. Coloration within a species can vary considerably in brightness, tone, and patterning. Structural features such as the arrangement of spines and the development of sigilla (impressions on the dorsal surface of the abdomen that mark the placement of internal muscles) can still provide reliable indicators of species identity, as (of course) can features of the genitalia. You have to learn to look past the superficial daubings and focus on the underlying form.

From the Bug of the Week Mailbag: Non-native mantids, the European mantis, Mantis religiosa, and Chinese mantis, Tenodera sinensis, enjoying North American cuisine

 

A small black spot often with a white center, on the inside of each front leg, provides a quick clue used to separate the European mantis from other species found in our region. Image credit: Bjorn Larson

 

While digging through the Bug of the Week mailbag last week, I ran across an interesting photograph sent from Portland, Oregon a few weeks before Christmas. The critter in question was clearly a praying mantis taking a stroll across a driveway. The question, of course, dealt with the identity of this handsome rascal. Fortunately, the image revealed the mantis in full stride with forelegs extended, thereby revealing the characteristic black and white bullseye on the inside of the foreleg near the joint of leg and body. This marking is diagnostic for the imported European praying mantis, Mantis religiosa.

European mantises vary in color with shades of green, brown, and sometimes bluish-green like this very pregnant beauty collected in Massachusetts.

First discovered in the US in 1899 in New York State, Mantis religiosa may have arrived as a stowaway on a shipment of nursery stock from Europe. In addition to its invaded range in North America, Mantis religiosa resides in parts of Europe, Asia, and Africa. On the east coast, some hoped that this remarkable predator might take a toll on dastardly gypsy moths which arrived in New England in the 1860’s. Unfortunately, this proved not to be the case as large hairy gypsy moth caterpillars were not on the menu for this European gourmand. However, hundreds of European mantises were imported and released in British Columbia during 1937 and 1938 to help curb grasshoppers that regularly decimated agricultural crops. In addition to expanding its range in the eastern US and parts of British Columbia, it can be found in Washington, Oregon, and California.  

Mantis religiosa is not the only non-native mantis to join a cadre of more than a dozen members of the mantis family in North America. Perhaps the most well-known non-native mantis here in the US is the Chinese praying mantis, Tenodera sinensis. To learn more about this one, we travel back in time more than a century to October 16, 1897 when Mr. Joseph Hindermyer discovered a large insect “resting on the upper part of his tomato vines” in Mt. Airy, a suburb of Philadelphia. Fortunately, Hindermyer’s neighbor, Philip Laurent, was a member of The Academy of Natural Sciences in Philadelphia and Philip recognized this extraordinary mantis to be different from others found in the area. He later discovered it was an exotic species known from China and Japan. How it arrived in Mt. Airy remains forever shrouded in mystery, but Laurent noted that a large nursery, Meehan and Sons, in nearby Germantown had procured many plants from China and Japan. Could it be that this marvelous predator arrived as a stowaway, perhaps as an embryo in an egg case on a Japanese maple?

This brown egg case, or ootheca, deposited by the lovely blue-green European mantis featured above contains scores of eggs that will survive the winter and hatch next spring.

 Fast forward a century to the mid-1990’s. The brown marmorated stink bug arrives in the US less than 60 miles from Mt. Airy in Allentown, PA. In the mid-Atlantic, we all remember what home invasions by stink bugs were like in the decade that followed. The dramatic decline of stink bugs in many eastern states over the last several years is in part related to the fact that several of our indigenous predators, parasitoids, and pathogens are now using brown marmorated stink bugs as a source of food. Prompted by this notion, I decided that it was time to have a reunion between these two historical acquaintances from the east – the Chinese praying mantis and the Asian brown marmorated stink bug. Like many reunions, meeting old acquaintances can be fraught with joy and despair. In the case of the Chinese mantis, the reunion with the Brown Marmorated Stink Bug was gastronomic joy. She consumed a dozen stink bugs in quick succession before nibbling only half of unlucky stink bug number thirteen. As for the stink bugs, well, let’s just say their reunion was filled with short-lived despair. You see, the hungry Chinese mantis mercifully devoured the stink bug’s head first. The reunion between the Chinese mantis and the Asian stink bug evoke Hannibal Lecter’s famous quote, “I do wish we could chat longer, but I'm having an old friend for dinner.” 

The reunion between two old acquaintances from Asia, the Chinese mantis and the brown marmorated stink bug, was a happy one for the mantis but not so much for the stink bug. My favorite part of this video appears at the end as the fastidious mantis tidies up after her meal. And yes, this is several times life speed.

Stink bugs are not the only Asian delicacy on the menu for our non-native mantises. A recent report from Penn State revealed praying mantises to be among the top predators of the newest landscape invader, the nefarious Spotted lanternfly. In light of the unending influx of invasive pests to the US, we are fortunate that some of our exotic predators will welcome the arrival of their historical dinner guests.  

Acknowledgements

Bug of the Week thanks Bjorn Larson for spotting the European mantis and providing the inspiration for this episode. The fascinating articles “Recent range expansion of the Praying Mantis, Mantis religiosa Linnaeus (Mantodea: Mantidae), in British Columbia” by Robert Cannings, and “Chickens, praying mantises appear to be top predators on spotted lanternfly, study says” by Marcus Schneck provided keen insights for this story.

Give Plateosaurus Its Due | Catalogue of Organisms

You could make a fascinating study (and many have) just looking at the history of which dinosaurs have held the foreground of popular culture when. The Iguanodon and Megalosaurus of the late 1800s, the Trachodon and Palaeoscincus of the earlier 1900s, the stratospheric rise of Velociraptor (sensu lato) with the release of Jurassic Park. And then there are those that never quite seem to get their dues. I've commented before on the odd relegation of Camarasaurus to the status of also-ran among famous sauropods. But perhaps the ultimate example of a dinosaur forced unfairly to the background is the should-be darling of the Late Triassic, Plateosaurus.

Plateosaurus 'engelhardti' in the Sauriermuseum at Frick, copyright Ghedoghedo.

Plateosaurus should, by all rights, be a superstar of dinosaur pop-culture. It was one of the first dinosaurs to reach massive size, extending up to nine metres in length and probably standing about as high (or slightly higher) than a tall man at the withers (Yates 2003). It is known from literally hundreds of specimens, many of them with large parts of the skeleton preserved, representing ages from juvenile to full maturity. Some of the bonebeds where it is found contain little but Plateosaurus and may have been formed in dramatic mass mortality events. Plateosaurus is easily the best known of the basal Sauropodomorpha, the 'prosauropods'. And yet, though Plateosaurus regularly appears in popular depictions, it rarely seems to make much more than a brief cameo. Why is this the dinosaur that gets no respect?

In part, it may be because it comes from a time period that gets less attention as a whole. The Triassic tends to get seen as a meer prelude to later, more 'exciting' parts of the Mesozoic. Plateosaurus itself, together with the other 'prosauropods', tends to also get overshadowed by its later, more eye-catching relatives, the sauropods. And when you get down to it, Plateosaurus may also be let down by the fact that it is perhaps the single most average dinosaur you could possibly imagine. Honestly, if you asked someone to depict a truly generic dinosaur, I don't think it would come out looking too different from Plateosaurus.

Reconstructed Plateosaurus, albeit in a now-obsolescent quadrupedal pose, copyright Elekes Andor.

All these criticisms aside, Plateosaurus is still a fascinating genus. Its remains have been found across central Europe, in Germany, Switzerland and France. The exact number of species in the genus has long been uncertain. As with other early-named dinosaur genera, 19^th Century palaeontologists named several species whose application has been subject to debate. Yates (2003) recognised two species in the genus, the earlier and smaller P. gracilis, and a larger, later species that Yates labelled P. engelhardti but which, due to various taxonomic shenanigans, should probably now be called P. trossingensis. Plateosaurus trossingensis is the better known of the two species, known from extensive bone-beds found at Trossingen and Halberstadt in Germany, and Frick in Switzerland (Lallensack et al. 2021). Some have questioned whether all these bone-beds represent a single species but Lallensack et al. found that examination of skulls from different locations failed to identify specific distinctions. Both Plateosaurus species would have been among the largest land animals of their times; even the smaller P. gracilis may have still reached lengths of five or six metres. Plateosaurus had a relatively long, narrow head though comparison of this feature with other prosauropods may be complicated by post-mortem distortion.

The life posture of Plateosaurus has historically been the subject of much dispute, whether it was bipedal, quadrupedal, or shifted freely between the two. However, recent models of the range of movement of the Plateosaurus hand and fore-arm have concluded that it was incapable of turning its hands palm-downwards, so it could not have supported itself comfortably on its fore limbs (Reiss & Mallison 2014). Obviously, the capacity for quadrupedal locomotion would evolve at some point in sauropodomorph evolution (in this day and age, I don't think anyone is proposing bipedal sauropods) but it was not before Plateosaurus.

Skeletal reconstruction of Unaysaurus talentinoi, copyright Maurissauro.

The phylogenetic relationships of Plateosaurus to other sauropods have been similarly disputed. Plateosaurus is, of course, the type genus of the family Plateosauridae but the concept of that family has varied significantly over time. For a large part of the twentieth century, 'Plateosauridae' was kind of a catch-all for all moderately large prosauropods, with Anchisauridae for the smaller species and Melanorosauridae for the giants. Redefinition of Plateosauridae to include only close relatives of Plateosaurus have significantly winnowed its contents. The current closest known relative of Plateosaurus is the recently described Issi saaneq, based on a pair of near-complete skulls from Greenland (Beccari et al. 2021). This species is close enough to Plateosaurus that its remains were previously assigned to P. englehardti. Offhand, "issi saaneq" is translated by the species' authors as "cold bone" in the local Kalaallisut language, but this looks to be another situation like "mei long" where a phrase was converted into a species name without considering that noun and descriptor order is reversed in biological names.

Other likely plateosaurids include two South American species, Unaysaurus tolentinoi and Macrocollum itaquii. The status of an Indian species Jaklapallisaurus asymmetrica is more uncertain. Beyond this, things become increasingly dodgy with little agreement over the details of prosauropod phylogeny. The overall conservative appearance of prosauropods means that phylogenetic studies are heavily reliant on fine details of the osteology that are debated between authors or not preserved in key taxa. Nevertheless, it does appear that the plateosaurids were widespread in the Norian epoch of the Triassic, and are bound to catch the attention of time travellers to the period.

REFERENCES

Beccari, V., O. Mateus, O. Wings, J. Milàn & L. B. Clemmensen. 2021. Issi saaneq gen. et sp. nov.—a new sauropodomorph dinosaur from the Late Triassic (Norian) of Jameson Land, central east Greenland. Diversity 13: 561.

Lallensack, J. N., E. M. Teschner, B. Pabst & P. M. Sander. 2021. New skulls of the basal sauropodomorph Plateosaurus trossingensis from Frick, Switzerland: is there more than one species? Acta Palaeontologica Polonica 66 (1): 1–28.
Reiss, S., & H. Mallison. 2014. Motion range of the manus of Plateosaurus engelhardti von Meyer, 1837. Palaeontologica Electronica 17 (1): 12A.

Yates, A. M. 2003. The species taxonomy of the sauropodomorph dinosaurs from the Löwenstein Formation (Norian, Late Triassic) of Germany. Palaeontology 46 (2): 317–337.

From the Bug of the Week Mailbag: Daddy-longlegs, the most venomous of all spiders? Opilionids and Pholcid spiders

 

One look at this arthropod and it’s easy to see why they are called daddy-longlegs.

 

A recent message to Bug of the Week described a pleasant adventure of nature enthusiasts with spider-like creatures known as daddy-longlegs. These interesting arthropods are at the heart of the urban legend proclaiming daddy-long legs as the most venomous of all spiders. A corollary of the legend is that although daddy-longlegs are venomous, their fangs are too tiny to pierce human skin. Like many urban legends this one persists, but fortunately it is baseless. Here’s why.

Pholcid spiders, like this cellar spider, are also known as daddy-longlegs.

With remarkably long legs, some crane flies are also called daddy-longlegs.

Let’s start with nomenclature. First of all, daddy-longlegs is a moniker applied to at least three different kinds of arthropods. According to spider expert Dr. Rick Vetter, daddy-longlegs refers to long-legged spiders in the family Pholcidae, an entirely different arachnid called an opilionid (a.k.a. harvestmen), and a primitive fly called a crane fly. We met pholicids rocking out in corners of a room in a previous episode. Crane flies are sometimes misidentified as giant mosquitoes and have appeared in Bug of the Week as well. But let’s talk about harvestmen, opilionids. The business of harvestmen being dangerously venomous is incorrect on two accounts. First and foremost is the fact that they lack venom glands. No venom glands, no venom. Their arachnid relatives, spiders, including pholcid spiders, subdue prey with potent venom delivered via fangs. Harvestmen lack fangs so the business of tiny fangs is also out the window. Harvestmen feed primarily on decaying vegetation or animals, but they may also be opportunistic predators. I have seen them snacking on hapless cicadas that failed to successfully shed their nymphal skin. Harvestmen are often seen in moist woodlands on vegetation, stumps, or leaf-litter where they search for food and mates. Harvestmen are easily distinguished from their spider relatives. Instead of the two easily seen body regions (cephalothorax and abdomen) characteristic of spiders, the distinction between body segments is indistinct and harvestmen appear to have a single pill-shaped body. If you want to get close enough to look them in the eye, harvestmen have at most two eyes whereas spiders may have as many as eight.

Despite their lack of fangs and venom, opilionids possess clever tricks to help them avoid being eaten by ground dwelling predators. Specialized glands along the margin of the harvestmen release noxious quinones that are mixed with fluids regurgitated from the digestive tract on the harvestmen.  The harvestmen smear the stinky concoction along its margins, forming a chemically deterrent barrier around its perimeter. This chemical defense has been shown to deter ants, spiders, and frogs and to make nosy bug geeks wish they hadn’t messed around with an opilionid.      

Watch as an opilionid munches on what appears to be the carcass of a small fly or bee. A pair of appendages called pedipalps are used to manipulate its food. On the surface of a small rock near a riverbank a handsome opilionid dines on the shriveled body of a stonefly, aquatic insect jerky.

To learn more about daddy-long legs and the venom-myth please visit the following UC Riverside website: https://spiders.ucr.edu/daddy-long-legs

Acknowledgements

Bug of the Week thanks Larry and his son for sharing their interesting observations of harvestmen and providing the inspiration for this episode. “Chemical defense of an opilionid (Acanthopachylus aculeatus)” by Thomas Eisner, Carmen Rossini, Andrés González, and Maria Eisner, and “Chemical defense in harvestmen (arachnida, opiliones): do benzoquinone secretions deter invertebrate and vertebrate predators?” by Glauco Machado, Patricia C Carrera, Armando M Pomini, and Anita J Marsaioli were used as references for this episode.

The Hairy Digger Wasps of Hong Kong | Catalogue of Organisms

Taylor, C., & C. Barthélémy. 2021. A review of the digger wasps (Insecta: Hymenoptera: Scoliidae) of Hong Kong, with description of one new species and a key to known species. European Journal of Taxonomy 786: 1–92.

On Christmas Eve, I received an e-mail from Christophe Barthélémy in Hong Kong to tell me that we'd gotten a Christmas present. Our big paper on the scoliid wasps of Hong Kong was now freely, publicly available! In this paper, we reviewed all sixteen species of Scoliidae known from the Hong Kong SAR to date, providing detailed descriptions and photographs of each. Nine of these had not previously been recorded from the region; one represented an entirely novel species. We also provided a detailed identification key and clarified some of the often convoluted taxonomy of this family.

Liacos erythrosoma, one of the larger scoliid species found in Hong Kong, copyright Jeffrey Cfy.

The Scoliidae, sometimes referred to as the hairy digger wasps or hairy flower wasps, are often large, striking wasps (the largest species found in Hong Kong get close to an inch in length) that are most often seen by observers when they visit flowers for food. They differ from other wasps in the structure of the wings which are shaped into radiating folds (often referred to as 'pseudoveins') towards the outer margins. In life, the wings have an iridescent appearance. Female scoliids are robust insects with powerful legs. This is so they can burrow into the ground in search of hosts for their larvae which develop as parasitoids on the larvae of scarabaeid beetles. Male scoliids are generally smaller and more slender than females. In some species (particularly members of the tribe Campsomerini), males can look very different from females, to the extent that it can be all but impossible to link one with the other in isolation. Males of some species can sometimes be found in large numbers as they form swarms in search of females.

Mating pair of Phalerimeris phalerata (male on top), perhaps Hong Kong's commonest scoliid species. Copyright Daphne Wong.

Christophe and I had lit upon the idea of producing a review of the family as I was attempting to identify specimens collected as part of the Hong Kong mangrove survey. Christophe already had an extensive number of scoliids as part of his own amateur collection; these formed the greater part of the material we used. One of our primary challenges was making sense of the group's taxonomy. As well as the aforementioned difficulties in matching males to females, scoliid taxonomy has its own individual tangles. The system has historically been beset with confusion, questionable decisions, and disregard for priority. Species have often been subdivided into a bewildering array of subspecies, varieties and formae, often on the basis of quite superficial differences and often with little apparent consideration as to whether they represented distinct populations (individuals of different 'subspecies' may often be found at the same location). As a result, I had to spend a lot of time digging into archaic publications to make sure they had been correctly quoted by their successors. Fortunately (as long time readers of this site will probably know), this is exactly the sort of thing that I love doing*.

*With a shout-out here to the Biodiversity Heritage Library. An absolutely brilliant resource that has just revolutionised the way we do literature research.

While I mostly took care of the taxonomy, key, and the first drafts of the descriptions, Christophe produced the photos, distribution maps, and revisions of the descriptions after I returned to Australia (including male genital dissections of all the species we had on hand). The end result is a paper I feel very proud of. Thank you to Benoit Guénard and the Entomology lab of Hong Kong University for providing access to resources, and if you have any interest in the wonderful world of Hong Kong hairy flower wasps, you can check out the final product here.