Sunday, July 15, 2018

A Weekend of Rare Cerambycids

This week a visit of my friend and co-author of the Arizona Beetle Book in preparation, Dr. Arthur Evans, and Pat Sullivan's annual Infestation party for entomologists promised a lot of fun field work and the probable discovery of more species to photograph for our book  (is that good or bad by now?) But the first exciting news came actually from a herpetologist and facebook friend in Clinton, Greenlee County, AZ. Terry Johnson informed us that 5 specimens of a striking looking Longhorn Beetle had been found there, and he got photos for us and promised me a specimen. It later turned out that there was only ONE specimen, not 5. But I did get it.

Megaderus bifasciatus, found in Clinton, Greenlee County, AZ
 Robert Velton identified the beetle as Megaderus bifasciatus. There were some few reports of this mainly Mexican and central American species from SE Arizona and from Texas. So I was quite happy, looking forward to adding this striking species to the AZ Beetle Book. But Terry's discovery coincided with the reviewing process of a paper whose authors were doubting that any of those old observations were valid. Luckily our community is small and close-knit so they were informed of the find and right now they are asking good questions about the provenance.. Five living specimens in situ are not easily explained as mislabeled or misidentified,  but were they maybe found right next to a pile of imported logs? That would raise the suspicion that they were recent adventives. I will report the result of this interesting story as soon as I know it. edit: only one pristine, newly hatched looking specimen in a residential development of 5 year old houses. Dan Heffern is now doing detective work to find out how our bug got there. Home Depot wood delivery for fences seems to be under suspicion.



 Meanwhile, we had our potluck feast at Pat's and I was working off some calories in his beautiful garden that slopes up the side of Ramsey Canyon behind his house.  I  picked mainly small leaf beetles from his perennials, all chosen for their attractiveness to insects I am sure. The diversity was delightful, even if they were all old friends.

But then I came across a little grey Cerambycid wit anulated antennae.

Mecas menthae. on  Salvia leucantha
  If it had been on a sunflower leave, I would have disregarded it as  the well-known Dectes texanus. But I have learned to trust the botanical knowledge of bugs implicitly.  I also remembered that lately a friend had compared species in the two Flat-faced Longhorn genera Dectes and Mecas because they resemble each other. Bingo! Genus Mecas! I showed it to Steven Lingafelter and with the help of Pat's house-synoptic collection, we had the species: Mecas menthae. Sure enough, not only did the plant turn out to be Salvia leucantha (Mexican Sage) in the Mint Family (Labiaceae) but we found 5 more specimens on the bush, making it clear that the beetles do consider it their host plant.


After a trip to Copper Canyon where our lights were inundated with scarabs from tiny Diplotaxis to sturdy  Phileurus truncatus and Strategus aloeus and a restful night's sleep in the back of my Subaru
I visited the garden again. This time I found a nice number of leaf beetle species on Sacred Datura and some morning glories whose leaves were just about skeletonized.

Elytroleptus luteus in situ
But then a little streak of orange on a leave of a tall evening primose where I had been watching pinhead sized jumping weevils. Another Cerambycid? Or a very narrow Netwing? From the expert came the e mail shout 'Holy cow, that is a fascinating beetle! ' We both tentatively talked of Elytroleptus sp., but none that we knew.  What Steven Lingafelter then found looked all wrong at first glance: A beetle not red, but yellow and even called E. luteus. But as an experienced collector and taxonomist he knows that dried specimens may change from red to yellow, and that species are sometimes described from dry museum specimens. Maybe the author was never lucky enough to see our bug alive and beautifully contrasted by a green leaf.  The other details, like proportions, leg coloration, and costae on the elytra fit very well. So I guess he got the correct id!

Elytroleptus luteus
 
Check out the distribution for this beetle: it just makes it across the Mexican Border into Arizona, but it's found all through Central America.


Longhorns in the genus Elytroleptus are considered mimics of toxic beetles in the family Lycidae whom they closely resemble.
Close to the Longhorn imitator, I found a Jumpingspider that was trying to take down one of the toxic Lycids. It released the beetle unharmed. I do not know if my camera disturbed it or if it found the beetle unpalatable.



2 comments:

  1. Sounds like an awesome trip! Did you see a lot of P truncatus? It's currently my favorite beetle because they live so long in captivity. I got a few at Miller Canyon.

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