Tag Archives: wasps

The Aftermath: Dallas Arboretum Autumn at the Arboretum 2022 – 2

A little secret for those wanting to see carnivorous plants in action: whether it’s in the wild or in captivity, the absolute best time is in late autumn. Firstly, most carnivores are at their greatest size and best color in order to attract insects before they go dormant, storing the nitrogen and phosphorus gathered in those final days in preparation for reemerging in spring. (This is way beyond my abilities at the moment, but any enterprising biology and botany students looking for ideas on a paper likely to get lots of popular and professional news coverage should look at the sheer number of insects caught in Sarracenia pitchers and ascertain whether the plant absorbs nutrients during its normal dormancy or if the plant only accesses and processes the insect stew inside the old pitchers after it starts to bloom. Either would help explain why so many Sarracenia pitchers remain green throughout the winter, only dying off after new pitchers start up again during the next growing season.) Secondly, the potential insect population is at its height, and it’s hungry. The normal sources for nectar and sap for insects such as flies, wasps, bees, and moths trickle dry by the middle of autumn, and those insects are determined to stave off dying of starvation for as long as they can. With many, it’s going for unattended soda or margaritas, but a lot go for the voluminous nectar secreted by various carnivorous plants, and they get frantic for what usually becomes their last meal.

The resultant arthropod feeding frenzy made showing carnivores at the Autumn at the Arboretum exhibition at the Dallas Arboretum particularly, erm, riveting. It’s one thing to discuss dispassionately how carnivores attract and capture insect prey. It’s something different when a crowd of twenty to thirty people watch different insects at different plants to see which one falls into a pitcher first, complete with cheers and groans when a big fly or sweat bee succumbs to the promise of more nectar in a pitcher float and doesn’t reemerge.

A little aside that the Arboretum attendees didn’t get to experience: driving a van full of pitcher plants back to the gallery on a Sunday evening and listening to the angry buzzes of insects trying to escape their impending tombs. One of these days, I’ll have to record audio: the only thing creepier is when the Sarracenia leucophylla pitchers first emerge and open toward the middle of May, only to fill with click beetles. I can only imagine a field of leucos with every pitcher loaded with click beetles, all thumping the inside of the pitchers as the sun comes up and the pitchers start warming in the sun.

To be continued…

Gothic Gardening: “The Bugs You Don’t Expect”

(Background: this essay was one of several columns commissioned for the magazine Gothic Beauty between 2009 and 2011. Since the magazine hasn’t published a new issue in years, it’s time to drag up a few of these old columns so they can find a new readership.)

Dedicated to Steve Bissette, who helped me get on this odd path in the first place

Most typical garden books and sites include at least a thumbnail guide to beneficial and destructive animals that may visit, inhabit, or infest a garden area.  After describing and illustrating the usual pests (whitefly, stink bugs, grubs) and the usual overly cutesy garden helpers (honeybees, earthworms), the typical garden writer is at a bit of a loss.  This is a shame, because some of the ignored critters are the most interesting.

Let’s take a look at my new garden area, and note the animals that don’t make the usual “friends of the gardener” lists.  I have lots of visiting birds, including both red-tailed hawks and Harris’s hawks that pick off overly unobservant mourning doves and bluejays.  (I’d also like to mention that while years of Disneyfication of garden critters make hummingbirds out as “cute”, this comes from people who’ve never dealt with them.  Hummingbirds have no fear of man, beast, or god, and there’s a very good reason why the Aztecs considered them avatars of their war and sun god Huitzilopochtli.  I’ve seen hummingbirds challenge crows and hawks and win, and they’ll gleefully take on humans that get too close to their nests.)  Besides praying mantises, there’s also the wheel bug (Arilus cristatus), a determined predator so named because it appears to have a watch gear jammed into its back.  I have anoles (Anolis carolinensis) during the day that camp out on the trees in the back yard and flash their dewlaps at each other, and introduced Mediterranean geckos (Hemidactylus turcicus) that sing to each other all night.  I have spiders and beetles and glowworms, grass and garter snakes, and any variety of natural decomposers such as worms and sowbugs.  I’m not even going to start with the great horned, barn, and screech owls that buzz the house at night, or the plethora of Mexican free-tailed bats, or the great blue herons that fly over the neighborhood at dusk like misplaced pterosaurs.

The one set of regular travelers that are always welcome in my garden, though, are the ones that most gardeners try to drive off.  Even the biggest advocates of organic gardening grab a swatter or a spray can when they see one of these, and they go berserk with rolled-up papers and brooms in pointless attempts to drive them away.  Even mosquitoes only warrant repellent when their presence becomes too extreme, but any grocery store or garden shop has can after can of spray intended for my visitors, all promising to kill them dead from as much as 30 feet away.  Not only is this an irrational response to one of the best beneficial organisms you can get in your garden, but it’s almost completely without merit.  I’m talking about wasps.

Wasps are members of the insect order Hymenoptera, an order they share with their cousins (and possible descendants) the bees and ants.  Wasps range in size from microscopic to the size of sparrows.  Many species are social, such as hornets and yellowjackets, where they live in colonies of dozens or even hundreds of related individuals. Others are completely solitary.  Both males and females subsist on nectar and other sugary liquids (the reason why wasps always show up around spilled fruit juice and soda), but only the female has a modified ovipositor that it can use as a sting for defense.  Best of all, as far as the garden is concerned, most species are considered “parasitoid”, where they spend the first part of their life cycle feeding off a host.  Each species of wasp has one particular host arthropod it uses as a host, and that list includes bees, flies, cicadas, spiders, tarantulas, and even praying mantises.

Social wasps, such as hornets and various species generally lumped together as “paper wasps”, capture small prey such as caterpillars, masticate them with strong mandibles, and then feed the mush to their young.  As such, they’re very valuable predators.  Others go through a much more fascinating and disturbing process.  Many species fly to a host, lay eggs on or in the host, and then let the hatchlings feed upon the host’s body from within, ultimately killing it.  Still others capture their prey, paralyze it with carefully measured stings, and return it to a bolthole or gallery.  There, the mother lovingly places an egg in a particular location on or near the victim, seals up the space, and lets the youngster go through a complete metamorphosis from larva to pupa to adult.

Anyone studying wasps tends to use analogies from the Alien films to describe their reproductive behaviors: the larvae do feed on living hosts, and they emerge to metamorphose into beautiful and terrifying adults that capture new victims to continue the life cycle.  It’s just that the fictional analogy is lacking compared to reality.  For instance, picture a remake of Alien with Kane having three or four chestbursters ripping free, only to spend the next few weeks frantically guarding them as they pupated.  The wasp genus Glyptapanteles does something much like this, where as many as eighty larvae emerge from one caterpillar and spin cocoons: the caterpillar remains by the cocoons and violently repels anything attempting to disturb them. Likewise, Aliens might have been even more horrifying if Apone and Dietrich had been stung in the head and then led willingly into the alien hive.  The emerald cockroach wasp Ampulex compressa does just that to captured roaches.  You have wasps that infest aphids, ones that capture big insects like cicadas and bury them in carefully dug galleries, and even make containers of mud and pack them full of paralyzed spiders.  (For the record, the common mud dauber wasp Sceliphron caementarium is the main predator of black widow spiders.)  The tarantula hawks, genus Pepsis and Hemipepsis, paralyze and take off with big ground spiders, hence the name, and one group even uses adult praying mantises as hosts.  (In his book The Hunting Wasp, John Crompton compared this behavior to a mother deciding that the only food in the world good enough for her children was grizzly bear. Many times, the wasp loses the battle.)

The horror doesn’t stop there.  Many other wasps parasitize the eggs of other arthropods, such as the nearly microscopic wasps that carefully drill into mantis egg cases and lay their own eggs therein.  Other wasps modify the DNA of host organisms: the huge variety of plant galls are caused by wasp eggs that actually modify the surrounding tissue to form protective cases.  Every time you eat a fig, you’re eating the end result of a very complex and disturbing life cycle involving the fig flower and one particular wasp, and if the wasp becomes extinct, so will the fig.  Some wasps, such as the wingless ones known as velvet ants, live as cuckoos for other wasp species, laying their eggs on hunting wasp hosts and letting their young eat the hunting wasp eggs before they hatch. 

Even without this, wasps are fascinating and underappreciated creatures.  Fear of wasps is learned, usually due to parents who themselves were taught to fear wasps, usually way out of proportion to the actual pain of a sting.  (I’m severely sensitive to bee stings, to the point of nearly needing hospitalization after one good bout as a beekeeper, and I’m amazed at how little a typical paper wasp sting actually hurts.  For fun, look up the Justin O. Schmidt Pain Index for a useful and irreverent guide to the actual pain caused by many species.)  While most wasps can be very territorial around nest sites, the allegedly aggressive flight patterns of many big wasps is actually caused by simple curiosity, and I’ve surprised friends and family by holding still, letting a wasp big enough to fly off with small birds make two or three passes around me, and then watching it buzz off once it’s satisfied that I wasn’t a threat.  More often than not, individuals are stung in attempts to kill wasps, so the lesson is simple: DON’T TRY TO KILL THEM.

Like Gila monsters, Australian brown snakes, and snapping turtles, wasps have an insanely overwrought reputation for mayhem and menace.  Stop for a second, put down the can of Raid, and watch wasps for a little while.  I did the same a decade ago, and now anyone dumb enough to spray them in my yard is going to get more than angry wasps on their asses.


Shamefully, the literature on hunting wasps is very thin outside of scientific journals (even Carl Zimmer’s fascinating book Parasite Rex only contains a tiny bit on wasp parasitoid habits), and the two best available popular books are well over forty years old.  That said, both are still fascinating reading.

The Hunting Wasps by Jean-Henri Fabre.  1919, Dodd, Mead, 432 pp.  Although sadly neglected today, the French naturalist Jean-Henri Fabre was an inspiration to entomologists throughout the early Twentieth Century for his careful observations of insect life.  The Hunting Wasps goes into detail on Fabre’s firsthand excavations and experiments with both the wasps and their hosts.  (If you read French, go for the original: the English translation is exceptional, but I understand it’s still missing much of Fabre’s passion and humor.)

The Hunting Wasp by John Crompton.  Lyons Press, 255 pp., ISBN 978-0941130493 At times both irascible and awed, John Crompton’s 1955 book is still without peer on the subject of hunting wasps.  Very much written as a popular account, it may be outdated purely due to scientific advances, but it still rates as one of the best books on wasps ever written.

I’m Living In My Own Private Tanelorn: Wimberley, Texas – 3

After writing about carnivorous plant issues on this site for the last decade, it’s always funny when unrelated discussions lead right back to the subject at hand. A week ago, the subject was on bee burn, where Sarracenia pitcher plants catch more stinging insects than the plant can digest, particularly at the end of the growing season. A little trip to the Texas Hill Country, specifically to the town of Wimberley, independently demonstrated why.

Shortly after the actual wedding ceremony was over, when everyone sat down with beverages of their choice, we found ourselves surrounded by paper wasps. They weren’t aggressive, but they were persistent, and gentle shooing didn’t do much to convince them to go elsewhere. They weren’t just going for open drinks, either: they were going for particular pieces of clothing or jewelry, and even particular shades of lipstick. After a few minutes of consideration, Caroline of Caroline Crawford Originals, official wedding jeweler and spouse of nearly 19 years to your humble chronicler, discovered that all we needed to do was set out a spare glass full of something sweet at each table, and the wasps left us alone to get a good drink of margarita sugar syrup or Sprite. In the process, we were making our own artificial Sarracenia without realizing it.

The explanation for the wasp invasion was easy. While larval wasps are enthusiastic carnivores, adults are nearly invariably sweet-tooth acolytes, with a diet mostly made up of nectar, honeydew from aphids and scale insects, and whatever other sugary treasures they can find. (That attraction to sweets applies also to more derived wasps such as bees and ants, which explains how you get ants.) To this end, the members of the angiosperms, the plant order comprising flowering plants, that don’t depend upon wind for pollination depend upon insects, and nectar is an extremely effective way to employ insects’ services. Between sugar and bright patterns visible under ultraviolet light, we have approximately 90 million years of co-evolution between insects and angiosperms, and all of the pitfall carnivorous plants use one or both to capture prey.

What’s going on now is the end of the wasps’ life cycle, at least involving these. Most paper wasps designate one female as a queen, and she promptly finds a spot in a woodpile or compost pile to spend the winter before reemerging in spring. The others keep going on as long as they can find food, but with local flowers fading for the year, the competition with solitary and gregarious bees and the occasional indigenous hummingbird gets intense. By the end of October in Texas, the few paper wasps that haven’t become food for birds, spiders, or praying mantises are desperate for any available food source, which is why they come running to uncovered soda, wine, or mead. Since wasps see mostly in ultraviolet light, they’ll also check out any item that fluoresces under UV in the hope of catching a spare bit of nectar missed by everything else, and most humans would be amazed at how many items of clothing, jewelry, or makeup pop under UV. Eventually, that runs out, and the few wasps that don’t die of starvation will die with the first serious cold snap. That cold snap arrives in Wimberley this week: the odds are really good that these wasps will be dead by the weekend, but as the political writer Charles Pierce says every Friday about dinosaurs, they lived then to make us happy now. And so it goes.

“The first thing I’m going to do when I get back is get some decent food.”

Every time I come across new behavior among parasitoid and exoparasitic wasps, I figure that I’ve read it all. They can’t get any more surreal and horrifying than the one before, can they? And then a friend passed on the story of Polistes dominulus and Xenos vesparum: the former is a European paper wasp, and the latter is a parasitoid fly. Neonate flies that turn their hosts into anarchic wasp queens: that reminds me of a song about a distant relation of mine.

Review: Bees, Wasps, and Ants by Eric Grissell

(A bit of context. This blog features regular reviews of books, horticultural products, and interesting related items, under this proviso. All items reviewed will be purchased by the reviewer in advance, at full retail price, in order to prevent any conflict of interest. Information about upcoming releases is greatly appreciated, but receipt of advance copies or samples will be announced well in advance and will not influence the final review. The world has enough Jeff Craigs and Maria Salases as it is.)

Bees, Wasps, and Ants: The Indispensable Role of Hymenoptera in Gardens
by Eric Grissell. Timber Press, 2010. 335 pp., $27.95 US. ISBN-13: 9780881929881

I came across gardening in a very roundabout way, and I can credit one book as being my awakening to the possibilities. That book, discovered in a pile in the Natural History section of the local Half Price Books, was The Hunting Wasp by John Crompton. Before starting that volume, my attitude toward wasps was the same as with most humans: duck and wave your arms around your head if one approaches, and rush for the can of Raid when it retreats. Considering how sensitive I am to honeybee venom, I thought I had a good reason to keep up that attitude.

Well, that was before John Crompton. Without him, I never would have learned exactly how valuable wasps are in the garden, and in fact elsewhere. Honeybees can pollinate flowers, but they do nothing against common garden pests. With the exception of vertebrates, pretty much every gardener’s nemesis has a parasitoid or exoparasite wasp that uses it as a host. Tomato hornworm caterpillars, houseflies, spiders large and small, cicadas, and even praying mantises are all prey. The more social wasps such as paper wasps may not capture and paralyze prey, but they still do their part: I currently have a paper wasp nest on the back porch, right over my head when I’m repotting plants. Considering how much damage they do to the annual green looper plague every spring, anyone who wants to spray my paper wasps will have to go through me first.

That’s the biggest thing that Crompton’s book taught me: we’re taught our basic responses to wasps, and they’re a matter of conditioned fear, augmented by the pain of the very occasional sting. Wasps should be respected, yes, especially by those with allergies to their venom. However, a lot of what’s seen as wasp aggression is really little more than curiosity, abetted by our conditioning to react in a certain way to certain insect shapes and colors. What’s funnier is that this conditioning is one of the big factors in keeping male wasps alive, as they have no sting and are completely harmless to humans.

When it comes to books on members of the insect order Hymenoptera, the vast majority focus on the bees. Lots and lots on traditional honeybees, with maybe some mention of carpenter bees, mason bees, and sweat bees as a sidenote. Most books on ants are intended for grade-school students, and they’re discarded about the time the reader has to deal with carpenter ant damage to a house or Argentine fire ant infestations in the yard. Wasp books pretty much begin and end with Crompton and with Jean-Henri Fabre’s The Hunting Wasps, now nearly a century old. And on the wasp cousins the sawflies? Not a peep, outside of basic insect pest guides.

Part of the reason for that lack of care, obviously, is bad public relations. Bee folklore and mythology range the width and breadth of the planet. (How many of you know that the name “Melissa” is ancient Greek for “bee”?) Ants at least get the Aesop’s fable on the ant and the grasshopper. Ants and bees get cutesy Pixar movies made about them. The closest to popular respect given to wasps? A begrudging comment on how the life cycle of the title creature in the film Alien had a basis in the real-life habits of certain exoparasite wasps.

Yeah yeah, sure sure. The wasp’s world is a horrifying one compared to that of humans, and it’s not hard to see the comparisons. (Last year, I came across an unopened silkworm coccoon hanging from a maple tree, and found inside the coccoon a mummified silkworm with two tiny holes in its body from where wasp larvae, implanted as eggs before the caterpillar started spinning, had gnawed their way out before pupating within the coccoon. I couldn’t help but murmur “Alien life form, dead a long time. Fossilized. Looks like it grew out of the chair.”) That’s just part of the story. Most wasps are essential pollinators, as the adults only consume nectar and other sweets (this explaining why they’re always attracted to spilled juice or soda), and they’re often manipulated themselves, as with wasp orchids. Furthermore, each parasitoid (young develops within the host’s body) or exoparasite (young develops outside) wasp species has a specific host, and those can range from aphids to cicaidas. I was recently lucky enough to view two tarantula hawk wasps searching for prey, and as their name implies, their chosen hosts are tarantulas and other extremely large spiders. Crompton himself was impressed by one species of wasp that attacks and paralyzes praying mantises, and he described these wasps as being like a human mother who has decided that the only food fit for her children is grizzly bear. (With both tarantula hawks and mantis hunters, the wasps don’t always win their battles.)

It takes a special love to research a book on wasps and their preferred hunting methods, and I was afraid I’d hit the point where the only way I was going to find a book with the information I sought was by writing it myself. Thankfully, research entomologist Eric Grissell beat me to it, and in so doing, gave me a lot of ideas for future arrangements. For instance, he described going from butterfly to wasp garden by setting up a solar-powered water pump with a 5-gallon bucket as a well and covering the top with rocks that would get splashed during the heat of the day, encouraging wasps and bees to gather water without a chance of drowning. Considering the number of bees and wasps converging on my Sarracenia pots for water during the summer heat, this is going to be an essential addition to the garden come next spring.

And then there are the photos. Crompton’s and Fabre’s books are a bit lacking in illustrations, and thankfully Bees, Wasps, and Ants is thoroughly and copiously augmented by beautiful color photos. When the photos can make me appreciate the beauty of ants, this says something.

As a final note, one of the best reasons to buy this book lies with the insects even more disrespected than wasps. Learning about sawflies was intriguing enough, but for years, the only information I could find on the local velvet ants was that (a) velvet ants were solitary wasps, (b) the females are wingless, and (c) their sting packed a powerful enough punch that they’re referred to throughout Texas as “cow-killers”. (I haven’t seen one since 1980, but after narrowly missing being stung, I don’t plan to test its ranking in the Schmidt Sting Pain Index to make sure.) That right there made this book indispensable, as now I can get co-workers and family members to alternate between oohing in wonder and making vague squicking sounds when reading about braconid wasps on tomato hornworms. I was even able to make the Czarina’s head go “pop” when describing the color of tarantula hawk antennae as tango, and she definitely wasn’t expecting to learn about colors and historical significance from a discussion of wasps.

“I could lie to you about your chances, but you have my sympathies.”

Longtime readers of my Gothic Beauty gardening columns might already know of my fascination of and respect for the strategies and tactics of exoparasitic wasps. The common analogy comparing the life cycle of the typical hunting wasp to the title creature in Alien, while accurate, is also very simplistic. Using the ladybug exoparasite Dinocampus coccinellae as an example, pray that hunting wasps never see chordates as possible hosts.