Sometimes my reading and my outside explorations overlap wonderfully. This year I’ve been reading through Flies: The Natural History and Diversity of Diptera by Stephen Marshall, and it is an incredible book, one I will have to review on here at some point. One particular group of Flies that I came across while reading grabbed my attention: the Thereviidae. They’re known as Stiletto Flies, but what really struck me was the fuzzy white appearance of the adult pictured in the book. I thought to myself, I have never seen such a creature and would love to see one. Well, about a month after reading about that group of flies, I came across one very similar. I’m not sure that it’s the same genus, but it certainly seems to match the general look of the Acrosathe featured in the book.
A Thereviid Fly, possibly Genus Acrosathe.
I attempted to take pictures of the Bluebirds (Sialia sialis) that are at my parents’ place. I never see Bluebirds in Simcoe, so it seems they prefer more open farmland habitat. I was proud of myself, upon seeing the shape/size of the bill and the face that I thought they looked Robin-like. And it turns out that they are part of the Thrush family which includes the American Robin (Turdus migratorius). The Bluebirds kept their distance, so this is the best picture I managed.
Eastern Bluebird. Note the longish blunt bill reminiscent of their relatives, the Robins.
Another bird caught my attention in my parents’ garden by its beautiful song. I should have guessed its identity right then and there, since it turned out to be a Song Sparrow, but I’m very cautious in IDing small sparrows or sparrow-like birds in the field. Recently I’ve come to appreciate the diversity of these types of birds.
Song Sparrow perched in my parents’ garden.
The most exciting Arthropod find at my parents’ house, besides the fuzzy Acrosathe, was this Giant Mayfly (Hexagenia).
Giant Mayfly (Hexagenia).
When I arrived to take pictures of this individual it was somewhat entangled in a spider web, from which I freed it. The Spider owner of the web that caught a Giant Mayfly was suitably large and intimidating herself.
Long-Jawed Orbweaver (Tetragnathidae) that had caught the Giant Mayfly pictured above.
Two other notable observations should be mentioned, and both are Butterflies. In the sandy areas of my parents’ farm I encountered several Common Sootywings (Pholisora catullus) fluttering about.
Common Sootywing
And in the garden I managed to photograph a beautiful Northern Crescent (Phycioides cocyta) drinking nectar from flowers.
Northern Crescent, with its wings outspread, and wings folded for a look at its underwings which contain less colour but are still strikingly detailed.
For other Nature Observations like this post, see:
Twice on the Lynn Valley trail this past month, I managed to get some pictures of Wrens singing. These tiny birds burst with song much larger than themselves and it’s always a treat to see or hear them.
When I saw and photographed the two Wrens, I assumed them to be the same species, and even possibly the same individual bird. I had found them in the same general location on the trail, separated by about a week and in location maybe only 100 metres away from each other. After submitting the pictures to iNaturalist (a website I use extensively for my observations and identifications), they were identified as two separate species in the same Genus. The Genus was Troglodytes, an evocative title for such small birds, one that stems from their habit of nesting or foraging in hidden holes, which I suppose are like caves. My first Wren spotting was a Winter Wren (Troglodytes hiemalis).
Winter Wren
The Winter Wren constructs its nest of twigs and moss and often hides it in one of the most incredible places: the tangled roots of fallen trees (Bull and Farrand Jr., 1994). When I encounter fallen trees, I have often been struck by the vertical clifflike nature of the mass of dirt still held fast by thick tree roots. On these miniature cliff faces, the Winter Wren hides its nest, and hides it so well that they are notoriously difficult to find. Bernd Heinrich, in his excellent book Winter World, describes the nest as “a snug little cavity with walls camouflaged with a lattice of moss and conifer twiglets” (p 61). Amazingly, only the Male Wren constructs the nest (at least in the two Wren species I’m writing about here) and he will often create more than one as part of his territory, from which the female can choose her favourite. When the female chooses one of these nests, she will add the lining of fur or feathers and the male will know that his territory has been accepted (Stokes 1979). This strategy of nest building (though not the nest location) applies to the other species I spotted on the Lynn Valley Trail: the House Wren (Troglodytes aedon).
House Wren
The most conspicuous feature of Wrens (the Family Troglodytidae) in my experience is their stiff little tails and the way they flick them around often perpendicularly to their backs. According to A Guide to Bird Behavior, the tail is raised more and more to the vertical with increasing excitement or disturbance. This seems to indicate that I’ve rarely observed calm Wrens. House Wrens don’t nest among the upturned roots of fallen trees like the Winter Wrens, but instead in a natural or manmade cavity. The House Wren’s acceptance of human-made structures for nesting is the origin of their name. Besides nesting in nest boxes constructed by people for birds, House Wrens will apparently also nest in mailboxes, flowerpots, and jacket pockets that are hanging outside (Bull and Farrand Jr. 1994). I can think of few more appealing things to find in my jacket pocket than the nest of a tiny bird.
References:
Stokes, Donald W. A Guide to Bird Behavior. 1979.
Bull, John and Farrand Jr., John. National Audubon Society Field Guide to North American Birds: Eastern Region, 1994.
This is the second loop of my journey through the Big Creek Conservation Area Trail. For part 1, go here.
Having returned to the parking lot, I saw some amazing aerial masters. Similar to the Kingfisher and the Black Terns, I saw Barn Swallows (Hirundo rustica) maintaining a single position in the air, this time in groups. They were incredible to watch, and thankfully one landed for a moment so I was able to get a clear photo of it.
Barn Swallow, kindly sitting still for once for a picture.
It was only recently that I realized there were so many different species of Swallows in our area. Later in this same hike I took (very blurry) pictures of two other species: Tree (Tachycineta bicolor) and Northern Rough-winged (Stelgidopteryx serripennis) Swallows.
Tree Swallow (top) and Northern Rough-winged Swallow (bottom). Swallow pictures are usually blurry because they’re usually in constant motion.
I saw more Mute Swans, this time sleeping with their elongate necks tucked around themselves. In the picture below, you can really see how bizarre that long neck looks when it’s not extended.
Mute Swans, sleeping and preparing to sleep.
A small brown shape on the path ahead revealed itself as an Eastern Cottontail (Sylvilagus floridanus). Wikipedia says of this animal: “The cottontail prefers an area where it can hide quickly but be out in the open.” This seems to describe my sighting perfectly as the rabbit was fully exposed on the path, but disappeared into the plants at the edges as soon as I neared, and I was unable to spot it again.
Eastern Cottontail Rabbit frozen by my presence, until it disappeared into the vegetation.
One of the only Insect observations I made were some mating Deer Flies (Genus Chrysops). Although they cause pain when they bite and can be determined adversaries, when you get a good look at them you realize they are also quite beautiful. Look at those wonderfully strange eyes and patterned wings.
Mating pair of Deer Flies.
I had to pass through the Redwing assault again, and once through I saw the rarest observation of my hike. A black dome was crossing the trail at a decent rate for what I quickly realized was a turtle. In my excitement I couldn’t get the zoom lens to focus on the turtle for some reason. As I was trying to get a picture, I rushed forward, hoping to get a good picture of the turtle before it disappeared into the undergrowth that it was making for. While doing this, I startled something to my left. A Great Blue Heron (Ardea herodias) took to the skies, disturbed from its ambush site by the turtle-seeking human. I quickly snapped a couple of pictures of the Heron before moving forward, hoping to still find the Turtle.
The Great Blue Heron I disturbed while rushing toward my Turtle target.
After this mutual startling, I made it to the location of the Turtle, which had reached the shelter of the vegetation. I was still able to see the turtle (it was, after all, not moving incredibly fast) and took a few pictures of its shell. From this, I was able to determine that it was a Blanding’s Turtle (Emydoidea blandingii). I have only ever encountered Snapping Turtles and Painted Turtles before, so this was a very exciting sighting for me, even if I didn’t get a good photo.
My clearest shot of the Blanding’s Turtle as it barreled through the undergrowth.
Just a few dozens of meters further I came upon a young deer browsing in the middle of the trail. It still retained the spots of a fawn, and was smaller than an adult but certainly not a helpless baby. The deer seemed pretty unaware of me until I was quite close so I got some good pictures as it looked at me and after it saw me it wandered off into the marsh.
I could hear Marsh Wrens all around making their buzzing calls, but they are extremely difficult to spot and even more difficult to capture with the camera. This was one of my closest attempts, it’s almost as though the Wren is mooning me with its upright tail sticking out into the line of my camera instead of its chirruping face:
Most times in the summer, I have the Macro lens fixed to my camera because of the abundance of insect life, but on this trail I kept the telephoto equipped for all of the bird sightings I had. Near the end of my walk, I came upon a Dragonfly perched on the ground of the path and I was able to capture it adequately with the telephoto. It was A Blue Dasher Dragonfly (Pachydiplax longipennis), which occurs throughout most of the United States but only in the very Southern portions of Canada.
Blue Dasher Dragonfly resting in the path.
Ahead of me, meandering along the trail, was a pair of young Canada Geese (Branta canadensis). They were interesting to me, because they weren’t the Goslings following their parents and they weren’t Adult size either. The one appears to be much more “gosling-like’ than the other, which has started to acquire the characteristic facial markings of adult Canada Geese.
Young Canada Geese.
My final farewell to the trail this day was seeing a Heron stalking in the shallows, wreathed in fog. This Heron of the Mists was a perfect sendoff to my journey through the Long Point wetlands.
For previous posts about nature observations of this kind, see:
And if you’re interested in seeing more of my photos and learning some facts about the creatures I’ve observed, follow me on Instagram @norfolknaturalist.
This year I’ve discovered a new trail in Long Point. It’s called “Birding Trail 8” according to Google Maps, but the signs at the location say it’s part of the Big Creek Conservation Area. In any case, it’s right along the Causeway road that runs down Long Point into Lake Erie, and the trail goes through some of the conservation area’s wetlands. My most recent hike along this trail was this past weekend and I encountered some interesting creatures along the way.
Being a wetland, the air was filled with the calls of Red-winged Blackbirds (Agelaius phoeniceus), the males sporting their signature red/yellow epaulets and the females in their mottled brown stripes. Female Red-winged Blackbirds continue to catch my attention because they are often doing all kinds of different things and they don’t have the distinctive look of the Males. I’ve taken many a picture of Female Red-wings thinking they’re a different species only to review my photos and find that I’ve taken yet more pictures of Female Red-winged Blackbirds rather than new and unique species. Not that I mind much, as I find basically any species interesting. The only picture I took of a Red-wing on this hike was a Female that had what looks like nesting material in her beak.
Female Red-winged Blackbirdwith what looks like nesting material in her beak, or perhaps a mangled insect.
One thing you may have heard about Red-winged Blackbirds is their divebombing behaviour when you approach too closely to their nest. Well, there must have been a nest right on the edge of the trail because for the first stretch of this path I was running with my head down while I felt wings flapping at the back of my head. It was an exhilarating and frankly terrifying experience. If only I could have told the aggressive bird that I had no interest in raiding its nest. Thankfully I wasn’t physically harmed, just seriously intimidated by a bird not much bigger than my hand.
Having run through the Red-wing gauntlet, I got some decent photos of Mute Swans (Cygnus olor). There are 3 species of Swans that occur in Southern Ontario, but only one (the introduced Mute Swan) has an orange bill, so it’s pretty easy to identify at close range. If you’re wondering, the other two are Tundra and Trumpeter. Although called the Mute Swan (apparently because it’s less vocal than other Swans) this one was making creepy grunting noises, not sure why.
Mute Swan
Another bird caught my eye, hovering in midair above the water. I say hovering, because that’s what it appears to do, but the bird must have been doing some incredible movements to stay in one place as it pinpointed its prey below. The bird was a Belted Kingfisher (Megaceryle alcyon), the only species of Kingfisher that occurs in Canada. My pictures aren’t the greatest as it was decently far away, but you can still make out its incredibly long beak.
Belted Kingfisher “hovering” in place.
A much less noticeable bird than the Red-winged Blackbirds or the Kingfisher was the small Common Yellowthroats (Geothlypistrichas). I saw one Male on this loop of the trail, clinging to some reeds, and in my second round I encountered a Female in the same general area.
Male Common Yellowthroat
Female Common Yellowthroat
At the far end of the trail, the left side opens up onto a wider stretch of Lake Erie, and it’s here that I watched the amazing aerodynamics of the Black Terns (Chlidonias niger). I observed the Terns foraging for a long while; I find them beautiful birds, masters of the air. One or two would come out of the inner wetland and dip their beaks into the water surface, sometimes coming out with a small fish or tadpole. Prey acquired, they would return, cross the trail, and dip down into an area obscured by reeds and vegetation. I believe these Terns were foraging for their young or partners back in the nests that were hidden within the marsh. The Terns included in the Genus Chlidonias are known as the Marsh Terns for this reason, these Terns rely on wetlands for their breeding territories, often constructing their nesting colonies on floating bits of vegetation.
Black Terns foraging over Lake Erie
While watching the Terns, often through the lens of my camera, I was startled by the sight and sound of a large brown object leaping out of the marsh to my right, maybe 10 meters away. The creature responsible was a White-Tailed Deer (Odocoileus virginianus), and it loped ahead of me down the trail after its abrupt emergence from the reeds.
White-tailed Deer running down the trail. It had emerged with a splash from the marsh to the right.
One Tern hovered in the air above the trail and made its soft call. I’m not exactly sure why, but it gave me some excellent views of this beautiful animal.
Black Tern ‘hovering’ in place above me.
As I was walking along this stretch of the trail I could hear the unforgettable call of Sandhill Cranes (Antigone canadensis) and I could see that there was a pair at the corner of the trail coming up. These birds are fascinating creatures, and their sounds are similar to the Wolf in conjuring the wild in my mind, a call from another world.
Sandhill Cranes calling.
The constant calls of Marsh Wrens and Red-winged Blackbirds were my companions as I walked through a heavily reeded area. On my right, I could see the Terns hovering above the wetlands and descending among the reeds to where I suspect their nests were. Also to my right were the occasional sightings of Muskrats (Ondatra zibethicus), skimming through the water on important business.
Muskrats are a common sight in the wetlands of Long Point.
As I neared the parking lot, I was deciding whether to make another loop of the trail in the hopes of seeing more interesting creatures. If you read the title, you’ll know what my decision was, and be sure to return for Part 2 coming soon! As a teaser I will say that I saw more than just Birds and Mammals (even some Invertebrates) on my second round through the marsh!
For previous posts about nature observations of this kind, see:
And if you’re interested in seeing more of my photos and learning some facts about the creatures I’ve observed, follow me on Instagram @norfolknaturalist.
We tend to think of animals as “set in their ways”, following the pattern of their species and not varying in their behaviour or ecology on an individual basis. In fact, every species is made up of individuals. And once you start to think about it, of course this is the case.
People are often surprised to hear of diet variation, when wild animals feed upon substances that seem to go against their “pattern”. Crocodiles and Alligators will consume fruit, and could even act as seed dispersal agents (Grigg and Kirshner, 2015). White-tailed deer will eat nestling birds if they happen upon them. Chickadees will feed on dead mammals.
A recent observation reported in The Canadian Field Naturalist journal represents another of these striking behaviours that stands out because it is atypical for the species as a whole. The species concerned is one that many people are very familiar with: the Eastern Grey Squirrel (Sciurus carolinensis). There are already accounts of various Squirrel species hunting and feeding on other vertebrate animals, including birds and even other Grey Squirrels (ie. Cannibalism) (Squirrels as Predators, Callahan 1993). Perhaps more surprising is the recent report of hunting an animal that is outside of its normal environment: namely, a fish. In Guelph, Ontario, a Squirrel was seen to dive from a branch headfirst into a shallow portion of a river. After being underwater for a few seconds “the squirrel swam back to the snag with a fish 3-5 cm long in its mouth” (Sutton et. al. 2020). After feeding on the fish briefly, the Squirrel moved out of view into the woods.
There is so much out there to explore, in your own backyard or neighborhood. Animals are individuals, doing individual things. They are not programmed automatons following rigid beahavioural patterns. Even an animal as familiar and commonplace as the Eastern Grey Squirrelcan surprise us if we take the time to pay attention.
Eastern Grey Squirrel at Waterford Ponds, Ontario.
References:
Callahan, J. R. Squirrels as Predators. The Great Basin Naturalist, vol. 53, no. 2, 1993, pp. 137–144.
Sutton, A. O., M. Fuirst, and K. Bill. 2020. Into the drink: observation of a novel hunting technique employed by an Eastern Grey Squirrel (Sciurus carolinensis). Canadian Field-Naturalist 134(1): 42-44.
Grigg, Gordon and Kirshner, David. Biology and Evolution of Crocodylians, 2015.
Inspired by one of my favourite blogs on the internet, Tetrapod Zoology, or TetZoo (http://tetzoo.com/), I’d like to create a birthday article every year- not for the day I was born, but for the anniversary of my blog’s creation. In this post, I’ll summarize the past year of my blog, as well as the story of Norfolk Naturalist leading up to the blog’s creation. So here we go…
My first Tumblr Blogpost featured this twig-mimicking Geometrid Caterpillar, spotted on the Lynn Valley Trail in Simcoe, Ontario.
NorfolkNaturalist Version 1
I’ve tried to start creating blog content many times over the years, but it would usually fall to the wayside of my routine. A few years ago, I created a Tumblr blog in which I wanted to post articles about my own nature observations: norfolknaturalist.tumblr.com. My first post was about Cryptic Caterpillars, and I went on to explore various nature topics through the creatures I had observed myself (usually attempting to do so within a timely manner). Sometimes they were focused on a specific aspect of nature, or a specific animal or plant, and other times they were set up as a slideshow of my trip to a Provincial Park (such as MacGregor Point or Algonquin), giving brief comments about the creatures I observed on my trips. My first tumblr post, Cryptic Caterpillars, was published in March 2018, and it was only a month later that I would acquire my most exciting new tool for nature exploration: a Macro Lens. Up to that point, my nature photos were taken with a telephoto lens, and for insects that meant standing far away and cropping the picture later. Sometimes these pictures hold up, especially for insects like Dragonflies and Butterflies, but my dreams became reality when I was able to photograph Springtails dwarfed by the head of a screw. I had also become a member of iNaturalist at the beginning of 2018. So the ability to photograph the smaller creatures I was so fascinated with, combined with the support and community identification of the amazing iNaturalist website, expanded my horizons as an amateur naturalist.
One of my greatest passions has been learning about the animals and plants and fungi in my own surroundings, and these tools allowed me to do so. My tumblr allowed me to share this passion and interest with others of like mind, and I was excited to be sharing my wonder at the nature that is everywhere.
After a year of posting once or twice a month, I stopped for a while, until in November 2019 I began this current blog as a new platform for sharing my interests and observations. Before we look at Norfolk Naturalist in its current form, let’s take a little detour to Instagram.
One of my most exciting finds ever: a Megarhyssa parasitoid wasp on the Lynn Valley Trail, Simcoe, Ontario. I will have to write a blogpost about this amazing creature sometime.
Observations of the Day
In late 2018 I began to post “Observation of the Day” pictures on Instagram under the profile “norfolknaturalist” (for my Instagram account go here: https://www.instagram.com/norfolknaturalist/). These pictures very quickly became “Observation of the Week” as I really wasn’t that fast at finding interesting creatures to photograph, taking pictures, editing the pictures and transferring them to Instagram. Especially since a lot of my identifications were awaiting confirmation on iNaturalist. These first few pictures (which were titled with their species name and location observed) were then superseded by pictures from my archive of nature photos taken over the years. These photos were posted with a fact about the organisms involved, which grew into my new formula for Instagram: picture of a creature, and a paragraph of interesting information about them. It was really at the beginning of 2020 that I started to post regularly on Instagram, and it was exciting to be doing so. I had accumulated over the years a variety of photos of interesting creatures from local trails in Simcoe, Ontario, as well as various Provincial Parks during camping trips. Reviewing these photos and learning more about the creatures portrayed within them, then sharing that information was quite fun, and I’m really glad I started doing this, and I’m thankful for all the support and interest I’ve received.
A Moose photographed in Algonquin Provincial Park this year. It’s just a nice picture I took of a charismatic animal.
The Current Blog (norfolknaturalist.ca)
I created and posted my first page on this blog, norfolknaturalist.ca, on November 30, 2019. (Welcome to my New Nature Blog) The first post was simply a quick overview of my interests, ideas, and goals with the website: namely, sharing my passion and interest in the amazing animals and plants that provide me with neverending fascination.
In December 2019, I visited Pinery Provincial Park and had some excellent encounters with some of the beautiful winter birds.
Besides Nature Observations and Species Profiles, I want to share my love of reading Nature books, and so I’ve published a few book reviews on my site as well. First was a Book Review of The Flora of MiddleEarth. Many of the books I read are textbook-ish and I’ve found it difficult to find reviews of some of them online because they aren’t designed to be read for pleasure. Sharing my experience diving into some of these books, and some of the fascinating information within is one of my goals with this site, and since that first Book Review, I’ve written two more: one for Pterosaurs by Mark Witton, and one for The Social Biology of Wasps, edited by Kenneth G. Ross and Robert W. Matthews.
And that brings us to the sum total of 7 posts in a whole year. Not very prolific at all. But there’s one very good reason for that.
In April of this year, my son was born. I haven’t been writing as regularly as I might be otherwise, distracted in the best possible way.
My goal for next year’s Birthday Article is that I’ll be able to summarize more than 7 posts, because I hope to write on my blog a little more regularly.
I hope you enjoyed my small tour through Norfolk Naturalist history and I hope you can return soon for some new content! I’ve got a few things in the works: Savvy Squirrels, Sand Wasps, and maybe even Salamanders!
Here’s an Eastern Red-backed Salamander (Plethodon cinereus) that I found this year under a log on the Lynn Valley Trail, in Simcoe, Ontario.
Diprion similis larva at Algonquin Provincial Park, September 2019.
Sawflies are a group of insects that many people haven’t even heard of. Part of the reason is because, in appearance and behaviour, they are like a hybrid between two major groups: their larval stages look like caterpillars (larvae of Butterflies and Moths ie. Lepidoptera), and their adult stages look like bees or wasps (Order Hymenoptera). Despite appearances and lifestyle, it is the latter category that they actually fall under: Hymenoptera which also includes the Bees, Wasps, and Ants. The major features that set sawflies apart from their relatives is that they eat plants, and they don’t have the constricted “wasp waist”. You might find this a little confusing, as Bees certainly don’t have an obviously thin waist, but they actually do have a constriction between their thorax and abdomen, it’s just more difficult to see than in many wasp species.
Like many insect Orders, the name Hymenoptera refers to a distinct aspect of the members’ wings (‘ptera’ is derived from the Greek for wing). Hymenoptera doesn’t have an easy translation though, like say Diptera for the True Flies (di = two, ptera = wings). The beginning part of the word is either from the word “hymen” which means membranous, or from the word “hymeno” which refers to the Greek God of Marriage. Hymenopteran wings are membranous, but they also have tiny hooks that link their fore- and hind-wings, meaning that they could be said to be “married” wings as well (Grissell, 2010). Whatever the case, the group is one that includes thousands of species of wasps, bees, ants, and of course, sawflies.
The common name “sawfly” is describing the way the female sawfly lays her eggs. Instead of a stinger or stinger-like ovipositor (egg-layer) at the end of her abdomen (like most of the other Hymenopterans), the female sawfly has a saw-like ovipositor, a cutting tool that she uses to open up plant tissue, and then inserts her eggs within.
This is what the Introduced Pine Sawfly (Diprion similis) does to pine needles. D. similis prefers White Pine (Pinus strobus) as its host plant (in North America), but will lay eggs and successfully grow to maturity on several other pine species. The female lays about 10 tiny eggs inside a pine needle (Cranshaw, 2004). After inserting the eggs, the female seals them in with a secretion that hardens for protection (Wagner and Raffa, 1993). The larvae that hatch from the eggs begin to feed on the pine needles. For the first part of their life, they will remain together but begin to disperse as they grow older. These larvae prefer to feed on needles that are at least 1 year old, probably because the younger needles are full of more toxins (Wagner and Raffa, 1993). As they consume needles, they grow, from 2.5 mm long upon first hatching to almost 3 cm before the larva is said to be “mature”. They don’t grow continuously, but rather have to molt and enter a new size class each time they’ve gained enough nutrients. For female larvae, they have six growth stages between molts and the males have five (CABI, 2020).
During this time, you would be forgiven for thinking they were caterpillars, because they look very similar. The way to tell caterpillars from sawflies is to count the number of legs. Their first set of legs will be six, and jointed for both groups, but they will also have a number of legs behind these called “prolegs”. If the larva you’re looking at has more than 5 pairs of prolegs, it’s a sawfly. Another giveaway is the distinct single eyes of sawfly larvae, as opposed to tiny ocelli (miniature eyes in clusters) in caterpillars.
A Macremphytus sawfly larva. The head is to the right, behind it is the first three pairs of true legs, then behind those are a series of lumps that denote the pairs of prolegs, which number at least 8 (so more than 5).
A Monarch caterpillar (Danaus plexippus) whose head is facing down and to the left. The pairs of true legs are just behind the head. The lumpier prolegs are further back (up in the picture), and number only 5.
The difference between Sawfly larvae and Butterfly (or moth) larvae.
Once they’ve reached their final larval stage, they spin a cocoon around themselves with silk, and transform within. Diprion similis larvae prefer to form their cocoons in the pine trees where they feed, rather than on the ground like many other sawflies.
In Europe and most of North America there are two generations per year, which means that what happens next depends on what time of the year it is. If the larvae have grown enough and created their cocoons in the summer, they will develop within in about 2 weeks into adults, but if they have reached this point near the end of fall, they will enter diapause (essentially insect hibernation) for several weeks before emerging in the spring (CABI, 2020). When they emerge, the adult sawflies are entirely different creatures, just as butterflies and moths are very distinct from their caterpillar young. The adults have wings, and with these they search for mates.
Adult Male D. similis, displaying the feathery antennae used to track down a female (Photo credit: Scott R. Gilmore.)
Males are attracted to females by pheromones (a chemical signal between members of the same species), as one would guess by the male’s elaborate antennae. The males can be attracted to a female across 61 m of open field, which is a great distance for an insect only a matter of centimeters long (Wagner and Raffa, 1993). Once mated, the female lays eggs in pine needles, and we are back at the beginning of their life history.
One note about mating: it isn’t necessary for the female to mate to be able to lay eggs. She shares with the other Hymenoptera a bizarre (to us) chromosome setup known as haplodiploidy. Females have one set of chromosomes (the mother’s) and males have two (mother and father). What this means in practice is that a female sawfly can lay an egg that will develop into a fully functional male offspring without ever going through the trouble of mating. This has implications for the spread of such organisms, as not all members of the population need to pair up to contribute to the next generation.
Which brings me to my final discussion of this species: they are commonly referred to as the Introduced Pine Sawfly because they were accidentally introduced into North America from Europe, likely in plant nursery stock imported in 1914. They have become well established in North America since then. Thankfully, they only very rarely reach a high enough population density to be considered an “outbreak” invasive species, and though they feed on tree leaves (needles), many predators and parasitoids feed on them (Wagner and Raffa, 1993).
The last time we were camping at Algonquin Provincial Park, I encountered quite a few of their larvae likely because they were in the fairly mobile phase before finding a spot to spin a cocoon (it was the end of September, the beginning of October). They may be an introduced species, and they may feed on White Pines, defoliating some of the branches, but as with any organism, they have a story all their own, and I think it’s worth telling.
Diprion similis larva hanging onto the end of a pine needle in Algonquin Provincial Park.
References:
Wagner, Michael R. and Raffa, Kenneth F. Sawfly Life History Adaptations to Woody Plants, 1993.
Cranshaw, Whitney. Garden Insects of North America. 2004.
Marshall, Stephen. Insects: Their Natural History and Diversity. 2006.
Pinery Provincial Park is a great place to visit any time of the year, and Winter is the season when you can get closest to a few of the bird species that make their home there.
We always bring along bird-seed to Pinery when we go in the Winter, because there are a number of birds that will come very close when presented with a nutritious food supply. Some (Black-capped chickadees and White-breasted nuthatches) can be induced fairly quickly to landing on your hand and feeding from it. This year, we were a bit early in the season and most of the birds except a few brave chickadees were too wary to feed from our hands. Despite this, we were able to feed many birds by leaving out a pile of seeds on the railing on our site (we were staying in one of the yurts they have there). If you’re planning to do this yourself, remember to not leave the birdseed out overnight. During the day, you will attract small foraging songbirds but at night, you’ll most likely be feeding raccoons, who can devastate snapping turtle populations in the park, if they overpopulate themselves.
The first birds we attracted to our food supply were the bold chickadees, ever-eager to exploit any opportunity available.
A perched Black-Capped Chickadee (Poecilie atricapillus)
Next came the nuthatches, with their impressive ‘talons’ which they use to grip bark as they scale down tree-trunks to pry out insect food.
White-Breasted Nuthatch (Sitta carolinensis)
Tufted titmice were quite abundant as well. I’ve never been able to feed one from my hand, but they were quite content to fling seeds about in the pile, picking out the ones they desired.
Tufted Titmouse (Baeolophus bicolor)
The final visitor to our railing was a downy woodpecker. Downys are the smallest woodpeckers in Canada, at approximately 15-17 cm (Backhouse, 2005). Still jabbing as though he were piercing bark, the woodpecker walked awkwardly along the railing. It truly appeared strange to be perched and moving horizontally, as they are so superbly adapted for their vertical orientation on tree trunks.
Downy Woodpecker (Dryobates pubescens)
Although only a few landed on our hands to pick at seeds, we were pleased to see these little birds foraging nearby, bringing cheer to the wintry woods of Pinery Provincial Park.
The view of the seed pile being visited by the winter birds.
References:
Backhouse, Frances. Woodpeckers of North America. 2005.
Ocyptamus fascipennis adult, spotted at Algonquin Provincial Park, August 2019
When you’re interested in insects, you’re always going to be running into something new. There is always one more creature that you have never seen before, one more behaviour you haven’t heard of, and that’s because insects are incredibly diverse. Today, I’m going to pick out just one of the many species of insects to zoom in on, and explore its story.
The species I’ve chosen is Ocyptamus fascipennis, or the Eastern Band-winged Hover fly. Let’s start from the top: Ocyptamus fascipennis is a “True Fly”, a member of the Order Diptera, which is a division of the Class Insecta. Diptera means “two wings” which gives you the easiest way to identify this group of insects when you encounter them. Almost all insect groups have 4 wings (two pairs) but these pairs of wings have been modified into very different structures in different lineages of insects. For the True Flies, one pair of wings still provides lift and flight, while the other has been reduced into tiny knobs known as halters. These reduced wings act as stabilizers, giving the flies the ability to perform aerobatic feats of agility (as I’m sure we’re all familiar with in House Flies (Musca domestica)). The halters of Diptera are more than just balancing beams, they’re actually sending complicated signals to the fly about its aerial position.
Ocyptamus fascipennis is part of a Family of True Flies called Hover Flies, or Flower Flies (Family Syrphidae). The Syrphids are common insects in gardens where they feed on nectar and pollinate flowers. Because of this habit, many species of Syrphids have taken on the appearance of more conspicuous flower visitors such as bees and wasps, in order to gain some protection from the classic warning colours of black-and-yellow stripes. O. fascipennis in particular seems to mimic solitary wasps or types of parasitoid wasps with its elongated and narrow abdomen.
So far, we’ve been talking about adults of these flies, but all insects go through multiple life stages, some more dramatically varied than others. Diptera undergo holometabolous growth which is a fancy way of saying that they have life stages that look very different from each other and one of those stages is a transformation phase which is mostly immobile. When young hoverflies (larvae) hatch from eggs, they look very different from the adults landing and lifting from flower petals in gardens. Larval O. fascipennis have no wings, and no legs, and are sometimes known by the name that many fly larvae receive: maggots. O. fascipennis larvae don’t consume garbage or dead animals, but instead are active predators, squirming across leaves in search of their prey: aphids.
Stephen Marshall, in his incredible book about Insects describes Syrphine larvae hunting as this: “at night they move blindly among the aphids, grasping victims using typical maggot mouth hooks, then holding the doomed aphids up off the surface to consume the body contents.” (Marshall, 2006).
A Syrphine larva hunting a herd of aphids (photo credit: Christine Hanrahan)
It seems then that Flower Flies are very beneficial insects to have in the garden. They provide pollination for flowers, and their larvae consume plant-eaters such as aphids and related scale insects.
While I was unable to find very much information pertaining to Ocyptamus fascipennis specifically, one other member of the genus deserves special mention because of its interesting larval habitat: tank plants (Bromeliaceae). The Central American and South American species of Ocyptamus that inhabit these confined aquatic habitats (pools of water within the plant itself) ambush and consume other aquatic insect larvae that live in the plants alongside them. The larvae are even thought to use a paralyzing venom to subdue their prey (Rotheray et al, 2000).
All in all, Ocyptamus fascipennis and its relatives are fascinating flower flies with intriguing habits. I hope you’ve enjoyed taking a closer look at them today.
UPDATE NOVEMBER 2021: Near Point Pelee, Ontario, individuals of Ocyptamus fascipennis were observed apparently migrating. The flies were observed moving East to West along with several other insects including tens of thousands of potter wasps (Ancistrocerus adiabatus) (Skevington and Buck 2021). The authors of the paper note that insect migration is a largely understudied phenomenon, especially in North America, so further study is needed to figure out the details.
Marshall, Stephen. Insects: Their Natural History and Diversity. 2006.
Marshall, Stephen. Flies: The Natural History and Diversity of Diptera. 2010.
Skevington, Jeffrey H., and Buck, Matthias. 2021. “The first documented migration of a potter wasp, Ancistrocerus adiabatus (Hymenoptera: Vespidae: Eumeninae)”. Canadian Field-Naturalist 135 (2): 117-119.
If you’re interested in the living things that inhabit this world with us, then you’ve come to the right place. I’ve always found it fascinating that there are so many different kinds of creatures, living out lives in different ways to us humans. In some cases, it’s difficult to believe that we share the same planet, let alone the same backyard. There are countless species that surprise and delight in your own neighbourhood, and there are many more around the world. I’d like to explore this diversity, and try to share my own excitement about these creatures, whether they are insects, fungi, plants, birds, mammals, or any of the other species that crawl, fly, swim, run or grow across the planet.
To do this, I’m planning on producing posts detailing a specific species or group of species to get a taste of what sort of creatures are out there. I will also occasionally post about my own observations (and photos) of species that I’ve encountered in my own travels in Southern Ontario. Another thing I’d like to do is review books that are relevant to learning about nature, as I have a personal library stocked with some great books about the diversity and wonder of life.
I hope that when you visit this blog you learn a little something, gain a greater appreciation for living things, and get inspired to pay a little more attention to the world of nature that’s all around us.
Norfolk Naturalist 