Raising Dynastes successfully

Dynastes grantii development

 I have been asked repeatedly for the recipe of the wood mulch that I use for beetle larvae that feed on rotting wood. I got this recipe from my friend Bill Kaufman and it really works. Of course you need to prepare it at least 4 weeks ahead of time, so it's late now for Strategus larvae, but still time if you have and egg laying Dynastes female: those eggs take a break till next spring before they'll hatch.

For adults of scarab beetles, I usually use sieved peat moss for egg laying because it is easy to obtain in large amount and normally have success with it. Since peat moss usually carries mites that explode in their numbers very rapidly and cover adults and eggs, I microwave peat moss in a disposable tupperware (plastic bags can also be used) with a lid loosely placed on top; I usually put half-gallon container filled with peat moss in a microwave for about three minutes. After removing the tupperware from the microwave, I place the lid tightly and let the peat moss cool down for several hours. The moisture level is important for egg laying. You want the moisture level to be where peat moss forms a lump when pressed in your hand but easily breaks when poked by a finger. If a clump does not form, moisture level is too low. If a clump does not break easily, there is too much water. This rule of thumb usually applies to other substrate unless you are using very coarse substrate.

For lucanid egg laying, I do not use peat moss. I bury pieces of rotten wood in compost found in tree holes or homemade substrate. Compost is placed first in a container, and it is compressed hard for the first inch on the bottom. Rotten wood pieces are placed after being soak in water for a few hours. More compost is added to fill air space around rotten wood.

For scarab larvae, I usually mix multiple types of substrate. Compost found in deciduous tree holes is great. I also mix some well-rotten wood after braking it. Finally I add substrate I make. It is probably best to use only the homemade substrate if I can make enough of it. (since most dynastines prefer more decayed substrate than most lucanids do, it takes longer to make ideal substrate for scarabs than lucanids). The below are the steps I follow to make the substrate. Substrate that is commercially available in Japan and that generally produces larger beetles than the ones found in wild is made in a similar way. I sometimes use the homemade substrate only for lucanid larvae instead of mixing multiple types of substrate.

Supplies:
Barbeque wood pellet (I get oak from Ace Hardware)
Water
Yeast
Wheat flour
Plastic tub (10 to 20 gallon)
Large spoon or another item to mix substrate
Measuring cup
Bucket or plastic tub

Other items that may be helpful for you

1. Wash barbeque wood pellet by putting it in hot water in a bucket or another container. Rinse a few times. This process will remove most resin used to make the pellet. It is easier if you wash small amount of pellet at a time instead of trying to wash the whole bag of pellet.

2. Dry the washed wood pellet by placing in/on a tub, lid, newspaper, or tarp. If you make it shallow, it drys faster. The pellet becomes sawdust when it is dry. Make sure that it is completely dry before proceeding to the next step.

3. Add 7 to 8% (10% at most) by volume of wheat flour mixed with a couple of spoons of dry yeast into sawdust. It is very important that the container, sawdust, spoon, and your hands are dry during this step; otherwise, flour will make unwanted clumps, which will cause mold or lead to failure in the substrate making. Mix well so that sawdust and flour are mixed evenly.

4. add warm water and stir. Use enough water to get to a consistency that you can form balls of substrate that don't fall apart, but not more. It's moist, not wet.

5. Stir every day for a week, later once a week. Keep above 40 degrees Fahrenheit. White hyphens should run through all of it and the over all color will darken. But if you find black mold, throw it out, it's spoiled.


Important: The first time I tried this, all the males eclosed earlier than the females. This is normal for many insects. But in the confines of the terrarium, they got to the youg females before the females' exoskeleton had time to harden, and the females were killed. To prevent this sad situation, make sure you separate the male pupae (horned) from the females as soon as you can tell them apart. 




Good luck!

 

Evil Plants? Media Hype about the Buffalo Bur

Solanum rostratum, Buffalo Bur Nightshade Photo By leighannemcc

 A member of our SW U.S. Arthropods Face Book group wanted me to post a warning against the severe dangers posed by a plant that people might encounter while looking for insects.  The concerned and caring reader had found an older post on Fireflyforest.net. I think in the past I have used a very good plant guide to Arizona Wildflowers by the same author. 
But this time I was not impressed: After an anecdotal encounter involving the plant's burs and the author's dog, the native plant was maligned as evil, vicious and dangerous and called highly invasive. The plant: Solanum rostratum, Buffalo Bur Nightshade.
The attribute 'invasive' may stem from the usual reaction of landowners to an opportunistic plant that spreads in disturbed habitats. Worse - this one is said to form tumble weeds that roll about during droughts and spread the plant that way. Of course opportunistic colonizers among plants make no difference between 'disturbed' by natural causes or cleared by ranchers to raise cattle. In Marana, Arizona,  it grows happily on soggy, heavily grazed meadows along the Santa Cruz River. In Sonora Mexico I also found it in grazed meadows close to rivers. The plant is native to the United States and northern and central Mexico. It may be unwanted by the property owners, but ecologically, endemic plants are not considered invasive.

Solanum rostratun with Leptinotarsa haldemani and Coleomegilla maculata (Spotted Lady Beetle)

As for the danger the plants toxins pose and the warning I was supposed to put out on the FB group that I administer with my friend Robyn Waayers, I believe that the situation in the dog anecdote was unfortunate and the conclusions way overdrawn. 

As a Nightshade, Solanum rostratum contains a certain amount of solanine, glycoalkaloid poison, which can cause convulsions and death if taken in large doses. So do many of our wild Solanaceae.  Therefore, do never eat parts of nightshade plants if you are not sure if they are edible.

But the warning went further: the plant would be highly dangerous if simply touched. There are plants that do defend themselves efficiently against touch. I grew to know burning nettles as a little kid in Europe. 

Toxicodendron radicans, Poison Ivy and Mala Mujer, Cnidoscolus angustidens two truely untouchable AZ residents

 Poison ivy and oak are carefully avoided by most Americans. In Arizona, we warn people on excursions not to touch Mala Mujer in the family Euphorbiaceae. All those plants have irritating chemicals contained in glassy hairs that break on contact or glands that exude an oily substance that coats the leaves. 
In contrast, the buffalo bur has strong thorns protecting plant and seed pods, the burs. I have often touched the plant with no adverse effect when I photographed beetles or bumble bees on it (did I mention that this evil weed feeds lots of pollinators?). Of course the thorns prevented me from rubbing my fingers all over it and my usually careful approach kept me from being pierced by those obvious thorns.  So I think that the normal careful behavior of a naturalist will prevent the Buffalo Bur from becoming as evil a menace as described in the internet article. Media hype is all around us, though: A derivative article, mostly copied from the firefly forest post, was actually titled: Buffalo bur! This Arizona plant can kill you and your pets.

Leptinotarsa decemlineata (robably) here on silverleaf nightshade

In fact, there is another much more consequential side to the Buffalo Bur. Solanum rostratum is the ancestral host plant of the Colorado Potato Beetle, Leptinotarsa decemlineata. In eastern Nebraska in the eighteen-fifties, the beetle was accidentally matched up with a great new host, another Solanum originally from South America brought in by humans:  Solanum tuberosum.  (There aren't any convenient potato plantings where I could photograph the beetles here in AZ, so I have only founds them in Arizona and Mexico on wild growing Silver-leaf Nightshade)

The beetle thrived on that new, more succulent host, grown in convenient monocultures, and spread quickly eastward. New host plant and beetle were also carried from the Americas to Europe, where the host plant again went into agricultural mass production. So not only had the beetle combined with a super-optimal host that was further bred, fertilized, and pampered into defenselessness, but the natural enemies of the beetle had not been imported with it. Paradise for the Potato Beetle. The beetles multiplied and became THE most hated pest of potatoes in Europe (not counting fungal blight here).

What's in a name?

Often there is some interesting history in scientific names - and my friend Michael Ohl probably has a lot to say about that in his  book 'The Art of Naming', but I do not have the book yet, so sometimes I speculate by myself. For example the family of Metallic Wood boring Beetles is shortly called Jewel Beetles in Great Britain and Australia, in Germany we call them Prachtkeafer. All those names, from metallic to jewel to Pracht refer to their shiny beauty based on structural elements in their exoskeleton that refract the light that they reflect like so many prisms. 

But does their scientific name is Buprestidae have a similar meaning?  Buprestis is the name giving genus, and the ending 'idae' simply signifies that we are talking about the entire family of beetles that the genus Buprestis is a part of. 

So what about the name Buprestis? It goes all the way back to Carolus Linneus (Carl von Linné) who named the species in 1758, so right when he published his Systema Naturae, therein formalizing the binomial nomenclature, and thus becoming the father of modern taxonomy.

 But what did the name mean to him? It turns out that the Romans already called a colorful, maybe metallic beetle buprestis. Of course, they had stolen the word from the ancient Greek βούπρηστις. 

While trying to research the meaning of βούπρηστις, I nearly fell into a trap: I figured out that Πρήθω, f. -σω, p. πέπρηκα means to set on fire, burn, inflame. So I smartly concluded that the ancient Greeks had already observed that certain buprestid beetles were drawn to fire (females of some species lay their eggs into still smoldering logs, sometimes burning off their own feet), and called them something like 'Fire Bugs'.  So tempting an explanation, but wrong, sorry.

I then found out that βούς means Ox. This cured me of jumping to conclusions, even tempting ones. Burn-cow?
if βούς, πρήθω literally means burn-cow,  or rather cow burn, it seems to have referred to a something toxic that cattle might eat, only to die from colic and with burns and inflammations on their lips and tongues. To me, that sounds suspiciously like blister beetle poisoning. I also know that in Europe some blister beetles are quite metallic and colorful, just think of the shiny-green Spanish Fly (the one of Cantharine fame) that was once considered a Soldier Beetle, but clearly is a blister beetle. So I think the origin of the word buprestis lies in the toxic capacity of a beetle very different from our jewel beetle. Oh, well. I still think they are among the prettiest beetles.

All Buprestids, Jewel Beetles, Metallic Wood-boring Beetles shown here are Arizona Buprestids. Containing the enormously species rich genus Agrilus, Buprestids are one of the very largest families of beetles.

Longhorn and Jewel Beetles at Portal, Arizona

Many of my bug safaris are just naturalists' explorations of anything crawling or buzzing around or hiding under cow dung. At other times, the participants concentrate on a certain family of insects, which helps my blog writing tremendously. This focus may develop inadvertently because habitat, season or a weather event favors the appearance of certain groups of insects.  Or it develops because my excursion companion arrives with an interest in certain taxonomic groups, and we seek out habitat that supports those groups. Hopefully weather patterns and moon phase don't work against us. For several weeks now, I joined the Arizona tour of my friend and co-author for the book Arizona Beetles, Dr Arthur Evans. We looked for all kinds of beetle species in places that Art already fondly remembered from the past and a few that I introduced him to. At the same time we hoped for more monsoon activity.  On the last July weekend, the arrival of Ted MacRae made us concentrate somewhat more on his favorite groups, Cerambycids and most of all Buprestids. We all met in the Southfork Creek area near Portal in the Chiricahuas. In Portal I always enjoy the lovely hospitality of my friend Barabara Roth, definitely a great added bonus to the breathtaking beauty and the ecological richness of the area.

Many Cerambycids are night-active forest creatures and come to black lights quite willingly. Of course they have been much more active in wetter years, and I had many more species at my lights then. This year I strung my light's out in Barbara's back yard.

There, Ted and Art also found a very small Hardwood Stump borer that may have emerged from a cavity riddled stump, left in place from a tree that died,  and that is now part of Barbara's entrance steps.

Styloxus bicolor, a cerambycid with short elytra. From Barabara's place in Portal. Photo Steve Lingafelter

Tetraopes discoideus

Rhopalophora meeskei and Lycids

Tetraopes femoratus

Luckily the Southwest Research station further up Southfork Creek Canyon uses its leach field to create a wet meadow with an abundance of Narrow Leaf Milkweed. There we found at least  2 more species of Cerambycids, and I am adding here the larger Tetraopes femuratus that I have found in that location a couple of years ago.Tetraopes means Four-eyes, and in the portrait you see what that name points to.

Ericydeus lautus, my personal rain weevil

I used my big beating sheet to find out what's hiding in shrubbery along Sunny Flats CG. One beat delivered dozens of cm long grey weevils into the sheet and I knew immediately that the monsoon would get serious that afternoon: when these weevils climb vegetation in big numbers they are trying to stay away from serious flooding.

Mwcas rotundicollis

We discovered a couple more Longhorn species along the trail from Steward to Sunny Flat Campground, visually by gleaning grasses and leaves like a warbler would. It's my favorite collection method because I learn more about behavior and host plants and I can often take in situ photos. Though that tendency can easily result in the loss of a rarely encountered bug. As many beetles first drop and then fly, I held my sheet under the mysterious Acanthocine that is still unidentified. The more formal photo on white with better lighting shows more detail, for example the pronotal thorns that  indicate that it's not for example Pseudastylopsis  but rather Sternidius or another 'armed' genus.

Far more flighty and shy than the morning-sluggish Cerambycids are the Buprestids. Tiny  Pachyschelus secedens is the exception, usually clinging tightly to its legum host Desmodium.

On the soft, sunflower-like leaves of an as yet unidentified Asteraceae we found, as I had expected,  a number of red-necked Agrilus. There are 2 similar spp. around in SE AZ, so I have to wait for Ted to work on the exact identification.  A few Acmaeodera cazieri turned up on the very few flowering plants at Sunny Flats and along the road.

Leptinotarsa rubiginosa, arguably the prettiest of the 'Potato Beetles' diverted even Ted's intense buprestid-focus for a while.  The bright red bug really screams for attention, but I have never found more than a single one and never on its supposed host plant the ground cherry.

Leptinotarsa rubiginosa

After the pleasant canyon hike along the dry creek, always towards some threatening, grumbling clouds just beyond the towering cliffs, we moved out into the flats between Portal and Rodeo. Ted knew records of  Sphaerobothris ulkei (LeConte) on Mormon Tea plants Ephedra trifurca.  It grows among rather low scrubby Mesquite Trees and Sweet Acacias, some of which were blooming. But everything else, including the Ephedra bushes, seemed dried out and barely alive. The heat was quite oppressive in those open flats.

Desert flats below Portal, Arizona – dominant woody vegetation is mesquite (Prosopis glandulosa), sweet acacia (Acacia rigida), and three-pronged joint-fir (Ephedra trifurca). Photo and description Ted MacRae

Still, sudden buzzing noises announced some rather active beetles: big Hippomelas males and even larger females  were zipping around those   knee-high mesquites.

Hippomelas shenicus

 From Santa Ritas I am quite familiar with Hippomelas planicaudata. Especially in the evening, I often see dozens of them on the pink blooming Mimosa. They are blueish grey with a yellow wax exudant. The Hippomelas at Portal were larger, more brassy in color and the exudant was orange: Hippomelas sphenicus (above).  Compare to H. planicauda from Florida Canyon, Santa Rita Mnts, below

Hippomelas planicauda

Acmaeodera gibbula were sitting on flowers and branches of the one blooming Acacia rigida. 

These Acacias are also the host plant of the large large, yellow powdered Gyascutus caelatus, and Ted and Art found a few of those, too.

Gyascutus caelatus

But our target species was hard to find, until Art spotted the first two Sphaerobothris ulkei  running in their characteristic bursts of speed on the stems of a good-sized Ephedra plant. The beetles were a shiny, metallic blueish green, chunky and nearly a cm long. They actually stood out from the leaf-less grey-green plant branches to be visible from several meters distance. But I was also spotted easily by these highly visual creatures, so it still took me a long time to catch one female of my own.

Sphaerobothris ulkei

 I missed the first one because I tried to photograph her in situ. I learned that  they easily fly off when discovered, but land predictably on the next nearest Ephedra bush. They zoom right towards this target, even when it is hidden behind  dense taller vegetation. So I figured out how to find them again and followed. Hunting these beautiful beetles was very exhausting even though the area was flat. The upcoming thunderstorm made the air oppressive and hard to breathe. After our hunt we were happy to retreat to Barbara's living room to photograph our beetles

Sphaerobothris ulkei female

Art and Ted at work

And the rain storm that the 'rain' weevils had announced? Just before dinner at the South West Research Station, it hit the Southfork Creek area. When after dinner Art and Ted wanted to cross a wash on Foothills Rd they were stopped by racing water. Surprisingly, at Barbara's house the creek showed not even a trickle.

Minor flash flood and easterner, easily impressed

From San Simon to Paradise

Last Saturday I drove towards the Chiricahua Mountains following the narrow, straight, partly unpaved Road from San Simon on Interstate 10 to Portal at the eastern. edge of the Chiricahuas. The landscape was very flat and nearly uniformly covered in creosote bushes. But in some ares these were in full bloom, telling of recent rains, and at the horizon promising (or threatening)  clouds hung over a beautiful mountain panorama. My friends had indicated that there could be interesting insects in this bleak habitat, but they were delayed by not quite understanding the difference between the Tucson Airport and the Phoenix one - for Easterners they seem to be close to each other - so I struck out on my own with beating sheet and camera. I concentrated on non-creosote areas, mainly along washes that were lined with Mesquites, White Thorn Acacias, ans some herbal plants that began hesitantly to responded to recent rains.

   Shotgun like patterns on Datura leaves indicate the presence of leaf notcher weevil Trichobaris. I found 2 species of the genus.

 The Hawkmoth Manduca sexta (Carolina Sphinx) is not really a tomato specialist, it in fact prefers the local Datura.

Several similar looking Lema species could all be called Datura-phila, Datura-loving. Their larvae protect themselves with fecal shields, this one is just beginning to build one.

 Datura is also the host plant for this tortoise beetle, Plagiometriona clavata

Gratiana pallidula the egg plant tortoise beetle was introduced with agricultural products but is now quite at home on the local Silver-leaf nightshade.

I'm sure that  several leave beetles that like curcubitaceae  were drawn by patches of Coyote Gourd along the road. Paranapiacaba tricincta and Diabrotica undecimpunctata (Spotted Cucumber Beetle)

Very few knee high Acaciella angustissima were in bloom, so all nectar and pollen feeders concentrated on those few bushes. Here a big Sand wasp

Lycus fernandezi, the netwing beetle that can be separated from L. arizonensis by the little nodge in the black end-spot on the elytra. It is smoothly rounded in L. arizonensis

Finally an early Metalmark. There may be thousands when the desert begins to bloom and waves of these butterflies come up from Mexico.

On Mesquite trees I found a form of Cushion Scale. The white fluted part of the insect is an egg sac that can contain up to 1000 eggs. The insect is hermaphroditic, producing sperm that can fertilize its own ova, but in an alternate reproductive strategy it can also make winged males that can fertilize the female part of other individuals.

Two typical mesquite longhorns are Plionoma suturalis and the big black Stenaspis solitaria.

My best find of the afternoon was this little Ripiphorus sp. beetle. With long clear hind-wings and very reduced (orange) elytra, it could easily be mistaken for a wasp or a syrphid and also flies like one.

By the time Cathedral Rock and the entrance to Southfork Canyon came in sight, the wind had picked up enough to turn my beating sheet into kite and I was grateful to be heading straight for Barbara Roth's cozy Bavarian cottage. I never made it to the little town of Paradise, but guess what?