By Vidya Rajan, Columnist, The Times
Summer. A time to kick back, relax and read, or listen to podcasts.
I enjoy podcasts, especially science podcasts. Two of my favorites are The Infinite Monkey Cage from the BBC and Ologies with Alie Ward. Both are erudite but also light-hearted and don’t take themselves too seriously – which is one of the failings of politicians, economists and some scientists, as far as I am concerned. For a recent podcast on Bees v Wasps on the Infinite Monkey Cage, the presenters, invited a bee-ologist (Dave Goulson) and a wasp-ologist (Seirian Sumner) to battle it out in front of an audience for which group was “better”.
Now, I can hear you thinking, “How banal.”
Not so. A spoonful of sugar helps the medicine go down. When speaking to an audience of people not invested in a topic, a little levity helps to make esoteric concepts accessible. Seirian and Dave got to it with gusto. They boosted their respective little bugs with entertaining stories, and the program ended with the advice to keep both wasps and picnickers happy with the “ham to jam” strategy of providing picnic-busting wasps an offering of meat early in the year and sugar later in the year. Wasp adults are vegetarians, but in summer, wasps gather meat to feed their larvae who produce a sugary exudate that the wasps consume. Late in the year, after all the larvae have pupated, wasps turn to gathering nectar or the more easily accessed sugars in sodas and beer. And when the wasps fly back and forth in front of you at the picnic, it’s not to attack, but to use you as a landmark to orient themselves. Waving and flapping your hands is the very last thing you should do – the wasp will think it is under attack. Solid, sensible stuff.
It got me thinking, though, about the relatively good publicity that bees have compared to ants and wasps. So, I thought, time to redeem these misunderstood bugs with some anecdotes about their awesomeness. Of course, bees are pretty cool, so I am including them too. This is not meant to be a one-upmanship thing – these bugs are apples v oranges v peaches, each with their appeal – but it also gives us a baseline to regard and admire their differences and commonalities.
Wasps, ants and bees are closely related. They are all insects that share the same level of relations that we humans share with other great apes in the Order Primates. Hymenoptera have two sets of delicate wings on each side which hook together as if married (Hymen is the Greek god of marriage). Both wasps and bees have life-long wings, whereas ants grow wings to swarm in the early part of the year and then the wings fall off. All three undergo full metamorphosis from larva to pupa to adult. They all have the three body sections that are seen in insects: head, thorax, and abdomen. But wasps have a constriction – the wasp waist – between the thorax and a pointed abdomen which gives them a distinctive appearance. Wasps are also hairless with a shiny exoskeleton. Ants have a bump called the petiole between their thorax and abdomen, and distinctive elbowed antennae. As mentioned above, reproductive drones and queens have temporary wings with which to swarm. Bees are “cute”, in the words of Professor Goulson. They are hairy, with fat bodies lacking the wasp-like constriction between the thorax and abdomen. Their antennae are also elbowed, and they have corbicula (pollen baskets) on the backs of their last pair of legs for pollen gathering. Stings are ovipositors that have been coopted to deliver venom. Among the eusocial insects, where only some mature females lay eggs, the ovipositor has been coopeted to become a venom delivery organ. In wasps the stinger is not barbed, so a wasp can sting multiple times. Worker bees’ stingers are barbed, and they are also attached to the gut which causes the stinging bee to eviscerate itself. Think about that. It probably hurts the bee much more (and is fatal) than it hurts you when it stings you. So you somehow really panicked it enough to commit hara-kiri. Yeah, the blame lies in you, the big, blundering mammal. Bet that hurts.
Figure: Left: Potter wasp building a nest. [i] Note the constriction between the bulbous thorax (with wings) and the abdomen. Middle: Meat ant feeding on honey. [ii] 2 Note the extra segment (petiole). Right: Carpenter bee. [iii] Note the hairs all over the body and joined wings.
All three groups have coevolved with symbiotic partners. Pollination of flowers (which have been around for about 120 million years) show that wasps started the strategy of eating flower pollen – flowers only evolved in the early Cretaceous – which bees then perfected. The pollen-eating strategy may also have provided the habitat niche that led to bee evolution from a stinging wasp species in the first place. But the bee-flower relationship is not unique. Both wasps and ants also practice this tactic. Wasps have coevolved with the genus Ficus (fig) species to pollinate their enclosed, goblet-shaped flower through an aperture. Tiny female wasps crawl inside figs to lay their eggs, but the narrow aperture tears off their wings so they cannot escape. The eggs develop into males and females who mate (yes, incest) and the newborn females are winged and can leave the fig through openings chewed by the males. The males and the mother die inside the fig which absorbs their bodies into the fruit.[iv]
This wasp–fig relationship is an obligate mutualism, and has led to the evolution of volatiles that attract species-specific pollinators.[v] Although most bee-flower relationships are usually benign, the common Ascelpias (milkweed) will trap honeybees’ legs in pollen slits, and the little bee can die unless she’s strong enough to pull away,[vi] and some flowers (Carolina jessamine, summer titi, mountain laurel, rhododendron, California buckeye) produce toxins in their nectar that can be toxic to the bees themselves.[vii] Ants have domesticated fungi, animals and plants. Leafcutter ants “farm” fungi in the piles of leaf-litter that they gather, cultivate bacteria that fertilize and provide antibiotics to keep the crop healthy, and then feed on the fungus.[viii] The fungus is completely dependent on being farmed by these ants, and rewards the ants with enzymes which detoxify plant poisons. They have also domesticated some aphids and watch over them as a cowherd would his cows. In return for protection, the sap-guzzling aphids excrete nectar which the ants drink. Ants have also domesticated whole trees! The ants defend African and New World acacias from browsers with horrifically stinging bites (ants do not have stingers), nibble away plants and epiphytes that could compete with the acacia tree’s growth, and the acacia tree has evolved hollow thorns inside which the ants can live, produce a sweet secretion at the base of the leaves and structures called Beltian bodies which contain fats and proteins that are fed to larvae. The wide-spread nature of ants adopting plants to protect and vice versa is termed “myrmecophytism”.[ix]
All three animals live in nests, regardless of their solitary or eusocial nature. Nests may be located inside naturally existing structures or constructed in, or from, materials in the environment. Only honeybees make nests from their own body’s waxy secretions.
Wasps use wet clay or chewed bark to build their nests, dig holes in soil, or use existing cavities in wood for brood rearing. Wasp larvae eat meat, and they are provisioned by the “ham” gathering social wasps, or, definitely cooler – but so cringe inducing – parasitoid solitary wasps which paralyze prey, push it alive into a burrow, and lay their egg on its body. The larva hatches and eats the living pantry, avoiding the essential organs so that the prey remains alive and fresh as long as possible.
Ants dig their nests into soil or use existing cavities in structures or acacia thorns for laying their eggs. Accidentally disturbing an ant’s nest once, I watched the workers each gather a pupa in its mouth, quickly saving it from being killed by my blundering. It brought tears to my eyes. I wish people would observe the devotion of ants to their offspring and recognize their importance to the environment instead of blindly putting out ant bait. Ways to prevent ants and wasps and bees from building homes in areas of high traffic by spreading non-lethal deterrents like cinnamon powder is effective and definitely more benign than poison or lighting living animals on fire.
More personal experience: Paper and mud dauber wasps regularly build their nests on my deck and my family walks by them regularly. The wasps are watchful but not aggressive. The few times I have had to knock down a nest (usually built in the grill), the wasps don’t attack, but fly off. Sadly they return over and over to their old home to smell the area and assure themselves their home is really destroyed and their offspring gone forever before leaving for good.
Finally, bees too have eclectic housing. Eusocial honeybees make combs of wax in cavities or hanging from structures. A eusocial overwintered bumblebee queen commandeers a mouse hole (which the mice have already thoughtfully lined with chewed materials to make a soft pad) early in the spring. After singlehandedly gathering provisions for the nest, the queen lays each of her eggs on a ball of pollen which the larvae consumes as it grows. After pupation, the new bee emerges and joins her mother and sisters in gathering provisions for the next lot of brood. I have a bumblebee nest in my yard and watching the bumblebees emerge, orient and fly off, and then return unerringly to the hole is one of my simple joys. I am so glad I never use pesticides – any untreated yard is a haven for soil-living species – and the rewards are profound. Of course, setting up a bumblebee box (see this video on how to make one) or set up a bee hotel (gather a bunch of stalks of bamboo of different sizes and place them in a sheltered spot…make sure one end is sealed and the other is open) or pile up fairly dry but not loose soil that remains undisturbed…and the bees will come.
All three groups are smart. Wasps recognize each other’s faces[x] as well as those of humans, and learn by watch another wasp tackle a problem. Bumblebees can learn to play soccer. Ants have been cooperating, hunting, farming and fighting – all things humans do – for millions of years before humans evolved. If we are arrogant enough to call ourselves “wise” (that’s what the sapiens in Homo sapiens means) then we should be wise enough to watch and learn from these animals who have been there, done that, but don’t wear their accomplishment slogans on little t-shirts. There is so much more to write about wasps, bees, and ants but this already long article will become too long. I hope I am preaching to the already converted to care for these little critters with such bad press.
We need them more than they need us.
- 1. Photo credit: Ian Alexander. Reproduced under Creative Commons Attribution-Share Alie 4.0 International license. From: https://commons.wikimedia.org/wiki/File:Potter_Wasp_building_mud_nest_near_completion.JPG
[ii]. Photo credit: Fir0002/Flagstaffotos. Reproduced under CC BY-NC copyright. https://en.wikipedia.org/wiki/Meat_ant#/media/File:Meat_eater_ant_feeding_on_honey02.jpg
[iii] .Photo credit: Ludovic Ivsic. Reproduced under GNU Free Documentation License. https://commons.wikimedia.org/wiki/File:CARPENTER_BEE.jpg
[iv]. Nast, C. (2022). Are There Dead Wasps in Figs? Are There? [online] Bon Appétit. Available at: https://www.bonappetit.com/story/figs-and-wasps.
[v]. Zhang, X., Wang, G., Zhang, S., Chen, S., Wang, Y., Wen, P., Ma, X., Shi, Y., Qi, R., Yang, Y., Liao, Z., Lin, J., Lin, J., Xu, X., Chen, X., Xu, X., Deng, F., Zhao, L., Lee, Y. and Wang, R. (2020). Genomes of the Banyan Tree and Pollinator Wasp Provide Insights into Fig-Wasp Coevolution. Cell, [online] 183(4), pp.875-889.e17. doi:https://doi.org/10.1016/j.cell.2020.09.043.
[vi]. awkwardbotany (2018). When Milkweed Kills. [online] awkward botany. Available at: https://awkwardbotany.com/2018/07/18/when-milkweed-kills/ [Accessed 20 Jul. 2023].
[vii]. bee-health.extension.org. (n.d.). Are there plants that produce nectar that is poisonous to either honey bees or humans? – Bee Health. [online] Available at: https://bee-health.extension.org/are-there-plants-that-produce-nectar-that-is-poisonous-to-either-honey-bees-or-humans/.
[viii]. Science. (2012). How Leafcutter Ants Evolved From Farmers Into Cows. [online] Available at: https://www.nationalgeographic.com/science/article/how-leafcutter-ants-evolved-from-farmers-into-cows.
[ix]. Wikipedia. (2020). Pseudomyrmex ferruginea. [online] Available at: https://en.wikipedia.org/wiki/Pseudomyrmex_ferruginea.
[x]. Salon. (2023). Wasps are some of nature’s smartest, meanest and most misunderstood bugs. [online] Available at: https://www.salon.com/2023/07/07/wasps-are-some-of-natures-smartest-meanest-and-most-misunderstood-bugs/ [Accessed 20 Jul. 2023].
