Category: insects

Biology, wildlife, and food in Davis

January 22, 2024 • 9:20 am

The lazy days slip away in Davis, sadly veiled in sporadic rain and gray skies. However, all is not lost. For example, here’s a visit to my friend Phil’s lab in the Entomology Department of UC Davis, on the same floor where I spent three years as a postdoc in genetics.

Phil punches out paper tags to affix to his ant specimens:

A preserved ant is glued to the tag with special glue that has to be used immediately before it dries up:

The glued ants are then temporarily stored in boxes awaiting the collecting information:

The collecting information is put on other tags using offset printing on tiny labels. Here’s an example. The pencil shows how small the tags are:

This is a specimen of the world’s smallest ant, Carebara sp. nr. atoma, collected by Phil on a recent trip to New Guinea.

We measured it under the scope, which gives readouts in millimeters. Here’s the width of the head of the specimen above:  0.275 mm. It’s so small that it’s impossible to dissect the head, but inside is a brain that codes for a huge set of complex behaviors exhibited in all ants.  This is amazing!

Body length: 0.76 mm.

To show you how small this ant is, here’s the specimen of Carebara next to a “regular size” ant also collected in New Guinea, Mesoponera sp. It’s about ten times as large as the tiny ant, which is just a speck on the paper:

These ants are so tiny you wouldn’t be able to see it: these are collected by sifting leaf litter or soil using a Winkler sack (see here).

Davis is the site of the University of California’s only veterinary school, and so they keep both large and small animals for teaching instruction. We visited the outdoor pens to see them.

Here I’m petting a friendly cow (photo by Phil Ward):

The cow stuck out its tongue at me:

They also had llamas. They spit on people when they feel threatened, so you don’t pet them.

This must be a fancy breed of goat. Look how high its eyes are placed:

There was also a tiny bearded goat. With its short legs, I wondered if it had a gene for dwarfism. (I know that at least one reader will be able to tell us about these goats in the comments.)

Davis also has a lovely duck pond near the administration building, so I was able to get my mallard fix. I do miss my ducks!

Here’s a drake with unusual markings and a lovely but very orange bill. I wonder if he’s a hybrid between a wild mallard and a domestic Pekin duck (the white ones):

Davis has an In-N-Out Burger store: part of a highly rated chain of burger stands found mainly on the West Coast, but also in a few other Western states. So of course we had to go there for dinner.

Our dinner: I had a Double Double, animal style, with fries and a Diet Coke. That was a big burger!

In-N-Out was one of the late Anthony Bourdain’s favorite restaurants. Here he extols it and then eats a Double Double, also Animal Style. (Readers can explain that in the comments.)

And recycling bins in Davis with a bit of humor:

Readers’ wildlife photos

January 11, 2024 • 8:15 am

Today we have an assortment of photos (plants, one insect, and one reptile) from Rik Gern of Austin, Texas. Rik’s notes are indented, and you can enlarge his photos by clicking on them.

This is an odds and ends collection of photos that I would not have submitted were it not for the fact that your supply of reader’s photos is running so low. I’d call this batch “Reader’s Mildlife Photos” since they represent species easily observable on a walk around my Austin, TX neighborhood and nearby.

The first two pictures come from my back yard. The Texas Spiny Lizard (Sceloporis olivaceus) made an appearance while I was turning the compost pile and adding the semi weekly supply of kitchen scraps. Although hard to spot at first, it was easy to photograph since it stood incredibly still for a very long time.

The Green Pointsettia (Euphorbia dentata) started out as a weed, but looked too attractive to mow, so I waited to see how it would turn out. It was worth the wait to have a few patches of these handsome plants grace the back yard.

You might expect to see something like this Common Blue Wood Aster (Symphyotrichum cordifolium) in the Springtime, but this was taken in a creek bed in a local park in early December.

The following five pictures were taken in the Spring; the first three at a local cemetery and the others in a field just outside of Austin.

Field Madder (Sherardia arvensis):

Erect Bouchetia (Bouchetia erecta):

I couldn’t find a common name for this bug (Oncerometopus nigraclavus), but it certainly cuts a distinct figure among the green foliage:

The Dakota Mock Vervain (Glandularia bipinnatifida) photos are admittedly a bit overprocessed, but they appeared in a rather dull context and I wanted to simulate how their vibrant color jumped out from the drab background.

The last two pictures are of cultivated flowers from my neighbors’ yards. A rose by any other name is….well, there are over 320 species of rose, so they might go by any number of different names. The Seek app by iNaturalist (Thanks for the tip, Jerry!) couldn’t identify the species of this rose bud, and identified the second image as a China Rose (Rosa chinensis). Call them what you want, they’re nice to look at and I appreciate my neighbors for growing them!

After having had beginner’s luck with my old Canon Powershot, I went on a search for a more advanced camera I could feel comfortable with. I played around with a Canon EOS T21 and a Panasonic Lumix DC-ZS70 before settling on a Panasonic Lumix DX9 (for now). I have two large batches of photos from the T21 and the DC-ZS70 that were taken in Wisconsin last fall. My New Year’s resolution was to comb thru those and process a few a day until I ran out before going all in on using the DX 9. That would probably take a few months, and I’d planned on waiting till then to sift thru those for some I thought you could use, but I’m going to modify the resolution to keep working steadily at processing the pictures, but instead of waiting a few months to compile batches for you, I’ll try to put post submissions together as enough pictures become available. This feature adds a lot to WEIT, and I’m grateful to be able to contribute to it and want to see it keep going.

Readers’ wildlife photos

January 10, 2024 • 8:15 am

Thanks to the half-dozen readers who responded to my call for photos; our tank is now somewhat replenished and I can keep this going for a while. But please think of this site if you have good wildlife photos.

Today’s photos come from Jim Blilie of Washington State, but were taken by his son Jamie.  Jim’s captions are indented, and you can enlarge Jamie’s photos by clicking on them.

Jamie is now a freshman at Washington State University (WSU) at Pullman Washington. He is thriving there.  We love WSU.  It’s very welcoming and is focused on student success. Jamie is studying engineering.  Some of these photos were taken during backpacking trips he has taken to Idaho through the WSU Outdoor Recreation Center, a wonderful service WSU provides. Jamie is the wildlife photographer of the family, though has become a good landscape photographer as well.

Jamie did not identify this bird, photo taken a few feet from our house in Klickitat County, Washington; but I think it is a Western Kingbird (Tyrannus verticalis).  Any help with a positive ID would be welcome:

Bumblebee, species uncertain.  Taken on the trail to Lookout Mountain, Oregon, east of Mt. Hood:

Red-breasted nuthatch (Sitta canadensis) and an unknown species of flying ant, taken on Lookout Mountain, Oregon, east of Mt. Hood:

Golden Mantled Ground Squirrel (Callospermophilus lateralis), also taken on Lookout Mountain, Oregon, east of Mt. Hood:

A similar looking rodent:  Based on his location in the mountains of the Idaho panhandle, I think this is a Red-tailed Chipmunk (Tamias ruficaudus), although the eponymous part is not visible in the photo.  Jamie took this photo on one of his backpacking trips in northern Idaho:

Also taken on one of his backpacking trips to Idaho (Selkirk Range, close to Upper Priest Lake):  A very small brown spider (note the size of the adjacent moss).  We were unsuccessful in identifying this spider:

A Steller’s Jay (Cyanocitta stelleri), taken on our place.  We love the beautiful blue and black plumage of these jays.  These are very common here in winter.  In summer they seem to move to higher elevations (we are at 2000 feet (610m) above sea level) and then the Scrub Jays (Aphelocoma californica) move in for the summer.  The Steller’s Jays can make a pretty good mimic call of the Red-tailed Hawk’s scream (Buteo jamaicensis):

My favorite of the bunch:  A coyote (Canis latrans) in a snowstorm, taken from our back deck.  The coyote was perhaps 100 yards away:

A  beetle at 5600 feet (1707m) elevation in Oregon, taken on the Flag Point Lookout Tower.  Also unable to identify this beetle:

A Cyanide Millipede (Harpaphe haydeniana).  This millipede can exude hydrogen cyanide gas as a defense!  The photo was taken on the hike to the former fire lookout site, Sleeping Beauty, Skamania County, Washington.  This is a favorite hike (though unrelentingly steep) because of the very good views of Mount Adams from the top:

Finally, a ringer:  Jamie and me on top of Lookout Mountain with Mount Hood behind, just a day or so before he headed off to university:

Equipment:

Nikon D5600 (1.5 crop factor)
Nikkor AF-P DX 18-55mm f/3.5-5.6 G VR lens
Nikkor AF-P DX 70-300mm f/4.5-6.3 G ED lens
Sigma 150-600mm f/5.0-6.3 DG OS HSM lens
Canon PowerShot SX530

Readers’ wildlife photos

January 5, 2024 • 8:15 am

Today’s batch of photos (we have more!) comes from reader Leo Glenn of western Pennsylvania, who also pays tribute to another contributor. Leo’s text and IDs are indented, and you can enlarge his photos by clicking on them. Note the felid lagniappe at the bottom.

It’s been a while since I contributed wildlife photos. I’m no Mark Sturtevant, but here are a few photos of insects I’ve taken this year, mostly on the daily dog walks.

Bald-faced hornet (Dolichovespula maculata) on goldenrod (Solidago sp.). Not a true hornet, which are in the genus Vespa, bald-faced hornets are a species of yellowjacket wasps. According to Wikipedia, they produce colonies of 400-700 workers, which is the largest colony size in its genus. They construct large paper nests, which they aggressively defend, a fact to which I can personally, and regrettably, attest:

Imperial moth caterpillar (Eacles imperialis), in its fifth and final instar, undoubtedly look for a place to pupate. They are polyphagous, feeding on many tree species, including pine, maple, oak, sassafras and sweetgum:

Another imperial moth caterpillar (Eacles imperialis) in its fifth instar, showing their color variability:

The aptly named pale beauty moth (Campaea perlata). They are in the family Geometridae, derived from Ancient Greek and meaning to measure the earth, as their larvae, also called inchworms, appear to be measuring as they perambulate along:

Splendid earth boring beetle (Geotrupes spendidus) And splendid it is. They are named earth boring because they make burrows to lay their eggs. They prefer fungi, but will also feed on dung, carrion, and feathers:

Spotted cuckoo spider wasp (Ceropales maculata) on Queen Anne’s lace (Daucus carota). Members of the spider wasp family (Pompilidae) are nearly all solitary. They are so named because the female captures and paralyzes spiders, transports them to its underground lair, and lays an egg in the abdomen of the spider. The hatched larva then consumes the spider from the inside. The spotted cuckoo spider wasp, as its name implies, does things a little differently. The female seeks out a female from another spider wasp species which already has a spider, follows her, and when she drops the spider momentarily to prepare her lair, the spotted cuckoo spider wasp dips in, lays her egg in the spider, and flies off. The unsuspecting spider wasp then places the spider in her lair and lays her own egg. But the spotted cuckoo wasp spider egg has evolved to hatch first and eat the other egg, before moving on to consume the spider.

Zabulon skipper butterfly (Lon zabulon), sipping nectar from a red clover flower (Trifolium pratense). Its proboscis is considerably longer than its body:

Giant leopard moth (Hypercompe scribonia). I had to move it to my palm to get a decent photo:

Common eastern bumble bee (Bombus impatiens) on mint flower (Mentha sp.):

Viceroy butterfly (Limenitis archippus). It was long thought to be an example of Batesian mimicry due to its strong resemblance to the monarch butterfly (It can be distinguished from the monarch by the black lines transversing its hind wings.). However, after it was discovered to also be distasteful to predators, it is now considered an example of Müllerian mimicry, which, to quote Wikipedia, is when “two or more well-defended species, often foul tasting and sharing common predators, have come to mimic each other’s honest warning signals, to their mutual benefit.”

One of my personal favorites, a lovely dogbane beetle (Chrysochus auratus) on its host plant, dogbane (Apocynum cannabinum). You can see my reflection, and my dog’s reflection, in its elytra.

Felid lagniappe: And finally, a few photos of our neighbor’s orange tabby, whose name is Moses. Moses likes to sit perfectly still in our driveway for long periods of time and stare at our house. My family call him the spy cat. He also likes to come up to the sliding door on our back deck and harass our cats (which are strictly indoor cats), causing them to hurl themselves into the glass with a resounding bong, He seems to prefer to do this in the predawn hours when the humans are still asleep. The first time it happened, I thought someone was breaking in.(Now we just yell, “Moses!” and try to go back to sleep.)  My repeated attempts to befriend him failed, until recently, when persistence paid off, and I was finally able to get him to come to me. The photos capture that first successful encounter. Now we’re best buds, of course.

Readers’ wildlife photos

January 4, 2024 • 9:15 am

I overslept tonight, and may be coming down with the virus that’s going around. Posts will be fewer today, and late. But we still have readers’ wildlife, thanks to kind readers. (Send in your photos!)

Today’s batch was sent reader Rodney Graetz, but there are two authors.  The captions and IDs provided are indented, and you can enlarge the photos by clicking on them.

Australian Wildlife photos for WEIT January 2024

M. E. & R. D. Graetz

It is mid-Summer here in the Southern Hemisphere, and the natural world is bubbling with The Game of Life: If you win, you stay in the game.  Here a Noisy Miner (Manorina melanocephala), a very aggressive honeyeater, searches for the nectar of a flowering ‘Gum’ tree in our backyard.  Gum trees, aka Eucalypts, are Australia’s iconic tree with about 800-900 species, all of them evergreen with individual leaves living for 2-3 years.  When Gum trees decide to flower, the colours and nectar are very obvious:

In my neighbour’s yard another tree has burst into spectacular flower also dripping with nectar.  This species, erroneously named ‘Silky Oak’, is Grevillea robusta, a widely admired native tree cultivated for its unique cabinet-making wood, and for its spectacular flowering and providing so much nectar that birds noisily dispute access:

The first honeyeater on the scene is the Noisy Friarbird (Philemon corniculatus), so named by it featherless ‘bald’ head and for its continuous maniacal calling:

As well as the numerous honeyeater species, the common, large seed-eating Sulphur-crested Cockatoos (Cacatua galerita)  join in the nectar feasting.  There’s no delicate probing with slender beaks; they just bite off a whole twig, chew one or two flowers, then drop the twig and bite off another:

Back on ground level, several species of butterfly search ceaselessly for nectar during the warmest daylight hours.  What species they all are, and where they disappear to when the temperature drops remains a work in progress:

Again, in a neighbour’s yard, a male Australian King Parrot, (Alisterus scapularis) in exquisite breeding plumage, munches on the thin fleshy coating of seeds.  His permanent colouring is a very effective ‘look at me’ strategy:

We (happily) leave our lawn un-mowed to provide insects and worms for ground-feeding birds such as this female Magpie-Lark (Grallina cyanoleuca), probably the most widely distributed Australian bird.  Always in industrious pairs, apparently mated for life, they are yearlong visitors to our backyard:

This year, the resident Magpie-Lark pair are attempting to breed.  This is their nest in a street tree about 10 metres above ground.  The tail of a sitting bird is visible.  The substantial nest is a mud and grass bowl that was built beak-by-beak loads of wet soil and lawn clippings from our backyard.  So far, it has withstood several heavy storm rains:

A lurking threat to the nesting Magpie-Larks.  This long-tailed, deep satin-blue bird is an Australian Koel (Eudynamys cyanocephalus), a cuckoo-related, nest parasite.  It’s a migratory bird that appears when favoured susceptible species of birds are nesting.  Its mating call, regarded as Australia’s most annoying bird call, is loud and repetitive.  Once mated, the female finds a susceptible nest in which to lay one egg, which, on hatching, removes or kills the existing host bird’s nestlings.  The Magpie-Lark nest is one known to be susceptible to the Koel:

The ‘Look at Me’ season, when males display to attract a mate, began in Winter (July) with the ducks and still continues in mid-Summer with land birds.  Here a male Maned Wood Duck (Chenonetta jubata) performs for a seemingly uninterested female.  Considered choice is imperative when mating for life, as this species is thought to do:

Some of Australia’s smallest birds are the Wrens, and this is a male Superb Fairy-Wren (Malurus cyaneus) growing his breeding plumage.  Though small, they are hyperactive in hunting for insect prey, and, as many post-graduate research students have found, they are hyperactive in their breeding behaviour.  It’s always a joy to (briefly) spot their flash of colour deep in the foliage:

Some birds’ breeding signage is subdued but unmistakable.  With the Australasian Grebe (Tachybaptus novaehollandiae), a small bird by Grebe standards, both male and female temporarily develop coloured cheek-neck patches for their combined ‘Look at Me’:

The neck flexibility of an Australasian Darter is enviable.  We thought this young male (Anhinga novaehollandiae) was wounded until I realised it was vigorously rubbing its head on its oil-producing ‘preen’ gland at the base of its tail feathers.  Watching a little longer, it was not ‘Look at Me’ breeding behaviour, just ‘Looking Good’, everyday oiling of feathers:

The first job after successful breeding is looking after the offspring.  Two Dusky Moorhen adults are encouraging their reluctant chick to join them in the water.  The adult birds always appear polished and groomed.  Their chick has yet a lot to learn:

Joining birds in the trees are these temporary mammalian visitors.  In November, about 5000 Grey-headed Flying-foxes (Pteropus poliocephalus) arrive from the north-coast to restart their summer occupation of a ‘camp’ near the city centre.  Departing around April, they are noticeable by sight, smell, and sound, but most people remain unaware of their presence:

This species is Australia’s largest bat: a megabat with a wingspan of almost a metre.  Nocturnal nectar and fruit feeders, by day they roost hanging by one or two feet, using their wings to shroud their eyes, and sleep – briefly – because this species is inherently quarrelsome.  Facing away from the sun (and photographer), the orange-red hair collar and the pointed ears are obvious, which contribute to their ‘fox’ naming:

Frontal views reveal the grey-haired head and chest, along with the large eyes and snout that is the other component of the ‘fox’ naming.  Their looks are appealing, but current understanding is that any contact, such as with wounded animals, is hazardous because of the viruses they are likely carrying.  However, it is also known that Aboriginal Australians ate these and other bat species:

By chance, one of our images revealed this ‘Pup’: a young, chubby, and hairless bat.  By size, it is unlikely that it was born in Canberra.  Rather, it was carried here, clinging to its mother’s chest.  It is known that Pups of about this size remain when the mother flies out to feed at night:

Readers’ wildlife photos

January 2, 2024 • 8:15 am

Please send in your good photos. Tony Eales from Australia heeded my call, and here are some of his pictures. Tony’s captions and IDs are indented, and you can enlarge the photos by clicking on them.

Here’s are a few recent observations of interest.

Perhaps only the photographers will be able to tell but I’ve had a laptop breakdown and am using an ancient laptop with an even more ancient version of Photoshop. Hence a lot of these images aren’t up to my usual mid-tier quality.

Firstly some mimicry. I did a quick trip back up to Queensland in mid-December and photographed what I was pretty certain was an Ichneumonid wasp. Turns out it is a fly in the soldier fly family, Stratiomyidae, which includes a number of wasp mimics. Turns out this one was a rarely seen species and mine is possibly the first photograph of a living specimen. The fly is called Elissoma danielsi.

Offhand I can’t think of a specific model. Ichneumonid wasps are extremely varied and colourful and it may be that this fly is just mimicking the general form of this wasp family, rather than a specific species.

Here is a somewhat similar Ichneumonid photographed at the same location for comparison:

Soldier beetles, in the family Cantharidae, are relatively soft bodied for a beetle and rely more on their distastefulness to protect themselves from predators. One very common small soldier beetle genus is Heteromastix. The genus is in desperate need of revision so I can’t say what species this is, but they are all around 4-6mm long and look basically like this:

And naturally this colour and form is widely mimicked. Here’s a mating pair of Oedemeridae, probably Dohrnia simplex:

And this little guy totally had me fooled at first. I knew the antenna and pronotum didn’t look right for Heteromastix but I couldn’t think what else it could be. It had the experts on the Australasian Beetles Facebook page stumped too. In the end it turned out to be the first live photograph of Xylophilostenus octophyllus from one of the smaller families (Scraptiidae) in the darkling beetle superfamily, Tenebrionoidea. As far as I can tell the only record of this little beetle was the type specimen collected in Tasmania in 1917:

I also found my first true Blister Beetle, family Meloidae. It too was a mimic, this time of the nasty tasting Lycid beetles. I believe it’s Palaestra rufipennis, but there are other Lycid-mimicking blister beetles in Australia.

In the realm of camouflage, rather than mimicry, I found a species of Ceraon, a type of treehopper that has a variety of horn-like ornaments, making them look like a node on a twig when resting.

Other notable finds, an undescribed shield bug, Anischys sp., that seems to live in the mountains of southeastern Australia, known as the Australian Alps.

A hanging fly, probably Harpobitticus australis, with another hanging fly as prey. I wonder if it was an attempted mating gone wrong. The males supposedly bring ‘nuptial gifts’ of a recently captured prey item for the female to snack on while getting the deed done. I couldn’t see any gifts so perhaps he turned up empty handed and was rewarded appropriately:

And a spider I have been wanting to find for a while. They are small and not common, living in leaf litter and similarly overlooked habitats. It’s in the family Orsolobidae or Giant Goblin Spiders. Okay, it’s giant for a Goblin Spider but hardly giant for a spider. Anyway the peculiar six-eye arrangement was the key to its identity. Probably Tasmanoonops sp.:

And finally, I, along with some other citizen scientists, were mentioned in dispatches. Researchers Aiden Webb at The University of Melbourne, Joanne Birch and Russell Barrett described a new species of Grass-lily from South East Queensland. They were alerted to the fact that there appeared to be a difference in the SEQ population using photos uploaded to iNaturalist  by myself and two other citizen scientist observers. These differences in habit and colour would not be at all obvious from dried preserved specimens but the difference was plain in the live photos. Here’s the newly described flower, Caesia walalbai:

An a link to the paper https://openjournals.library.sydney.edu.au/TEL/article/view/17346

Readers’ wildlife photos

January 1, 2024 • 8:15 am

I have but three batches of wildlife photos left, so we’ll run out on Thursday—and then I’ll have to stop this feature (the website is moribund anyway). Please send in your high-quality wildlife pictures if you have them.

Fortunately, Mark Sturtevant is here today with a good batch of insect photos (and one crustacean). His captions and IDs are indented, and you can enlarge his photos by clicking on them.

Over a year ago, the family traveled to New Jersey to visit family. I had already posted pictures from that trip some months ago, but I had lost track of another set. Here is that set.

We had not been to the area for about 8 years, and since then the invasive Spotted Lanternfly (Lycorma delicatula) had arrived. I expected that I would be photographing them, and I admit to some initial excitement about that since they are very large for planthoppers and are quite beautiful. There was certainly no problem locating some, since the buggers were just about everywhere! They decorated my brother-in-law’s house and most of the trees, and they often aggregated in solid patches in shady areas. Lanternflies were meanwhile also flying through the air like locusts. Here are adults and nymphs. Younger nymphs are black and white spotted, but this was late summer so I did not see those. Photographing them was slightly challenging since they are powerful jumpers, but with so many opportunities to get pictures it was still like shooting fish in a barrel.

Although the nymphs and the hind wings of the adults are quite colorful, I have not found anything about the colors being a warning that they are toxic.

As I said, I was at first looking forward to photographing these exotic insects, but it did not take me long to develop a strong dislike for Spotted Lanternflies! They were a constant presence when simply walking down a street or exploring a park. We even had to shoo them away when trying to enter a local restaurant, and taking care to not let any of the damn things fly inside

The Spotted Lanternfly is native to China, where it is under control by parasitic wasps. There seems no prospect of replicating that here, and I am not sure why. But such means of pest control do often fail because they are not cost effective, and similar approaches have resulted in unintended consequences. Spotted Lanternflies were first detected in the U.S. in 2014, and they have spread mainly because their egg masses can be accidentally transported on anything man-made. Now much of the eastern half of the country has them, and there are isolated populations out west as well. I understand that the main eastern population has now spread to my state of Michigan, and it’s probably only a matter of time before they turn up in my area, like the Spongy Moths (formerly Gypsy Moths), and Japanese Beetles before them.

These plant-sucking insects will feed on almost 200 plant species, and are considered a serious pest on grape vines. But many of our ornamental trees are fair game as well, and besides being obnoxious to humans, their large numbers are stressful for their host plants. But by far their preferred host is Tree of Heaven (Ailanthus), a rather attractive invasive tree that has become widespread in the U.S. for at least a century. So with a favored host plant already well established, there is little to slow further migration of the Spotted Lanternfly! The last picture is a typical scene on an Ailanthus sapling. But I have seen gatherings far denser than this.

Well, let’s move on. At a nearby park (also awash with Lanternflies), there were several of these Yellow-legged Mud Dauber Wasps (Sceliphron caementarium) collecting mud to build their nests. I had to hang head down on a steep river bank and hold the camera way out to get close pictures. When she completes her mud-pot nest, this wasp will stock it with paralyzed spiders for her young. [

On another outing near the ocean, I visited some tide pool areas where there were large numbers of these Atlantic Marsh Fiddler Crabs (Uca pugnax). They would all scatter to their burrows when I approached, so I had to wait in hiding. When some crept back into range, I was able to dive on this one for pictures. It’s the males that have the super-sized claw, which they wave at females to attract them. They will also use the claw to ritualistically arm wrestle other males.

 

In the same area there were numerous dragonflies, and on that one day I scored two new species from the Skimmer family. Here are Seaside Dragonlets (female and male, respectively) Erythrodiplax berenice.

And finally, a male Great Blue Skimmer (Libellula vibrans). This is one of our largest Skimmers, and I was very excited to get this picture!

Readers’ wildlife photos (and story)

December 30, 2023 • 8:15 am

Today we have another photo-and-text lesson from Athayde Tonhasca Júnior. Athayde’s text is indented, and you can enlarge the photos by clicking on them.

Enormous armies with countless skills

As natural history narratives go, the 1954 ant-inspired motion picture Them! was not up to David Attenborough’s standards because giant, deranged, radioactive ants don’t exist. Despite the factual liberties, the film was a commercial success and had the novelty of depicting two myrmecologists (ant specialists) as heroes who helped to save the planet from a myrmecological doomsday. Malevolent ants have a long history in Western popular culture. In The Empire of the Ants (1905), H.G. Wells tells us the story of a gunboat forced to turn around and abandon an Amazonian village overwhelmed by intelligent killer ants.

A bad ant infestation in the New Mexico desert © San Bernardino Sun, 1954. Wikimedia Commons:

Those who have witnessed an army ant raid or had the unfortunate experience of stepping (or even worse, sitting) on a fire ant mound, understand why ants elicit fear or a grudging respect; many of the 14,147 – and counting – species of ants (family Formicidae) are territorial and highly aggressive to perceived intruders, man or beast.

Lieutenant da Cunha being overwhelmed and killed by evil Amazonian ants in H. G. Wells’ The Empire of the Ants © Amazing Stories, 1926.Wikimedia Commons:

JAC: I’ve added the video of the army ant raid (narrated by David Attenborough) below; do watch it

But aggression is only one aspect of ants. They can be predators or feed on seeds, nectar, honeydew, or fungi they cultivate. They are found everywhere except Antarctica and a few remote islands, and are incredibly important in decomposing organic matter, recycling nutrients, and controlling plant-eating insects (many of them agricultural pests). Ants are essential ecosystem engineers: many species build nests and dig tunnels in the ground, increasing aeration and drainage, and improving soil fertility with their waste and food stores. Some seed-eaters are important for plant reproduction: they stock their nests with seeds that are not all eaten. The spared lucky ones germinate in a nutrient-rich, herbivore-free environment. More than 3,000 plant species depend on myrmecochory, which is seed dispersal by ants. Plant-eating by ants is not always benign; leafcutter ants (genera Atta and Acromyrmex) are incredibly destructive; in Brazil, saúvas (their local name) have been the scourge of agriculture since the beginning of European colonisation. French naturalist Augustin Saint-Hilaire (1779-1853) supposedly said that ‘Brazil must destroy the saúva or the saúva will destroy Brazil’, which was a slogan adopted in successive – and unsuccessful – eradication campaigns.

Digging a leafcutter ant nest in Brazil. Concrete was poured into the nest to create a cast of the inside. The nest covers more than 67 m2 and contains 1,920 chambers © O’Brien & Bentley, 2015:

All these ecological services and impacts are intensified by ants’ mindboggling numbers. The distinguished myrmecologist E. O. Wilson estimated that 1015 to 1016 ants crawl on Earth’s surface at any given time (that’s quadrillions, figures usually discussed in astronomy). A later appraisal fine-tuned the number to 20 × 1015 individuals, which corresponds to ∼12 megatons of carbon. This is more than the combined biomass of all wild birds and mammals, and is equivalent to ∼20% of human biomass (Schultheiss et al., 2022). Another study following a different methodology suggested a population size of 5 × 1016, excluding arboreal ants (Rosenberg et al., 2023). So Wilson wasn’t far off, as a billion here or a billion there is not that important when we are talking quadrillions. For comparison, there are some 7.9 × 109 human beings on the planet.

A representation of powers of 10 to help us grasp the magnitude of ants’ abundance: each block is ten times the size of the previous block, up to a billion (109). One quadrillion would be 1.000.000 bigger than the billion block © Cmglee, Wikimedia Commons:

Ants are everywhere and interact with a vast number of animal and plant species, but they seem to be mostly absent from one ecological process: pollination. Which is a bit puzzling, considering that bees, their close relatives, are the main pollinators of a large number of plants. Many reasons have been proposed for the dearth of ant pollination, from their grooming (self-cleaning) behaviour to scant ‘hairiness’ (body bristles), resulting in few pollen grains being transported. But bees groom themselves, and some ants are as hairy as bees. The ‘antibiotic hypothesis’ is the most accepted explanation for ants’ unsuitability for pollination. Most ant species feature a specialised gland located in the metapleuron (a thoracic plate; pl. metapleura). The metapleural gland – and to a lesser extent some other parts of the body – secrete chemicals that serve as signals for nest-mate recognition and territory marking, and especially as antiseptics that prevent the proliferation of bacteria and fungi. But these substances have a disagreeable side effect: they also inhibit pollen germination and the growth of pollen tubes.

Parts of a typical ant, highlighting the all-important metapleural gland © Mariana Ruiz, Wikimedia Commons.

Ants’ chemical defences seem to make them incompatible with the job of pollination. Which is a pity for the plants’ point of view, as ants often crawl all over them in search of nectar from their flowers and, in some cases, from specialised nectar-secreting glands. But inevitably and predictably, natural selection intervenes to fill the voids of missed opportunities.

Honewort (Trinia glauca) is an unassuming herb found on dry, rocky sites with sparse vegetation in southern England. Elsewhere, it ranges from continental Europe to southwest Asia. On some of the English sites, flowers of this rare plant are visited mostly by ants, especially Lasius alienus, which are also their main pollinators (Carvalheiro et al., 2008).

Honewort on limestone, a habitat shared with its main pollinator, L. alienus © BerndH, Wikimedia Commons.

Honewort is an addition to the ever increasing number of reported cases of myrmecophily, or pollination by ants. These ant-friendly plants may have developed tolerance to the ill effects of metapleural gland compounds. This seems to be the case for the waxy-leaved smokebush (Conospermum undulatum) in Australia: in an experimental setting, pollen from some plant species suffered substantial decreases in germination after contacting the integument (‘skin’) of Camponotus molossus and other ants. Pollen of waxy-leaved smokebush however was not affected. Not surprisingly, ants contributed significantly to the plant’s pollination (Delnevo et al., 2020).

A, B: waxy-leaved smokebush flowers. Bee visitors: Leioproctus conospermi (C) and Apis mellifera (H), which only steals nectar. Ant visitors: C. molossus (D), C. terebrans (E), Iridomyrmex purpureus (F) and Myrmecia infima (G) © Delnevo et al., 2020.

Brute force is another possible explanation for myrmecophily. A single ant may be a poor pollinator, but a mass of them visiting flowers repeatedly may end up doing the job properly. Apparently this is the scenario in high mountains and arid zones, where ants make up a substantial proportion of flower visitors (Gómez et al., 1996).

In their monumental 1991 Pulitzer Prize-winning book The Ants, Bert Hölldobler and Edward Wilson skimmed over myrmecophily, as it was viewed as a minor feature. Bees, flies and moths are by far the champion pollinators, but more and more studies suggest ants are important for some plants in some habitats. So we can add pollination to ants’ long list of ecological services – unhinged, angry and radioactive ants notwithstanding.

Edward Osborne Wilson (1929-2021), myrmecologist, environmentalist, secular-humanist, and pioneer in the fields of ecology, evolution and sociobiology. Despite underhanded attacks from some of his peers while he was alive and attempts at character assassination by the Woke Rabble after his death, Wilson remains one of the greatest and most inspiring scientists of our times © Jim Harrison, Wikimedia Commons.