Today we have another photo/narrative piece by reader Athayde Tonhasca Júnior. His narrative, about stinging and non-stinging bees, is indented, and you can enlarge the photos by clicking on them.
No pasarán [“They shall not pass“]
Between 150 and 200 million years ago, some ancestors of today’s wasps (order Hymenoptera) experienced a momentous transformation. The females’ ovipositor – the egg-laying apparatus – evolved into a stinger that produces a cocktail of chemicals capable of paralysing or killing prey and enemies; egg-laying was moved to an opening at the base of the stinger (you can learn details of this evolutionary tale here). By weaponising their ovipositors, those primitive wasps gained a tremendous boost; they could hunt, forage and defend themselves much more efficiently. The venom-injecting lineage flourished, and today comprises over 70,000 species of ants, bees, and stinging wasps known collectively as the Aculeata (derived from the Latin aculeus, meaning barb, thorn). Some of the most successful organisms on Earth are aculates; ants are the main movers and shakers in almost every terrestrial ecosystem (Hölldobler & Wilson, 1990), while bees are the most important pollinators of flowering plants.
A wasp stinger, with a droplet of venom on its tip. The oviduct that carries eggs to the outside is at the base of the stinger © Pollinator, Wikimedia Commons:
Many people’s attitude towards honeybees (Apis spp.) and social wasps such as hornets (Vespa spp.) is of wariness, if not downright hostility, because of their stingers. But these weapons, despite being unpleasantly effective and potentially dangerous to people and animals, are rarely deployed when bees and wasps are flying about. Most stings happen when these insects are handled, or unintentionally squeezed or trapped. Otherwise, they carry on with their busy lives, ignoring us.
The venom system of the violet carpenter bee (Xylocopa violacea) © von Reumont et al., 2022:
The mood changes, though, when they feel their homes are being threatened by a raider. The nest is their main reason for being: it harbours the reproductive queens, their young, and food stores. If its walls were breached, in no time the nest would be overcome by parasites, predators and usurpers, and that would be the colony’s demise. So bees and wasps rely on their stingers to fend off enemies, and few wannabe looters can endure the onslaught of hundreds of tiny, poisonous flying daggers.
Animals tend to keep their distance from the honey bee’s stinger, a sharp, barbed stiletto loaded with venom. L: a beehive fence to keep elephants from farms in Kenya © Kengee8. R: some creatures put up with bees’ wrath for the nutritional rewards of their nests. Art by Ernest Howard Shepard, 1926. Wikimedia Commons:
Despite its efficacy as a defensive mechanism, the stinger is used sparingly. Animal venoms are protein-rich, complex chemical mixtures and therefore metabolically expensive. So bees, wasps and other aculeates can’t afford to go stinging willy-nilly. Some bees reduce the need to sting by making their homes hard to find. You may watch bumble bees (Bombus spp.) time after time in a garden or local park and never find their nests. Other bees use the same tactic of discreet living for protection.
Living inconspicuously for safety. L: a common entrance to several nests of the chocolate mining bee (Andrena scotica). R: nest of Scaura latitarsis inside a termite mound at the top of a tree, 5 m above the ground; A: diagram of the nest; B: entrance; C: detail of the entrance gallery; En – entry; Tm – termite mound; Gl – entrance gallery; Fc – brood combs; En – honey and pollen pots © Camargo, 1970.
Possessing a stinger sounds like an essential feature for social bees, but a whole group of them do without one: the stingless bees, or meliponines (tribe Meliponini). Stingless bees comprise over 600 species spread around tropical and subtropical regions of the world, but mostly in South America. They have vestigial stingers and so are unable to sting. You may think the lack of a functional stinger makes them defenceless and vulnerable, but you would be wrong.
Some species resort to simplified but no less effective stinger substitutes. The tataíra (Oxytrigona tataira) and similar species secrete large quantities of highly caustic formic acid from their cephalic glands, which is excruciatingly efficient in discouraging enemies, man or beast. The defensive power of O. tataira, named after the Tupi-Guarani tata (fire) and ire (bee), explains its alternatives epithets of cospe-fogo (fire spitter) and the charming caga-fogo (fire shitter).
An innocent-looking tataíra © Clara Matos, and the consequences to an obstinate man on a mission to destroy a tataíra nest in his small holding, only to be mobbed by angry bees. Two painful weeks later, the man was back on his feet and wiser © Morais et al., 2020.
Other stingless bees deploy less hurtful weapons (at least to us). The sugarbag bee (Tetragonula carbonaria), an endemic Australian species, defeats invading small hive beetles (Aethina tumida) by mummifying them alive. This beetle, a serious pests of the European honey bee (A. mellifera) in some countries, adopts a ‘turtle posture’ to protect itself from bites and stings once inside a bee nest. But the beetle is being too clever by half; the sugarbag bee coats and immobilises the invader with a gloopy mixture of resin, wax and mud. This pharaoh’s approach (Greco et al., 2010) is known as social encapsulation, and it’s practiced by other bees.
A sugarbag bee © James Niland, and a small hive beetle © James D. Ellis, University of Florida, Bugwood.org, Wikimedia Commons:
Unarmed and dangerous
While the bees discussed so far resort to chemical warfare, the majority of stingless bees have nothing of the kind to defend themselves. The South-American Trigona spinipes is a good template for the behaviour of a great number of little known species in this category.
Don’t mess with me: a T. spinipes stingless bee © José Reynaldo da Fonseca, Wikimedia Commons.
In lieu of a stinger, T. spinipes has five sharp teeth in each of her mandibles; any aspiring nest invader – mostly other bees and ants – will be mobbed, harassed and bitten relentlessly. A colony could be over 100,000-strong, an order of magnitude larger than the size of honeybee colonies. So a T. spinipes swarm is capable of inflicting a lot of painful pinches. And biting has one advantage over stinging; is not as metabolically expensive as producing venom.
These bees often coordinate their attack; some of them clasp their legs around the intruder while others go for the victim’s sensitive parts such as antenna and neck. T. spinipes is not deterred by gigantic trespassers: people lolling about can be nastily surprised by a cloud of perky assailants that dispense painful and persistent bites, get into their nostrils and ears, and tangled in their hair.
Considering its success in discouraging enemies at home, T. spinipes has the wherewithal to apply its blitzkrieg strategy in other situations; for example, when looking for food. And it does exactly that. It attacks and drives away other bees fancying the same flowers, and is not put off by its opponents’ size; T. spinipes has been observed biting off legs, antennas and wings of honey bees and carpenter bees (Xylocopa spp.). Just the sight of dead Trigona specimens on flowers is sufficient to convince carpenter bees to look for food somewhere else (Sazima & Sazima, 1989).
Mandibles from some stingless bee species. The pain caused by biting is shown on a scale, where 0 = no bite, 1 = biting was visible but could not pinch skin, 2 = able to pinch skin but caused no pain, 3 = mild pain, 4 = moderate pain, and 5 = sharp pain and capable of breaking skin if persistent. All pictures to same scale © Shackleton et al., 2014.:
Some stingless bees don’t even bite, or their bites are too weak to cause any harm. But that doesn’t make them less effective. Inexperienced nature-lovers, emboldened by bees’ small size and apparent vulnerability, get too close to a nest only to make a run for it, screeching like banshees despite not receiving a single sting or bite. Naturalist and biologist von Ihering (1883-1939) described an encounter with an unidentified species of stingless bee nesting behind a wall:
‘We knew the bees would attack us, but we were also sure we would not be harmed, exactly, if we resisted the defenders’ petulance. We covered ourselves with a lot of cloth, put some cotton in our ears and started to demolish the brick wall. Countless bees clung to the cloth and everything buzzed around us; some of the attackers managed to reach our face, others, through the back of the neck, reached the neck and hair. No sensation of pain, but an unspeakable irritation […]. Suddenly, without knowing what we were doing, we realized that our legs had taken us away, running fast. The biologist was defeated by the unarmed bees, who the countryman himself respects, because he doesn’t know how to resist to them either’ (Ihering, 1930. Biologia das abelhas melíferas do Brasil).
All these defensive strategies are costly: many bees die when their victims defend themselves. If we were attacked, we would have to pull away chunks of bees to dislodge them from our hair, ears and nostrils. Such kamikaze tactics are not unusual among social insects; Johnson & Hubbell (1974) recorded 63% mortality for three colonies of T. corvina after a two-day battle over sucrose baits. Honey bees detach the stinging apparatus from their bodies (autotomy or self-amputation), which helps in maintaining the injection of venom and the release of alarm pheromones after the stinging action. But sisterly self-immolation is of little relevance to the colony, as long as queens and progeny are protected.
The antics of O. tataira, T. spinipes and other easily irritated stingless bees may give the impression that this lot is all bad news, but far from it: they contribute to the pollination of about 90 crop species (Heard, 1999), and the breeding and management of some of the more docile species have been practiced for centuries by native peoples in Central and South America. The activity, known as meliponiculture, is growing in economic importance, particularly for rural and native communities in Latin America, Africa and Australia.
L: Nest entrance of Tetragonisca angustula, one of the most reared honey-producing stingless bees in Latin America. R: honey pots from a commercial nest. The flavoursome and aromatic honey is a source of income for countless families.
Why are some stingless bees such bullies? Scarcity of resources and predation pressure are the most likely factors to explain it. Tropical and semi-tropical habitats can be harsh for bees: nectar, pollen and nesting sites are scarce and highly seasonal, and predators, particularly the ubiquitous ants, are a constant menace (Janzen, 1971). In such environments, aggressiveness is a vital survival strategy. Even bees known to us to be mild-mannered such as bumblebees show a Mr Hyde side in the tropics. B. pullatus, native to Central America, and the South American B. morio are notoriously bellicose. Adding to the bad attitude, the venom of B. morio is particularly nasty: people stung repeatedly have been made seriously ill or, on rare occasions, killed.
Despite being bad-tempered, B. morio is an excellent pollinator © Leonardo Ré-Jorge, Wikimedia Commons.
When we stop to watch bees lazily visiting flowers in a garden or park, we may not think about the hazards they face back at home. By storing nourishing food and producing lots of juicy eggs, larvae and a nutrient-rich nest in the case of social species, bees whet the appetite of a variety of looters. They could be ants in the tropics, badgers (Meles meles) in Britain, and countless others. Fleeing or moving away are not options. Survival entails mobbing and scaring your enemies away, poisoning them, or suicidally biting them to death. Whatever it takes for protecting the colony. And life goes on.
An intimidating gang of stingless bees © Bernard Dupont, Wikimedia Commons.
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Lagniappe (a word I learned from Jerry)
Speaking of cantankerous venomous animals, many years ago I bumped into a cottonmouth (Agkistrodon piscivorus) crossing a road in the back of beyond of Mississippi. I stopped the truck and the snake stopped. I stepped out and took a few photos, and the cottonmouth, which I reckon was at least 1.5 m long, wouldn’t budge, staring at me. After a few minutes of this Mexican standoff (cultural appropriation?), the snake started to slither towards me. Not racing, but obviously with intent. I scampered back to the truck and drove around my antagonist, muttering: “I could have run you over, you sun of a gun”. From then on, every time I worked in the swamps, I wore anti-snake chaps, which were a killer in the Mississippi summer. I never met another cottonmouth, but was attacked by a snapping turtle. So it goes.
An unyielding cottonmouth in Mississippi.
I have had encounters with fer-de-lances (Bothrops spp.) and rattlesnakes (Crotalus spp.), but those snakes at most stand their ground; they don’t come after people. I wonder if any American reader has had any intimate experiences with cottonmouths.
Brilliant as always. Ever since an apparent misadventure when I was too young to recall it consciously, I’ve been reflexively afraid of bees and especially paper wasps. But they are certainly fascinating creatures, and this is wonderful mini-course on them.
I’ve heard tales of water moccasins being strangely aggressive snakes, but I have no personal experience with them anywhere outside zoos. Most snakes in south Florida that I see are non-venomous, but I once saw a poor coral snake someone had needlessly killed on a nature path. Though highly venomous, they are known not to be assertive, let alone aggressive. It was probably sunning itself on the path and someone saw it and panicked.
Another thrilling episode!
I was floating down the Black river in South Carolina as an adolescent and had dozed off. We floated under some branches and when I looked up I saw a cotton mouth about 1 foot above me sunning itself on a limb. I stayed still as did the snake and everyone in the boat floated by without incident.
I have always thought of cotton mouths as being less aggressive than copperheads as I see plenty of bites from the latter but none from the former in the pediatric ICU.
Athayde: Thanks for another interesting post!
I’ve never encountered a cotton mouth, but I can understand this one’s behavior. The heat and humidity of Mississippi’s summers can make mourning doves kind of spiteful and even the Sisters of Mercy unmerciful.
That’s not a cottonmouth. Cottonmouths are heavy-bodied with triangular heads, and don’t have alternating dorsal-lateral-ventral blotches. The snake looks like a colubrid of some sort, based on body shape and general pattern gestalt. A possibility is a water snake, of which there are several species in Mississippi, but I don’t know them well enough to make a suggestion. The northern water snake, which has a subspecies in Mississippi, has a reputation for being bitey, so other Mississippi water snakes could be aggressive, too.
Greg
Yes, the large glare spots on the head suggest big head scales. Those large head scales are the best distinguishing feature between colubrids and pit vipers, which have only small scales on their heads.
I have been chased by a fer-de-lance in Csota Rica. It lunged at me multiple times with mouth open. Yet I have also accidentally led people right over resting fer-de-lances in the middle of trails, with no problems. One client actually sat on a fer-de-lance and was not bit!
I have regular encounters with northern water snakes. Knowing they are bitey, I don’t attempt to pick them up. But they always want to slither away.
Here’s an earlier WEIT post on cottonmouths; go through the habitat photos to get to snake pix and a video.
GCM
A guide to the aquatic snakes of Mississippi – https://birdwatchinghq.com/water-snakes-in-mississippi/
I’m not sure if any of these quite fit the bill, although the diamond-backed water snake seems to me to come close.
The “water” snakes that I have encountered in Mississippi ponds do have a funny propensity to charge at you while they are in the water, so this reported behavior on land doesn’t surprise me.
Of course, lots of people call them cottonmouths–and act accordingly–no matter what they are. I guess that is the prudent course.
Definitely not a cottonmouth. Looks to me like a pissed off gray rat snake (Pantherophis spiloides) but it’s a bit hard to tell from the photo.
“They shall not pass”
Now I know where Tolkien drew from for the famous line “You shall not pass!” – consistent with Lord of the Rings as an allegory (or something, and so on,) for World War I.
I appear to remember ‘no paseran’ was the battle cry of the Spanish Republicans (nothing to do with present day US ‘Republicans’) fighting Franco’s fascists during the bloody Spanish civil war. But Franco, the ‘Caudillo’, won and kept Spain in an iron grip for decades.
[The only positive -very positive indeed- in Franco’s regime I can think of is that he remained neutral in WWII, he did not align Spain with the Axis. European Jews reaching Spain were basically saved.].
You are correct about the Spanish connection. I believe that’s the better known usage of the expression, although it has a French origin.
Wikipedia offers, from the Cottonmouth entry :
https://en.wikipedia.org/wiki/Agkistrodon_piscivorus
“The common watersnake is a species of large, nonvenomous, common snake in the family Colubridae. The species is native to North America. It is frequently mistaken for the venomous cottonmouth.”
there’s photos, and I think it’s pretty clear – the venomous one is scarier, IMO…
^^^ that was a reply to GCM (… PCC(E)GCM?… not sure…)… but oh well.
Great photos and text, thanks!
Always great stuff! I frequently have to earnestly convince people who want to get into insect photography that bees and wasps out foraging on flowers are not aggressive. At times they will fly toward you with an elevated buzzing sound that seems to say “anger”, but in fact they are just a bit lost and trying to find their bearings. The louder buzzing happens when they are trying to navigate slowly and carefully, is all.
Hold still. Get into a zen connected-with-nature frame of mind, and they will just move on.
As usual, this entry is chock full of fun info!
Great article – I have always wondered how stingless bees managed to defend themselves.
Athayde, was that snapper.that attacked you on land? Generally they’re not belligerent in the water, unless you are trying to catch them.
It was my fault. I nudged it with my foot to get it out of the middle of the road and not be run over. The speed of the snap astonished me (it was my very first encounter with such animal). It grabbed the tip of my shoe, and it was my luck the shoe was oversized. I quickly removed it and sat by the roadside with the offended reptile until it decided to release its grip and bugger off into the bushes.
A grammar school classmate was bitten by a water moccasin behind our school; it was in an abandoned shopping cart on the edge of the bayou. [He recovered fine,] When walking along the swampy edges of the Mississippi (summer job with Corps of Engineers checking river bottom) I stepped over a log almost onto a water moccasin – was a lot more careful after that but had no other snake issues.
Great details on bees, thanks! I have had several close calls with venous and non-venomous snakes. Once when visiting the Entomology Department at the University of Florida in Gainesville I had a break in my schedule and walked over to a nearby canal to see what dragonflies and damselflies might be present (my early academic interest). Being so absorbed, I failed to notice a cottonmouth in the long grass at the water’s edge that lunged at me with its white mouth wide open. I managed to snap back just in time, but it had a second go at me before I leapt back from the water’s edge. It did not chase me though. I had a similar experience with a Gaboon viper in South Africa many moons ago, that is not a snake to back down, so I did instead. And that genus is appropriately named Bitis! Finally, water snakes are quite common in Illinois lakes and when windsurfing and kitesurfing it is not unusual to have encounters with them, and they do try to bite.
The snake in the photograph is NOT a Cottonmouth. Rather, it is a ratsnake (formerly known as Pantherophis obsoletus spiloides before its taxonomy was bastardized). Ratsnakes can be quite defensive when disturbed. Cottonmouths, which have an undeserved bad reputaion, are generally relative mild mannered.
That doesn’t look like a cottonmouth from Tn. I’ve had run ins with them here, with nothing worthy of note. But I saw them before I was close enough to step on them. And I’m not silly enough to provoke one.
One of my boys caught one by hand once. I still can’t believe he was that stupid. He escaped being bitten, how I do not know. I told him, ok you caught one, what you going to do with it now? He had it by the neck and 2/3 of the way towards the tail, I told him go to the waters edge and sling that thing as far out as you can, releasing both hands simultaneously. Everyone walked/slithered away unharmed.
I gave him a good chewing out. We got there by boat, and were miles from the truck, and miles from decent civilization. I hate to think how bad it could have been.