Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
Two kind readers sent photos yesterday, so we’re good until Tuesday. If you’re off work for the Thanksgiving week, why not collect some of your good wildlife photos (if you have them) and send them in?Thanks!
Today we have some lovely butterfly pics from Pratyaydipta Rudra, a professor of statistics at Oklahoma State. Pratyay’s captions and descriptions are indented, and you can enlarge his photos by clicking on them. (I just found out that he and his wife share a photo website called “Wingmates“).
When birding gets slow during the summer, we often pay closer attention to the insects, especially the pollinators that are quite abundant during the hotter months. Our garden (as well as some local botanical gardens and farms) has plenty of native species that attract a variety of pollinators including butterflies and moths. Below are some butterfly images that I took earlier this year.
Gulf Fritillaries (Dione vanillae) on our Swamp Milkweed (Asclepias incarnata). This plant attracts a huge number of pollinators over the summer, and it is also one of the host plants of Monarch butterflies:
Monarch (Danaus plexippus), caught in flight with an interesting morning lighting:
Variegated Fritillary (Euptoieta claudia) on Indian heliotrope (Heliotropium indicum). This plant is not native to North America, but it is quite widespread in our area, and the flowers are pretty:
Gulf Fritillary (Dione vanillae) coming in for landing on a zinnia. Flight photography of butterflies is way more difficult than birds-in-flight photography, but possible with modern cameras and a lot of patience:
The larval stage of Gulf Fritillary (Dione vanillae), on a purple passionflower (Passiflora incarnata) plant, the host plant for them:
Two generations… This adult Gulf Fritillary (Dione vanillae) might be quite worn, but she stopped by to lay eggs, perhaps one last time, as one of the caterpillars from the next generation keeps munching on the leaves:
Great Spangled Fritillary (Speyeria cybele) on Garden Phlox (Phlox paniculata). A relatively uncommon fritillary for us in this part of the state. In fact, it’s the first time I found one in our county:
Diana Fritillary (Speyeria diana) and Monarch (Danaus plexippus). This is one of my most favorite images from this summer. This was also my first encounter with a Diana Fritillary. This male Diana was nectaring on the Butterfly Milkweed (Asclepias tuberosa) when the Monarch flew in. Mr Fritillary wasn’t happy at all:
There was some kickboxing that took place at this point and there was a clear winner…:
The fritillary was able to hold ground, and the Monarch took off:
American Snout (Libytheana carinenta). Not difficult to see why it is named that way. It’s always fun to find one of these little ones with the long “nose”!:
Eastern Tailed Blue (Cupido comyntas). These so-called tails are parts of their wing which they keep moving. This is theorized to be useful to fool the predators into thinking that these are their antennae. Many butterflies actually have several traits like this that give a “false head” impression. We present a Gray Hairstreak in the second image which has a similar false head:
A recent study found that these traits have evolved in a correlated manner, likely driven by a common selective pressure helping them to develop complex head-like structures on their posterior side.
Gray Hairstreak (Strymon melinus) – Another common butterfly in our area that has a similar “tail”:
Pearl Crescent (Phyciodes tharos) – A common butterfly, especially during the fall migration. For those of you who are interested in photography, this image was taken at ISO 256000 (by mistake), but the modern noise reduction programs are unbelievably capable of removing such noise due to low exposure:
Phaon Crescent (Phyciodes phaon). This one is relatively uncommon here. I was glad to find several this year:
The crescents are quite small, and Phaon Crescent (Phyciodes phaon) is typically smaller than the more common Pearl Crescent. Here is an image that has my two-year-old daughter’s finger as a reference. I am glad to have this new butterfly-watcher in our camp!:
Today we have a contribution of miscellaneous flora and fauna from reader David Riddell, a Kiwi. His descriptions and IDs are indented, and you can enlarge the photos by clicking on them.
Recently I sent in some pictures of seabirds to be posted here, several of them taken on a trip to New Zealand’s Chatham Islands. I thought I’d add a few more images from that trip, starting with this group of Pitt Island shags (Phalacrocorax featherstoni). These are endemic to the Chathams – one of two species found only there, and one of 13 New Zealand cormorant species, which are generally all referred to as shags in this country. There are fewer than 500 pairs of both Chatham species, and their numbers appear to be declining. Unfortunately these are not in breeding plumage, when they look a lot more handsome:
Shore plovers (Charadrius novaeseelandiae) were wiped off the New Zealand mainland by exotic mammalian predators by the 1870s, and for more than a century existed only on Rangatira Island, which lies just off Pitt Island in the Chathams. Small populations have now been re-established on a couple of predator-free islands off the New Zealand mainland, as well as another island in the Chathams group, but the global population is still below 200. Intensive predator control on Pitt (where a few feral cats persist) has recently allowed the odd pair to breed there, which is where we saw this one, along with a recently fledged juvenile:
In the 1970s there were only about 50 Chatham Island oystercatchers (Haematopus chathamensis). With management there are now over 300, but they are still the world’s rarest oystercatcher. These were on Pitt, very close to the shore plover above:
Back on main Chatham, the parea, or Chatham Island pigeon (Hemiphaga chathamensis) has benefited from predator control which has seen its numbers rise from a low of about 45 birds in 1989 to an estimated population of more than 600. They are larger and greyer than the New Zealand pigeon, or kereru (Hemiphaga novaeseelandiae), with a stouter, more brightly coloured bill:
For comparison, this is a kereru, which are reasonably common and widespread on the New Zealand mainland:
Not the most photogenic of creatures perhaps, but this is a chick of one of the world’s rarest seabirds, the Chatham Island taiko, or Magenta petrel (Pterodroma magentae). First described from a bird collected in 1867 by the Italian research vessel Magenta it was tentatively identified in the 20th century with the taiko, which was believed to be extinct. The identity was confirmed in 1978 when ornithologist David Crockett found live birds in the southwest of Chatham Island. About 20 breeding burrows are currently known, many with observation hatches like this one, and mostly within a predator-fenced reserve. The total population is probably fewer than 200, though slowly increasing:
The Chathams only have one lizard species, the Chatham Island skink (Oligosoma nigriplantare). It’s extinct on the main island, but is still common on Pitt and the outlying islands:
The Chatham Island red admiral (Vanessa gonerilla ida) is an endemic subspecies which is notably common throughout the islands:
The Chatham Islands’ plants also show a high degree of endemism. This is a rautini (Brachyglottis huntii), sometimes called the Chatham Island Christmas tree as it flowers conspicuously in the height of the southern hemisphere summer. This one is a bit past its best in March:
The Chatham Island geranium (Geranium traversii) is a pretty little flower sometimes grown in rock gardens on the mainland:
There was an attempt to establish a business farming emus (Dromaius novaehollandiae) in New Zealand late last century, but it never became a significant industry, though a few of the big birds remain here and there, mostly in small flocks (herds?) on lifestyle blocks. They’ve gone feral in a few areas, although they are still not officially recognised as part of the local avifauna. Chatham Island now has dozens roaming wild through central parts of the island; there’s talk of trying to eradicate them, but for now they’re an unexpected addition to the landscape:
Much of Chatham Island is occupied by a huge brackish lagoon, along the shores of which, at a spot called Blind Jim’s Creek, you can find fossilised shark teeth. These are between 30 and 60 million years old; most are mako (Isurus oxyrhynchus, or perhaps an ancestor), but other species, including Otodus megalodon, also occur. In the background of the picture below there are also some fossilised urchin spines, which are present along with the teeth. Three of us found this collection in about an hour of searching:
It’s a bit hard to make out, but this is a dendroglyph, markings carved into the bark of a kopi (Corynocarpus laevigatus) tree by the Moriori, who were the original inhabitants of the Chathams. They had one of the world’s only true pacifist societies, and when Maori from New Zealand invaded in 1835 they put up no resistance. Consequently they were massacred, many of them were eaten (Maori were cannibals), and the rest enslaved. Within a century the last full-blooded Moriori was dead, though a few people today still claim Moriori ancestry, descended from slaves and their Maori masters. The dendroglyphs are now at least 190 years old, and very few are left. We found this one, not signposted and not visible from the track, entirely by chance, in a patch of forest where their presence was not known, or at least not publicised:
Today’s photos of insects were sent by Marcel van Oijen from Edinburgh, who notes that “these 13 pictures of insects we (my wife Netty and I) saw in Greece last April, one of which I hope you or your other readers can identify! All the photos were taken by Marcel, his captions and IDs are identified, and you can enlarge the photos by clicking on them.
Insects in northern Greece
Marcel van Oijen & Netty van Dijk
We visited Greece in April 2025, mainly to look for orchids. But beautiful insects kept showing up. All pictures were taken with a Fujifilm X-T5.
The first four pictures are from Delphi. To the east of town are the famous ruins, but just north are mountain meadows with orchids and insects. This is a Clouded Yellow (Colias croceus).
The next two pictures are from the busy town of Nafpaktos. If you walk up to the old castle, you find peace and butterflies. This is a Scarce Swallowtail (Iphiclides podalirius):
The small island in Lake Pamvotida can be visited hourly by boat from Ioannina, the largest city in NW Greece. This is a Long-horned Bee (Eucera longicornis) on a bee orchid (Ophrys sp.):
The next three pictures were taken along the wonderful path through the Aoös gorge from Konitsa to the Stomio monastery. This is a Speckled Bush-cricket nymph (Leptophyes punctatissima) on a bee orchid (Ophrys sp.):
This little guy (Morimus asper funereus) was sitting quietly on the path and allowed me to lie down for a tête-à-tête:
A pair of mating European Firebugs (Pyrrhocoris apterus). They can stay coupled like this for many hours, making it easy to take pictures:
Copper Chafer (Protaetia cuprea) near the famous waterfalls of Edessa:
Male Beautiful Demoiselle damselfly (Calopteryx virgo) among the Roman-era ruins of Dion in Thessaly. The next picture was taken at the same spot:
Today we have some lovely insect photos by regular Mark Sturtevant. Mark’s ID’s and captions are indented, and you can enlarge his photos by clicking on them.
Here are more pictures of insects taken two summers ago from area parks near where I live in eastern Michigan.
First up is a slightly embarrassing accomplishment, which is a decent picture of one of our Sulphur butterflies. Sulphurs are an exceedingly common group with several local species, but for some reason they are extremely wary around me. Anyway, this one was unwary, and I think it is the Orange Sulphur (Colias eurytheme):
Next up is our largest butterfly, the Eastern Giant Swallowtail (Heraclides cresphontes). They are often challenging since they tend to keep their “engines running” (meaning their wings are almost always in motion) when rapidly foraging from flower to flower, but this one paused very briefly:
One of my favorite insects is shown next. This is Anotia uhleri, or what I call the “Flat Derbid”, although this Derbid planthopper has no common name. They can be found in forests sitting on the undersides of leaves. The orange thingies sticking out of the head are stumpy antennae:
I was finding quite a few of these Lacewing egg clusters along a forest trail. Lacewings lay eggs on the ends of long stalks for protection. Having the eggs tied together in a bundle suggests that these are one of our larger Green Lacewing species, Leucochrysa insularis. This species tends to stay in forests, sitting under leaves by day, and like the Derbid above they lay their wings flat.
An occasional visitor to the porchlight at home are Mosquitos of Unusual Size, and one is shown in the next picture. I was eventually able to identify this giant mosquito as the Gallnipper, Psorophora ciliata. This one is a female. Although she will require a blood meal to reproduce, and they are described as being rather aggressive in pursuit of humans, a relatively good thing about them is that the larvae are predatory on other mosquito larvae. I have pictures coming up later that compares one of these beasts to a regular mosquito, but for now the attached picture can give some idea:
The next three pictures show a surprise, but the story starts out unremarkably. The beetles foraging on flower pollen are Brown Blister Beetles, Zonitis vittigera. Blister Beetles are a large family, and are so-named because they are chemically protected by exuding an irritating fluid if annoyed. It is relevant to point out that they have interesting biology in that they grow up as parasites on other insects, usually on bees. The mobile first instar larvae are called triungulin larvae, and they start their journey by clambering up onto flowers and wait for a bee to visit. Once the flower is visited by their intended target, they hitch a ride to the nest where they move in and eat the bee provisions and even bee larvae:
I almost did not bother processing the 2nd picture because it had motion-blur, though the composition was nice. But do you see the tiny things on the thorax of the beetle? The 3rd picture provides a blow-up. Those little things are Blister Beetle triungulin larvae! Possibly not this species, though. So, what is going on? I have sent these pictures on to a Blister Beetle Facebook group and to iNaturalist to ask for opinions. There is no answer yet, but possibly the larvae attach to any insect visitor. Although non-bee visitors would be temporary dead-ends, one can imagine that this would at least disperse them to other flowers:
Finally, here are pictures of our most common Sand Wasp, which is the Four-banded Stink Bug Wasp (Bicyrtes quadrifasciatus). Females of these highly energetic wasps will provision a burrow with paralyzed stink bugs, and these are used to raise the next generation of wasps. In the first picture you can see the spray of sand being flung out as she excavates her burrow:
This paper in Science (click screenshot to read) describes a very unusual Hawaiian caterpillar (the larva of a moth): it is very rare, found only in a 15 km² area of Oahu, patrols spider webs on the ground for its prey, and then affixes the uneaten parts of insects to its body, so it looks really weird. Its rarity in both number of individuals and habits (almost no caterpillars are carnivores) makes it imperative to save the small area of its habitat, which, to use non-metric measures, is about an area the size of a square 2.4 miles on a side.
You can also see a writeup of this weird insect in the Smithsonian, from which I’ve taken a few photos that come from Daniel Rubinoff, the study’s first author of the Science paper. Click below to go to the Smithsonian article:
The caterpillar has the ghoulish name of the “bone collector caterpillar”, and its species, not yet named, is in the genus Hyposmocoma, a genus endemic to Hawaii that has radiated into over 350 species on the archipelago. Here’s the adult of this species, which is also rare because only 62 species of its caterpillar have ever been found. Photo is by Daniel Rubinoff, a Professor of Entomology at the University of Hawaii.
(From Smithsonian article) A museum specimen of an adult female bone collector moth that was reared in the Rubinoff lab Daniel Rubinoff
But the weirdest life stage is the larva or caterpillar, which spins a silken web around itself that it carries with it, affixing insect parts to the silk after it crawls around spider webs eating dead or trapped insects. Look at this (photo from the paper). You can’t even see the caterpillar, as it’s covered with scavenged body parts.
This part of the Science paper tell you how it does this, and suggests a reason:
When decorating their silken portable cases, the caterpillars are particular. Body parts are carefully measured for size before the caterpillar weaves them into its collection. Each prospective new addition is rotated and probed with its mandibles several times, and parts that are too large are chewed down to a size that will fit its case. If denied access to arthropod body parts in captivity, the caterpillars do not accept other bits of detritus, suggesting that they recognize and exclusively use corpses in nature and that this decoration is important to their survival. Given the context, it is possible that the array of partially consumed body parts and shed spider skins covering the case forms effective camouflage from a spider landlord; the caterpillars have never been found predated by spiders or wrapped in spider silk. Bone collector caterpillars have been recorded from the webs of at least four different species of spider in three different families, none of which is native to Hawaii, so adaptability to non-native elements is likely crucial to their persistence.
So it seems to be camouflage, as spiders have not been reported to go after these things, even though they hang around webs for a long time (they do move from ground web to ground web). But this is just a guess at this point. It could also be protecting the caterpillar from other predators as well.
Here’s a bone collector caterpillar in a spider web along with a spider and its eggs; I’ve circled the caterpillar, which, as the one above, is covered with insect body parts:
(From the paper): Fig. 2. Rotting wood log broken open to expose a bone collector caterpillar resting on a clump of webbing next to a non-native spitting spider (Scytodes sp.) with its egg sac. The web is partially obscured by termite and other wood-boring insect frass.
As I said, this genus has radiated widely, and the authors did a molecular phylogeny of the group, showing that it’s most closely related to the cigar caterpillar:
(From paper): Fig. 3. Molecular phylogeny of Hyposmocoma lineages based on 38 genes and 82,875 aligned base pairs. The phylogeny was molecularly calibrated using age estimates from Kawahara et al. (17); 95% highest posterior density confidence intervals for the molecular dating estimates for nodes are indicated with blue bars. Outgroups are cropped, and the full tree is shown in the supplementary materials. Different lineages are indicated by their larval case type (8), and exemplar cases are shown on the right. Bone collector and cigar case species are the only ones that are carnivorous. Current terrestrial areas of the Hawaiian Island chain are shown in dark green; shallows that were once above sea level are shown in gray. The islands are placed along the timescale according to age and geographic position.
Although the paper says this: “The bone collector species is the only one known of its kind, representing a monotypic lineage without a sister species. Although it is related to the other carnivorous lineage of Hyposmocoma, their ancestors diverged more than 5 million years ago.” But the phylogeny clearly shows a sister species, the cigar caterpillar, so I’m a bit puzzled, unless “cigar” represents itself a whole group of caterpillars, in which case the bone collector is the sister species to this group.
Since Oahu is only 3-4 million years old, the bone collector’s ancestor must have evolved on another island and then the adult (probably) made its way to the younger island to continue its evolution there.
Just two more show-and-tells. First, from the Smithsonian article, a series of bone-collector caterpillars. Since they adorn themselves with whatever is suitable in a spider nest, each individual will look different from the others:
(From Smithsonian): These six bone collector caterpillar specimens adorned their cases with beetle wings, ant heads, fly wings and legs, spider legs and other insect body parts. Their cases—the gray material seen through the detritus—are made from caterpillar saliva and silk. Photo by Daniel Rubinoff
And here’s a video of a bone-collector caterpillar, again taken by Daniel Rubinoff. It’s not clear to me whether it’s eating another member of its species (they are cannibalistic) or is chewing up insect parts with which to adorn itself. But you can get a glimpse of the caterpillar’s head.
Just think about how many bizarre creatures there are like this yet to be found. Another reason to save as much natural habitat as we can.
These are additional photos from reader Loretta Michaels trip to the tropics (part 1 is here). Her IDs and identifications (the binomials are from me) are indented, and you can enlarge the photos by clicking on them. Some of the IDs weren’t supplied, so readers are welcome to try their hand. From Loretta:
These were taken in Oct/Nov 2024 on the Upper Amazon in Peru, as part of a boat trip around the region. If you wanted to add this to my description, I use a Sony DSC-RX10 M4 (a fantastic camera that for some reason Sony has discontinued, much to the disappointment of fans.)
Three more: The first one is a rare hybrid of a white-fronted capuchin and a red uakari (Cacajao sp.); when we visited a village, an old lady was caring for this juvenile, and said it had just shown up one day. Our guide was amazed, he’d never seen one. The other two are poison dart frogs:
