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Hi Angus, Thanks for narrowing the bumblebee search to Bombus ternarius and B. rufocinctus. On the way to Hall's Harbour yesterday, we stopped in at the Mt Uniacke House grounds briefly for me to check for diagnostic thoracic markings you had indicated, and I later checked on BugGuide.net to clarify what you meant by the difference. From the images there, the buff band of hairs over the prothoracic area is similar in both species and did not look to be readily diagnostic. In B. rufocinctus, the central patch on the dorsal mesothorax is black, while the buff hairs behind this zone (over the metathorax) form a more or less continuous band across the metathorax. In B. ternarius, the black zone is similar, but a strip of black continues back through the mid-dorsal metathoracic zone, so that there appear to be two lateral buff zones at the back of the thorax, not one, now separated by a central black line. Do the differences in pattern just described agree with your views? All four bumblebees that I examined clearly conformed to the latter description, and so identified themselves as B. ternarius, which you indicated is much more common locally in your experience. Regarding my earlier description as 'small', the four I measured roughly with a ruler were 11-13 mm long, but the bees in the wild visiting the knapweed bend at both ends and so look a bit smaller still. There were a lot of these flying again yesterday in the sunshine around 2 PM, along with several Virginia Ctenucas (red thoracic zone rather than the yellow of Jeannie's similar moth, identified just now by Bev). For those interested in bristletails, Petrobius brevistylis (that's probably just me), disconcertingly, we failed to find any last year in a couple of visits to HH, and wondered if they had been extinguished locally by over-collecting. Perhaps this was just a weather thing on the days of those visits, though: yesterday, happily, they were distributed very widely along the bases of the cliffs in the seepage zones, present probably in the 1000s, ranging from medium to large in size. These will all disappear into fissures in the cliffs for a long hibernation and probably for egg-laying, surprisingly early, in September. Steve (Hfx) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Quoting Angus MacLean <cold_mac@hotmail.com>: > Hi Steve: > The two bumble bees with orange on the upper part of the abdomen are > B. ternarius & B. rufocinctus. The former is quite common in the > Valley & in Cape Breton so I assume over most of the province. > However ternarius is the average size of B. impatiens so I cannot > imagine the small size of so many that you describe. (Rufocinctus in > my experience is rare). > > Ternarius can be separated from rufocinctus by the shape of the > black on the thorax. There are a few exceptions where the shape is > somewhat ambiguous or the individual is worn. > > As for size there is much literature on bumble bees on the Net but I > have yet to see any size mentioned!! Presumably that means size does > not help in identification. > > I expect David McCorquodale will read this and solve the mystery. > > Angus ############################################ >> Date: Sun, 18 Aug 2013 18:10:55 -0300 >> From: srshaw@Dal.Ca >> To: naturens@chebucto.ns.ca >> Subject: Re: [NatureNS] bumblebee identity -- was Miner's Marsh-Kentville >> >> Yesterday we visited Mt Uniacke House grounds again ostensibly for >> 'gathering', while I spent most of my time 'hunting' in the old >> greenhouse area and on the drumlin, but not finding much. Apart from >> meadowhawk dragonflies and a few larger species, the only insect that >> was common was a small bumblebee -- seen literally in the 100s. I >> assumed that it would be the same species as Angus's 25, below, >> feeding on 'jewelweed', but in checking the many Bombus impatiens in >> BugGuide, it doesn't look like a match. >> >> The Mt U bumblebee was decidedly small and had the upper abdomen of >> dark orange with the tip of the abdomen blackish, and would not be >> much more than 10 mm in length. Of the Bombus group figured on >> BugGuide, it most resembles B. ternarius, reported from Maine, though >> some images there put the length of B. ternarius a good bit longer >> than my estimate. I took no photos -- is there any hope of guessing >> the ID from this limited description? What about B. centralis? >> >> This species was less interested in goldenrod (everywhere, but some >> flowers now are fading) than in what my daughter says is 'ironweed', >> which I initially assumed would be an alternative name for Angus's >> 'jewelweed', but not so. Jewelweed is apparently Impatiens spp, with >> pretty pink flowers, while the very abundant stuff that these bees >> were visiting does look like the ironweed found on-line, with small >> purple thistle-like heads, Vernonia spp., of a different family. >> >> The only butterflies around in these open areas in ~2 hours of looking >> were Common Wood Nymphs, though these were much less abundant than 2 >> weeks ago in the same places. Quite a few Virginia Ctenuca moths were >> flying late on, and some small syrphids (hoverflies) plus small >> grasshoppers. I saw a few native wasps and a couple of bees, but only >> a single honeybee. Having largely given up I tried instead sweeping >> grassy vegetation at one spot near the greenhouse, which turned up >> large numbers of jumping bugs, including several thorn-head >> treehoppers and buffalo treehoppers. So not all insects are down and >> out, or scarce. >> >> For fairy fern ring afficionados (all 3 of us, if that), there are >> actually three fern rings up on the Mt. U drumlin, though the two new >> ones are further up, smaller and less perfect, all sensitive fern. >> The first ring I originally estimated by eye at ~20 feet across, but >> this is way off. I've since surveyed it fairly accurately and it's 30 >> feet across and close to perfectly circular. So something odd is >> going on underground up there. >> >> Steve (Halifax) >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> Quoting Angus MacLean <cold_mac@hotmail.com>: >> >> > Last evening at MIner's Marsh, I was pleased to find ~25 Bumble Bees >> > on Jewelweed (N. side of marsh). Even more surprising, they were all >> > the commonest BB in our area, Bombus impatiens. So there are pockets >> > of these bees still surviving although in many areas, one can only >> > find a couple. >> > >> > There was a number of small skippers flying too but never allo