Life Cycles in the Bush

This bush in front of my house is where the entire drama plays out..

Praying mantis egg case from 2012.

I hope you like complex stories with lots of twists and turns full of treachery and just a touch of gore. If so, you have come to the right place. That place is a single bush in front of my house. This year the bush has gotten a reprieve from the hedge clipper, mainly because I didn't want to disrupt what I thought might be happening there. It did not disappoint.

Mantis shedding exoskeleton.

Last year I saw several praying mantis egg cases attached to this and other nearby bushes so I was expecting a big year of mantis sightings. well, that didn't happen. Instead I was treated to something I had never seen before, a single female praying mantis molting for the last time, her final instar, the one that would reveal her final majestic form and give her the power of flight with long newly revealed wings. There she was slowly working her way out of her penultimate exoskeleton. She would finally work herself free then wait for those wings to unfurl and for her soft shell to harden into a protective armor. For the next hours, though, she was vulnerable to anything that spotted her and wanted a soft insect meal. It was a risky time. I watched for a long time before I realized something was going wrong. Her transparent wings never seemed to completely unfold and the beautiful green and brown outer wings didn't fold neatly against her body.

The molt that didn't go right.

This mantis was never going to be the beauty I had anticipated but she would be the only one I would see on this bush this year. After a few days she disappeared and I was left to face a mantis-free Summer, at least as far as that bush was concerned. Sure, I would see others elsewhere but it was not the same as seeing one in my special bush.

The mantis may have gone somewhere but that didn't mean that the bush had nothing to offer. If the mantis is the top arthropod predator on the bush, the spiders, dragonflies, and robber flies are close behind. The bush is teaming with tiny spider webs housing an unbelievable variety of spiders whose names I don't know. There are also larger ones. One day came across a green lynx spider feasting on a brown stinkbug.

A green lynx spider consumes a brown stinkbug.

I had seen these beautiful spiders hiding on the undersides of larger leaves or lying in wait in some other place on the plant. The are lightning quick and rely on ambush attacks and even chasing their prey. No web traps for these guys. They are the real deal. With eight eyes facing front, up, and sideways, their depth perception is exceptional. Formidable indeed. This one, however had company. If you look closely you can see a swarm of flies helping themselves to the bounty of the stinkbug. They are parasitic flies who are particularly fond of spider kills, especially stinkbugs These kleptoparasitic (Isn't that a great word?) bugs feed almost exclusively off the captures of spiders. I am sure there is much more to this story than I know now but rest assured I am going to find out. In any case, this would not be my last encounter with parasitic flying things.

One day on my way to make my daily check on the bush, I noticed a large moth hanging out near my front door. In some ways, no surprise since I keep my porch light on all night for security purposes. It attracts all sorts of bugs and consequently many spiders as well but that is another story.

Hawkmoth

This moth, though, was quite something. As it turns out, it was intimately connected to my bush. It  was a hawkmoth, a beautiful creature that spends part of its life as a tobacco hornworm caterpillar (closely related to the tomato hornworm). Well since I have no tobacco and no tomato plants in my yard and none that I know of anywhere nearby, what to make of this moth? The bush provided the answer.

A tobacco hornworm denuding a stem.

I may not have had any tobacco or tomatoes growing in my yard but I certainly did have a tobacco hornworm. I found this one pausing to swallow his meal and look over his work as he made his way down one stem of my favorite bush, denuding it as he went. That stem was stripped clean from the tip down to where he was. Other nearby stems had already been stripped. Should I kill it to save the bush? Maybe later. For now my reflex was to get the camera and so I did. I resolved to just watch for a couple of days to see what would happen. After all, how much damage could a single caterpillar do? I looked for others just in case but found none so this one was safe, at least from me. Some bird might consider it to be a tasty morsel but not likely. Most caterpillars either taste bad to birds or resemble those that taste bad. This guy should be there for a while.


Well he might have been safe from me and the birds but he was far from safe. In fact when I first saw him, his fate had probably already been sealed. It was just not apparent to me. A few days later, I looked for the caterpillar and found him or one like him having a really bad day. He was covered with tiny white egg-like structures that made him stand out from everything else around, a flash of white in the sea of green.

Tobacco Hornworm with Empty Wasp Cocoons

 
 They were not eggs though, They were cocoons from which dozens of tiny wasps would emerge and fly
away to continue a bizarre life cycle. This caterpillar had been host to these wasps and paid for it with its life. After some time, the wasps did emerge from the tiny cocoons and most flew away to begin the cycle all over again.

Wasps and cocoons to show actual size.

The whole story is like something out of a science fiction horror story. Let's start with the tiny female wasp. At just over an eighth of an inch long, she flies around until she finds a well developed tobacco hornworm in which to deposit her eggs. With her sharp ovipositor, she penetrates the tough skin of the caterpillar and lays dozens of eggs beneath the skin. That would be bad enough but there is more. While she is depositing the eggs, she is also infecting the hornworm with a virus that attacks its immune system so it cannot protect itself from the newly laid eggs and the larvae they will produce. The same virus also attacks muscle (to slow the caterpillar's movement) and the central nervous system (to change its behavior). The wasp larvae hatch inside the caterpillar and begin feeding on blood and other tissues, all the while avoiding damage to any vital organs or systems. When they are mature and ready to become wasps, they chew their way through the tough outer skin, weave those tiny cocoons around themselves and start the metamorphosis into flying wasps. Now the caterpillar changes behavior (remember that virus?} and becomes the defender and protector of the firmly attached cocoons. It will strike violently and repeatedly at any disturbance to its body. It is probably enough to ward off at least some predators who might approach.  In some other species of caterpillar/wasp parasitism, the caterpillar actually uses its own silk supply to weave a second protective cocoon around the emerging larvae. There is something very scary about viral control over behavior. Great fodder for the sci-fi writer but absolutely based in the real world.


Needless to say I was being naive to think that there was only one hornworm in that bush. They tend to crawl up the undersides of stems and blend in very well with the colors. Stripped stems are the main giveaways. Well, the naked hornworms may be hard to see but those that have been parasitized are easy to spot. It is like seeing small white flags waving in the green foliage. There were several more in the bush so I decided to watch the story unfold again. I already knew the sequence. The caterpillar was going to have some very bad days then die, my bush would suffer some leaf loss, and the little wasps would emerge from their cocoons, fly away, and start the cycle all over again. They would do something like "live happily ever after."

Then out of nowhere an old friend showed up, bad wings and all. The mantis was back. It was like in the movies. A character is casually introduced at the beginning then fades away for the entire flick only to reappear at the end looking for something, . . . .in this case, an easy meal. She consumed the caterpillar and most of the silken cocoons including the tiny wasps inside. A few of the cocoons fell off the hornworm and into delicate spider webs below below but all the rest were eaten along with the host. Who knows? Maybe she is why I hadn't seen many other hornworms on the bush. Now, who gets to live happily ever after? The apex predator of course.

Neither the hornwom nor its parasites will survive this time.

End of story? Well not quite. You see, there is another kind of small wasp with long grasping legs who latches onto the backs of praying mantises, out of reach of those grasping claws. There she sits and simply waits. When the mantis is ready to lay her eggs, the wasp lets go and deposits her own eggs in the newly formed but still soft mantis ootheca (egg case). Her young will hatch early and feed on the developing mantis larvae . . .  and so it goes.

By the way, that first caterpillar continued to chew on leaves even after the little wasps had emerged. It was a futile effort to develop into a pupa. One day it just let go and fell dead from the stem, empty cocoons and all. I picked it up for a closer look. Like so many other things from my front yard adventures, this ended up in my studio as part of a new still life.

Still Life with Tobacco Hornworm and Parasitic Wasps.       21" x 14"  Print

The Last Mantis

 

I have to say that for me there is something totally fascinating about praying mantises. I never tire of seeing them as I always do in late Summer and early Fall. Take a look at this one. On the one hand they are kind of comical. On the other hand they seem alien, almost like they are not from this planet. They are slow moving but capable of flight. They are clumsy afoot in their chosen habitats but swift of "hand" when it comes to capturing prey. They are masters of stealth and camouflage but easily seen once the eye is trained to look for them. So, permit me one more entry about mantises. Actually this one is about a particular praying mantis whom I got to know over the course of a few weeks, right outside my front door. I call her "The Last Mantis." The story is not pretty and a few of the images may be upsetting to some. Click on any image to see a larger version. Reader/viewer discretion is advised.

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The Last Mantis

As the season stretched toward Winter without showing the slightest hint of what is to come, I continued to watch this one praying mantis just outside my front door where she had taken up residence in a large boxwood bush. Normally by this time of year all of them are gone. The females have deposited their last eggs into those tough brown egg cases and cold weather has weakened or killed them. Sightings are rare. The Last Mantis had already outlived her expected time. Her lifespan was extended into early November by the unseasonably warm temperatures of this year's Fall. For weeks, I had counted on seeing her in the same bush almost every morning as she basked in the early sun.

Sometimes it was not all that clear who was watching whom. At first when I approached, she would immediately turn and look at me with that typical mantis stare; the one that says, "I am watching you and I hope that's enough to keep you from getting too close." After a while, though, she seemed to get used to my presence and more often than not she just ignored me. Most days I did nothing more than just stand and look at her for a while. On a few occasions, I brought my camera out with me just to capture a few shots of whatever she was up to at the time. Sometimes she was moving slowly toward some other position. Other times she was eating. Mostly, though, she just seemed to be sitting there waiting and watching.

I suppose one could say she was hunting, but for her the hunt was not much of an active stalking, at least not at first. It was more like being in the right place at the right time. It meant being someplace where there was some reasonable likelihood that another insect would land nearby or perhaps crawl within striking range of those extremely quick forelegs. If something landed a bit too far away she would creep toward it but speed-of-leg was not her strength. It was the speed of those forelegs that really did the trick. She hung out in the upper parts of that boxwood where her favorite perch was at least four feet above the ground. That was something of a puzzle for me. Why was she so high in the bush when all of the good stuff seemed to be on the ground?

On several occasions, I had seen The Last Mantis consuming either a cricket or a grasshopper. No surprise that she would catch and eat them. The surprise was where she caught them. For some time I had wondered why I never saw the mantises down on the ground in the very thick grass where, it seems, all the grasshoppers and crickets lived. Instead mantises seemed to prefer the higher perches in bushes and heavier brush, at least during this time of year. Perhaps it has something to do with preferred egg laying sites. Whatever the choice, it did seem to work. Enough grasshoppers, crickets, and other insects ventured toward the upward reaches of the bushes to make large and presumably tasty meals for the mantises that waited there.

--- The Last Days ----

One day in late October, The Last Mantis managed to catch a really huge grasshopper,  much bigger than she could normally hope for in that bush and much larger than anything I had seen her tackle before. As it turns out, this largest meal was probably be her last, at least as far as I know.

Normally they eat from one end to the other. Everything goes down. This time it would be different. She removed one hind leg and ate the juiciest part of the large muscle before just dropping the rest of it to the ground. Then she moved to the soft body parts in the abdomen and thorax and ate her fill there. A little fly who, at any another time might, itself, have been a tasty morsel for the mantis, now sat right in front of her watching the feast, perhaps hoping to share some of the leftovers.

But this was not going to be a windfall for the fly, not that day. As I watched, The Last Mantis suddenly lifted her head from the open cavity, released her grip, and dropped what was left of the grasshopper to the ground. She was done. It was time for some preening to remove the spatters of the meal. I watched as she carefully wiped and licked every part of her face, eyes, forelimbs and anything else that had been soiled during the capture, struggle, and subsequent meal. She reminded me of a cat. The meticulous preening seemed such a counterpoint to the rather brutal scenario that preceded it.

Within seconds of hitting the ground, the grasshopper was discovered by dozens of ants who may already have been alerted by the earlier droppings from the meal. It was amazing. They dispatched the entire corpse in less than an hour. It was like it never happened. The ground was absolutely cleaned of any trace.

As for The Last Mantis, after cleaning herself all over, she just hung in the same place for a long time, upside down, her quick and powerful forelimbs just drooping, as if they were limp. She was looking down, almost reaching, toward the fallen grasshopper, now teeming with ants. She seemed to watch as they consumed the remains particle by particle. It was as if she were contemplating her own future; a future that would come sooner rather than later.

A few days later it got very cold. Nighttime temperatures fell into the thirties. I knew what that would mean for The Last Mantis but on the following days I went looking for her anyway. Nothing. I probed the bushes, gently pulling the branches apart so I could peer into the lower areas. To be honest, at this point I was looking for her remains, hoping to take her inside for some last photographs. Nothing. She was gone. Perhaps a bird picked her off or perhaps she dropped to the ground and the ants took her away. In any case I know I will never see her again.  She is now a memory, a collection of photographs, and another source of deep gratitude for my many experiences that come from just watching.

Oh, there is one more thing. In rambling through the branches of the bush looking for her body, I discovered one more fresh egg case left there by The Last Mantis. She had not wasted the nutrients she took in during her final days. Something to look forward to next Spring.

Praying for Mantises

I don't remember much about praying mantises from my childhood. I have to think that I didn't see very many of them if I saw any at all. Surely anything that fascinates me so much as an adult would have grabbed my attention as a curious youngster. Oh, and rest assured I was curious if nothing else. I examined everything and brought way too much of it home. Many of my childhood fascinations have followed me into adulthood. Since I cannot remember them from childhood, I have to assume that praying mantises came relatively late into my life. Oddly, though, I don't remember when that might have happened. But  it did happen and for a long time since they have occupied a prominent place in my consciousness, especially at certain times of the year.

It is usually in the late Summer and early Fall. I go into a state of high vigilance as I go on the lookout for one of those most interesting of insects, the praying mantises. When the weather is hot and the vegetation is lush in mid season, I almost never see them. It is not that they are not there. It is that they are secretive, stealthy hunters who are well camouflaged in the vegetation they use for ambush. They are busy eating and growing in the run up to the mating season when their normally solitary existence begins to change to something more social. Once the Summer starts to fade into Fall, I know I can count on seeing one or two of them, usually females, somewhere in my yard.  Nevertheless, there is always an element of suspense to my annual search. I never know for sure when and where I will have that first sighting. I just know I can't wait.

Perhaps I should call it a hunt even though that sounds too predatory for the way I feel. If I am the hunter or predator in this case, it is only with my eyes and my camera. My shot does not ring out with the explosion of gunpowder and my target does not fall fatally wounded from a high tech projectile hurled from ambush. I do not stuff their murdered bodies and mount them in my den for all to see and I don't eat them. I am only after the image and maybe the connection with this most interesting creature, not the body and not the soul. I have to trust that those are simply wrong who believe that by capturing an image I am imprisoning a soul .

The first sighting of an adult mantis is always a thrill. This year it was a real bonanza. There were three different mantises in one bush at the same time. They were in a place I always check because at least one seems to show up there every year. I worried that these three might encounter each other and that some sort of conflict might ensue. Nothing happened that I could see. The three of them stayed there for most of the last part of Summer. They were all females and it was egg laying time. Conflict with others was probably the last thing on their minds.

Finding that first mantis is one thing. Getting the photograph I want is another. Don't get me wrong. It is very easy to get a picture of a mantis  once you have found the insect. They are very cooperative in that way. It is almost as if they can't wait to pose for the camera. And that is precisely the problem. Getting a candid shot of a mantis is a bit of a challenge because the are difficult to sneak up on.  Here I have spotted one deeply concealed in a bush but I can get only one shot off before she turns  and looks me straight in the eye. So much for mantis candids.

 They are very wary but show little or no fear of humans. If they do feel threatened, they either move away or turn toward the threat and show a threatening posture of their own. Even though they can fly, that doesn't seem to be their first impulse when confronted.

This one has assumed a threat/defense posture which is telling me that I have gotten too close and should back off. Students of the martial arts, especially Kung Fu, will recognize the classic raised arms of the Praying Mantis Style. If one persists in getting too close, some mantises might actually attack by jumping toward the threat. That despite the fact that they represent absolutely no real danger to humans. They have no stingers and the grasping forelegs that are deadly to smaller insects can barely penetrate human skin. Nevertheless, the quick strike of a defensive mantis can be an intimidating experience, even for old school nature lovers like myself. I am forever grateful that they do not get much bigger. A two-foot mantis would be something to contend with.


Both of the adult mantises in this entry (one brown and one green) are female and both are heavy with eggs. Hence the large abdomens. In late Summer they lay their eggs in foamy secretion that forms a surprisingly tough bell-shaped case once it is dry. The foam comes out as a very wet, bubbly, sticky foam not unlike that expandable foam used by builders to insulate and fill cavities in home construction. It hardens quickly to form a tough, almost impenetrable place for the eggs to develop. The small case shown below was deposited late in the season by the very same female shown above in threat posture.  The case is small as she was nearing the end of her egg supply and the end of her life cycle. Her last few eggs were probably laid in the smaller, incomplete case just to the right. She will spend the remaining days in a weakened state and vulnerable to predation by other creatures seeking provisions for the upcoming Winter.

If all goes well and some pesky parasitic wasp doesn't find the egg case right away, the little ones are safe for now. Over the cold months of Fall and Winter, they begin their slow development, accelerating when there are warm spells and slowing down during the coldest periods.

(I once made the mistake of bringing one of these egg cases home after finding it during a fall hike. I left it out on a warm window sill in my kitchen. You can guess what happened. One day in December I noticed lots of little grayish "ants" crawling all around the egg case and well beyond. They weren't ants at all. They were what seemed like hundreds of little praying matises busy trying to make a life for themselves. Sadly none of them survived. The few I managed to capture just ate each other until only one or two remained. They did grow a bit but finally succumbed despite my best efforts to feed them fruit flies and some small bugs that I managed to find outside in Winter.)

By Springtime they are ready for the world and the end of anything even close to safety. The little ones hatch as soon as it starts to get warm in early Spring. They emerge by the dozens, maybe hundreds, from the egg cases and begin life as formidable little hunters. Barely over a quarter of an inch long, they come out as nymphs, fully formed preying mantises except for the wings. They are complete with over-sized eyes and those lightning fast front legs that have inspired martial artists for centuries. They emerge as minuscule but very effective little predators.  The little ones will attack and eat anything that moves as they disperse quickly from the egg case. Often that means attacking and eating any of their kin they happen to encounter. For many of them, life is a simple zero sum game to be played out first with siblings and later with other small creatures. Eat or be eaten is the rule. One is either the diner or the dinner. It is just that simple. These two youngsters are in just such a standoff. In this mini-drama, the one on the left must decide whether to turn and face the advancing sibling or leap for the closest branch. In this case discretion proved to be the better part of valor. He made the leap.

Most mantises don't survive their infancy. Those that do have made it through a gauntlet of spiders, wasps, birds, big raindrops, their own kin, and lots of other potential misfortunes. At least they do not have to worry about adult mantises. None of those will have survived the previous Fall or Winter. The big ones are all gone. Some of the new ones will grow up to be adults in their own rights and take their places among some of the top predators of the insect world.

Here is one of the adult females at work gathering in the last bits of nutrients for the season. She has caught a grasshopper. This is the same mantis that was looking so threatening in one of the photos above. For now she is getting just enough nutrition to see her through the physically demanding process of laying her eggs. While it might be difficult to tell them apart by color and some elements of structure, there is no mistaking their different roles. Mantis and grasshopper are diner and dinner respectively. It may not be pretty but it is what there is to be seen. So I watch and learn and share, another carryover from childhood.

And so it goes every season with little variation. I plan to be there again in the Spring to watch it unfold all over again. Maybe next time I will get lucky and see something I have never seen before. That, after all, is why I keep looking. If I am really fortunate I'll have my camera close at hand. In any case, you know I will share.

Who Else Lives Here?

The place I call home is home to others as well. Not all of them are cute, furry, or feathery. Once one gets past the bunnies, squirrels, and birds, there is much more to see.  I try to pay attention to the seldom seen beings and their stories when I can. This is a small collection of some of those episodes from my yard.  All of the images are from right here on Nelson Street. It is amazing how many dramas are played out on a small scale right under our noses. They are all parts of the ordinary cycles of life and death amongst the small creatures that for the most part escape our notice. For them almost every encounter is a zero sum game that has a definite winner and a definite loser. We can start with one I have rarely seen, let alone photographed.

This female parasitic wasp has captured, stung, and paralyzed a caterpillar. She will drag it into a nesting hole she has dug in the ground.
There she will entomb the caterpillar and lay a single egg. The caterpillar will remain alive but paralyzed and sealed in the hole until the young wasp hatches. You can guess what it eats until it is ready to emerge and begin the cycle all over again.


Had that unfortunate caterpillar escaped the sting of the wasp and lived to complete its normal life cycle, it might have grown up look something like this beauty just out of the chrysalis.


Then there is the magnificent black and yellow mud dauber as seen here from underneath. I caught this lovely one inside my house and couldn't pass up the opportunity to take a closer look. After keeping her in the fridge long enough to slow her down, I placed her on my scanner and got this image. She was later released unharmed. Mud daubers, another of the parasitic wasps, build those crusty clay nests that seem to show up under eaves, mailboxes and other protected places in our homes that we do not clean very often. They sting and paralyze (but not kill) mostly spiders which they stuff into cylindrical clay tubes. Once they have enough spiders in a tube, they lay a single egg on one of the spiders and seal the tube with clay. She may create multiple tubes, each containing one egg and enough spiders to do the job. Then the whole thing is plastered over to make it look like a clay blob. When the young ones hatch, -- well you know the story by now. I will do a more detailed blog on the mud daubers later.

Speaking of spiders, I don't necessarily recommend allowing black widow spiders to hang around in places that you frequent, but they do make interesting neighbors, worth paying attention to.

This one has just captured a June bug in her web. If all goes according to plan, she will wrap her prey with silk bindings, paralyze him with venom, inject digestive juices into the body, and leave the chemicals to do their work of turning the insides of the bug into a juicy pulp. Then she will return, suck out the nutritious bug juices, and discard the empty shell of a carcass.

June bugs are probably not a favorite prey for the spider. It would be a big meal but they  have too much strength and too much armor. This captive has already wrecked the web with his struggles. He eventually escaped before she could wrap him up. As it turns out, this arachnid mother  had more than a few mouths to feed. Shortly after the June bug escaped, dozens of miniature black widow spiders emerged from an egg sac that had been hanging hidden under a nearby rock.

There is no way such a small area can accommodate that many black widow spiders. Most won't survive anyway since they are cannibalistic at that age. Others will fly away attached to a fine thread of silk blown by the wind. My guess is that some of them will wind up in one of those clay tubes that the mud daubers prepare.

My favorite predator neighbors are the preying mantises that show up every year. They deserve their own blog entry which is forthcoming. For now just consider this beauty looking back at me as I invade her space. Imagine being a fly and coming face to face with this.



That's it for now. In future postings I'll talk in more detail about other specific animals or plants that inhabit this little corner of the ecosystem and share some of my photos of them. For now I hope you have enjoyed these little sketches.