Wednesday, October 31, 2012

Happy Halloween!

Soon, trick-or-treaters will start coming to the door for candy.  However, I've already had one visitor that seemed more interested in a different kind of treat: my pumpkin.

The bug that was sitting on my pumpkin.
Now for another treat, or maybe a trick --

A caterpillar that I found on a bush next to the highway.
-- or perhaps even a "costume" of sorts.  The "face" on this caterpillar is actually on its body and the top of its head (which is bent forward as it eats the leaf).

Tuesday, October 30, 2012

A late bloomer

After several frosts and a snow shower, winter does not feel very far away.  Nevertheless, there is one plant in the garden that has just started blooming.  With its leaves tinged red, it had appeared to be shutting down as the weather turned colder.  However, this little plant is now covered in bright purple and yellow inflorescences. 

Flowers of the late-blooming aster.
I have been curious whether anything will come to pollinate these aster flowers, since the cold and wet create considerable difficulties for flying insects.  During brief periods in which the sun has come out, I have checked the flowers for visitors.  However, some of the flowers still needed more time to dry off after the rain.

A water droplet trapped in the aster inflorescence.
Even when dry, the flowers haven't seemed very successful in attracting pollinators.  I only found one insect visiting the flowers, and it was a bug that may have been doing more harm than good for the plant.

A bug in the aster flower.

Friday, October 26, 2012

Beetles uncovered

Last weekend I worked on preparing the garden for winter.  I was careful when cutting back plant stems, as I thought I might find the egg cases (ootheca) of the praying mantises I had seen before.  Although I didn't find any ootheca on the plants, I did find a new one on a sheltered part of the garden fence.

A mantis egg case (ootheca) attached to the fence.
My other interesting -- and much more colorful -- finds were all under the plant stems I was pruning.  As I gathered the dead leaves and stems from around one plant, I saw several bright red shapes nestled in the dirt.  They were ladybugs that had been hibernating under the shelter of the leaves.

Ladybugs that had been underneath some dead leaves.
I had been finding ladybugs hibernating in the mulch for the last few weeks, so these weren't a big surprise.  However, the next beetle that I uncovered was much larger, with an unusual purple and bronze sheen.

A European ground beetle (Carabus nemoralis) that had been underneath some plant stems.
From above, the coloration of the European ground beetle (Carabus nemoralis) makes it look attractive. However, once you look at it face on, I'm sure you will understand why I was glad to be wearing gloves when I caught this predatory beetle.

Wednesday, October 24, 2012

Living between a rock and a hard place

There are a number of rocks and paving stones scattered around the garden.  Every once in a while, I flip one over to see what is hiding underneath.  I usually don't find much besides earthworms and small, dark things that run for cover before I can get a good look at them.  However, one of the rocks I chose to lift recently had been concealing something more interesting: a small colony of ants.
An ant nest that was sheltered underneath a rock.
In a cavity beneath the rock, worker ants were attending the larvae.  After the colony was exposed, the workers began to carry the larvae deeper into the colony.  When I looked closely at the larvae, I noticed that they were surprisingly hairy.

You can click on this picture to view a larger version.
Additionally, the larvae appeared to be suspended on a nearly vertical surface.  These two observations may be connected; some ant larvae have hairs that are specially shaped to anchor them to the walls of the colony.

Explore some more: Velcro Hairs Allow Ants to Hang Their Larvae

Monday, October 22, 2012

One rotten crabapple

As the crabapple fruits have ripened, they have turned a brilliant red.  They are still not edible, but they have brought a welcome splash of color to the garden at a time when most of the plants are fading.

The ripening crabapple fruits have turned bright red.
Although I think that the fruits are too sour to eat, the taste has not proved an obstacle to all.  Some of the fruits, such as the one pictured below, have holes filled with insect frass.

A crabapple fruit with a hole filled with insect frass.
I wanted to see what was eating the fruits, so I picked the one pictured above and sliced it open.  At first, all I found was more frass.

A crabapple fruit filled with insect frass.
However, after I carefully sliced more of the fruit away, a small caterpillar came wiggling out.  It was a codling moth (Cydia pomonella) larva, a major pest of apples that also attacks the fruits of other trees including crabapples, pears, and walnuts.

The codling moth (Cydia pomonella) larva that had been eating the crabapple.

Friday, October 19, 2012

A walk in the woods, part 2

From a distance, the brilliant colors of autumn leaves make an inspiring sight.  However, a closer view is often not so pretty.  Many of the leaves that I saw on my walk were marked by bacterial, fungal, and viral diseases.

Infected maple leaves.
Infected oak leaves.
Other leaves had been skeletonized by insects while still on the trees.  Interestingly, the leaves that had been consumed in this way were often attached to a neighboring leaf, perhaps forming a shelter for the hungry herbivores.

One of many skeletonized oak leaves.

Thursday, October 18, 2012

A walk in the woods, part 1

I spent the last few days in Syracuse, New York.  Although I was kept very busy on my trip, I did get to spend part of one evening walking through the woods.  Many of the trees were turning from green to red, orange, or yellow, and the forest floor was carpeted with the leaves that had already fallen.  All along the path, silk-tufted seeds were being released from dry brown pods.  Despite these signs of autumn, I found several flowers that were still blooming.  

It was late in the day, as well as chilly, so it was not surprising that these flowers were deserted.  The more promising places to look for animal life were further down: in the leaf litter and underneath rocks and fallen branches.

A spider in the leaf litter, probably a wolf spider (Lycosidae).
A red-backed salamander (Plethodon cinereus) that had been hidden underneath a fallen branch.
The salamander pictured above looks just like the ones I remember finding under rocks in our backyard when I was growing up.  It was a treat to see one again after many years!

Monday, October 15, 2012

Arthropod identifications

I have been traveling for the last few days, so today's post is just a quick advertisement for my companion blog Natural Current Events: Arthropod Identifications.  If you would like to see more close-up photos or read some quick facts on the insects and spiders featured in Natural Current Events, click on the link!

Friday, October 12, 2012

Escaping an enemy can cost an arm and a leg

Grasshoppers are notable for their large hind legs that enable them to jump long distances.  Therefore, I've been surprised that several of the grasshoppers I have seen recently have been missing one of these important legs.  

A short-horned grasshopper (Acrididae) nymph missing one of its back legs.
Apparently, a grasshopper can easily detach a leg from its body in order to escape from a predator.  Although costly and somewhat gruesome, this process of "autotomy" or "self-amputation" is preferable to the alternative: being consumed by the predator.  Furthermore, once the grasshopper reaches the adult stage, its wings are fully developed and it no longer has to rely on its jumping prowess.

A short-horned grasshopper (Acrididae) adult missing one of its back legs.

Wednesday, October 10, 2012

Saved by the camera

I was standing near the crabapple tree when a dark shape on one of the leaves caught my eye.  As I moved closer, I saw that there were actually two dark shapes -- a parasitoid wasp and a jumping spider. 

A jumping spider sneaking up on an ichneumon wasp.
The jumping spider was stalking the parasitoid wasp, which was preoccupied with laying an egg.  With the spider poised to strike, I thought the wasp had no chance to escape.

The jumping spider closes in on the ovipositing parasitoid wasp.
Mysteriously, though, this was as close as the spider got.  After looking at the wasp for a couple of seconds, the spider abruptly turned and moved back down the leaf.  Perhaps it was spooked by the camera, or perhaps the wasp was simply too large for the spider.  Meanwhile, the wasp continued laying its egg.  A couple of minutes later, it turned to face the site where it had been laying an egg or eggs, then spent some time apparently chewing.

The ichneumon wasp chewing nearby its oviposition site.
Once the wasp had flown off, I turned the leaf over to see what had been parasitized.  What I found was the mine of a tentiform leaf miner, with a hole where the wasp had been facing.

A tentiform leaf miner mine with a hole (on the left) where the wasp appeared to be chewing.

Monday, October 8, 2012

The decoy

After finding three praying mantises last week, I have been hoping to find one or more of them again.  Praying mantises will hide in order to ambush their prey; thus, I have been scanning plant stems more carefully than usual.  Although I haven't had any luck finding the praying mantises, I did manage to find another inconspicuous insect -- a western conifer seed bug (Leptoglossus occidentalis).

From the side, the western conifer seed bug (Leptoglossus occidentalis) can easily be overlooked.
It is more obvious when seen from above.
While I was watching the bug pictured above, I suddenly had the feeling that something had fallen into my hair.  I instinctively flicked the object with my hand.  Luckily, I didn't grab the mystery object -- since it turned out to be another western conifer seed bug.  Though these bugs don't bite, they can release a noxious odor, similar to that of a stink bug.

The bug was initially knocked to the ground, but it recovered quickly and took flight.  I followed it until it landed in a nearby pine tree, which is one of its host plants.

A western conifer seed bug (Leptoglossus occidentalis) on a pine tree.

Friday, October 5, 2012

Home sweet home

Inside a leaf, an insect can gain food and shelter simultaneously.  The challenge is that leaves are nearly flat.  It seems like it should be very difficult for insects to live inside them -- at least not without making a gall.  Yet, the larvae of numerous species of moths, flies and other insects have overcome this challenge.

These larvae are known as 'leaf miners' and they leave distinctive marks on the leaves they inhabit.  Some leaf miners take long, winding paths through their leaves.  The resulting 'serpentine' trails are often filled with the frass (droppings) of the larvae, which turns the trails black behind the leaf miners.  To me, this seems like a big drawback of living inside your food.

The trail left in a rose leaf by a leaf miner, possibly a larva of the moth Stigmella rosaefoliella.
Other leaf miners consume large patches of leaves, creating opaque 'windows'.  Sometimes, as in the picture below, the leaf miner can be seen through the window.

A leaf miner is visible through a 'window' in a common morning glory (Ipomoea purpurea) leaf.
To get a better look at the leaf miner pictured above, I flipped the leaf over.  I found that this morning-glory leaf miner (Bedellia somnulentella) was keeping its feeding area clean by expelling its frass through a hole in the leaf surface.  It would seem that, in the case of leaf miners, outdoor plumbing is the significant innovation.

A morning-glory leaf miner (Bedellia somnulentella) in a common morning glory (Ipomoea purpurea) leaf.

Wednesday, October 3, 2012

The mantis is greener on the other side of the fence

A few weeks ago, I found a praying mantis in my kitchen.  Since my kitchen isn't stocked with mantis food (i.e., live insects), I took the mantis back outside.  After that, I didn't see a mantis again until this weekend.  When I found the mantis pictured below, I thought it must be the same one that had made its way into the house.  It was considerably bigger than I remembered, but it was the same tan color that had worked so well as camouflage against the kitchen cabinets.

A tan colored European mantis (Mantis religiosa) female.
However, to my surprise, I soon encountered a second tan praying mantis in the backyard.  This one was sitting in the middle of the path, so I decided to move it to a safer spot.  Many years ago, I learned the hard way that a praying mantis can give a nasty pinch.  At least I learned that lesson well -- this time I put on my gardening gloves before picking up the mantis. 

A second European mantis (Mantis religiosa) female.  The spikes on the forelimbs can deliver a painful pinch to bare hands.
The second mantis wasn't my last surprise of the day.  When I started clearing dead plants from the front yard, I disturbed a third praying mantis from its hiding place.  This praying mantis was the same species as the two in the backyard, but bright green.

A green colored European mantis (Mantis religiosa) female.
This mantis quickly moved towards a bunch of dried plant stems and climbed up off the ground.  It was not very well camouflaged in its new spot; nevertheless, it soon began grooming itself, seemingly unaware of the large mammal hovering over it.

The green European mantis (Mantis religiosa) grooming itself.

Tuesday, October 2, 2012

New arrivals

This weekend, I went in search of the source of the woolly alder aphids (Paraprociphilus tessellatus) that have been swarming my neighborhood.  When on tree branches, these aphids form white, woolly masses that should be easy to spot.  I don't have their host plants (alders and maples) in my yard, but I thought some of those trees must be nearby.  I checked the alders in a nearby park, but their branches appeared clean.  If it hadn't been windy, I might have gotten a clue about where to look from the density of the aphid cloud.  As it was, I didn't see any aphids flying at all.

Wherever they had come from, the woolly alder aphids were still all over my backyard.  Some were sitting on foliage, presumably sheltering from the wind; quite a few others had been caught in spider webs.  While looking for the woolly aphids, I also discovered several more typical aphids -- ones that might be content with the plant selection in my yard.

A winged aphid on a morning glory leaf.
A winged aphid surrounded by her juvenile offspring on a rose leaf.
For much of the year, aphids reproduce asexually.  Without mating, the females can give birth to many live daughters, which are soon ready to produce their own daughters.  Therefore, a single aphid can quickly generate a large population. 

However, there is little chance that these new aphids will pose a threat to the plants in my backyard.  Starting tomorrow night, we are expected to have a series of hard freezes.  Even if the aphids survive the frost, there won't be much more damage that can be done to the plants this fall.