What's that bug?

While I immediately recognize a few of the arthropods in my photographs, I have to file away many of my pictures for later identification.  Most of these can initially be filed to family or at least order, but a few remain complete mysteries.  The strange, butterfly shaped scale insects pictured below lingered anonymously in my "Hemiptera" folder until I serendipitously came across a similar picture when looking for images of invasive species.

Lobate lac scales (Paratachardina pseudolobata) in South Florida last December.

Further research on the internet confirmed that these scales do belong to an introduced species, the lobate lac scale (Paratachardina pseudolobata).  However, learning more about this insect just raised more mysteries.  Although the lobate lac scale is not thought to be native to Florida (or the Bahamas or Christmas Island, where it is also found), it is not clear where this species came from.  A related species (P. lobata) is known from India and Sri Lanka, so this species is likely to be Asian as well.  The spread of this species -- from wherever its native range is -- is somewhat surprising, given its lack of wings and the fact that adults remain relatively sessile.  Also unusual is the absence of males; unlike its relative P. lobata, this scale reproduces parthenogenetically (asexually), developing from unfertilized eggs.

Explore some more: Featured Creature: lobate lac scale

A problem for roots

The invasive Japanese beetle (Popillia japonica) is notorious for the damage that it causes both above and below ground.  Above ground, adult beetles can be seen voraciously consuming foliage and flowers.  Below ground, beetle larvae feed so extensively on the roots of grasses that conspicuous dead patches form on the lawn above.  However, not all dead patches of grass should be blamed on Japanese beetles; some may be due to another Asian beetle with a large appetite for roots: the oriental beetle (Anomala orientalis).

An oriental beetle (Anomala orientalis) sitting on a daisy.

Like the Japanese beetle, the oriental beetle was also accidentally introduced to North America from Japan in the early 20th century and has been gradually expanding its range.  In contrast to the Japanese beetle, though, adult oriental beetles are not very destructive (I have seen several but never observed one feeding).

Another brown oriental beetle sitting on, but not eating, a fern.

A particularly interestingly aspect of oriental beetles is that they come in several color variations.  Can you spot the slight differences in the patterns of the two beetles above?  I've put a hint below the next picture, which illustrates a more extreme example of color variation.

The less common, black form of the oriental beetle (Anomala orientalis).

Hint: The biggest difference is on the thorax (the segment between the head and the abdomen).  The first beetle has a solid brown patch, whereas the second beetle has a white line dividing the brown patch.  The patterns of white and brown on the elytra (the wing converings on the top of the abdomen) are also not quite the same.  See even more examples on the Natural Current Events Facebook page.

More than a pain in the neck

Since beetles are well defended against spiders by their tough exoskeletons, I was curious how Japanese beetles were falling victim to the candy stripe spiders.  However, each time I found a Japanese beetle and a candy stripe spider together, I had already missed the decisive moment.  Therefore, I was limited to reconstructing events by inspecting the aftermath of the beetle-spider encounters.

A Japanese beetle (Popillia japonica) being eaten by a candy stripe spider (Enoplognatha ovata, ovata color morph).

While watching the spiders consume their prey, I noticed that they were exploiting a weakness in the beetles' defenses.  Like human armor, beetle exoskeletons are vulnerable at the joints.  In the pictures above and below, you can see that each spider has bitten between the beetle's head and its sternum (where the beetle's neck would be if it had one).  Though these spiders had already moved on to feeding, the same spot seems a likely target for the killing bite.

Another Japanese beetle being eaten by a candy stripe spider (Enoplognatha ovata, lineata color morph) in 2012.

Going back through some of my other photographs of the candy stripe spiders, I found that the strategy of "going for the throat" also appears to be effective with other difficult types of prey, such as wasps.

A female candy stripe spider (Enoplognatha ovata, redimita color morph) with a wasp.

Winsome invaders, lose some invaders, continued

Despite the superabundance of Japanese beetles (Popillia japonica) in the yard, I have hardly ever seen anything attempt to eat the beetles.  (One attempt, made by an eastern phoebe chick, was fatal for both the beetle and the chick.)  However, while hunting for the beetles, I have occasionally come across ones that were already dead.  In each case, the dead beetle was loosely wrapped in spider silk; in a couple of cases, the spider was still there.

A Japanese beetle captured by a female candy stripe spider (Enoplognatha ovata, ovata color morph).

The spiders making meals out of the Japanese beetles were a type of cobweb spider.  Although they belong to the same family as black widows, they have a much friendlier name: "candy stripe spiders" (Enoplognatha ovata).  Interestingly, this predator of Japanese beetles is itself an introduced species, yet it comes from Europe not Asia.

A green and white knight

As I was strolling through a nearby botanical garden, I heard a rustling sound coming from a bush alongside the path.  After searching for a moment, I located the source: a green lizard that was considerably larger than any of the anoles in our garden.

A green lizard with white markings amongst the foliage.

Although I expected the lizard to scurry off as I approached, it did not.  Instead, the lizard froze, and I was able to get a closer look at it.

A juvenile knight anole (Anolis equestris).

However, a closer look just convinced me that I had never seen a lizard like it before.  I thought that the distinctive-looking white bands would make identifying this lizard a simple task.  In fact, it was the reverse.  I eventually learned that the white bands are only present in some juveniles (possibly only the females) of this species: the knight anole (Anolis equestris).  In contrast, the stripes below the eyes and above the shoulders persist into adulthood; these can be used much more reliably to recognize the knight anole, which is yet another species introduced to Florida from Cuba.

Lounging lizards

I was not able to find any native frogs in the garden.  Consequently, it may be too late to help the native frog community by actively removing Cuban tree frogs (Osteopilus septentrionalis).  Yet, native frogs are not the only ones threatened by Cuban tree frogs.  Among the many other types of prey that Cuban tree frogs consume are lizards.  Nevertheless, despite the presence of several very large Cuban tree frogs, anoles were extremely abundant in the garden this winter. 

A Cuban brown anole (Anolis sagrei).

Unfortunately, the majority of these anoles belonged to another species introduced from Cuba: the Cuban brown anole (Anolis sagrei).  This anole has itself played a large role in displacing native anole species.  The second most common anole was also a non-native: the bark anole (Anolis distichus), which has been introduced to Florida from the Caribbean.

Another anole, probably a bark anole (Anolis distichus).

I did find one native species persisting: the Carolina anole (Anolis carolinensis).  However, this species was quite rare compared to the two introduced species pictured above.

A Carolina anole (Anolis carolinensis) on a palm frond.

Given this composition of the anole community, it is not clear to me whether removing Cuban tree frogs would improve or worsen the situation for the native anoles.  Removing the native anoles' predators might simply increase the number of their competitors.

They are only cute when they are young

Cuban tree frogs (Osteopilus septentrionalis) are commonly available as pets.  Yet, the ones that I encountered in the garden during the day were quite unattractive.  For a while, it was a mystery to me why anyone would want one of these frogs as a pet.  Then, I started to find juvenile Cuban tree frogs. 

A juvenile Cuban tree frog (Osteopilus septentrionalis) in a bromeliad at night.

The juvenile frogs appeared mostly in and around bromeliads, but only at night (except for the first one I saw).  Juvenile Cuban tree frogs are more difficult to identify unequivocally than are the adults, but by process of elimination, these frogs did not seem to belong to any of the native Florida species.

Another juvenile Cuban tree frog (Osteopilus septentrionalis) in a bromeliad at night.

With their smooth skin and large eyes, the appeal of these young frogs as potential pets is more understandable.  However, they do not keep their good looks forever and can continue to live in captivity for up to ten years.  Moreover, the mucus on their skin can cause irritation and allergic reactions if these frogs are handled.

Yet another young Cuban tree frog (Osteopilus septentrionalis) in a bromeliad at night.

Thus, despite their innocent youthful appearance, Cuban tree frogs do not make very good pets.  Furthermore, if no longer wanted pets are released, they may invade new habitats and disrupt native communities -- just as our backyard frog community was disrupted.  In the end, I was not able to find any frogs in the garden other than Cuban tree frogs.

Frog in a hole

After finding a Cuban tree frog (Osteopilus septentrionalis) in the garden, I began a survey to determine whether there were any native frogs persisting.  Many frogs are nocturnal, but my daytime searches did reveal three large frogs. 

A Cuban tree frog (Osteopilus septentrionalis) in a rusted pipe.

I found these frogs in sheltered nooks around the exterior of the house.  Once I had located their hiding spots, I could reliably find the same frogs day after day.  However, being able to see the frogs on a daily basis was not very comforting, since they were all Cuban tree frogs.

A Cuban tree frog (Osteopilus septentrionalis) in an exhaust vent.

At night, these frogs would emerge from their daytime retreats.  Sometimes I would see them nearby (such as the frog pictured below, which would spend the day tucked between the duct and the wall), while other times I would simply find their usual spots temporarily vacant.

A Cuban tree frog (Osteopilus septentrionalis) near its refuge in the evening.

The large frogs were coming out of hiding in order to hunt, and so too were many smaller frogs.  To be continued...

Cuban tree frog crisis

On my very first morning back in Florida, I encountered not only sea gulls and a snake, but also a small frog sitting in a bromeliad.

A tree frog in a bromeliad.

My excitement at finding the frog did not last long.  Although there are several tree frog species native to Florida, this frog did not belong to any of them.  It was a Cuban tree frog (Osteopilus septentrionalis), a member of an introduced species that is known to outcompete and even to eat native frogs.  Cast in this light, the frog quickly shifted in my view from a welcome resident of the garden to an imposing villain.

A Cuban tree frog (Osteopilus septentrionalis) in a bromeliad.

Nevertheless, Cuban tree frogs also eat insects, including some pests.  Thus, they may provide an important service in the garden.  We were left with a dilemma: should we catch and euthanize these introduced frogs (as has been recommended by some), or leave them alone?  We decided that the answer to this question depended on others: What was likely to happen if we did manage to cull the Cuban tree frog population in the garden?  Would any native frogs return?  I read a couple of anecdotes that suggested removing Cuban tree frogs would result in increases in native frogs.  However, would the same happen deep within the invaded range?  Were there any other frogs left in the garden that could benefit from the removal of the Cuban tree frogs?  To be continued...

Explore some more: Invasive Cuban Treefrogs in Florida; The Cuban Treefrog in Florida

Cleaned out of house and home

When some of the spotted oleander caterpillars (Empyreuma affinis) looked large enough to leave the oleander tree, I decided it was time to clean away the old, empty cocoons from the surrounding area.

Spotted oleander caterpillar (Empyreuma affinis) cocoons in the corner of a window frame.

I wanted to be able to keep track of the new pupae, but I couldn't do that very easily with tens of cocoons from past generations filling every nearby sheltered spot.  However, I acted a bit too late -- there were already a few new pupae hidden among the old cocoons.  Some were already several days old...

Spotted oleander caterpillar (Empyreuma affinis) pupae.

... and one was still being formed.

A brand new pupa of a spotted oleander caterpillar (Empyreuma affinis).

I kept the pupae in an enclosure and for several days saw no change, except that the youngest pupa darkened to match the rest.  Then, one morning, two of the moths emerged.  Unlike my recent experience with the monarch butterfly, there was no sign (that I could recognize) that the moths were about to emerge; thus, I missed both events.  Later that day, we took the moths to the oleander tree and released them into the open.

The first stop for this recently emerged spotted oleander caterpillar (Empyreuma affinis) moth was my mother's leg.

The moths showed no interest in their host plant, and in this they were exactly the same as the monarch butterfly.  Although one of the moths did rest briefly on my mother's pants (as shown in the picture above), they were both soon headed high up into the trees.

One of the moths resting on a palm frond after its first extended flight.

Bad hair day

Even though a caterpillar's skin appears soft and stretchy, it is an exoskeleton that cannot grow. Therefore, a caterpillar must periodically take breaks from eating in order to molt; it develops a new, larger skin underneath its old skin, which is then be shed.

A queen butterfly (Danaus gilippus) caterpillar just after molting.

The queen butterfly caterpillar pictured above had recently molted.  Its old skin can be seen clasped higher up on the leaf vein and its old head capsule can be seen to the left of the caterpillar.  However, the queen butterfly caterpillar itself does not look much different than usual.  In contrast, a freshly molted spotted oleander caterpillar can be recognized easily by its clumped and curly hair!

A spotted oleander caterpillar (Empyreuma affinis) just after molting.

The bee's knees are covered in pollen

The first destination of my southward migration was Santa Barbara, CA, where I spent a very full week.  Although I was kept busy working all day each day, I did manage to set out first thing one morning in search of flowers.  Despite it being December, there were blooming plants nearly everywhere I looked.  The most impressive displays were the towering inflorescences of the foxtail agave (Agave attenuata).  These curved spikes could be eight or more feet long and were densely packed with light green flowers.

Flowers of a foxtail agave (Agave attenuata) in Santa Barbara, CA.

The foxtail agaves were very attractive to honey bees as well.  Even though it was only a few minutes after sunrise, honey bee foragers had already collected large amounts of pollen in the "pollen baskets" on their hind legs.

A honey bee (Apis mellifera) forager collecting pollen from the agave flowers.

The agaves benefit if the bees transport their pollen to other flowers, fertilizing seeds.  However, the honey bee foragers have a different objective: to feed the protein-rich pollen to their developing sisters back in the hive.  Nevertheless, the bees I saw were getting so coated in pollen that they may have been doing some pollinating as well.

A honey bee (Apis mellifera) forager covered in agave pollen.

Down with the thistles

Canada thistle (Cirsium arvense), an invasive species from Eurasia, is common in this area.  However, so too are its enemies.  Even though the thistles have died down for the winter, I have found several Canada thistle bud weevils (Larinus planus) in the yard.  These weevils seem to be seeking out spots where they can stay sheltered until the spring.

A Canada thistle bud weevil (Larinus planus) sheltering on the lavender bush.

Another of the thistles' enemies has found a very cozy way to spend the winter -- within galls on the thistles' own stems. 

A gall on a Canada thistle stem.

As I was clearing dead plants out of the garden, I came across a couple of dried thistle stems interrupted by these large galls.  I was curious to see what, if anything, was still inside.  Cutting open one of the galls, I found several very odd larvae.

Inside the gall there were several larvae of the Canada thistle stem gall fly (Urophora cardui).

The larvae did not have anything resembling legs or even heads.  They also failed to show any sign of life.  Thus, I initially thought that I must have cut them in half.  However, on closer inspection, I determined that they were all whole.  Although strange to me, this form is normal for Canada thistle stem gall fly (Urophora cardui) larvae at this time of year.  In the fall, the larvae finish growing and suspend their development.  Only in the spring will they pupate and then emerge from the gall as adult flies, ready to parasitize a new generation of thistles.

Two of these things are not like the others

Fruits all over the garden have finally ripened to a vibrant red.  There are crabapples, rowan berries, rosehips, trumpet honeysuckle fruits, and cotoneaster fruits (pictured below) -- all of which add attractive autumn color to the garden.

Berries and autumn foliage of a Cotoneaster sp. shrub.

The bright color of the fruits is not only appealing aesthetically; it also attracts seed dispersers, such as birds, that consume the fleshy fruits but fail to digest the seeds within.  However, not every red thing on the branches is aiming to be eaten.  Spot the exceptions in the photo below!

Two seven-spotted ladybugs (Coccinella septempunctata) among the Cotoneaster sp. berries.

Interestingly, in the case of the ladybugs, the red color serves as a signal that they are distasteful. 

Painting the garden red

We had a few days of warmer weather this week and, as a result, the ladybugs have come out of hiding.  Almost wherever I go in the garden, I find more of these little red beetles.  Some of them, such as those pictured below, appear to be just sitting around in clusters.

Seven-spotted ladybugs (Coccinella septempunctata) gathered on a hollyhock leaf.

Seven-spotted ladybugs (Coccinella septempunctata) gathered on a rose stem.

Others are going for the last remaining flowers.  Although ladybugs are predators of other insects (particularly aphids), they will consume nectar and pollen when their prey are scarce.

A seven-spotted ladybug (Coccinella septempunctata) on a dandelion (Taraxacum sp.) inflorescence.

A seven-spotted ladybug (Coccinella septempunctata) on an aster inflorescence.

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.

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.

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.