Thursday, April 19, 2018

Book Review: Dr. Eleanor's Book of Common Spiders

One resource that has been missing from the recent explosion of spider-related material coming from various publishers has been a book aimed squarely at the average homeowner or gardener with something other than an all-consuming passion for arachnids. "Dr. Eleanor" to the rescue with Dr. Eleanor's Book of Common Spiders (Chicago: The University of Chicago Press. 2018. 96 pp.).

Eleanor Spicer Rice, who already has several related titles under her belt, mostly about ants, has teamed up with Chris Buddle to deliver a nicely organized, thoroughly researched book on the spider species that the public most often asks about. You know, the eight-legged critter crawling across the kitchen floor, the infamous "shower spider," and the ones you always see in the (insert shed, basement, garage, or other appropriate venue).

The authors treat their subjects with accuracy, clarity, and brevity, while still managing to cultivate the same sense of fascination in the reader that they, as scientists and writers, have already found for themselves. This is no small feat. There is a dash of humor here and there as well, and they are not above poking fun at themselves. Color photographs, mostly by Sean McCann, complement the lively text and enhance the impact of the book. Whether arachnophobes will reach for it on the bookstore shelf, or over the online vendors remains to be seen. I hope they do.

Even if the book were a complete failure otherwise, it would bear recommending for this passage alone:

"Striped lynx spiders prefer biding their time in agricultural fields. When we plant our crops with only one or two types of plant per field, we humans essentially sow arthropod grocery superstores. In nature, any given species of plant is often mixed in with other plant species and so bugs that like a particular plant species may need to search to find the plansts they like. As a result, only a limited number of bugs can live in an area. It's like living in a town with a gas station-sized grocery store. In our human-planted superstores, however, tons of insects that like our crops can move into the giant all-you-can-eat buffet of a farm, filled with only their favorite foods. These insects become agricultural pests, gobbling up billions of dollars' worth of food we grow for ourselves each year."

Exactly. I have said the same thing myself in my own publications, about how humans are responsible for creating their own insect pests. Further, all the crop plants are equally vulnerable because they have identical genetics. Not so in nature. Watch a butterfly laying eggs. She won't oviposit on every plant; only on those a little weaker in their chemical defenses.

My only quibbles with the book stem mostly from the fact that I am a writer, too. There were a couple of bad word choices, but I see worse errors in other books. There was one implied assertion that is incorrect, however. In the Frequently Asked Questions part of the back matter, one FAQ concerns whether all spiders are venomous. The authors indicate they are. This is not true. Spiders in the family Uloboridae, common in North America, lack venom glands. Lastly, there are some common English names for certain spider species or genera that were apparently created just for this book. There is no such thing as a "Ceiling Spider," even though I would endorse that name for Cheiracanthium species because that is exactly where you encounter them.

Enough nit-picking. The "up sides" of this handy volume are much more numerous. It is a paperback, and of a size that is large enough to not lose easily in a stack of other books, and comfortable to handle for those of us who are all thumbs. Again, the text is a joy to read. Spicer and Buddle manage to give each spider a personality that reflects its biology. This style comes close to anthropomorphism, but I am all in favor of whatever it takes to win more arachnophiles. Spiders need all the friends they can get in Humanland.

One of my measures of the goodness of a book like this is whether it teaches me, a longtime naturalist, something new. This book did that, in spades. I love being surprised with new knowledge, and with that I heartily recommend Dr. Eleanor's Book of Common Spiders.

Saturday, April 7, 2018

Mark Your Calendar....

Time for updates on upcoming events, point out a new feature to this blog, and solicit additional sponsors. It may not feel like spring everywhere, but don't let it sneak up on you and catch you unprepared. Here are some things to look forward to, in Colorado and elsewhere.

Tiger Beetle Hunt, Lake Pueblo State Park, April 14
April, 2018
  • April 14 (Saturday), 9:45 AM - 3 PM (maximum): Second Annual Tiger Beetle Hunt at Lake Pueblo State Park, Colorado, USA, by the Mile High Bug Club. We can expect to see at least five species of colorful Cicindela tiger beetles.
  • April 18 (Wednesday), 6:30-8:30 PM: "The Magic of Moths,", presented by yours truly at Bear Creek Nature Center for the Aiken Audubon Society, Colorado Springs, Colorado, USA.
  • April 21 (Saturday), 9 AM - 3 PM: Mile High Bug Club at Garden of the Gods Park for Earth Day, Colorado Springs, Colorado, USA.
  • April 22-24 (Sunday through Tuesday), various times: daytime insect walks and evening presentation by "Bug Eric" for the Austin Butterfly Forum, Austin, Texas, USA.

"The Magic of Moths," Bear Creek Nature Center, April 18
May, 2018
  • May 12 (Saturday), 9 AM - Noon: "Tarantulas of Colorado" with the Mile High Bug Club for the Pikes Peak Birding & Nature Festival at Bear Creek Nature Center, Colorado Springs, Colorado, USA. Register now for field trips and other activities!
  • May 14 (Monday), 6:30 PM - 8:30 PM: Mile High Bug Club membership meeting at the Gold Hill Division Police Station, Colorado Springs, Colorado, USA. Come learn more about our education and conservation organization and what we have planned.
  • May 19 (Saturday), 11 AM - 3 PM: "Tarantulas of Colorado" with the Mile High Bug Club at the Rocky Mountain Dinosaur Resource Center, Woodland Park, Colorado, USA. We will have live examples of the three tarantula species found in Colorado, plus much more.

That's all for events as of now, but watch this blog for additions as the weather warms.

© Megan Miller
Tarantulas of Colorado, Bear Creek Nature Center, May 19

New! "How to Make an Insect Collection"

You may have noticed the new tab at the top of this page. Click on it and you will be taken to a comprehensive and highly organized text and graphic document on how to make an insect collection. This may prove useful to teachers, students, naturalists, and citizen scientists wishing to collect insects in a fashion that will enhance their historical and scientific value as preserved specimens. I recognize collecting is not for everyone. I know some people who only collect specimens they find already dead. Whatever your personal inclination, please understand that without specimen collections, our collective scientific understanding of the world would be non-existent. Thank you.

Sponsors and Advertisers Welcome

As always, I welcome sponsors and advertisers to support this blog. BioQuip and Tender Corporation are currently my only sponsors. I did apply recently for a grant, but am not assuming anything about the outcome. Long-term loyalty is what I am most looking for. Please contact me if your institution or business is compatible with the educational goals of this blog, and you would like advertising space.

Thank you, Donors!

I would like to publicly thank the many individuals who have contributed financially or in-kind to the endurance of this online publication. Your support is immeasurable and invaluable. I am considering adding another tab (page) to recognize donors by name. Please let me know if you think this is a good idea, an invasion of privacy, or whatever. I will not exercise this option without consent and consensus. Please comment below if you would be so kind. Thank you, and happy spring!

Wednesday, April 4, 2018

Odd Little Weevils

Over the eons....ok, decades, but it seems like eons, I have honed my search image for cryptic insects that other people overlook. Last week I was rewarded for discerning a pebble-mimicking insect from debris on the sidewalk. I will not disclose the number of times I have scrutinized some little object that turned out to be an actual pebble, bird poop, or other inanimate thing. This particular creature turned out to be a common but seldom-seen "bison dung weevil," genus Thecesternus.

These beetles, also known as "bison snout beetles," get their name from having first been discovered as habitually seeking shelter under chunks of bison dung on the North American plains. The weevils are nocturnal, flightless, and need protection from the searing heat of the day. Back in the day, "buffalo chips" were the most plentiful answer to that problem.

There are seven species of Thecesternus collectively found in the central, eastern, and southwest U.S. north to Alberta in Canada. They are only about six millimeters in body length, have a very truncated "nose," and are expert in feigning death by drawing in their face, antennae, and, to some degree, legs when frightened by a potential predator. It was difficult to get images of this particular specimen with its antennae extended, so sensitive was it to motion, vibration, and apparently even the camera flash. This represents only the third specimen I have found in Colorado, and one of the other two was dead when I discovered it.

What little we know about these beetles is thanks to the evaluation of one species, T. hirsutus, as a potential biological control in Australia for Parthenium hysterophorus, variously known as Santa Maria, Santa Maria Feverfew, Whitetop Weed, Famine Weed, and Bhajpa Weed, among other aliases. Native to the New World tropics, this plant is known for causing respiratory allergies, contact dermatitis, and genetic mutations in both people and livestock. It is not without redeeming attributes, too, but it has no place in regions where it did not originate. Consequently, several insects have been employed to control it.

Thecesternus hirsutus spends the winter in the larval stage, underground. Larvae hatch from eggs laid in the soil by the adult female weevils in the fall, when autumn rains trigger growth in plant life. The C-shaped grubs then burrow deeper and begin feeding externally on the roots of the host plant. Their activity stimulates the formation of a gall that eventually reaches about ten millimeters in diameter. Each larva encloses itself in an earthen chamber around its feeding site for protection from soil-dwelling predators. The cell is initially rather fragile, but is reinforced internally by anal secretions the larva applies to the interior walls with its mouth. The resulting "room" is quite durable.

The larvae feed into the winter months, reaching maturity between December and February (remember we are talking northern Mexico). The larvae remain dormant until early April when they molt into the pupa stage. Adult beetles emerge in April or May. The beetles feed above ground over the summer before starting the cycle anew.

In the laboratory rearing of T. hirsutus, a few young larvae were found in spring, indicating that some adult females may oviposit (lay eggs) at that time, resulting in a partial second generation of grubs during the summer months when it is usually adults that are present. Both of the living adult specimens I have encountered were found in April here in El Paso County, Colorado.

T. hirsutus turned out to be a poor candidate for control of Parthenium hysterophorus, but the rearing of the weevils demonstrated how well adapted they are to unpredictable weather patterns and volatile changes in climate. This may be a genus of beetles worth examining more in-depth as models of flexibility in the face of global warming and its attendant yearly extremes of heat, drought, and deluge.

The first specimen I discovered in Black Forest, Colorado

Sources: Arnett, Ross H., Jr., Michael C. Thomas, Paul E. Skelley, and J. Howard Frank, eds. 2002. American Beetles (vol. 2). Boca Raton: CRC Press. 861 pp.
Jacques, H.E. 1951. How to Know the Beetles. Dubuque, Iowa: Wm. C. Brown Company Publishers. 372 pp.
McClay, A.S. and D.M. Anderson. 1985. "Biology and Immature Stages of Thecesternus hirsutus Pierce (Coleoptera: Curculionidae) in North-eastern Mexico," Proc. Entomol. Soc. Wash. 87: 207-215.
Patel, Seema. 2011. "Harmful and beneficial aspects of Parthenium hysterophorus: an update," 3 Biotech 1(1): 1-9.

Friday, March 23, 2018

Pinyon Problems? Maybe, Maybe Not

I always seem to be caught off guard by the first insects to emerge in spring, and this year was no exception. The chance finding of a male scale insect prompted me to investigate an ornamental Pinyon Pine in our Colorado Springs townhouse complex, and that revealed yet another insect, or at least signs of one.

Walking in our neighborhood as I do most days, weather permitting, I happened upon what I figured must be a tiny midge or winged aphid, about one millimeter in length, on a wooden fence. Upon closer inspection it turned out to be a male scale insect of some sort. Scale insects generally give the impression of anything but an insect, a small, unmoving, button-like bump on a twig or branch. Mature male scale insects on the other hand often have wings and fly to find females. I was not aware they can appear so early in the season.

Male Pinyon Needle Scale

Back home, I took images of the specimen and tried to match it with something online. Male scale insects are so rarely noticed, let alone imaged, that I was not optimistic. Surprisingly, I found a close match in the genus Matsucoccus, family Matsucoccidae. This is a relatively new family, separated from its previous placement as part of the Margarodidae or "ground pearls." The tiny black and yellowish bug, with white waxy streamers emanating from its posterior, most resembled the Pinyon Needle Scale, Matsucoccus acalyptus, but I was hesitant to jump to conclusions. Our neighborhood is more in the high plains than a forest, though we do have many ornamental conifers.

Sure enough, I noticed a Pinyon Pine between two buildings in our townhouse complex. Now that I knew what I was looking for, I checked for sessile female scales, and managed to find a few. They are barely over one millimeter themselves. It turns out that the life cycle of this species is rather complex, with a lot going on at this time of year.

Adult female Pinyon Needle Scales

Mature females back out of the waxy covering that forms the "bean stage," and render themselves sexually receptive. As near as I can tell, the adult females have this mosaic pattern to them, whereas the "bean" stage does not. Once mated, the female crawls to an appropriate place to lay her oval cluster of yellowish eggs, encased in loose, white, silky webbing. Favored sites for egg laying include the root collar of the tree, in the crotches of large branches, the underside of large branches, or in deep fissures in the bark of the trunk.

"Crawlers" emerge from the eggs roughly five weeks after they are laid. This tiny, orange, first instar immature stage migrates up the tree to begin feeding on needles that grew the previous year. The insects use their piercing-sucking mouthparts to tap fluids inside the foliage. As they feed they begin secreting the wax coating that covers them. That coat turns black shortly after it is produced. The nymphs also molt into their second instar. This is the "bean" stage in which the immobile females pass the winter.

"Bean stage" of Pinyon Needle Scale

Second instar males crawl to the ground in October or November. There they go into a prepupal stage, wrapping themselves in white silken webbing beforehand. Three or four days later the males molt again into the pupa stage, spending the winter there. The female nymphs resume feeding the following spring, molt into adults, mate, and start the cycle anew.

The Pinyon Needle Scale is a native insect, but heavy infestations can severely weaken trees, making them vulnerable to subsequent attack by Pinyon Pine Beetles, Ips confusus, in natural ecosystems. Landscape trees are even more at risk because they are not always planted at appropriate elevations, in proper soils, with proper sun exposure. They are often planted in isolation, too.

Galls of Pinyon Spindle Gall Midge

While looking for the scales, I could not help but notice that many of the needles on the tree on our property were greatly swollen and yellowing. This is the work of an entirely different insect, the Pinyon Spindle Gall Midge, Pinyonia edulicola. It is a tiny fly in the gall midge family Cecidomyiidae. Its life cycle begins when a female lays several eggs in a developing needle in mid-summer. The larvae that hatch crawl to the base of the needle and their feeding activity stimulates the plant to grow needle tissue around them. From five to forty larvae occupy the resulting gall, continuing to feed and grow within it. They pupate in late spring of the following year. The adult flies emerge in mid-June to mid-July.

More Pinyon Spindle Gall Midge galls

Our Pinyon Pine tree seems to be doing ok despite the onslaught, and we tend to underestimate the resilience of plants in the face of insect attack. Our current drought is no doubt undermining the tree's natural defenses, but the insects feeding on it are also not immune to their own predators, parasites, and other enemies. It may be a good idea to keep tabs on the trees in your own yard, but resist the temptation to intervene at the first sight of some insect. Do your homework, ask for expert assistance, and then decide what, if anything, to do.

Sources: Cranshaw, Whitney. 2004. Garden Insects of North America. Princeton, New Jersey: Princeton University Press. 656 pp.
Furniss, R.L. and V.M. Carolin. 1977. Western Forest Insects. Washington, DC: U.S. Department of Agriculture Miscellaneous Publication No. 1339. 654 pp.
Phillips, Gene. 2018. "Pinyon Needle Scales, Matsucoccus acalyptus," Nevada Division of Forestry