Friday, September 22, 2017

Secrets of An Assassin Bug's Diet, or Beware of First Impressions!

When I went out with the dog, first thing this morning, I noticed a ladybug on one of my milkweeds, so I went inside and grabbed my camera to photograph it.  I just don't see ladybugs very often any more.  The ladybug turned out to be a Multi-Colored Asian Lady Beetle (Harmonia axyridis), which is very disappointing but not too surprising.  This is the species that is displacing so many of our native ladybugs.

As usually happens when I get my camera out, however, I found a couple other things to photograph while I was outside, and I'd like to share one of them with you tonight.

As I was photographing the ladybug, I noticed another orangish red and black insect nearby, a nymph of a Milkweed Assassin Bug (Zelus longipes).  I'm fairly used to seeing these in my garden nowadays, so I didn't pay too much attention to it at first....

Then I noticed the long, small, white insect it was eating.  "Damn!" I thought to myself, "It's a tiny monarch caterpillar!  No wonder I haven't been seeing any larger monarch caterpillars around."

Since I'm a pretty firm believer in "the circle of life", especially when the life forms involved are native, I did nothing but take a couple pictures.  The assassin bug nymph soon finished its meal and started hunting again, but I didn't notice it capture anything else.

Tonight I went through this morning's photos on the computer - and, lo and behold, that wasn't a tiny monarch caterpillar!  The Milkweed Assassin Bug nymph was actually eating a newly molted (still white) leafhopper!  The leafhopper was just so small that my eyes couldn't make out what it actually was until the magic of photography enlarged it for me.

I have no idea which species of leafhopper this was, but all leafhoppers drink plant sap, so this is a perfect example of a predator keeping a plant-eating insect population under control.  (To be brutally honest, of course, the same could be said if the assassin bug HAD actually been eating a monarch caterpillar.)

Once again I had a dope slap moment and had to remind myself not to jump to conclusions when I'm out in the garden, observing.  I am continually amazed at the intricate functioning of the web of life...when we humans can avoid mucking around with it.

Thursday, September 21, 2017

Am I Still On Track?

Reading a magazine about blogging earlier this week, I tried to remember exactly why I began Gaia Garden.  Was it simply to share the photos I was taking as I gardened?  To share the plants and animals I found as my hands dug in the soil surrounding our home?  Amazingly, I realized that I started writing this blog over 11 1/2 years  - and 2 gardens - ago, in March 2006, while we lived in Mobile, Alabama.   I must say that my memory is fuzzy on many of the details.  I do remember clearly, though, that our son Sean had a LOT to do with my starting this blog.  He basically bullied me into picking a name ("It doesn't have to be perfect, Mom!"), picked a platform he felt would work well for me, and in those lovingly irritating ways, actually got me online with my first posts.

To refresh my mind about my deeper motivations, however, I decided to go back to the earliest posts and see what I had to say for myself....

In my very first post, "New Beginnings", I wrote that "...it's not just gardening that interests me.  It's gardening within the genius of the place, gardening that celebrates the local flora and fauna."  That certainly still rings true.  If anything, I think I've become even more fascinated by what is now known as "gardening with native plants".  I like the way I phrased it back then, though.  "The genius of the place..."  It sounds much softer, even somewhat romantic.  That is a concept that I haven't thought about for a long time.

So different from the prairies of southcentral Kansas and our last garden, the "genius of the place" here in our Florida panhandle neighborhood is reflected in Spanish moss literally dripping from evergreen oak trees.

A little further along in that same post, I mentioned hoping to gently encourage a sense of cooperation between gardeners and the natural elements in their gardens, as opposed to the more common combative feel of gardeners battling nature's tendencies.  At least in my own mind, this concept is central to most of my posts to this day.

Towards the end of that original post, I started to wrap up by expressing a broadening mission for my new blog: "Since gardening works so well as a metaphor for living, along the way I expect to be looking for ties to philosophy, politics, literature, and any other subject that "crops up."  I hope to hear from others who are similarly involved...or even just interested in the process."

It's in that final, broader hope for where my blog might lead me that I feel I've perhaps lost my way.  In recent years I have found it quicker and easier to share photos and explore what I'm actually seeing as I garden than it has been for me to delve into other facets of life that I think about or learn while I'm  getting my hands dirty.

So my blog has become more photo driven.  Is that a good thing...or not?  We all seem to respond instinctively to photos, so in that regard it's helpful, but it can also be limiting to rely too heavily on them.  For example, so far in 2017, the only "philosophical" post that I have written was to think a bit about what I think about as I garden.  Hardly deep stuff, but I was able to find photos to illustrate my thoughts!

It's also not deep (literary) stuff, but if a book seems relevant to science or gardening or the environment, I still do book reviews, as in this 2014 post about "A Sting in the Tale" by Dave Goulson.  In the last several years, though, this is about as close to "...ties to philosophy, politics, literature..." beyond gardening as I get.  Sigh.

Another big change I see in my post topics, compared to 2006, is that I am a lot more involved these days in identifying insects and figuring out what they are doing in the garden.  For example, note this little halictid bee, feeding on the nectar and pollen of the Gaillardia bloom - and pollinating the plant in the process. Sometimes I actually feel as if growing plants has now become secondary, for me, to learning about and nurturing bees, butterflies, spiders, and other wildlife in my gardens!  Ironically, photos are a big part of WHY this change has occurred, as I got a DSLR camera several years ago and am now able to take pictures of a small insect, enlarge them, and identify the species.  Knowing the actual identity of the insect I'm seeing allows me to research its biology.  In fact, I'm becoming quite the bug nerd, at least in my own mind.

Well, it's time to wrap this up.  Enough navel gazing.

Upshot?  In general, I think I'm still on track.  I'd like to work in some more "tangential" subjects as blog post topics, if only because I'm finding it fun to go back and read those posts, years later. 

For my own sanity, I'd like to get back into regular posting - blogging feels creative in a way that Facebook posts don't.  I think more carefully about what I'm saying when I write a full blog post, and I rework the wording to get as precise as possible about what I mean.  I can more easily choose my topics, too, which in this current political clime is not all bad.

So, onward into the next 11 1/2 years!  I wonder how many gardens I'll have made in that next interval of time - and where we'll be putting our literal and figurative roots down by then?

Sunday, September 17, 2017

Fall? Well, maybe.....

While all my friends in more northern climes are talking about goldenrod blooming, ducks and geese flying south, and the massive Painted Lady butterfly migration, I am left looking around for signs of the seasons changing in my Florida panhandle garden.  What do I notice here?

First and foremost, I realize that I am finally back outside!  During the peak heat of the summer, it's hard to motivate to do more than look out through the windows at the flowers blooming.  Now, though, I'm back out in the garden, pulling the summer weeds that have grown up, working to lessen the seed load for next year and to give my perennials a bit of breathing room.  It's still hot.  After a couple hours, I still come in dripping sweat and craving water.  Somehow, though, the worst of the sauna is gone and I leave the garden looking forward to my next time out in it.

With the autumnal equinox approaching rapidly, the days are definitely shorter now and, while I want to work outside more, I have fewer daylight hours to do so.  I awake to dim, early sunlight and find myself with extra evening time on my hands after darkness falls.

Along with shortening days, another fall change is that hummingbird migration is in full swing.  Walking out of the back porch, I can count on being buzzed by at least one hummer, zooming past as close as an inch or two from my face or shoulders: "This is OUR territory, lady!" They never seem to take into account that I am their FRIEND, the one who fills the feeders they so dearly love.

Looking up, there are Fall Webworm webs in our Pignut Hickory trees (Carya glabra)...

and. looking down, the Fall Webworms (Hyphantria cunea) are starting to leave their nests and look for a place to pupate.  Eventually they'll become white moths with black spots.

The hickory nuts are beginning to drop, resounding sharply off the metal roof of the playhouse like a sudden shot or thudding loudly on the resonant boards of the deck. 

The squirrels are busily gnawing away at the fresh largesse, leaving tiny sculptures scattered around the yard in quiet testimony to their appetites.

Butterflies and moths, while sadly still not common this year, are seen more frequently now.

There are the Gulf Fritillaries (Agraulis vanillae), busily nectaring at Beggarticks (Bidens alba) and laying eggs on the Passionvine (Passiflora incarnata), ...

Long-tailed Skippers (Urbanus proteus) nectaring at the Flyr's Nemesis (Brickellia cordifolia) and Agastache, ....

Monarchs (Danaus plexippus) dropping eggs on the milkweed (Asclepias sp.), ....

Cloudless Sulfurs (Phoebis sennae) stopping to snack at Scarlet Sage (Salvia coccinea) on their way to points south, ...

Swallowtails majestically visiting, but generally camera shy, like this Eastern Tiger Swallowtail (Papilio glaucus) nectaring at Flyr's Nemesis, ....

and even the occasional "rarity", like this Hummingbird Clearwing moth (Hemaris thysbe) that dropped in to feed at the Flyr's Nemesis while I was sitting quietly nearby, weeding.

With summer basically done, many plants are starting to look ragged, and that's okay.

There are the annuals and short-lived perennials, like this Indian Blanket (Gaillardia pulchella), that have bloomed valiantly all summer long and are suddenly just tired out, ready to call it quits.

There are the milkweeds, whose lower leaves dropped months ago and whose upper leaves are now caterpillar food, busily making new Monarchs.  (Look how tiny this little Monarch caterpillar is!  See how thick the leaf he's eating is in comparison to his size?!)

There are passionvines (Passiflora incarnata), whose holey-ness (or is it holiness?) speaks of many more Gulf Fritillaries to come.

The signs of fall may be more subtle here in the southland...but they are here all around me, nonetheless.

Monday, August 07, 2017

Syrphid Fly Scouting Place to Lay Eggs

In my recent post on aphids and their predators, I shared photos of two types of syrphid fly larvae that I am seeing.  A few days later I was lucky enough to get this photograph of an adult syrphid fly, looking for a place to lay eggs on my milkweed.

If you click on the photo, you can see the details that are not apparent in the smaller image imbedded in the text here.  Note the aphids at the base of the flower cluster?  There aren't a lot and I didn't see the female syrphid fly lay any eggs, so she may have decided that she needed to look for more populous aphid clusters.

Going by the Latin name of Ocyptamus fuscipennis, there is no common name for this syrphid fly.  I am pretty sure that this is the adult form of the "gray slug" syrphid fly larva that I see munching on oleander aphids. 


Here is a closeup of this individual....



(Note:  I have not raised an individual from larva to adult to know for sure, but this is both the most common syrphid fly that I see laying eggs on the milkweed and the most common adult syrphid fly larvae that I see.  Others have raised this species from larva to adult, and the larva does look very similar to this.)

What predators are you seeing munching on YOUR aphids?!

Friday, August 04, 2017

Sand Wasp Grows Entirely On True Bugs

When I first saw this good-sized wasp, I thought it looked a lot like a cicada killer.  I couldn't get very close to it to get decent photographs, but I was able to get good enough images that I knew it wasn't my old friend from Kansas.

Tonight, after I cropped the photos to more closely see the insect I had "captured", I tabbed over to BugGuide.net and started looking around.  After a while, I thought I had probably figured out the identification...but the eye color was wrong and the markings on the thorax were not quite right either.  So, I posted the photos and asked for help.

Meanwhile, I continued searching through BugGuide, looking for a better match to my mystery wasp.  As I was checking out a particular species, a sand wasp that is known only as Bicyrtes quadrifasciatus, I saw a couple photos that looked remarkably familiar.  When I checked my email, I was stunned.  My original identification had, indeed, been wrong;  the species I was looking at now was the correct species; and - most surprising of all - one of the contributing editors at BugGuide had already made the identification and moved my photos to the correct spot!   Those WERE the photos I had just uploaded a few minutes before.

BugGuide for the win!

So why do I try so hard to identify "my" insects to the correct species?  This wasp is a good example.  By learning the identity of this wasp, peacefully feeding at a flower, I learned that I host a species of solitary wasp that raises its young completely on true bugs, on insects like stink bugs and assassin bugs and maybe even milkweed bugs.

Seriously.  This species of wasp finds enough true bugs in the general area of my yard to raise its entire brood of young for the year on the bugs that it finds and paralyzes, drags back to its nest, and lays eggs on.  Isn't that incredible?  Talk about natural pest control.  Talk about the "balance of nature".

To top it all off, as an adult, this wasp acts as a pollinator on flowers in my garden.  Before I started learning about the specific identities of the insects in my garden, I had no idea that wasps were such extraordinary predators or that adult wasps generally just ate pollen and nectar.  Based on a childhood experience, I was actually quite scared of them.  Now wasps fascinate me, and the more I learn, the more fascinated I become.

I am continually stunned by the complex interactions occurring all around me - interactions that I simply don't see or even know to look for.  The natural world is truly a marvelous, intricate web of life whose structure we would be wise to cherish, rather than destroy.

Thursday, August 03, 2017

Predators and Parasites on Oleander (Milkweed) Aphids

My milkweeds are hopping these days.  Sadly, I've only seen one monarch caterpillar, but I am still fascinated by all the insect life that I am seeing.  Most of my observations have been on tropical milkweed (Asclepias curassavica) simply because I have several big, healthy plants in pots on my back patio and they are easy to check on and photograph, but I'm fairly certain that what I'm seeing isn't unusual for other milkweed species.

The orange-yellow oleander aphids (Aphis nerii) are common on these plants.  A week ago, when many of these photos were taken, the aphids covered about 2-3" of the top of every shoot.  This week their numbers are much reduced, with just a few hardy individuals remaining where hundreds dined last week.  This is at least the second rise and fall of aphid numbers on my plants this summer.  I'm sure they will go through at least one more population cycle up and down before frost comes this autumn.

So what's keeping the aphid populations from exploding out of control?  If you look closely at the photo above, you can begin to see the answer.  Specifically, here are some of the candidates I've been seeing....

Each milkweed shoot with its covering of yellow aphids near the tip seems to also have at least one or more of these blobs of gray and white protoplasm which, I am pretty sure, are actually syrphid fly larvae.  Although the blobs are stationary when I usually see them, I have occasionally seen one "hightailing" it from one area to another.  Looking on BugGuide.net, this looks like the larva of the syrphid fly, Ocyptamus fuscipennis.  I have certainly noticed syrphid flies that look like these adults hovering around the aphid clusters.  There is no common name for this little fly that I know of, but the BugGuide link will allow you to see what the adult looks like, so that you can notice if your milkweed aphids are attracting attention from this species, too.

Less common, but still easy to find, are these little bumpy caterpillar-like animals that are also, I believe, syrphid fly larvae.  I've not been able to figure out which species or even genus these guys belong to, but I do find it fascinating that two different species of syrphid flies are munching on my oleander aphids!  The only way to really tell for certain would be to raise up some of these larvae to adulthood, which sounds like a fun project when the boys get a little older.

If you ever see a piece of trash seeming to move on your plant, look a little more closely....

You may be seeing a green lacewing larva, which hides under a pile of debris that includes its castoff skins from earlier molts. 

If you look closely in the photo above, you can easily see the yellow oleander aphid being eaten...by the actual lacewing larva at the bottom of the pile of debris.  Lacewings are fierce aphid predators as both larvae and adults.

Not uncommonly among my aphid populations, I will see a dark brown aphid that doesn't move.  This is an aphid mummy.  Tiny parasitic wasps lay an egg in an individual aphid and the developing wasp larva eats out the insides of the aphid, leaving the aphid a literal shell of itself.  Only one baby wasp per aphid, but each female wasp can then go on to lay eggs in many aphids, so aphid mummies are welcome sights on my milkweed plants.

There are other more generalist predators that I'm seeing around my milkweeds, too, which may or may not be preying on the aphids.

I often see tiny, longlegged flies, for example, flying around and landing on milkweed leaves for short periods of time.  Longlegged flies (Family Dolichopodidae) are iridescent green or brown and are known to be predators in both the larval and adult forms.  Although I have never seen one pay attention to, let alone eat, an aphid, I can still hope.  They've got to be eating something!

Clad in the red-orange and black colors of the classic milkweed insect, milkweed assassin bugs (Zelus longipes) are another generalist predator that I see these days, both on milkweeds and on other plants around the yard.  I see the milkweed assassin bugs hunting up and down the plants, sometimes hanging out in the flowers, but just as commonly walking up and down the stems or inspecting both sides of each leaf.  Their eyesight is superb and it can be hard to sneak up on one to take its picture.  At first it will simply duck to the other side of a stem or leaf or flower cluster, but if you persist, it will readily fly away.

The final predator I've been consistently seeing around my milkweeds in recent weeks is a damselfly.  Again, I don't know if this dainty creature is eating winged aphids or not, but I doubt it would turn one down.

So, as you look at the aphids on your milkweeds in horror and dismay, look a little closer - there's a good chance you'll see some other, interesting insects drawn in to the feast that they represent in the animal world!

Monday, July 31, 2017

Elephant Mosquito: The First Mosquito I'm Glad to Find in Our Yard!

It's hard to decide what I love the most:  photographing insects and other animals around my gardens or identifying the insects I see and then learning about how they fit into the patterns of life around me.

Once again I want to sing the praises of BugGuide.net and its community of volunteer entomologists for their help and expertise.

A few days ago I was doing my afternoon walkabout, using my newly "discovered" tripod, and capturing the images of just about any animal I could find.  One of those animals was a fly that looked suspiciously like a very large mosquito, over 1/2" in length.  Thanks to the tripod, I was able to get a reasonable series of photos and look at the little beastie with a more discerning eye.

As I took the photos, one thing I noticed with my "naked eye" was that, as it fed, the insect seemed to be signalling by raising its hind legs, first one side and then the other, showing off a white "bootie" on the end of each leg.

Since the signalling was done slowly and methodically, I was able to capture pictures of it without trouble.  As I looked at the photos, though, I was not a happy camper.  Damn.  Despite all my mental attempts to make this animal into a non-mosquito-type insect, the images revealed that it simply was, indeed, a very large mosquito.  "That's all we need here in the yard," I thought, "an extra large mosquito joining the ranks of the more normal sized, always-seemingly-hungry, stealth mosquito squadron."

However, this mosquito, which appeared to be a female due to its non-feathery antennae, was obviously feeding on the nectar in the mountain mint flowers.  Hmmmm.  Was that normal?

I tried wading through the images of mosquitoes on BugGuide to learn more, but I simply wasn't getting anywhere because I really didn't know what features to focus upon.  So I asked for identification help earlier today.  Within a few hours, I had my answer - and what an answer it is!

My giant mosquito is known as the Elephant Mosquito or Treehole Predatory Mosquito.  In scientific parlance, that's Toxorhynchites rutilus.  As larvae, these mosquitoes are actually predators on other mosquito larvae!  Best of all, the adults feed at flowers, as mine was doing, and the females do not appear to require a blood meal to lay eggs!  I didn't have the slightest clue that predatory mosquitoes existed, so this has really made my night.

What a truly marvelous world we live in!