Giant Casemaker Caddisfly - Ptilostomis ocellifera
With today's post, the blog has provided many of the large-winged, uncommon insects a good spotlight. Especially among the orders of Neuroptera (Lacewings) and Trichoptera (Caddisflies) whose finds can be hit and miss as the years go...unless you know where to look. Caddisfly find can come a bit easier if you look near water at the right time, this species very much included. With regards to this Giant Casemaker, it's the overall largest among all the Trichopterans you can find here (but not the longest in length) which occasionally leads it to being confused with the Moths of cottage country as it flutters around a screen door. As a reminder, this species is more well known by its scientific name, but it has a descriptive common name here for ease of discovery. Should you find one of these or a similar-looking Caddisfly near your outdoor lights, always remember to carefully check their wings while at rest, which should be held in a familiar tent-shape. Their heads will have different features of note as well. The extended mouthparts especially, and the white spots along the outer side of the forewing.
On the subject of those mouthparts, while the diet of a Caddisfly's adult stage can be variable (or even non-existent) depending on the family, it is my understanding that most Caddisflies still make use of their mouthparts in order to tear through their pupal casing. However, there's more nuances to that story that just biting your way out underwater. It's more so apparent since it's fairly evident that the filament-like mouthparts of the adults are better suited for sensory and lapping up liquids, and are insufficient for breaking through a pupa. Since Caddisfly Larvae radically change from gilled larva to air-breathing adult during their metamorphosis, they require provisions in order to survive the journey to the surface. As such, mandibles do break through a Caddisfly's pupal casing, but the emergent insect is a stage called a "pharate" adult. This encased, waterproof stage allows the adult Caddisfly (contained inside the pharate exoskeleton) to swim or crawl, depending on the family, through the water toward the water's surface or land respectively. This is a miraculous process, but it's also dangerous. If it goes wrong, the adult will be in an unforgiving environment, and the pupa themselves are vulnerable to fish, amphibians and birds throughout the travel and molting process.
Pictures were taken on June 25, 2022 in Muskoka with a Google Pixel 4. I've enjoyed re-examining these examples of large-winged insects (and I have many more examples to share), but next week we will return to some of the more "common" insect orders. Perhaps there will be a surprise or two along the way...