~57 mm, caught in a bottle trap baited with beef liver & placed in a typha filled ditch among some emergent grasses. Still working on a write-up for the larvae of this species, but the main things I am looking out for is the shape of the anterior margin of the frontoclypeus, and the setal arrangement of the metatarsi.
Interestingly, this individual is a decent amount larger (~4mm) than the larvae of this species that I caught in Richmond. Upon catching them they were already exhibiting prepupation behaviours so I put them in a container with some damp peat and they are currently digging their pupation chamber as I write this.
Update: they have since emerged as an adult with a final length of 32 mm, added pictures to confirm D. cordieri.
Dip netted among some emergent grasses in a non-fishless blackwater slough. L3, ~35 mm at time of this observation, same species as my last Dytiscus observation.
Will be hopefully rearing to adulthood to confirm species.
Update: they have since pupated, final larval length of 52 mm.
Update: they have since emerged as an adult, confirming a female Dytiscus cordieri non-sulcate elytral morph. Better photos to come tomorrow.
Instar II larva, dip netted out of a non-fishless blackwater slough among some rushes. ~22 mm, same species as my previous non-D. hatchi Dytiscus larva observation.
Will be rearing them to adulthood to determine the species and take many more pictures & notes to hopefully come up with a comprehensive description of the larvae of this species.
Update: they have since pupated with a final larval length of 55 mm.
Update: they have since emerged as an adult, confirming them to be a male D. cordieri with a length of 31 mm.
~39 mm, caught in a bottle trap baited with beef liver & placed among a clearing of Typha in a beaver pond. No noticeable exterior damage to their integument so I suspect either an adult that emerged this summer or last summer. Pictures taken and individual released at the location of the trap.
First adult I have caught in this location, earlier in the year larvae were particularly abundant throughout this wetland as well as caddisfly larvae. Interestingly this individual has a strong green cast, yet the larvae I have raised from this population both have a duller green cast so I am wondering if there is an epigenetic factor for this colouration.
Hand netted out of the margins of the pond here around some Typha and grasses—about an hour after initial observation (last picture and the time of this observation). ~31 mm, smooth elytra morph female. Released back into pond shortly after taking pictures for this observation.
I had a suspicion that there would be adults of D. cordieri (or possibly D. marginicollis) in this pond because of my earlier Dytiscus sp. larva observation here. While it is too early to say whether that larva is D. cordieri, as at the time of this observation they are still a pupa, I am guessing as much because I found a distinctly different species of Dytiscus larva not too far in Richmond in a habitat that seemed much more conducive to D. marginicollis from what I have read.
Instar II larva, saw quite a few Dytiscus sp. larvae throughout the vernal pools in this area.
Update: raised from a larva and allowed to pupate, looks like they're a D. hatchi. New pictures added, taken when they were still teneral probably around an hour or 2 after emergence.
L2 Dytiscus larva, another species I haven't seen before, not D. harrisii or D. hatchi, also doesn't appear to be the species of my last Dytiscus larva observation. Caught dip-netting in a blackwater slough.
Also hopefully going to rear this larva to adulthood to see what species they are.
Update: they have ecdysed into third instar.
L3 Dytiscus sp. larva, not D. harrisii or D. hatchi. Caught dip netting in the margins of this pond among some bur-reeds, will be rearing them to figure out the species.
Update: they have now pupated, final larval length of ~53 mm.
Update: they have now ecdysed into an adult, confirming them to be a female Dytiscus cordieri. ~29 mm, sulcate elytra morph.
L1 Dytiscus sp. larva, caught while dip-netting through a Potamogeton natans-filled, lentic, beaver pond runoff stream.
Looks to be the same species as my last Dytiscus observation which I believe to be D. harrisii on account of the larvae matching morphological and behavioural descriptions of the larvae described in Leclair et al. (1986) "Prey Choice in Larval Dytiscus harrisii Kirby and D. verticalis Say."
Notably, they have a relatively small head for the genus, shorter mandibles that are thicker basally than other species, a head that bends easily at 90°, and a frontoclypeus that's anterior margin is not rounded as in other Dytiscus sp. larvae and that's lateral apices extend beyond the anterior margin.
Update: has since pupated, with a final instar III length of ~62mm measured from urogomphi to mandibles.
Update: they have emerged as an adult with a final size of ~39mm, spending 19 days as a pupa before emergence.
L2 Dytiscus sp. larva, caught in a bottle trap inspired by Inoda and Ladion's (2016) "New box trap for large predaceous diving beetles" baited with pig liver and placed in a clearing of sedges & Typha in a beaver pond.
All I can say is for certain is that they are not a D. hatchi larva. They do, however seem to be a caddisfly specialist such as D. harrisii based on morphological features such as a relatively small head and shorter mandibles as described by Leclair et al. (1986) in "Prey Choice in Larval Dytiscus harrisii Kirby and D. verticalis Say", and on account of behaviour and ability to predate caddisfly larvae as viewed in a captive setting.
Update: they have since ecdysed once and are now L3, pictures of caddisfly larvae hunting added.
Update: they have now pupated, length at the time of pupation was ~62mm, new pictures added. Pupation container 8 cm × 10 cm × 28 cm filled with 5 ½ cm of damp peat.
Update: they have reached adulthood, confirmed male D. harrisii—final adult length of ~39mm.
Saw a Dytiscus observation here from a long time ago that I saw the subapical fascia on the elytra and I wanted to confirm if it was actually Dytiscus harrisii or not, turns out it was!
Guessing that the ponds here have a population of them—it certainly would make sense considering the amount of caddisfly larvae I've seen around the plants in this pond.
Caught in a bottle trap baited with pig liver placed among some typha that was left out for 24 hours, ~39mm. Missing right mesothoracic tarsus, left maxillary palp, & has a small bite out of their left elytron.
Spotted ovipositing eggs into an aquatic plant.
Found in the water along the shoreline of beaver lake; I now keep her as a pet.
Found hunting water bugs at night at Beaver Lake; I now keep him as a pet.
Found in the grass in Old Yale Park, Langley. (I now keep her as a pet)