Wednesday, June 23, 2010

Cicada Time

Here in southern Arizona it is cicada season. It is fitting that these insects should appear at the hottest time of the year, for their shrill “songs” seem to be the very sound of heat, reminiscent of something sizzling in the frying pan that is the Sonoran Desert in late June.

Cicadas are “true bugs” in the order Hemiptera, suborder Auchenorrhyncha, and family Cicadidae. They have piercing-sucking mouthparts used to tap sap flowing in the limbs of trees and shrubs. Actually, they live underground as nymphs for the bulk of their lives, sucking on sap in the roots of trees and shrubs.

As if the racket of male cicadas is not enough to announce their presence, the ghostly exuviae of nymphs adorn nearly every vertical surface in the wake of their emergence from their underground youth. Examining one of these shed exoskeletons reveals several interesting details. The front legs of the nymphs are stout, toothed, and built for digging through the soil and getting from root to root. When their development is complete, those muscular appendages double as grappling hooks, pulling the insect up a tree trunk, fence post, or other handy object.

Once above ground and firmly locked on to a perch, the insect splits its exoskeleton down the back. An adult cicada then unfurls itself. The stubby wings gradually inflate, pigments manifest themselves, and the new exoskeleton hardens. All of this takes place under cover of night, when they are at least somewhat less vulnerable to predators and parasites. [This emergence series was taken in Mission, Texas]

The grand entrance of the adult is the culmination of a life cycle that spans between three and seven years, on average, for most species of cicadas. The celebrated periodical cicadas in the genus Magicicada that appear only every 13 or 17 years, depending on the population or “brood” assigned Roman numerals, are synchronous in their massive emergences. Most cicadas qualify as “annual” species where individuals appear every year (or nearly so), because the generations are staggered.

Only the male cicadas “sing,” most species possessing an elaborate internal percussion organ called a tymbal. The tymbal is vibrated at a high frequency by muscles in the abdomen of the insect. The sound resonates in a largely hollow abdomen and comes pouring out of paired chambers, each covered by a large plate called an operculum. The insect can bend its abdomen in such a way that the sound can be amplified at will. Any person within earshot wishes they had brought their earplugs. Apparently, the serenade works on female cicadas, for they are indeed attracted to the males.

There are apparently at least ten species of cicadas within ten miles of Tucson, and they seem to be separated by elevation. Here on the simmering valley floor, Diceroprocta semicincta is the dominant species, clinging to the branches of mesquite trees for the most part (see image above). A mere couple of hundred feet higher, in the foothills of the Santa Catalina Mountains, the “cactus dodger,” Cacama valvata almost completely replaces D. semicincta. Besides differences in the “songs,” cactus dodgers live up to their name by appearing quite wary. Approach one and he begins walking backwards down the branch from where he is singing. Hanging upside down from a slender creosote branch seems to benefit C. valvata in a number of ways. It allows maximum projection of its “music,” and the white, wax-coated belly of the beast reflects the intense desert heat, preventing the bug from cooking in the mid-day sun.

Higher still, in the oak-juniper zone, we find another Diceroprocta. D. swalei is easily recognized by the dark zig-zag band across each front wing.

Around 6,000 feet in elevation we come across the “wing-bangers” of the genus Platypedia. Putnam’s cicada, Platypedia putnami, occurs in among the evergreen trees, in the understory. Male wing-bangers lack the tymbals of their cousins, so they produce sound by tapping their wings on the branches where they sit. The tick-ticking noise is subtle to humans, but apparently effective enough to attract mates.

Cicadas are not without their enemies. Many a bird preys upon them, repeatedly smashing the insect against a hard surface to “tenderize” it before gulping it down. Sometimes the cicada escapes during this treatment.

Cicadas are a lot less likely to escape the paralyzing sting of a huge “cicada killer” wasp. Here, the western cicada killer, Sphecius grandis, is harvesting cactus dodgers. Each female wasp excavates a burrow that branches into several underground cells. Each cell is stocked with one or two paralyzed cicadas and a single egg is then laid in the cell. The egg hatches into a larva that will eat the cache of cicadas. One cicada yields a male cicada killer. Two cicadas yields a female wasp.

I just learned of an insidious cicada parasite from my friend Carl Olson, Associate Curator of Entomology at the University of Arizona. Apparently there is a type of sarcophagid fly, Emblemasoma spp. that attacks the tymbal organ of a male cicada. The larval fly effectively renders the cicada host unable to sing in “stereo.”

It may not be possible for you to “enjoy” cicadas, at least not in the auditory sense, but one has to marvel at these amazing insects and their place in the ecosystem. Find out what species are in your own area. You might start by surfing such great websites as Cicada Mania, or Cicada Central.

Wednesday, June 16, 2010

Yet another new venture I am involved in is an educational (though still commercial) website, It is the brainchild of webmaster Kyle Williams who in the course of building another website on outdoor survival discovered that a great number of people want to know which spiders are potentially dangerous.

Kyle posted a recruitment notice for spider experts on and I hastily replied, along with another spider expert, Mandy Howe. The two of us have been sharing moderator duties in the Forums section of the website since March. The site now offers an FAQ (frequently asked questions) section and a glossary of terms. An image gallery will follow shortly, along with expanded information on dangerous North American spiders.

One of the more pleasant surprises to come out of this has been the rapid development of a community of spider-lovers who have been eager to share their own images and discoveries while helping solve the “mystery spiders” presented by other folks.

Another reward has been the conversion of many spider-phobic individuals into spider-tolerant people, or even new spider-lovers. Nearly everyone who has posted an image to the “Submit Your Picture” section, even if they have done so in a state of panic, has offered generous compliments to us for the work we are doing.

What is next for We need your help to publicize the website as the resource for accurate identifications of spiders, essential information about them, and where empathetic staff understand squeamish and fearful reactions to arachnids and won’t admonish you for those sentiments.

The website currently generates revenue through Google Ads, though we do not explicitly endorse any product or service. Finding additional sources of income is another challenge we face.

I am very grateful to be working with such fine people on this website, for the income it is generating for me, and for the opportunity to continue learning and passing along my knowledge of the arachnid world. Special thanks to Kyle and Mandy for making it such an exciting venture.

One of the reasons my blog posts were sparse for a few weeks in May was because I was working up articles for the educational website Yes, I was financially compensated for my research and writing services. Yes, the website is tied to another website for a manufacturer of dust mite mattress covers and related products. I am not promoting the products here. What I do hope is that my blog followers will point out any inaccuracies in the text, and/or give me a nudge if they hear of any new research or information pertinent to updating

This project, likely to be an ongoing exercise, was quite challenging. Our collective knowledge of dust mites and their allergens is in relative infancy. One of the two most abundant and important species was only named and described in 1961. We still don’t fully understand the properties of some of the allergens, or how they act on our immune system.

There is also conflicting opinion as to the best way to alleviate asthma symptoms that are aggravated chiefly by dust mite allergens. According to one person who contacted me, rhinitis (upper respiratory system inflammation) symptoms are substantially relieved by dust mite covers on mattresses and box springs, but asthma (lower respiratory system inflammation) symptoms often persist.

A personal note: This kind of work, helping people through the dissemination of scientific information, is what I most enjoy doing. I welcome more projects like this in the future, be they related to entomology or natural history in general. Thanks for your patience during those times I am thus engaged and not as prolific in my blogging.

Tuesday, June 8, 2010

Meet Mary Jane

I owe a big thank you to my friend Joshua Stuart Rose for suggesting that I become friends with Mary Jane Epps via Facebook. Mary Jane (“MJ”) is currently a PhD student here at the University of Arizona. She came to know Josh when they were undergrads in biology at Duke University in Durham, North Carolina. She is a wonderful young lady with many talents and an endless fascination for the natural world.

I got to meet her in person last week when we made a spontaneous half-day journey up the Mount Lemmon Highway in the Santa Catalina Mountains north of Tucson. She was due to leave in two days for her “field season” in southwest Virginia and wanted to make a quick getaway here before she left. I was honored to join her.

MJ grew up in Virginia with a brother, sister, and parents who both teach at the University of Virginia. She decided to attend Duke in part to avoid student-teacher conflicts with mom and dad, but she also has a great love of the longleaf pine forests of the Carolinas. No matter where she goes, MJ excels in academics. She recharges her batteries by literally “fiddling around.” She is an accomplished musician who jams with friends playing traditional Appalachian music as well as a bit of bluegrass here and there.

There are many qualities I admire in Mary Jane, not the least of which is that she takes initiative in meeting other people. She has a warm smile and friendly personality that is instantly disarming. It is impossible not to feel relaxed and welcome in her presence.

She also uses all of her senses to familiarize herself with the flora and fauna wherever she finds herself. She reawakened my own sense of smell by crushing leaves to help her identify a particular plant and then sharing the scent with me. She literally looks closely at the tiniest of organisms, carrying a magnifying loop and using it liberally, like here in Molino Canyon last Wednesday during our outing together.

Mary Jane is studying the relationship between fungi and beetles (the beetles to be found in mushrooms for example), and is two years into what she expects will be at least a four year doctoral thesis project. She told me she dissected over 1,500 tiny rove beetles (family Staphylinidae) to identify them to species by differences in their genitalia. I told her I would have just handed her the degree already. That is the kind of dedication she applies to her passions. I can only imagine what her musical talents must be like.

I’m already looking forward to spending more time afield with MJ when she returns here in the fall. Meanwhile, I wish her well with her studies.

Tuesday, June 1, 2010

Meet Margarethe Brummermann

If there is one person in Tucson who has single-handedly made my life here a true joy, then it is Dr. Margarethe Brummermann. We met through that wonderful social network known as BugGuide, when she began posting insect images to that site. There is much more to Margarethe than just insects, though, and I have enjoyed learning about her former adventures while sharing in some of her new ones.

Margarethe actually lives just outside of Tucson, west and north of the city in Picture Rocks, on the other side of the Tucson Mountains. She lives in a very nice home with her husband, Randy, and a “pack” of five dogs: Montana (“Tana”), Cody, Leika, Frodo, and Bilbo (plus two cats, Boris and Natasha, named of course for the villainous duo in Rocky and Bullwinkle).

They have neighbors, but houses here are widely scattered by city standards, and there is lots of space around their residence. Plus, they are adjacent to state rangelands where cattle graze, coyotes roam, and rattlesnakes are common. It is an austere but scenic landscape, save for a vast mountain of rubble from the nearby quarry.

Indoors, Margarethe’s passions are evident in every room in the house. While she has degrees in zoology and vertebrate physiology, she is also an accomplished and popular artist. Working mostly in watercolor, she paints everything from pets to western life and landscapes. She erects a booth in several outdoor art shows and festivals each year, and her work also hangs in local galleries. She has also done commissioned work.

The last couple of years, Margarethe has created a new project for herself: documenting in digital images the many colorful and unique beetles of Arizona. She shoots images in the field, but also brings specimens home to photograph on a clean white background to bring out the finer details and truer colors of her subjects. Her intention is to publish a “coffee table book” with plates of her images and a brief explanatory text. She has already had interest from publishers; and her latest count is over 800 species of Coleoptera she has imaged.

German by birth, Margarethe has traveled the world and done field research on a wide array of animals. Her stories are vivid and entertaining, as well as educational, and she shares them freely when we take day trips together out of town. She is not above poking fun at me, too, but she’s endlessly patient with my quirks and tolerant and forgiving of my sometimes irresponsibly slower pace in the field.

One of the many joys we have is introducing each other to other entomologists, insect enthusiasts, and wildlife photographers here in Arizona. We often go together to gatherings like the annual “Beetle Bash” hosted by Fred and Carol Skillman at their home in the Dragoon Mountains; and Pat Sullivan and Lisa Lee in Sierra Vista who have recently started holding an annual “Infestation” of entomologists at their own residence.

I can honestly say that my life would be a great deal poorer for not knowing Margarethe and Randy, and certainly a lot duller without our regular excursions away from the city and into the lovely canyons and mountains. Scenic landscapes, incredible fauna and flora, and great company: Who could ask for more? Thank you, Margarethe!

NOTE: You will want to follow Margarethe’s adventures, observations, and passions for yourself at her new blog, Arizona: Beetles, Bugs, Birds and More.