The Good Bugs, the Bad, and the Not as bad as you might think

Bumble Bee queen at Canada Thistle

Even after having been stung by bumble bee a few weeks ago in a misguided attempt to be a bumble bee lifeguard, I still view bumble bees as entirely good bugs. I think the picture above is of a new queen of Bombus (Subterraneobombus) borealis Kirby, 1837, the Northern Amber Bumble Bee, but I could be mistaken. I don't like killing 'good bugs' and especially don't like to kill bumble bee queens just to be sure the name is right. In any case, it is covered with pollen and undoubtedly is being an efficient pollinator. Unfortunately, it is pollinating a Canada Thistle (Cirsium arvense) - a noxious weed that I have spent much time and money trying to control. So is this really a good bug or a bad bug? I think I'll stick to my original feelings and just keep in mind that life is complicated.

Bad, bad horse fly Hybomitra nuda (McDunnough, 1921)

Now here's a bad bug for sure - a horse fly Hybomitra (aka nitidifrons ssp.) nuda (McDunnough, 1921). I'm more sure of my identification here, because this sucker went to the microscope and and through a key. But then I'm not  a specialist on flies and a new key to the 40 species east of the Rockies was not available at the time, so don't take my word for it. Still, I had no problem killing this 'bad bug' even though it is rare that a Hybomitra has successfully bitten me. They do try, but are rather clumsy and easy to swat. At most, they are annoying when they bump into you or fly about (these are large flies with an angry buzz). But they are definitely a pest of livestock and wildlife and transmit a number of disease causing microbes such as anthrax.

Ankle-biting bad relative of the not-so-nice House Fly: the Stable Fly

Not that I haven't often been bitten by flies such as this very annoying, but rather small and drab, Stable Fly (Stomoxys calcitrans (Linnaeus, 1758)). Except for the long 'beak' (proboscis) that juts forward under the face when they are resting on the side of a barn, shed, or house, this fly looks rather like its cousin the House Fly or a dozen other irritating, but non-biting relatives. The Stable Fly has accumulated a lot of common names, but 'lawn mower fly' seems particularly appropriate. They seem to know when your hands are employed with power tools and if you are wearing shorts - they love your ankles.

Note the jutting proboscis of the Stable Fly

I really don't like this unfortunate addition to the North American fauna (first noticed sometime around 1700) and would happily spend any time available reducing their populations. This is a throughly nasty biting fly and vector of disease. Unfortunately, Stable Flies are fast and seem to know we don't like them. Also, they breed in rotting vegetation and dung, so they will always be with us.

More Ferdinand the Bull than bully: Male Aerial Yellowjacket at Snowberry

Late summer and pre-frost fall are also time for annoying visits from yellowjackets and hornets. This is the time when the nests are at their largest and the workers are busy feeding hordes of new queens and drones. However, not every yellowjacket is interested in what you are eating and drinking. While all yellowjackets will defend their nests, it's really only the members of the Vespula vulgaris group that like to feed on our sandwiches and drinks. In Edmonton that means three species: Common, Western, and German Yellowjackets (and the larger, black and white Bald-faced Hornet). That is certainly enough to be annoying, but there are a number of other social wasps that spend most of their time hunting insects (so, more or less good bugs) or gathering nectar at flowers. The yellowjackets that you see at flowers in the fall are almost entirely males of these more-good-than-bad wasps, e.g. the Northern Aerial Yellowkacket Dolichovespula arenaria (Fabricius, 1775). You can enjoy these wasps for their colourful patterns and flowery obsessions with no worries about being stung.

Male Dolichovespula arenaria (Fabricius, 1775)

Soggy Sunday Soldier Flies: Stratiomyidae

Yet another hornet mimic - Soldier Fly Stratiomys sp.

One can generally tell a fly mimic from a social wasp or hornet model most easily by looking at the head: the antennae are usually a dead giveaway. Wasps and hornets have geniculate antennae, that is a few long basal segments joining a multi-segmented flagellum at about a right angle. Although 'geniculate' comes from the Latin for knee (genu, as in genuflect), the less technical term is 'elbowed antenna'. In the social wasps and hornets (and their solitary relatives), their elbowed antennae are typically much longer than the head is wide.

Long, elbowed (geniculate) antennae of Bald-faced Hornet

Although thread-horned nematoceran midges, mozzies, crane flies, and the like have long antennae with more or less distinct segments, almost all fly mimics are in the suborder Brachycera (Greek for short + horn). The brachyceran antenna is composed of a few distinct basal segments sporting a finger-like style or bristle-like arista composed of the remaining segments shrunken into obscurity. 

Non-mimic Soldier Fly with antenna ending in a style Odontomyia cincta Olivier, 1811

Most flies, including most mimics, have antennae shorter than the head is deep and rarely as long as the head is wide. That seems enough for their purposes, which may include everything from smell, to sensing gravity, to hearing.

Blending into the vegetation seems the goal of this Soldier Fly's colour pattern

Yet, as usual, there are exceptions. Some soldier flies (Family Stratiomyidae) in the genus Stratiomys (Greek for army or soldier + fly) do their best to look like hornets including sporting unusually long antennae. Each antennal segment seems to have been stretched by evolution to its maximum misleading length and elbowed to boot. 

Male Stratiomys sporting rather waspish antennae

Our previous very good wasp mimic Spilomyia sayi (Syrphidae) also has unusually long aristate antennae - much longer than in most Flower Flies except those like the exceptionally good yellowjacket mimics in the genus Chrysotoxum. It seems a bit strange to me that antennae seem so integral to a good wasp constume, but then social wasps are very particular about how they look. If fooling wasps is a primary goal of these mimics, then putting on a waspy face may be important.

Mystery male Soldier Fly apparently sending chemical messages

In general, insects lead far more complicated and interesting lives than we generally give them credit for. Of course, we know relatively little about even the best studied insects, so we make our assumptions in ignorance. And then most are so small and seemingly inconsequential.

Actina viridis (Say, 1824) - the most common Soldier Fly in the Home Bug Garden

The larvae of Soldier Flies are often aquatic or semiaquatic or at least inhabit wet soil, rotting vegetation, dung, or compost. They seem to mind their own business and not cause us problems, so they are likely to remain mostly obscure. Sometimes they are very common, like the little metallic green Actina viridis (Say, 1824), which perhaps breeds in our compost bin (or at least the adults hangout around it).

Microchrysa polita (Linnaeus, 1758) - a tiny Soldier Fly with a common  name - Black-horned Gem

Few of the 250 or so species in North American seem to have common names other than solider fly, but some with wider distributions have attracted some whimsy. At least one species, the Black Soldier Fly Hermetia illucens (Linnaeus, 1758), is actually useful in composting, as chicken feed, and frog and lizard pet food. This is largest soldier fly that I've ever seen - and a good wasp mimic with very long antennae like the rest of its genus Hermetia. So, here we can end this soggy Sunday morning on a positive note and a good insect.

I just want to bee ... Up close and personal

Toe-licking Anthophora terminalis - a sweat bee in the loose sense

I like bees. I mean what's not to like - they tend to be cute and furry and buzzy and like flowers and pollinate most of our vegetable and fruit crops. In popular culture bees are almost universally presented as good (unless they are killer bees) and 'bad bees' usually turn out to be wasps. I'll even let bees lick my toes as in the honeybee-sized solitary relative of the honey bee above and below.

Anthophora (Clisodon) terminalis Cresson, 1869 aka the Tickler

I don't advise that anyone else do this. For one thing, it tickles. For another most bees have stings and can and will use them when provoked - and the bee decides when it is provoked, not you. For example, last weekend I found some poor bumble bees drowning in a bucket of water. The first two I 'saved' were dead, the third wasn't and she proceeded to sting me right  in the thumb. Hurt like hell for 10 minutes and I can still see the ~ 1mm diameter wound. Most bee stings are similar - strong but fleeting reminders to leave bees alone - but if I were allergic to the proteins in the venom and went into shock, I would likely now be dead. Anaphylactic shock can kill quickly (within 30 minutes) and that is a very good reason to admire bees and wasps from a distance.

A Northern Hemisphere Sweat Bee - Halictus confusus Smith, 1853

Some bees, though, like to get up close and personal. I've read that honey bees are sometimes attracted to brightly coloured clothing or floral perfumes. I have no first-hand experience in these areas, but I have been known to sweat. In the Northern Hemisphere, 'sweat bee' usually refers to rather small solitary bees in the family Halictidae that land on sweaty skin and slurp away. Usually they are only of minor annoyance and the occasional very mild sting. In the Southern Hemisphere 'sweat bee' usually refers to the small, stingless (they can bite) social bees in the genus Trigona. I kept hives of stingless bees in Australia, and never found them annoying, but the South American species have a worse reputation, especially for swarming around the head.

Solitary caterpiilar-hunting wasp sharing an ankle with the Home Bug Gardener

The urge to lick skin is usually attributed to an addiction to salt (sodium chloridae). In general, plant tissues contain less sodium than animal tissues, so herbivores - bees or puddling butterflies or moose at a salt lick (or people eating their veggies) - appreciate salt.  But perspiration has many minerals and nutrients that may be useful to an insect raised on pollen and nectar, so we should keep an open mind on exactly what these bees are after. They seem too persistent to be just after salt, but it could be the 'can't eat just one' phenomenon, as with potato chips.

Euodynerus leucomelas (de Saussure, 1855) - a sweat wasp?

Some days I think I may be the potato chip of the insect world as a surprising diversity of bees, wasps, and bugs have landed on me with salt-lust rather than bloodlust in mind. One at a time, I find them interesting, but in numbers these insects can be annoying, especially if you can run, but not hide. For example, this description of a trip down a river in the Amazon: "As they moved through the silent forests, the men's only constant companions were the insects that thickened the air around them. Sweat bees tickled their mouths and eyes, piums [no-see-ums] hovered over them in thick clouds, and ants and termites regularly raided their camp and devoured their few belongings." (Millard, C. 2005. The River of Doubt, p. 248). Sounds like more than one interesting insect too many.

I just want to bee ... Mistaken for a wasp by wasps

Spilomyia sayi (Goot, 1964), not a wasp, just a good mimic

Every summer from late July through August an unusual flower fly (Syrphidae) shows up in the Home Bug Garden. Many, if not most, flower flies are brightly and contrastingly coloured more or less like wasps or clothed in furry hairs like bees. But some look more like the stingers than others. That is true of this fly, Spilomyia sayi (Goot, 1964) (known in earlier works by the preoccupied name Spilomyia or Paragus quadrifasciatus Say,1824). 

Two syrphids of varying waspishness - both in looks and behaviour

As well as being coloured like many a vespine wasp, its antennae are longer and more wasp-like than most syrphids, its wings waspishly dark, and its demeanour as it struts across the heads of yarrow and goldenrod as recklessly fearless as any hornet. Most flower flies dodge quickly away when approached, but not Spilomyia sayi. In fact, this fly is easy to catch by hand - in which case it emits a loud and very bee-like buzz.

Flies have died from time to time, and birds have eaten them, but how about wasps?

But who is Spilomyia trying to fool? Well, it is pretty good at fooling people, but the usual argument for this kind of Batesian Mimicry is bird brains. I suppose birds do eat flower flies, from time to time, but how often does a bird swoop down on a goldenrod or yarrow in a field? I can't say that I have ever seen this happen, but I have seen many a fly scarfed up from such flowers by patrolling hornets. Could it be that these flies just want to be left alone by their fellow insects as they gather some nourishment on flowers that are often covered in wasps (many of which are stingless males)? I suspect that predatory wasps and hornets have exerted more evolutionary pressure on these flies than any bird. Alas, behavioural ecologists seem obsessed with birds, so I am not sanguine about seeing any studies that test this idea.

Blackjacket (Vespula consobrina) - a likely model for and predator on our local Spilomyia

Not Yet Native of the Week: Strawflower

Waspy interest in this Australian flower

I had trouble deciding if this was my inaugural Wasp Wednesday or an Australian of the Week, but I haven't been keeping up with the NYN of the Week, so behold Helichrysum bracteatum, the Australian Strawflower, Golden Everlasting, or Paper Daisy. Well, actually, if you check on the USDA website you will find it called Bracteantha bracteata the Bracted Strawflower, which seems a bit of a bract overkill, and if you check the more recent botanical literature it is called Xerochrysum bracteatum.

Golden in the wild, but a rainbow in cultivation

If you've grown strawflowers, then the Golden part of Golden Everlasting may not make much sense, but in the Australian bush the flowers in this complex of species are often yellow (some are white). It would be interesting to see if the colour range in cultivation is being maintained where Strawflower is naturalized in Connecticut and Massachusetts. However, the 'everlasting', 'paper daisy', and all the bract-formations all come from what look like petals, but are actually colourful bracts that when dry make quite nice dried 'flowers'.

Flaming bracts and a ring of golden florets

Like all members of the Asteraceae (aka Compositae), the apparent flower is actually a composite head of mostly tiny florets that each produce pollen and, if lucky, a seed (aka achene). Unlike may composites, the brightly coloured rim of the Strawflower head is not composed of ray flowers, but of sterile, and usually more leaf-like structures called bracts.

Bract-licking Western Yellowjacket

The petal-like bracts, and also the leaves directly under the bracts, on Strawflowers secrete nectar. Nectaries outside of flowers (and remember the true flowers here are tiny and enclosed by the bracts) are called, logically enough, extrafloral nectaries. Nectaries that surround a flower or cluster of flowers are thought to attract natural enemies of the things that like to eat seeds and often the bract-licking insects attracted are ants.

Black ants feasting at peony bracts

 Ants are attracted to Strawflower nectaries, apparently too commonly for us to have thought it worth a picture, but it is questionable how much they help the Strawflower set seed. O'Dowd & Catchpole (1983*) tested this hypothesis in Australia, but although fewer insects were present when ants were around, there was no effect on seed set. It seems unlikely that Strawflowers are simply being generous with their nectar, but perhaps any benefits vary from year to year. In Alberta, Strawflower is an annual, although it sometimes comes back from seed. In Australia, Strawflowers are usually perennials, so they tend to have more than one chance to set seed. But science is very strict about hypotheses: fail the test and the hypothesis should be summarily executed (well, in theory, anyway).

Whatever their function may be, hornets approve of extrafloral nectaries on Strawflowers

*O’Dowd DJ & EA Catchpole. 1983. Ants and extrafloral nectaries: no evidence for plant protection in Helichrysum spp. – ant interactions. Oecologia 59: 191-200.

What's afoot in the Winter in the Home Bug Garden?

Young Basement Spider Tegenaria domestica

I've always found the first official day of winter somewhat strange, coming as it does, months after winter actually starts. I guess there must be some rhyme or reason to picking the solstice as the beginning of winter instead of say, Winter Hump Day. In much of the world today would be well on the way to Spring. Not in Edmonton, though, we've still a long way to go if previous years are any indication.

A typical March in the Home Bug Garden

So what is the arthropod addict to do with so many more months of winter in the way? Well, our friend John Acorn has come up with the Arthropod Winter Challenge! How many living arthropods can we find in Alberta in the winter? John thinks we can find more arthropod than bird species. Well, inside our house that certainly is true - first look around found three species of arthropods including the half grown Funnel-web Spider (Agelenidae) at the top. That is not quite fair to the birds - we have none to compete - but outside? Yes, there is a cornucopia of arthropods outside that brave the winter weather - but you need to look very closely for them and for many you need to put your nose to the ground.

Microarthropods from a few handfuls of spruce litter under the deep snows of last winter

All gardeners know that a good blanket of snow protects their plants from winter extremes, but even in very cold climates a good snow cover can also capture enough warmth for the tiny animals (microarthropods, nematodes, tardigrades, etc.) and microbes that live in the soil to go about their business. A few degrees above freezing is all they need; but so far, snow has been relatively scarce in Edmonton this winter and so no layer of relative warmth has been trapped. And, while I've enjoyed the less than usual shovelling, it has put a bit of a damper on my response to John's challenge.

A Fairy Wasp (Mymaridae, Polynema sp.) from under last winter's snow

Well, we Edmontonians know that good weather rarely lasts long and I expect that in the New Year I'll have a chance to see quite a bit more snow. I'll take comfort in knowing that under that snow my plants will be safer and there will be tiny arthropods having a good time, like the Fairy Wasp above. This tiny wasp - 0.6 mm long from head to tip of its ovipositor -  is a parasite of the eggs of leafhoppers. Bad news for baby bugs, but good news for the garden.

Aculeata Agonistes: The Good, the Bad, and the Indifferent

Western Yellowjacket - note folded wings, yellow eye loop, and feeding at nectary

I know I tend to harp on this, but people seem to like to view the world through simple dichotomies. Good and Bad Bugs is one such model. So, to most, mosquitoes are bad bugs, ladybird beetles good bugs. Or if you are of a more pedantic school of entomology, Hemiptera are good bugs and other arthropods are not. Yellowjackets, hornets, and wasps probably tend to fall into most people’s bad bug category because they can sting you and cause pain and possibly death, as in this sad story of a man who bumped into a wasp nest while taking a hike with his 13-year-old daughter in Queensland.

 Wasps in the family Vespidae are those most likely to sting you, but not all vespid wasps are equally quick to use their venom delivery apparatus on something as large as a person. For example, the industrious mud-dauber Ancistrocerus waldenii that I spent some time studying early in the summer never paid much attention to me, even when my point-and-shoot was only a few centimeters above her. You can tell she is a good vespid wasp by the fact she did not sting me and by the way the front wings fold lengthwise when held at rest (in other wasp families, the front wings are typically held flat).

Mud-duber Ancistrocerus waldenii - a good wasp

Other solitary vespids in the HBG go about their lives in an equally oblivious way, doing the things wasps like to do. If I get too close to them, they flee, although sometimes they have too much on their minds to do more than hang around. Mostly, though, we share the yard without a problem.

Ancistrocerus parietum exploring the erotic potentials of dill

On the other hand, worker yellowjackets in the Vespula vulgaris group are bad. They invariably give me a buzz on their way through the yard. The Western Yellowjacket (Vespula pensylvanica) at the top is one of this group – the workers are pushy and aggressive. When I swat at a wasp, I expect it to move on with alacrity – but these wasps respond by buzzing around and getting in my face. This is especially true if I have food or drink with me – they scavenge as well as hunt.

Male Aerial Yellowjacket nectaring at goldenrod

The taste for colas and hambugers of the vulgaris-group species is not shared by other yellowjackets in my yard –those workers spend most of their time hunting insects and males malinger on flowers. I guess that makes them good, unless I bump into their nest.

More black than yellow - Vespula alascensis male (note 7 abdominal segments)

The vulgaris-group gets its name from the Common Yellowjacket Vespula vulgaris. This species used to be common here, but then taxonomists discovered that vulgaris was restricted to Europe (and areas of the world into which it has been introduced such as Australia and New Zealand). Our North American vulgaris-like species is Vespula alascensis – smaller and darker than the Western Yellowjacket, but also annoying. Being newly rediscovered (it was actually described in 1870), V. alascensis lacks a common name (BugGuide gives it none). The ‘More Black than Yellowjacket’ would be descriptive of its looks and the ‘Lesser Annoying Yellowjacket’ would describe its behaviour well enough.

Hi, I have no common name - Vespula alascensis male

One interesting aspect of the HBG the last couple of warm weeks (now replaced by cold, wet) was the number of male yellowjackets. Although the males can’t sting, and so I guess are good, I still sent about two dozen to science heaven. Almost a third were V. alascensis – although none annoyed me. Actually, they were very unobtrusive, other than wanting drinks from around the edge of the pond. They don’t seem to be interested in nectar, wine, or even barbecues. I guess they must have gotten fed enough as youngsters in the nest to last out the autumn.

13-segmented antennae identify a male - scape, pedicel, and 11 flagellomeres

Most of the rest of the males were the Western Yellowjacket (Vespula pensylvanica). This was no surprise – the few annoying yellowjacket workers around this summer were V. pensylvanica. Unlike the workers, these males are entirely innocuous and seem to be mostly interested in landing on lawn or low vegetation and then crawling to the ground. I find this behaviour mysterious, but those I followed around did nothing more exciting than lap up water.

From its yellow eye loop, a Western Yellowjacket (and male)

Two of the males, though, were yet another vulgaris-group species, Vespula germanica, a recent colonist from Europe. Apparently the common name now used is German Yellowjacket – which seems unfair to the Germans and a poor descriptor of a more widely distributed European species. Since the German Yellowjacket is expanding its range in North America, technically it must be an invasive species; and therefore, even the males must be bad.

A doubly bad German Yellowjacket - well, at least the eye loop is absent

As far as I can tell, the German Yellowjackets are no worse that the Western Yellowjacket, but they are hard to tell apart. The best field character is the colour around the eyes:  the yellow around the eyes of germanica is absent at the top of the eyes, but in pensylvanica it is usually present. Usually, but not always, so like most dichotomies, this is a bit more complicated than it should be.

7-spotted Ladybeetle - 6 US states have designated this beetle
their state insect - but it is an invasive species; and therefore, bad.

Aculeata Agonistes: When hornets are not

Dolichovespula adulterina - a blackjacket and a social parasite

At various times over the last few years, the Home Bug Garden has been blessed with the visits of 10 species of social wasps* – all members of the vespid subfamily Vespinae. Paper Wasps in the subfamily Polistinae, such as the Polistes species common in much of North America, do not occur in Edmonton. Perhaps the introduced European Paper Wasp Polistes dominula (Christ, 1791) may be able to survive our winters, but so far it hasn’t shown up and the nearest Polistes species is in southern Alberta.

Polistes dominula an introduced and spreading paper wasp

 Most years, if not exactly welcome, hornets and their kin are greeted with some interest by the HBG, at least early in the season. Mostly hornets go about their business hunting insects. Some times their prey are pests and sometimes not (e.g. hover flies), but all in all they are as interesting and unassuming as most of the insects in the HBG. 

Yellowjacket worker chewing-up insect prey (a planthopper of some kind)

Telling one species of wasp from the other isn’t easy, except for the Bald-faced Hornet Dolichovespula maculata which is about twice the mass of the next largest social vespine. It is also black and white – but so are other species of both Dolichovespula (D. adulterina - see picture at top) and Vespula (V. consobrina) and yellow and black species occur in both genera too.

A Bald-faced Hornet - the largest blackjacket

 The easiest way to tell the two genera apart is by close inspection of the area between the eye and the mandible. Just what one would like to do – stick your nose in the face of a hornet! Dolichovespula have a relatively large distance between the bottom of the eye and the top of the mandible and Vespula have eyes that almost meet the mandibles. I’m sure one can get pretty good with practice, but for most of the summer being too nosey runs one a strong risk of getting stung.

A Dolichovespula - eye and mandible well separated

 As the summer progresses yellowjackets, blackjackets, and hornets become more and more common. Towards the end of the season, their numbers seem to explode for a few weeks – and then they are gone. This year, though, their appearance was much delayed and when they finally arrived, only three species were present: D. maculata, D. arenaria, and V. pensylvanica. The first and the last of these can be pretty annoying – they will scavenge and so anything you eat or drink is of interest to them – and if you get one annoyed enough, you may encounter the venom delivery machinery at the end of the female workers.

Vespula pensylvanica Western Yellowjacket worker

 At the moment, though, the risk of being stung is pretty low, at least in my backyard. We haven’t had a hard frost yet, so worker wasps are still active, but 95% of the yellowjackets in my backyard for the last week or so have been males. You can easily tell a male wasp from a female, because males have antennae with 13 segments and females have only 12! Also, the males have 7 apparent abdominal segments and females only 6. Easy right? If all else fails, there is a bioassay. If you capture a wasp in your hand and then experience a sharp and violent pain (followed by a strong systemic reaction and death if you happen to be allergic), then you probably have a worker (the new queens mysteriously disappear soon after mating). If not, you may have a male.

Male (note 13 segmented antennae, 7 segmented abdomen) Western Yellowjacket

 The last time I was stung by a vespid, an Australian paper was in the genus Ropalidia, I experienced a strong local reaction. That may not mean much – in Australia a variety of ants, wasps, and bees stung me – but it may indicate a developing allergy. It is always best to avoid being stung. That is one reason I stomped the male in the picture below with the exposed claspers. With claspers instead of a sting, I was pretty sure I had a male, but calling it a hornet made less sense.

A male -  the claspers prove the point

 *Home Bug Garden Vespine Wasps:

Dolichovespula adulterina (du Buysson, 1905)

Dolichovespula arenaria (Fabricius, 1775)

Dolichovespula maculata (Linnaeus, 1763)

Dolichovespula norvegicoides (Sladen, 1918)

Vespula atropilosa (Sladen, 1918)

Vespula austriaca (Panzer, 1799)

Vespula consobrina (de Saussure, 1864)

Vespula germanica (Fabricius, 1793)

Vespula pensylvanica (de Saussure, 1857)

Vespula alascensis (Packard, 1870)