Categories
August 2021 Observations Nature Observations

Parasitic Plants and other Non-Fungi (NFN Fungi Hike Part 3)

Last August, I went on a hike in Backus Woods with the Norfolk Field Naturalists to identify and photograph fungi. For the first two parts of the observations I made during the hike, see Part 1 and Part 2. My two previous posts covered all of the fungi (and several interesting non-fungi including wood frogs and fungus weevils) that I photographed and described some of their interesting biologies and ecologies. This final post is a roundup of the non-fungi observations I made during the hike.

You would be forgiven for thinking that this next observation also represented the fruiting body of a fungus. Instead, this drooping white organism is actually a plant without chlorophyll (and thus without the colour green and without the ability to capture light from the sun and turn it into sugar). Ghost Pipes (Monotropa uniflora) are parasitic plants, which feed indirectly on the roots of their host trees via underground fungi that attach to the roots in a mycorrhizal relationship (Runtz 2020). The flower heads droop, and give this strange flower its name of “pipe” but when they are pollinated (by bees usually) they will raise their flowers straight upward (Runtz 2020).

Some more traditional plants (you know, ones that are green and perform the magic of photosynthesis) were also spotted along the trails. I learned that the bright red clusters of berries were the ripened fruits of George-Michael-in-the-Banana-Stand (Arisaema triphyllum)*. Besides the red berry clusters, we also saw representatives with green berries that hadn’t ripened yet. Although they may look edible, these red berries contain high levels of oxalic acid and cause painful burning in people that eat them… although apparently white-tailed deer, wild turkeys and wood thrushes will eat them and be fine (Holland 2016).

*more traditionally, the common name is Jack-in-the-Pulpit and most people probably know it by this name, but I couldn’t resist using the new common name proposed by The Field Guides Podcast (for my review of the Field Guides Podcast go here)

Another red-berried plant was a new one for me: Partridgeberry (Mitchella repens). These red berries are edible, but apparently tasteless. The flowers are pollinated by bumblebees and as the name suggests the berries are consumed by ground-birds (such as grouse and turkeys), but also by skunks and white-footed mice (Hayden 2012). You would think that partridges would eat these berries… but we don’t have any partridges in North America, and this species only grows here… so here we have a very useless common name.

Partridgeberry growing and spreading through the leaf litter.

Two other wildflowers added colour and beauty to our hike: Spotted Jewelweed (Impatiens capensis) and Great Blue Lobelia (Lobelia siphilitica). Spotted Jewelweed is pollinated mainly by hummingbirds and bees, while the Great Blue Lobelia is pollinated mostly by bumblebee (Eastman 1995). I unknowingly captured this interaction between Ruby-throated Hummingbirds and Spotted Jewelweed in the past, so I’ve included a picture here.

A few interesting arthropod encounters also enhanced the hike. An American Giant Millipede (of the Narceus americanus complex)* was found in curled defensive posture. 

*the complex refers to the fact that this “species” is actually made up of many species that may be extremely difficult to distinguish

American Giant Millipede in defensive spiral. I didn’t mean to disturb you!

On the way out of Backus Woods, I spotted some speedy insects scurrying across the sands and gravels of the path, those predatory jewels known as Tiger Beetles (Cicindelinae). The two species that I spotted and photographed were the Punctured Tiger Beetle (Cicindela punctulata) and the Big Sand Tiger Beetle (Cicindela formosa). 

I hope you enjoyed this tour through Backus Woods with a focus on Fungi. I know I learned a lot and am excited for future outings with the Norfolk Field Naturalists!

References:

Eastman, John. 1995. The Book of Swamp and Bog.

Hayden, W. John. 2012. “2012 Wildflower of the Year: Partridge Berry, Mitchella Repens.” Virginia Native Plant Society Brochure, 2012, 1-3.

Holland, Mary. 2016. Naturally Curious Day by Day.

Runtz, Michael. 2020. Wildflowers of Algonquin Provincial Park.

For more Nature Observations in Norfolk County, see:

-Fascinating Fungi (NFN Fungi Hike, Part 2)

Freezing Frogs and Fascinating Fungi (NFN Fungi Hike Part 1)

-A Visit to Big Creek, Part 1 and Part 2

The Wonders of Wrens

Cuckoo Wasps and Carpenter Bees

Flies Falling to Fungi and Other Dipteran Observations

Fuzzy Flies and Song Sparrows

Leafhoppers, Lepidopterans and Longhorns

And for more nature observations, photos and natural history facts, follow me on instagram at norfolknaturalist

Categories
August 2021 Observations Nature Observations

Fantastic Fungi (NFN Fungi Hike, Part 2)

Back in August, I went for a hike with the Norfolk Field Naturalists to search for Fungi to photograph (see Part 1). Along the way, I encountered many organisms both fungal and not-so-fungal.

One non-fungus was photographed perched atop some fungi on a log. The creature was a Marbled Fungus Weevil (Euparius marmoreus), which feeds on polypore fungi (Marshall 2018).

Marbled Fungus Weevil, the only time I used my macro lens on this entire hike.

The next observation brings us back to the focus of the hike: Fungi. This strange spherical object covered in a lacework pattern is the fruiting body of an Earthball (Scleroderma). These fungi actually interconnect with tree roots to form mycorrhizal associations, benefitting the trees and the fungus (Stephenson 2010).

Earthball (Scleroderma), the fruiting body of a mycorrhizal fungus.

Another spherical object caught our eye while hiking through the woods: an Oak apple gall. This particular one was caused by Amphibolips cookii, a Gall Wasp feeding within the bud of a Red Oak (Quercus rubra). The bud developed into this spherical gall, while the larva fed within and then this “oak apple” detached and fell to the forest floor, and I guess the adult wasp has already left this gall behind? I don’t know, it was very difficult to find any information about this species or gall wasps (Cynipidae) in general despite them being fascinating insects (what I did find was a website that contains some information: gallformers.org, a site worth checking out if interested). I have a particular fondness for galls caused by insects… they’re plant growths that create particular species-specific patterns for the insects that inhabit them… what’s not to like?

Oak Apple Gall (caused by Amphibolips cookii).

Further down the trails, we encountered some classically shaped mushrooms unlike the more bizarre (in my opinion) Earthballs (Scleroderma). A member of the genus Oudemansiella and a member of the genus Russula.

Oudemansiella mushroom.

Russula fungi are ectomycorrhizal, meaning that their underground mycelia (the major part of the fungal body) connect with roots of trees and other plants to transfer and exchange nutrients (Stephenson 2010). 

Russula mushroom.

Some of the most common fungi that we spotted were associated (as many fungi are) with dead or dying wood. Fungi that feed on dead or decaying material are known as saprotrophs. Orange Mycena (Mycena leaiana) were spotted multiple times throughout our excursion and I have to say they might be my favourite fungi that we found simply for aesthetic reasons. The beautiful colour of their fruiting bodies really brighten up the dead logs and fallen trees in the forest. 

Another wood-feeding saprotroph we found often is known as the “Oyster Mushroom” (Pleurotus), apparently because of its fishy smell (which I couldn’t detect, perhaps it needs to be cooking?). These are very commonly collected for humans to eat.  As mentioned above, the Oyster Mushrooms feed on decaying and dead wood, but they also feed on microscopic creatures called nematodes. The details of the interaction are incredible. The Pleurotus fungi has special cells among its hyphae (the underground components of the fungal mycelium) which produce a toxin that paralyzes nematodes. After contact, the nematodes continue moving (usually much slowed, and erratically) for 30 seconds to several minutes before succumbing to the paralyzing toxin. The immobilized nematodes are then attractive to fungal growth from the Pleurotus mycelium, which produces hyphae that thread through the material (usually dead wood or soil) to reach the nematodes and enter their bodies. These fungal threads break the nematode down, consuming it while it is still alive but paralyzed. If you’re interested in more of these details, you can read the full paper where it’s described (Barron and Thorn 1987) here: https://cdnsciencepub.com/doi/10.1139/b87-103.

Pleurotus mushroom, unassuming destroyer of wood and nematodes.

There were a couple of other saprotrophic fungi found feeding on logs during the hike. Resinous Polypore (Ischnoderma resinosum) has a strange texture that was unexpected, though appearing like tougher shelf fungi it was actually quite soft and pliable. Our guide likened it to the feel of a donut and I can attest that this assessment is bizarrely valid.

Resinous Polypore, strangely soft and light.

Not all fungi grow on logs however, and there are several interesting groups that are very easy to miss. One colorful but tiny fungus is the Red Chanterelle (Cantharellus cinnabarinus) which grows singly or in clumps and is connected to the root systems of trees in yet another mycorrhizal relationship.

Red Chanterelle peeking out from the leaf litter.

Two representatives of a more bizarre ground-sprouting group would have been easily missed. This group is known as the “Earth-tongues” (Family Geoglossaceae). You can (perhaps unfortunately) see their resemblance to strange tiny tongues protruding from the soil. Our guide was quite excited to have spotted the dark Earth-tongues (identified via iNaturalist as Trichoglossum because of the tiny hairs) because they would be very easy to miss.

That brings us to the end of the fascinating fungi that I spotted on our hike! It is not the end however of the non-fungal sightings. A few more of those to review in the final part of this ‘series’.

References:

G. L. Barron and R. G. Thorn, 1987. Destruction of nematodes by species of PleurotusCanadian Journal of Botany65(4): 774-778. https://doi.org/10.1139/b87-103

Marshall, Stephen. 2018. Beetles: The Natural History and Diversity of Coleoptera.

Stephenson, Steven. 2010. The Kingdom Fungi.

For other Nature Observations in Norfolk County, see:

Freezing Frogs and Fascinating Fungi (NFN Fungi Hike Part 1)

-A Visit to Big Creek, Part 1 and Part 2

The Wonders of Wrens

Cuckoo Wasps and Carpenter Bees

Flies Falling to Fungi and Other Dipteran Observations

Fuzzy Flies and Song Sparrows

Leafhoppers, Lepidopterans and Longhorns

And for more nature observations, photos and natural history facts, follow me on instagram at norfolknaturalist

Categories
Podcast Review

The Field Guides

I’ve started listening to podcasts over the last few years, and I especially enjoy a podcast that has a good balance of entertainment and education. That description is perfect for one of my favourite podcasts: The Field Guides. This podcast first started in September 2015 and now has over 60 episodes released so if you’re just tuning in now you have plenty of excellent content to catch up on. The presenters’ goal is to bring a trail experience every month or so, though that doesn’t always happen which I think we can all understand. Life happens. Even so, they have released quite a few episodes and they’re usually about an hour long each. Some episodes are split into two parts, with each part being about an hour long. Each episode focuses on a nature topic (or the occasional nature location, such as their tour of the Roger Tory Peterson Institute). The topics range from Goldenrod Galls to Bird Banding. Sometimes they focus on a particular species, such as the Purple Pitcher Plant, and sometimes they focus on a broader natural phenomenon such as the relationship between Ants and Plants or Fall Colours.

Here’s a Goldenrod Gall (spherical swelling on the stem), which I photographed in Macgregor Provincial Park, Ontario. The various galls that form on Goldenrod (Solidago) are the topic of the first episode of The Field Guides.

I like that whatever their topic of choice is, Bill and Steve delve into it with real research from papers published in scientific journals or credible book sources. I appreciate the level of detail that is provided on each given topic as it’s not all surface-level same-old natural history facts. This is especially true in some of the two-part episodes as the extended time allows for even deeper exploration of a nature topic. With the use of scientific papers and research, there can be some discussions that are difficult to follow because of scientific jargon or complex topics, but for the most part they bring out the significance of the science and explain in a way that doesn’t leave one struggling to keep up.

Besides discussing a nature topic or species (which would be good enough in my opinion), Bill and Steve also hit the trail in various locations mostly in New York State. There is an episode about Spruce Grouse where they traveled to Algonquin Provincial Park in Ontario which was especially exciting to me as I love Algonquin Provincial Park. This was the only location familiar to myself, but if you’re in New York state I’m sure you’ll recognize many of the trail locations they visit. Despite walking around through leaf litter and beside streams, the audio experience of the hiking enhances the listening experience rather than detracting from it. Rare is it that the sound of wind on the microphones or crunching footsteps overpowers the discussion or intrudes in any sort of negative way. Instead, the sounds of birdsong (some recognized by me, some unfamiliar) and the calls of amphibians add a lot to the ambience.

I have never photographed a Spruce Grouse, but here’s a relative I photographed in Algonquin Park: a Ruffed Grouse (Bonasa umbellus).

As I mentioned at the beginning of this post, for a podcast to be especially enjoyable for me, it needs an entertainment factor. In this case, The Field Guides Podcast delivers with sarcasm throughout (often by Steve, but Bill gives his fair share as well), and humorous anecdotes or comments. I think one of my favourite jokes was the two of them coming up with alternative common names for Jack-in-the-Pulpit because common names can be whatever you want them to be. Some of their excellent suggestions were “Ripley-in-the-Power-Loader” and “George-Michael-in-the-Banana-Stand”. I will mention here that their humour is enjoyable for an adult audience, as there are occasional jokes and comments that are inappropriate (or indecipherable) for younger audiences. They even have a two-part episode which has the Explicit tag called “Eat Sh*t and Live, Bill”, all about coprophagy (animals/plants eating poop). The episode was fascinating, but just in case any teachers wanted to play this podcast for younger students it does contain some adult humour.

In summary, The Field Guides is a must-listen if you’re interested in Nature and Science. I have spent many hours of enjoyment laughing at the jokes and sarcasm and learning a lot about the animals and plants and nature phenomena that are all around us. Give it a listen!

For Previous Norfolk Naturalist Media Reviews, see:

The Paleoartist’s Handbook, by Mark Witton

The Social Biology of Wasps, ed. by Kenneth Ross and Robert Matthews

Pterosaurs, by Mark Witton

Flora of Middle-Earth, by Walter Judd and Graham Judd

And if you’re interested in seeing more of my photos and learning some facts about the organisms I’ve observed, follow me on Instagram at norfolknaturalist.

Categories
June 2021 Observations Nature Observations

A Visit to Big Creek, Part 1

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 Blackbird with 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 (Geothlypis trichas). 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.

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.

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:

Pinery, Winter 2019

MacGregor Point Observations (May 2018

-Algonquin Observations (July 2018), Day One, Two, Three, Four, Five, Six

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.

Categories
Uncategorized

Swimming Squirrels

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 Squirrel can 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.

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sand wasps

The Sand Wasps, Part 2: The Tribe Alyssontini

The Wikipedia entry for the Tribe Alyssontini reads as follows: “The Alyssontini are a small tribe of small Bembicine wasps.”

And that’s it.

The lack of easily readable information about this group of Sand Wasps reinforces the vast diversity of life, that an entire group of insects with 65 known species (according to the Catalog of Sphecidae.) is so poorly known. To me, it’s exciting. What could each of those species be doing. What might their stories be? There are a few things I can say about this group, entirely gathered from the chapter about this Tribe in The Sand Wasps.

The Tribe Alyssontini are known for being adapted to cooler environments than many other Sand Wasps. Like many of the Sand Wasps, they collect Homoptera (Bug “hoppers”) of various families, mostly Cicadellidae (Leafhoppers). They make their nests in somewhat harder soil than many other Sand Wasps, and have relatively stout mandibles which they use to loosen this harder substrate for nest construction.

Alysson melleus female. Photo taken by Owen Strickland.
Alysson melleus male, photo by Owen Strickland.

For my Introduction to the Sand Wasp Series of posts, go here!

References:

Evans, Howard E. and O’Neill, Kevin M. The Sand Wasps: Natural History and Behavior, 2007.

Categories
Species Profile

Introduced Pine Sawfly

Diprion similis

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.

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.

Grissell, Eric. Bees, Wasps, and Ants. 2010.

CABI, 2020. Diprion similis. In: Invasive Species Compendium. Wallingford, UK: CAB International. www.cabi.org/isc.

Categories
book review

Flora of Middle-Earth

Despite paying a lot of attention to the little invertebrates that scurry about in the undergrowth, I tend not to pay too much attention to plants. This isn’t on purpose, or because I dislike them for any particular reason, but I think it’s difficult for us to look at them in the same way that we look at animals because they don’t move about (on the same timescale or in the same ways) and they don’t seem to display varied behaviours. If we can move past these false ideas about plants we may realize that life doesn’t flourish against a green background, but rather, the drama of life plays out amid the foliage and thorns and seeds and roots just as much as it does amid the fur and feathers, claws and teeth.

One book that has opened my eyes to this world of green, growing things is Flora of Middle-Earth by Walter S. Judd and Graham A. Judd. 

I have been an avid fan of Tolkien’s mythos and the science of living things for most of my life, so when I found this book, I felt that it had been written specifically for me. What really drew me to the book was that it was written by a world-renowned plant scientist and this knowledge shows through details of plant biology and ecology within its pages. The book succeeds on both a scientific and a literary level, as the author and illustrator understand plants and Middle-Earth extensively. They even draw on the History of Middle-Earth series which are unfinished manuscripts by J. R. R. Tolkien put together by Christopher Tolkien, to fill out the botanical landscape of this fictional, yet powerful world. The first chapters give an overview of plant biology, evolution and ecology, as well as outlining the biogeography of plant ecosystems in Middle-Earth throughout its known history (First to Third Ages). After this, there is a chapter that contains a key to identifying the plants that are detailed through the majority of the book so that if you encountered a plant in our world you could follow the descriptions to its genus or species. This section isn’t particularly useful in my opinion because although Tolkien mentions over a hundred plant groups within his legendarium there are many more plants that exist, so that you could very easily follow the keys to a dead end. Next is a chapter devoted to the two most important plants in Middle-Earth: Telperion and Laurelin, the Two Trees of Valinor. This was interesting, seeing where Tolkien might have drawn his inspiration for the fictional Trees from plants that exist in our time and place. 

Following this is the largest section of the book which runs through over 140 plant types mentioned in Tolkien’s writings. For each plant, there is a quote containing a mention of it, a general overview of its place within Middle-Earth ecology and culture, a study of the plants names (how Tolkien can you get?), a description of the plant’s ecology and biology in our world, a mention of its place in human culture and a botanical description of its form. Alongside this impressively detailed treatment, many of the plants receive a woodcut-style illustration which shows them in the context of Tolkien’s stories and world. 
The final chapter is a Note from the Illustrator, so if you’re interested in this book primarily for the artwork, there is a description at the end of how and why he created the illustrations the way he did.

Part of what enhanced my appreciation of the book was reading it while in Algonquin Provincial Park, a place filled with memory and meaning for myself, just as Middle-Earth is. Reading about a plant’s place in Tolkien’s writings while encountering some of the same plants in Algonquin Park was an experience that is a microcosm of what is so special about this book and the Tolkien legendarium as well. Tolkien’s writings shed a new light on the world around us, just as this book sheds light on a piece of that world (Middle-Earth) and our own world.

The greatest accolade I can give this book is that I learned a lot about Tolkien’s Middle-Earth and the ecology of plants in our own world. If you’re interested in either of those things, I would highly recommend this excellent, beautiful book.

Algonquin Park in Autumn.