Wednesday, August 22, 2012

I love organic gardens!

The citizens of the little town of Patagonia in Santa Cruz County, Arizona, maintain a beautiful butterfly garden and a lush community garden with vegetables. We never fail to visit there on our insect field trips.

These gardens seem to be kept under a strictly organic regimen. While this keeps the produce healthy and delicious, it comes of course with some trade-offs for the gardeners and bonus points for the entomologists.

Melanoplus differentialis nymph
One gardener philosophically watched his cobs of sweet corn disappear into the stomachs of countless juvenile Differential Grasshoppers. Smartly, he had planted his plots in three time intervals, and only one set of corn coincidet with the hungry hoppers, so next year he will just skip that planting date.

Black Swallowtail caterpillar - Papilio polyxenes
The Dill plants sported beautiful and undisturbed Black Swallowtails caterpillars of all ages.  These guys aren't shy. They flaunt their warning colors in front of all the hungry birds on those nearly bare branches - the must taste really awful.

Zygogramma exclamtionis, the Sunflower Leaf Beetle.
The leafs of the annual sunflowers were eaten to shreds by the larvae of Zygogramma exclamtionis, the Sunflower Leaf Beetle.

Disonycha politula
Pigweed, maybe grown for use in salads at a younger age, was hopping with Amaranthus-feeding Flee Beetles. Some folk with 'Careless Weed' allergies may even like to see these guys at work.

Deloyala lecontei
Morning Glory leaves were punctured by the iridescent tortois beetles Deloyala lecontei. They were hatching from pupae and mating right away.

Lema daturaphila (Three-lined Potato Beetle)
Tomatillo plants had all but disappeared under the onslaught of Lema daturaphila. The beetles seemed to be much more restrained on their name-giving host, the Sacred Datura.

Leptinotarsa haldeman
Bell Peppers were attacked by the blue relative of the Potato Beetle, Leptinotarsa haldemani, here  shown on a wild Nightshade.

Gratiana pallidula: larva, pupa, adult. Here on Silverleaf Nightshade
For a keen observer, the full life-cycle of a the tortoise beetle Gratiana pallidula was displayed on the leaves of Egg Plants. All stages were very cryptic.

Epilachna varivestis (Mexican Bean Beetle)
Bean leafs were skeletonized by bright yellow, spiny larvae which I first mistook for those of another tortois beetle. But because I hadn't seen this particular one before I collected some. They pupated, and out came - yellow Ladybugs. I know. They are supposed to be the gardener's little helpers and devour aphids and other pests. Not this species. The Mexican Bean Beetle is a Cocinnellid, but also a vegetarian and can become a pest of its own when he gets into big commercial bean growing areas. In the US, there is one more vegetarian Ladybug, also genus Epilachna, that feeds on the leaves of cucumbers, squash and related plants.

I met Fred an Mary Heath who were doing an annual butterfly species count and ecitedly noted that they had 90 species total in the Patagonia area, and 60 of those just in the gardens. There are no butterflies without caterpillars, and they need to feed on plants!

Visiting the Patagonia Community Garden reminded me of the difficulties and joys (if you come from the angle of a bug-lover or of an insectivorous bird) of organic gardening.
Yearly crop changes or under-plowing of left-over plant material could probably prevent a part of the infestations. But organic gardening faces more challenges  in Arizona  than for example in Germany. One reason is the lack of really cold winters that annually kill scores of insects in more northern climates.
But there is another factor that cannot be overlooked: The Americas are the original home of many cultivated crops. Potato, tomato, tobacco, corn (mais), sunflower, squash, many species of beans, all were first cultivated here thousands of years ago. The wild ancestors or relatives of those species are still all around us, and so are many of the insects that evolved with these plants as their hosts. Those were the ones that I found at work in the Patagonia garden.

In the sequel of this blog, I will discuss the advantages of gardening with locally derived plants as opposed to cultivating imported species.

Until then, here's a great article by one of my BugGuide Friends:

Thursday, August 16, 2012

Our Peppersauce Field Trip Made the News

 The Arizona Daily Star sent a photographer to join our first Audubon insect field trip. He stayed for hours, interviewing and photographing. The images that were published today in the Northwest section of the paper capture very well what one participant called a magical night.

Saturday, August 11, 2012

Black Lights to draw Moths and the Public

Since the beginning of August I have been quite busy. After those heavy monsoon rains there were a lot of insects to photograph and collect and in addition I had gave an insect themed power point presentation at South West Wings in Sierra Vista, combined with a black-lighting field trip to Ramsey Canyon.

Dysschema howardi (Northern Giant Flag Moth - Hodges#8040)
 Last Thursday I was leading an Audubon field trip to Peppersauce Canyon on the north side of the Catalina Mountains. We had a nice list of sign-ups through Audubon, Flickr and facebook.  The local newspaper, the Arizona Star, surprisingly sent a photographer, and local author and moth expert Mike Wilson joined us in the canyon where he and Doug Mullins were collecting caterpillars.

 Fellow BugGuide Member Patrick Coin from Durham, NC, was staying in Tucson and took the opportunity to see more of the local fauna.  Muriel Béchu, a young German Scientist at the U of A College of Optics came to see the structural prismatic colors of moths in real life. She stayed to the very end at around 11 pm and actually discovered the prize of the night, the beautiful Northern Giant Flag Moth (She posed with Glover's Silk Moth)

Chrysina gloriosa
The beauty of Chrysina gloriosa, the Glorious Jewel Scarab made up for the lack of  variety of beetle species. Either the drought of the last years is taking its toll or the Mercury Vapor light that I am using now is more appealing to moths than to beetles.

Males of the tribe Dynastini
 We got scores of Rhinoceros Beetles walking all around us, two Dynastes grantii and one Strategus aloeus. The last three were females, I'm showing the males above.

Amblycheila baroni (Montane Giant Tiger Beetle) and Leptinotarsa rubiginosa (Reddish Potato Beetle)
 Very special to me were the Giant Tigerbeetle and the Tomato-red Potato Beetle. We also had smaller tigerbeetles, fungus and darkling beetles, and several scarabs. Please refer to my flickr gallery for picture of those species.

 After a couple of hours, our two sheets were so covered in moths, that it took a lot of enthusiasm to get close to them.

Kerrah Cutter was especially undeterred: decorated with moths all over she took a great series of photos to post on her facebook page. I'm sure we will meet again in the field to have some more interesting adventures with bugs and herps.  My friends Collins Cochran, Doug Mullins and Carol Tepper saved the night by keeping my new generator running and helping with set-up and take-down. Hanging the sheets from an easy-up tent frame and using three lights driven by a generator is too involved an undertaking do manage by myself, especially in a hurry with lots of people around who expect to hear me say something interesting while waiting for the slowly arriving bugs just after sunset.

I hope everybody enjoyed the trip and saw something interesting and new. I haven't had time to do a species count, but Patrick, who is a founding member of BugGuide and has a lot of experience from other parts of the world, was very impressed with the diversity of insects.

We were speculating why Arizona is ranked so very highly among all US states, and bordering Sonora, Mexico is even one of the locations with the highest species diversity world wide. There are many reasons:

1.The geological history here has been quite dramatic, so we are living on a mosaic of many different soil types, and hence among a patchwork of vegetation types, providing hosts for many different insect species.
 2.Our sky islands rise from the surrounding desert high enough to provide along their slopes everything from lowland sandy desert to pine forest and tundra like bare mountain tops at over 10,000 feet.
 3.Our two rainy seasons and high temperatures give us growing conditions for different organisms all year round.
4. We are at the border between temperate zones and the tropics.
5. We are experiencing a phase of climate changes that cause the spread of Mexican species into Arizona and may lead to the extinction of some long-term residents. The species distribution along the elevation levels of the mountains is most likely going to shift with rising temperatures and prolonged droughts.

I have collected images of most species that we saw last Thursday in Peppersauce Canyon in a flickr file. I will add additional identifications over the next week.

Wednesday, August 8, 2012

I have lapped filthy water from a hoof print

"I have lapped filthy water from a hoof print and was glad to have it."
"If I ever meet one of you Texas waddies who says he had never drank water out of a horse track I think I'll shake his hand, give him a Daniel Webster cigar."
In Charles Portis' True Grit the Texas Ranger LaBoeuf tries (and fails) to impress U.S. marshall Rooster Cogburn.

Couch's Spadefoot, Scaphiopus couchii
 In the real West in Arizona, the filthy water of a hoof print could well be your amniotic fluid, cradle, bathwater, and hunting ground -- if you are a young Couch's Spadefoot.  

Land-under in the bajada of the Tucson Mountains (our backyard)
On July 29th a huge thunderstorm rolled over our land and brought nearly three inches of rain in one hour. It poured down so hard that most of the water just raced down hill, carving out old arroyos, piling up new sand dunes, and slicing through flat areas to form new washes. For a couple of hours the sound of rushing water swallowed everything else.

Calling male Couch's Spadefoot by Seth Patterson
As soon as that din calmed down, a faint bleating like from a herd of sheep lost in the dark could be heard. The mating concert of Couch's Spadefoots.  

Mating spadefoots by Manuel Nevarez
 Spadefoots are also called toad-like frogs (Pelobatidae). While their shape is toad-like (short-legged, squat, with a bluntly rounded snout) their skin is smooth like a frogs and they lack the obvious paratoid glands of the Bufonids (most of our toads). But their vertical pupils and the spade-like tubercle on the underside of each hind foot set them apart from both frogs and toads. If you set a spadefoot on loose substrate you can watch how quickly he disappears backwards by shuffling those hind feet. These amphibians hold endurance records: they can stay under ground for years during droughts, nearly dried up and motionless in a little chamber plastered with their own skin excretions.

Spadefoot tadpoles Photo by Jeff Mitton
 Drumming raindrops of a substantial monsoon storm get the Spadefoots up and ready to find temporary rain pools to mate and lay their eggs. Tadpoles can be found a day later, feeding on organic debris and quickly developing algae.

The surface of the desert soil is reshaped by the heavy hoofs of horses.
Today, on the 8th of August, all rain pools have disappeared. But every morning, depressions in the soil are still visibly moist.

A tiny youngster in a hoof print
Walking our dogs around sunrise, we found tiny spadefoots emerging from those muddy spots,  scrambling for cover under freshly green Triangular-leaf Burr Sage bushes. Most of the deeper mud spots were the hoof prints of our neighbors' rodeo horses.

The little amphibians are still smaller than grasshoppers, not much more than a quarter inch. They are able to absorb moisture through their skin, but they have to leave the exposed muddy tracks before the morning sun reaches them.

Some will try to risk the heat of the day in the cracks that open up as the mud in the hoof impression dries. I hope they make it!

Young Red-spotted Toad (Bufo punctatus)?
When I went through this morning's photos, I realized that some of the larger anuran kids seemed to have horizontal pupils and looked rather toad-like. These are young Red-spotted Toads.

Adult Red-spotted Toad (Bufo punctatus)
They supposedly need more permanent creeks and pools for breeding, but the adults are around, and those rainwater pools are all our desert here has to offer. I may  have even heard their monotonously trilling mating call and mistaken it for the purring of some of the local Night Hawks.