Sunday, September 30, 2012

Adventures in Spider Misidentification: Agelenopsis

Albertan Funnelweb Spider: Agelenopsis cf utahana (Chamberlin & Ivie, 1933) 
In Australia, a funnel-web spider is something to respect. Typically these are rather large spiders with large, forward-striking fangs that can deliver a good quantity of dangerous venom. Although the females tend to stick to their funnel webs, the males wander and often get into trouble. The most notorious of these, the Sydney Funnel-web Spider Atrax robustus O.P.Cambridge, 1877, exhibits all the characteristics you'd least like to find in a spider sharing your garden: they are large, aggressive, and their bite can kill you.
Alberta Funnel-wb aka Grass Spider: not very large, aggressive, or venomous
In Alberta we don't have any relatives of the Sydney Funnel-web, but we do have spiders in a very distantly related family, Agelenidae, that make funnel-webs and are called Funnel-web, Funnel-weaver, or Grass Spiders. If you have walked through a grassy field in the early morning and seen a funnel-like web covered in dew, then you have probably seen the home of an agelenid spider. Last week as my wife and I were sitting on our back porch enjoying an Indian Summer evening, we discovered we had our own resident funnel-weaver sitting right behind us. Mostly she lurked in her funnel within the door drain, but she'd quickly dash out for a picture when an insect was tossed on the web.
Striped carapace and body, long spinnerets, funnel web, and eye pattern = Agelenopsis
You can just see the long spinnerets sticking out behind the longitudinally striped body of the spider above and the funnel web (at the top of the post). Along with the eyes set in two down-curved rows, all of these characters indicate we have a species of Agelenopsis. We think this is Agelenopsis cf utahana (Chamberlin & Ivie, 1933) because it looks right and the Strickland Museum has numerous records for the species, and no other, from Alberta.
The eyes have it: two curved rows = Agelenopsis
I'm pretty sure this is an Agelenopsis, but I use cf - an abbreviation for the Latin word confer ('compare') - as a CYA on the species. Other species may occur here and the identity in this genus, as in many spiders, is best confirmed by examining the palps of the male. If you want to see some excellent photos of the male of A. utahana, and an amusing video of the kind of trouble a wandering spider can get into, visit Splendor Awaits. As you can see from Adrian's video, male funnel-web spiders in Alberta are nothing to be afraid of and probably would much rather not make our acquaintance.

Friday, September 28, 2012

Friday Bug: Broad heads, thin necks, and ant mimics

Reaching for the sky, getting it in the neck
I don't suppose anyone ever asked General Sherman his opinion on good bugs, but he may very well have said that the only good bug he saw was dead. Then again, may be not. Entomophobia isn't universal or even all that common in people who are both observant and enjoy being out-of-doors. Few, except perhaps eccentric entomologists, are entomophiliacs, but even fewer are completely misentomonic. For example, seemingly everyone loves butterflies, and even it they have reservations about butterflies in general ( (e.g. if their cabbage was just eaten by green worms), few would be rash enough to cast aspersions on a Monarch.
Alydus eurinus Say 1825 meets well-camouflaged Crab Spider
Thomas Say was one of those eccentric entomologists who may have loved insects. He described more than 1400 species of them and, as both a Quaker and a resident in the New Harmony utopian experiment, one might expect him to have held a benevolent attitude even toward bugs. In any case, we can thank Thomas Say for today's unfortunate bug meal for a near perfectly camouflaged crab spider (probably a species of Xysticus): Alydus eurinus Say 1825, a member of the Alydidae or Broad-headed Bugs.
Ant-mimicing nymph of Broad-headed Bug (Alydidae)
We have three species of Broad-headed Bugs inhabiting our pasture. The late Alydus eurinus, its congener Alydus conspersus Montandon, 1893, and its more colourful relative Megalotomus quinquespinosus (Say, 1825) all belong to the subfamily Alydinae and so are probably feeding on the vetch, clover, and alfalfa. In any case, they are common and as nymphs (or larvae if you prefer) do their best to look like black ants.
Mystery alydid mimic of black ant
Unfortunately, I can only key them as adults, so the nymphs remain mysterious, but rather good mimics of ants (presumably the common Formica podzolica and its relatives). 
Megalotomus quinquespinosus (Say, 1825)
The "Broad-headed" aspect of these bugs is more or less visible in the picture above - the head is rather broad compared to the thorax, at least compared to most of their relatives in the Coreoidea. But I do think this 'common name' (possibly made-up by an entomologist) leaves something to be desired. It's nowhere as evocative as, for example, the Tarnished Plant Bug, which also seems to make a habit of getting bitten in the neck by crab spiders.
A Tarnished Plant Bug gets it in the neck from another Xysticus.

Thursday, September 20, 2012

Flyblown Thursday: Picture-winged Flies

Pseudotephritis corticalis (Loew, 1873) - a pretty fly with no common name
The world is full of attractive and harmless flies, although many are small enough that one never notices them unless they are an inveterate fly-perver. This tiny, but very attractive picture-winged fly (family Ulidiidae) was hanging out on the wall of our cabin last June. The generic name implies that it looks like a real fruit fly (Tephritidae - as opposed to a pomice fly in the Drosophilidae), but isn't and the species name suggests that it is associated with bark. This is true of many picture-winged flies in the Ulidiidae (once called Otitidae) whose larvae breed in decaying wood, but picture-wings occur in many families of True Flies (Diptera) and not all Ulidiidae like logs.
Seioptera vibrans (L.) a less spectacular, but still nice Ulidiidae
For example, there is Seioptera vibrans (L.), which likes to breed in rotting vegetation and dung and so finds people their friends. There's also a larger speciesCeroxys latiusculus (Loew, 1873), with nicely patterned wings that tends to enter homes and gather at windows. I suppose this is annoying, but the larvae feed on the seed heads of composite flowers, so they really aren't usually a pest and are much more attractive than House Flies. Anyway, Ulidiidae is one of the families of flies that are more fun than annoying and sometimes a treat.

Tuesday, September 18, 2012

Tuesday Flutterby: a Mourning Cloak for BugGirl

Portrait of a Mourning Cloak Nymphalis antiopa (Linnaeus, 1758)
The Home Bug Garden sputtered to a start on Monday 13 April 2009 for a number of reasons, mostly omphaloskeptic, but also with some inspiration from my friend Adrian who had a host of blogs and, in particular, his now defunct Gardening Zone 3b. I originally wanted to call my blog "Bug Gardeners for Bush", but Adrian convinced me that any point I might be trying to make was now moot (and definitely strange). So, I settled for a name that, if not deluded with hope and change, was at least to the point and I've tried to maintain a skeptical but positive view of the value of bugs in the home garden ever since. 
My least crappy picture of a Mourning Cloak
Preaching to one's belly button about the wonders of insect life in the garden is not that easy, especially when you discover a bit of lint in the form of prized plants turning into bugs, but it hasn't been just navel-gazing that has kept me going. It seems I share a love of insects with a large community of bloggers, many of whom are listed in the sidebar For the Bugs. Foremost among those in their influence on me have been Myrmecos and BugGirl, sort of the alpha and omega of bug blog nerdery. Even though I still don't have a decent picture of a Mourning Cloak Butterfly, thanks to the inspiration of Myrmecos' unfailingly fine images, Thrify Thursday, and the Compound Eye I sometimes take a point-and-shoot that is more than just a poor record of a bug. Thanks to BugGirl, I rarely rant, for who wants to be a second-class bug-ranter?
Mourning Cloak chrysalis - not art, but slightly more than a record
I still remember the day I first stumbled across BugGirl's Blog - a wonderful rant about green potatoes. Not just an entertaining rant, but chock-full of good information and with bug poop for dessert. I've been back several times a week ever since. Alas, after 8 years of developing probably the best known of all bug blogs, BugGirl has now gone into diapause. Bugger! Where am I going to go for bug-rants now? Well, at least diapause is a pause and not necessarily an ending. Sometimes even crap can be an element of a successful diapause. So, I'll end on a hopeful note and an image that, while it would probably make Myrmecos shudder, BugGirl might enjoy: a Mourning Cloak taking what comes along and using it with every intention of surviving until next spring.
This picture sucks as an image (but has some good natural history information)

Saturday, September 15, 2012

Sun-loving Marsh Flies, Frost, Tomatoes & Bulbs

Marsh-loving Helophilus Flower Fly on Thistle
When the bees start to go and it's mostly flies at flowers, frost is on the way. One of the more common and colourful at the moment is a hover fly / flower fly in the genus Helophilus (possibly fasciatus Walker, 1949). I always assumed that 'Helo-philus' meant 'sun-loving', and seeing the flies bask on sunny leaves during the summer reinforced this delusion. As a result, I constantly misspell the genus as 'Heliophilus' and found very strange images when googling. This morning I decided to check my assumption and found that 'helo' is Greek for marsh. As BugGuide notes, this probably refers to the larval habitat and I hope that proves my pneumonic, I mean mnemonic.
Siderno Hybrid Tomato: tasty, productive, and begins early
This morning it was a nippy +4 in the Home Bug Garden and there's a good chance it will sink to Zero tonight. Yesterday was spent collecting the last of the Tumbler and Siderno Tomatoes from the tubs scattered around the sunnier parts of the Garden and reinvesting their spent soil into a new bulb bed. That leaves me with only one bed of tomatoes to cover tonight.  I highly recommend the Siderno for those who like fresh tomatoes in their salad, but have limited space and short seasons: highly productive, good size for salad or snack (mostly 10-20 g) and early. The photo above was taken on 19 August and the first ripe tomatoes harvested on 6 August. Even with the hail, slug-heaven rains, and unrecorded snacking, the two plants in this tub yielded 7.5 kg of tomatoes.
Front yard bulb map - overcrowded and out-of-date
The potting soil used for the tomatoes could be refreshed and used again next year, but no sense in encouraging the flea beetles and other pests. I usually turn the potting soil into the dense clay to make new beds for herbaceous perennials and bulbs. Unfortunately, the HBG is check-a-block with bulbs already (about 2000 have been planted over the years) and due to poor record keeping I'm not too sure where bulbs have died out (orangy colour in the map above) or are on their last legs. I'm pretty sure none of the Lady Jane's (Tulipa clusiana var. chrysantha) survived last winter, the southwest corner was  generally tulip-free, and the Red Emperors (Tulipa fosteriana) have been looking more impoverished than imperious the last few springs. I suppose I should have taken a photo in May, but it somehow doesn't occur to me until Fall that I should have records of areas without flowers. Oh well, I guess some careful hand-digging will let me lever in a few more bulbs. Time to get to work.
Tachinid fly enjoying a Smooth Aster (Symphyotrichum laeve) 

Friday, September 14, 2012

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)

Saturday, September 8, 2012

Katy Didn't: The silence of the summer nights

Broad-winged Bush Katydid Scudderia pistillata Brunner, 1878
Summer nights in central Alberta aren't really silent, the coyotes, frogs, owls, and honkers see to that. Anyone who has camped near where a beaver is chewing on a tree knows that the nights can be quite noisy (and a bit worrisome - where will it fall?). But the pulsating throbs of insects singing in the dark that are so dominant in warmer parts of the World are generally absent here. That led me to the false assumption that Alberta lacked the crickets (Gryllidae) and katydids (Tettigoniidae) of the eastern North American nights. Imagine my surprise, when I found I was sharing a pasture with a large Broad-winged Bush Katydid

Sometimes called the 'counting katydid' because the males add a syllable to each successive phrase of its song, I had to be startled by a large katydid springing up from a bush to know they were there. Am I going deaf? Well, possibly. The songs of bush katydids are rather high-pitched and difficult for some people to hear. Also, bush katydids are members of the subfamily Phaneroptinae - also known as False Katydids - and they are more of the clicking than singing variety. The true katydids (confusingly placed in the subfamily Pseudophyllinae, meaning 'false-leaf') in the Eastern nights loudly argue Katy's virture: Ka-ty did! Ka-ty didn't! Ours seem to be quietly counting their scratches in a pitch too high for me.
Slender Meadow Katydid Conocephalus fasciatus (De Geer, 1773)
But wait, there's more! Once I started looking I found our cabin was surrounded by hundreds of small meadow katydids (subfamily Conocephalinae - 'cone heads'). They all seem to belong to one species, the Slender Meadow Katydid Conocephalus fasciatus and although much smaller (about an inch long) than the bush katydids, they should be making some noiseLike other katydids, male meadow katydids sing by rubbing their wings together. Alas, again like bush katydids, it seems our meadow katydids are singing a bit too high for me to hear more than a faint buzz.
Female Katydids listen, Male Katydids sing - the sword-like ovipositor means silent female
Fortunately for my aging, rock-addled ears, there is a wonderful website called Songs of Insects where I can listen to both our species both in their too high-pitched for the Home Bug Gardener or lowered a couple of pitches for the hard of hearing.

For more on the sounds of insects:

Songs of Insects

and for the sounds of nature in general:

The Music of Nature

and while they don't yet seem to have anything on Alberta (alas no beaver gnawing), there is a very nice Manitoba dawn chorus:

Friday, September 7, 2012

Friday Stink Bugs: from the gaudy to the dowdy

Fall aggregation of stink bug nymphs
When I was a child, life was so much simpler. For example, a stink bug was a stink bug was a stink bug (although sometimes a stinkbug) and always Pentatomidae. 'Penta', of course means 'five', as in Pentagon, pentagram, etc., and 'tom' means 'cut'. Undoubtedly, this refers to the antennae of these bugs which are 'cut' into five segments. Most true bugs (Heteroptera) which get along with four or fewer. Alas, now we have two families to choose from: Pentatomidae and Acanthosomatidae. Well, whatever family they now inhabit, stink bugs usually live up to their names - they smell and, e.g. if one is too hasty eating a blackberry (not the electronic kind), taste bad too. Of course, many and possibly most 'true bugs' have thoracic glands that produce an odour that no one would mistake for a rose, but stink bugs are reliably smelly. Usually, though, they are not so brightly coloured.
Understated stinkyness - One-spotted Stink Bug
Take, for example, the One-spotted Stink Bug Euschistus variolarius (Palisot de Beauvois, 1805). Although not leaf green, as many stink bugs are, she clearly has no interesting in standing out. This is a full grown adult, but what I think is a nymph is similarly unremarkable.
What I think is a nymph larva of the One-spotted Stink Bug
Well, in my youth this was a nymph, as all immature terrestrial insects that did not go through complete metamorphosis were called. But now 'nymph' is out of fashion and hip entomologists call all immature insects, from maggots to hoppers, larvae. I'm sure the heuristic value of a holistic view of metamorphosis makes up for the loss of information conveyed by anachronisms like 'nymph'. Anyway, as long as someone knows that 'larvae' is plural and 'larva' singular, I'm unlikely to have a fit. (Although this information does not seem to be being passed down very well to the larval generation of entomologists.)
Twice-stabbed Stink Bug Adult and Larva: Cosmopepla lintneriana Kirkaldy, 1909 
Stink bugs are capable of advertising their distastefulness in both the adult and larval stage, as in the Twice-stabbed Stink Bug above. That our larval One-spotted Stink Bug does not is is interesting, in a rather intricately drab way. Why not advertise one's ability to make one go 'yuck!'? The One-spotted has a rather broad diet, everything from grass to veggies to fruit trees to other insects. So perhaps it finds being rather averagely drab an advantage in a variety of habitats. Sure, brightly coloured stink bugs may taste inexecrably bad, but who's to know until one tastes one?
Ground beetle that likes smelly food?
So is this predatory ground beetle (Carabidae) about to get the surprise of its life or does it like stinky food? Or perhaps caution will get the better of hunger. Alas, the photographer didn't stick around to find out, so we will have to end with a double mystery: and unknown larval bug and an unknown ground beetle.

Monday, September 3, 2012

A Tiger Beetle, not exactly glowing, but with a very long name

Kirby's Oblique-lined Tiger Beetle Cicindela (Cicindela) tranquebarica kirbyi LeConte, 1866
In the previous post we took a look at a fairly diverse family of flies where most were obscure and lacked common names. Today we have the cultural opposite: Tiger Beetles! Here every species has a common name and many "species" are subdivided into 'subspecies' with their own additional name. Ours is most impressively endowed as Kirby's Oblique-lined Tiger Beetle Cicindela (Cicindela) tranquebarica kirbyi LeConte, 1866.
Iridescence at a distance = crypsis
I'm not sure why tiger beetles are so beloved, but the tribe Cicindelini are called Flashy Tiger Beetles, so I suppose their metallic glitter is part of the allure. Many are very brightly coloured in metallic greens, coppers, and reds. Linnaeus named the genus Cicindela from the Latin for a 'glow worm', so I suspect even he found them showy. And Tiger Beetles are both aggressive predators and on the largish side - often 2-3 cm in length.
Not especially showy, but large enough to be seen and fleet enough to be fun chasing
Part of their allure may be that many are hard to find and not easy to catch. In spite of all their glitter, many blend into their habitats very well.  And Tiger Beetles are fast! So, gaudy, diverse, fast, and only active when the sun is shining. Pretty much the butterflies of the beetle world and with the added attraction of being deadly hunters of other insects. If you see an entomologist dashing madly about with a net, and no butterflies are in evidence, they may well be after tiger beetles. I suppose I should read John Acorn's book on these beetles. But, alas, it is at the lab, so my Labour Day afternoon must be spent on more mundane matters.

Acorn, John. 2001. Tiger Beetles of Alberta: Killers on the Clay, Stalkers on the Sand. University of Alberta Press.

Sunday, September 2, 2012

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.

Saturday, September 1, 2012

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.