Saturday, November 27, 2010

A Cremastocheilas relative, Lissomelas flohri, Bates 1889

During the July Sabino Canyon Butterfly Count Doug Mullins found a beetle that he described as big, black, rectangular and flat. It seemed too big for any Cremastocheilus, and though I suspected Lissomelas, there was something missing in this description...

Sca Cet Cre: Lissomelas flohri Bates 1889
Now I finally got the beetle.What a strange guy! 24mm long, it  looks like a plastic toy model of a beetle, with all unnecessary detail omitted. Even mouth parts and antennae were hidden under a round plate that completely closed off the head before I teased it open

 This photo of  the type specimen curated at the British Natural History Museum was posted for me on flickr. Many thanks to the curators for their help!
Photo: Hillary B. Warner NHM
I couldn't find much about the biology of these beetles. By most accounts they hilltop here in Arizona after the first summer rains. Doug, the butterfly man, notes that  this one was on "Cynea" hilltop with a mating aggregation (I still need to find out what that means. Aren't field notes fun? He told me later that several of the beetles were seen in the tops of smallish trees on a ridge close to Windy Point on Catalina Highway).
A guest at Fred Skillman's Beetle Bash in early July mentioned that he watched Lissomelas cruising the road in front of the Madera Canyon Lodge that morning.
Charles O'Brien found a whole series of very fresh dead ones after watching them cruise the parking lot of Kitt Peak. These fresh ones had a big patch of velvet on their elytra. The total, traceless lack.of this feature  made me doubt my initial identification of Doug's beetle until Bill Warner checked the picture above.
CW O'Briens's specimen with velvty spot on the elytra
Biology of Cremastocheilini:
I have often watched our tiny local fire ants grab half inch-sized scarabs that tumble down after blundering into the wall at the porch-light. The giants have no chance against those Lilliputian armies. In that case it means certain death for the beetle.

Solenopsis xyloni (Southern Fire Ant) tackles a small aphodine Scarab

 Cremastocheilini - Anteater Scarab Beetles make use of their own of this ant behavior. In Arizona, they  fly after the first monsoon rains until they find a fitting ant hill (species specific association, I think). They drop like dead and the ants will come running to grab the easy "prey" and carry it into their nest. But these beetles are uniquely  protected.

They pull down the lid that covers their heads (including antennae and mouth parts) like a soldier in a tank in battle mode. Ants dismember their prey by pulling off the legs, but here they find few spines or texture to grab onto. No exposed membranes to place a paralyzing sting- the sclerites of these beetles are a tight-fitting armor. Some sacrifice of leg flexibilty is noticeable. Once in the nest, the pitted bodies of most species of Cremastocheilus seem to absorb the ant's odor while also producing pheromones of their own from Thoracic glands to pacify the hosts. The velvety patch on the elytra of Lossomelas may serve a similar purpose. Supposedly the adult Cremastocheilus feed on ants and their brood. They lay their eggs in the ant nest and the beetle larvae feed on decaying plant material that the ants have discarded at the nest entrance.
The position and reduced size of the mouth parts of Lissomelas flohri make me wonder whether this species feeds much at all as adult. Lissomelas has not been found in any ant nests and the biology of this mostly Mexican beetle is still largely unknown Scarabaeus 11/1980

Sunday, November 21, 2010

Florida Canyon Buprestids - a last Hurrah in late November

On November 20th Randy and I loaded four of our five dogs into the bed of my little pick up truck with camper shell, but the fifth, our Husky Tana, run off to visit the neighbors instead. She missed a beautiful autumn hike in Florida Canyon in the Santa Rita Mountains. Florida (pronounced floor-EE-da in this part of the country) is the Spanish word for "flowered". Of course, November is not quite the right time to experience that aspect of the canyon.

Great Purple Hairstreak
Chauliognathus profundus

Tachypompilus unicolor

When I discovered this area two weeks ago, at least the Desert Broom along the dirt road that connects Box and Florida Canyon was still in bloom and attracted scores of wasps, butterflies, beetles, and grasshoppers.  But even those bushes had gone to seed by now.

The rocky dry creek bed under its dense canopy of Mexican Blue Oaks (Quercus oblongifolia) where I had found several interesting grasshoppers now also seemed quite abandoned by insects.

The hiking trail begins next to the Florida Work Center of the Santa Rita Experimental Range. The range, the first of its kind in the country, was established by President Theodore Roosevelt in 1902 to study recovery efforts on land that suffered from the devastating effects of overgrazing and drought.

Following the creek and its gallery of 400 year-old oaks, we hiked through lush grassland towards the juniper-oak-pine forest of the higher elevations.

 The dry grasses still carried their feathery plumes, golden in the light of the low sun.
Only Cody’s tail rivaled the effect. All four dogs loved exploring the unfamiliar terrain.

 Rusty old stock tanks held only a few inches of water. Tadpoles and insect larvae were moving in the murky green soup and made us wonder whether they would find their way out in time. As we started to feel the strain of the steady climb we marveled at the miles of partly buried metal feeder  line that brought water from the mountain top: what a plumbing job.

It was a cool day by Arizona standards, but we welcomed the shady forest of the higher elevation.  Here oaks, pines and junipers dominated in shades of cool bluish greens. By contrast, the golden foliage of a few sycamores and mountain ashes seemed to glow from within.

Agaves, Sotols and Yuccas added some spiky silvery accents.

Eventually we reached clearings and openings that had been created by a fire that swept through the canyon in 2005. Beautiful skeletal remains are still recognizable as those of Aligator Junipers and various species of oaks, and even of the rare Madrones.

Fresh growth around the dead trunks announces that the roots survived and the trees are coming back.

We didn’t quite make it to the 7,800 feet high Florida Saddle but climbed a lower hilltop – to enjoy the great view over the Santa Cruz valley, eat some apples, let the dogs rest, and maybe see some hill-topping insects? It was quite cool and windy…

Lampetis webbii LeConte 1858.
A big insect appeared. I heard the low buzz and saw a blurr of dark and lighter stripes out of the corner of my eyes and mistook it for a big paper wasp. But the heavy body that was hanging upside down from in the leaves of one of those fire damaged oaks was unmistakeably that of a buprestid beetle.

 Loose rows of golden spots reflected the sunlight, but he most striking feature were the electric blue legs and feet: Either Drummond's or Webb's Blue-footed Buprestid. Buprestids are called jewel beetles in Europe with good reason: they are beautiful. Their ponderous and prosaic American name Flat-headed Metallic Wood-boring Beetle points to their biology: While the adults live on pollen or sweet juices, the larvae of the larger species live mostly in the sap or core wood of trees. The flat thoracic segments of these legless larvae are what’s described by 'flat-headed'. The cross-sections of their tunnels (galleries) and the exit holes are broad ovals while those of Cerambycids are more round. Buprestids attack mostly weakened or damaged trees. The females of some species are so attracted to the smell of fire that they fly nearly into the flames of a forest fire to lay their eggs.

Last September, the manager of the Little Outfit Ranch in the Canelo Hills had collected a couple of  Lampetis  for me, also from a fire damaged oak, but this one in Florida Canyon was the first that I saw in the wild. As for the species:  
Lampetis drummondi and Lampetis webbii
Lampetis drummondi that were collected further east in Texas, New Mexico and Cochise County Arizona have spots that are nearly fused into irregular bands. The specimen above, left, was collected by Jason Schaller in Texas Canyon, Cochise County, in late July of 2010. My specimens of L. webbii from Montosa Canyon, Santa Rita Mountains and theLittle Outfit Ranch in the Canelo Hills, AZ  have clearly independent spots. It seems to me that in the larger females of L. webbii the spots that are more lined up than in the smaller males but always distinctly separated. So my Florida Canyon guy is also L. webbii.  The host plant for that species is supposedly the Palo Verde of the lower desert, but none of the beetles was found in habitats where those occur, instead all were associated with fire damaged oaks.

Hippomelas sphenicus
On our way back through grassland interspersed with small bushes of Velvet-pod Acacia Randy spotted another big Buprestid: Hippomelas sphenicus. From early October to mid November these beetles could be found all over the lower parts of the western Santa Rita Canyons. They met on the acacias to mate and probably lay their eggs. Surprisingly for Buprestids, they were especially active at sunset.

Tree Cricket Oecanthus sp.
The musical song of the Tree Crickets accompanied us all afternoon. David Ferguson commented: 'I suspect it is of the O. californicus "group", and likely of the "pictipennis" segregate, which seems to like to sit in (and probably feed on) Junipers and perhaps Piñons.'

The last few Arizona Thistles were visited by so many Mexican Yellows Eurema mexicana that the butterflies sometimes looked like flower petals.

After a great exhausting day we were greeted at home by our wayward Husky who was waiting in the driveway and very happy to have her pack-mates back.