Subject: [Tweeters] One Wierd Beetle
Date: Jul 27 21:59:25 2011
From: jeff gibson - gibsondesign at msn.com



Back in August of 2008 I first posted about my 'discovery' of Fields Riffle Park just downstream from Snohomish. Basically the place is some open hayfields at the entry bordered by the river dike. Crossing the dike one enters an interesting chunk of fluvial geomorphology - the whole place being a big sandbar enclosing a small tidal basin (Norwegian Bay) that empty's out at a +.9 tide. If one comes here during a spell of high water in November, December ect. you can see where the sand comes from - the whole place outside the dike is underwater. In spring, lots of new sand.

Sand is the key to this story, because it attracts a whole different bunch of insects - Tiger Beetles, Sand Wasps ect. (I call the place Hymenoptera Hectares due to the amazing variety of bee's and wasps here). Dry sand, as apposed to river mud, isn't too common along the lower river. Another bug found here is the amazing "Bumblebee Scarab" Lichnanthe rathvoni. I found one on my maiden voyage here and haven't seen one since.

Today I lucked out. Just over the dike is a little patch of dry sand. I doesn't look like much, but close observation often reveals many cool bugs. This year had been pretty quiet there so far - no doubt due to our cool wet weather. Today though, looking for the Sand Wasps that have a little 'colony' there, I found two Lichnanthe rathvoni ! I walked out to the river, and down the firm, but surface-mucky ( don't wear your dance shoes) riverbar downstream to the larger area of dry sand down there - a high sandbar at mouth of Norwegian Bay. There I saw quite a few more Lichnanthe rathvoni - a dozen or so.

"Bumblebee scarabs" are beetles that mimic bumblebee's. And they do a very good job of it. Looks like a bee, flies like a bee. Only on close inspection do you see something amiss. These beetles have club (like golf) shaped antennae. Bee's don't. Like other beetles they have Elytra - the hard "shell " covering the wings . They fly very well - usually about a foot or two above the sand.

Also amazing to me is that these beetle's come in different color forms - today I saw three: one with an all black body, a few with orange-tipped abdomens, and most of them with a pale yellow body. I cant think of too many bugs that share that much color variability - especially in a single locale.

In my Cosmogony, God and Mother Nature are co-conspirators - they get along fine. They enjoy pulling a good prank on the unsuspecting public (human and other). One of these is the "Bumblebee Scarab". God told Mother Nature "you sure do have an eye for detail". "Well", she said "when you gave me this job you said 'go for it', so I did". God asked " do you think you've got enough beetles out there - you sure seem fond of em". " I am " she said " but you know, I was thinking of a sort of beetle that looks like a bee. Mimicry has always been popular down here". God said " Go for it".

Jeff Gibson
Everett Wa