The caterpillars eat their match, part two

When they eat the leaves of their host plants, the caterpillars of the orange-barred sulphur butterfly are green.  However, the one that I found was not eating the leaves, nor was it green.

An orange-barred sulphur (Phoebis philea) caterpillar on a Christmas cassia (Senna bicapsularis) flower.  The flower to the right had already been reduced to almost nothing, presumably by the same caterpillar.

Instead, the caterpillar was the same bright yellow as the flower on which it rested -- and which it would soon eat.  The only thing that prevented the caterpillar from blending in with the flower completely was its pattern of black stripes and spikes.

A few minutes later, the flower's style had already been consumed by the caterpillar.

The caterpillars eat their match, part one

Sulphur butterflies are large and tempting targets for my camera, yet they are surprisingly elusive.  Therefore, I was excited to discover one landing repeatedly on a row of Christmas cassia bushes -- and thrilled once I realized that the butterfly was depositing eggs on the plant.

An orange-barred sulphur butterfly (Phoebis philea) laying eggs on a Christmas cassia (Senna bicapsularis).

Even when laying eggs, the butterfly did not remain still for long, but at least it was long enough for me to get close and take a good look.  Then, after the butterfly had visited a few different spots on the bushes, it departed.

The sulphur flying off.  Some herbivore damage is visible on the leaves, but I didn't find any caterpillars feeding there.

Once the butterfly had moved on, I turned my attention to finding the eggs it had laid and any caterpillars that might have already hatched from previous clutches.  I found a couple of eggs on the tips of young leaves.

A recently laid sulphur butterfly egg.

However, the leaves were not where I found an orange-barred sulphur caterpillar feeding.  To be continued...

The host with the most, part two

The mining flies and galling mites inflicted peculiar injuries to the lantanas, but last year I saw plenty of ordinary herbivory of lantanas too.  Of course, after finding evidence of herbivory, I sought out the herbivores themselves.

A lantana leaf fastened in half by silk.

When the damage was fresh, I did not have to look far before finding the herbivore.  One type of caterpillar, the lantana leaftier moth, made pouches out of the lantana leaves by tying them with silk.  It then consumed the leaf down to a membrane while remaining concealed within the folded leaf (until I came along and pulled the leaf open).

A lantana leaftier moth (Salbia haemorrhoidalis) caterpillar eating the leaf from within.

Another, much larger caterpillar made an even more complete meal of the lantana leaves.  After it had finished with a leaf, there was often not much left besides the tough central vein.

A lantana after a visit from a very hungry caterpillar.

Looking for the first relatively intact leaf adjacent to the consumed leaves, it was easy to find the lantana moth caterpillars that were responsible for the devastation.

A lantana moth (Diastema tigris) caterpillar underneath a lantana leaf.

The spider at the end of the line

A crab spider may hide itself by matching the color of its flower or by constructing a refuge among the petals, but how can an orb-weaver hide on its web?  In an empty web, an orb-weaver is an easy target for its own predators and parasites.  Many orb-weavers avoid this problem by spending the day hidden nearby their webs, but not Allocyclosa bifurca.

Which lump is the spider?

These spiders sit in wait right in the middle of their webs, where they are disguised as part of a line of similarly shaped and colored egg sacs (above the spider) and bundled prey (below the spider). 

A female Allocyclosa bifurca eating prey that had become snared in its web.

Each time I find these spiders, they seem to be doing very well -- with several egg sacs per web and sometimes several spiders on neighboring fronds of the same palm. 

A female Allocyclosa bifurca spider briefly moving out of its hiding spot.

Yet, as successful as A. bifurca's camouflaging may be, it pales in comparison to what related Cyclosa spiders can do.

One tuft customer

Frequently, I will approach a leaf to investigate a mysterious object resting on its surface... only to discover a bit of debris that has fallen from some other plant.  However, every once in a while, my curiosity is rewarded.

Just some debris on a leaf?

The speck on the leaf shown above, although not very promising from a distance, turned out to be one of those rare objects that merited a closer inspection.

A small moth with a large tuft.

It was a small moth that had managed to obscure its shape by tucking in its legs and folding back its antennae.  Another unusual feature that stood out (quite literally) from the moth's otherwise streamlined appearance was a dark brown tuft of scales behind its head.  As I studied the moth from a variety of angles, it began to attract some more intimate attention.

An ant approaches the moth.

An ant came up and used its antennae to feel the moth.  For a moment, neither the ant nor the moth made a move and I wondered if the ant would attack.  Then the moment passed and the ant continued on its way, leaving the moth behind as if it really were just an uninteresting bit of debris.

The vanishing act, continued

After the caterpillars on the papaya had all disappeared into thin air (surrounded by white fuzz), the papaya leaves were left to grow undisturbed once again.  Yet, not that many days went by before I began to notice a new set of bites taken out of the leaves up at the very top of the papaya.

Papaya leaves with some tips chewed partially off and other tips completely gone.

Another sphinx moth must have visited the papaya to lay her eggs and make the tree play host to a new batch of caterpillars.  How many caterpillars were in this new batch?  Standing on the ground it was difficult to see up to the top of the tree and I only spotted one caterpillar.  However, with the help of my camera, I was able to count not just one, but seven new caterpillars.

The seven caterpillars circled in red.

That is, I counted seven new caterpillars just on the small part of the papaya shown in the pictures above.  I didn't count how many caterpillars were gobbling up the rest of the papaya leaves.  Happily, however many caterpillars there were, they didn't stop the tree from also producing a nice batch of papaya fruits.

Papaya fruits growing from the trunk of the papaya tree.

The vanishing act

The monarchs were not alone in facing danger in the garden this winter.  On the papaya, there were signs that Alope sphinx moth (Erinnyis alope) caterpillars had been chewing on the edges of the leaves.  However, the caterpillars themselves were nowhere to be seen.  These caterpillars can be well camouflaged against papaya leaf veins, but in this case the caterpillars were not simply disguised.  The caterpillars were gone, and in their place, something else was lined up along the leaf veins.

A ball of white fuzz along a papaya leaf vein.

On several of the papaya leaves, there were fuzzy white objects.  Although the objects were roughly cocoon shaped, they were obviously not the cocoons of the sphinx moths (which pupate on the ground).  Looking from another angle, I could tell that the white fuzz was hollow inside -- just as if it had been made around a caterpillar.

The hollow center of the white fuzz.

Indeed, it looked that way because it had been shaped around a caterpillar.  Parasitic wasp larvae had eaten the caterpillar and then spun their own cocoons within a fuzzy matrix around the quickly disappearing remains of their host.  In a previous year, we kept some of this white fuzz in a jar to find out what was inside; the result was a jar full of tiny black wasps!

Explore some more: Erinnyis alope life cycle

The fallen monarchs

Last winter, we found a monarch chrysalis that had fallen to the ground.  We brought it inside and several days later the story ended happily as the monarch successfully emerged and took flight.  This winter, falling was still a danger -- my mother found two chrysalises on the ground -- but there were also more serious threats lurking in the garden.

The remains of a caterpillar that had begun to form a chrysalis.

When I arrived in Florida and surveyed the garden, the only monarchs that I found were a caterpillar that had died while metamorphosing into a chrysalis (possibly due to disease or parasitism) and a chrysalis that did not look much healthier.

Something seems to have gone wrong for this monarch chrysalis.

The chrysalis was a dark brown color instead of bright green.  Although a healthy monarch chrysalis should turn dark shortly before the butterfly emerges (see here), something was wrong in this case -- the monarch's wing pattern was not visible.

A few days later, the chrysalis was still intact... but empty.

After a few days, the chrysalis was hollow with no obvious sign of what had happened to the butterfly that had been developing inside.  Meanwhile the chrysalises that my mother had rescued from the ground were also brown and hollow.  What had happened to all the monarchs? 

Pupae (left) from the flies that parasitized this monarch chrysalis (right).

Looking in the container below the rescued chrysalises, we found several pupae. These pupae belonged to flies -- flies that had parasitized the chrysalises and then emerged instead of the butterflies.  Unfortunately, since the container was not sealed, the adult flies had already escaped.

Out of the old and into the new

Today, millions of New Year's resolutions are going into effect, including many for a new image to go with the new year.  On New Year's Eve, the spider pictured below was also preparing to make changes in the new year.  The spider began its extreme New Year's makeover by dropping out of its old exoskeleton and emerging with a fresh new exoskeleton. 

An orchard orbweaver spider (Leucauge venusta) that had just molted.

However, rather than hoping to lose weight, the spider was preparing to increase in size.  Since the exoskeleton is relatively inflexible, a spider must shed its old exoskeleton and replace it with a roomier one in order to continue to grow.

The spider hanging below its old exoskeleton.

Happy Halloween!

Is your Halloween costume ready?  The females of the dragonfly species known as the "Halloween penant" stay "dressed" in orange and black their entire adult lives.  Yet, they are only likely to be seen on Halloween in the southernmost (and warmest) part of their range -- Florida.

A female Halloween pennant (Celithemis eponina).

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

Spilling the beans

While I was in Florida, I was asked to solve a new mystery involving a very strange object that had appeared on the fence.

A mysterious and very large (6" x 2.5") seed pod that appeared on the fence.

Although it seemed to be a seed pod, it did not resemble any seed pod we had ever seen before.  However, back in December and January, we had seen clusters of what looked like bean (Fabaceae) flowers on some of the vines.

Yellow bean (Fabaceae) flowers that were frequently visited by ants.

Since the seed pod did not appear to be ripe, I turned to the internet to find out what kind of seeds were developing inside.  Surprisingly, the answer was something quite familiar -- for years, we had been finding the seeds washed up on the beach.

A brown hamburger bean (Mucuna sloanei) partly buried in the sand.

We brought many of these seeds home and most of them ended up in jars.  A few others were left by the gate – and one or more of these must have eventually sprouted and grown into the vines that now cover the fence.  After identifying the vine, I checked the outside of the fence for more seed pods.  Though there were none on the vine, I did find an older one that had fallen to the ground.

An earlier crop of brown hamburger beans (Mucuna sloanei).

... and a surprise welcome present!

A short visit to Florida last week gave me the opportunity to check on the progress of the egg sacs that had posed such a mystery a couple of months ago.  So many spiderlings had hatched recently that I found miniscule spiders and their similarly diminutive webs nearly everywhere I looked in the garden.  Many of the young spiders (such as the one pictured below) were easily recognizable as spinybacked orbweavers (Gasteracantha cancriformis).

A small spinybacked orbweaver (Gasteracantha cancriformis).

However, many others were even smaller and simply looked dark and round.  Nevertheless, I was eventually able to establish that these too were spinybacked orbweavers.  As I was looking for thrips on the ficus hedge, I noticed yellow and green silk sticking up from the back of one of the leaves.  When I turned the leaf over, some of the silk snagged on a branch, revealing a ball of white silk underneath.  Within this inner silk compartment,  I could see a mass of spiderlings that had hatched from their eggs but still remained within the egg sac.

A spinybacked orbweaver (Gasteracantha cancriformis) egg sac.

Once disturbed by my handling of the leaf, some of these spiderlings were ready to enter the wider world.  One by one, they crawled out of the silk ball, made their way to the edge of the leaf, and jumped.  

A spiderling emerging from the egg sac.

Although I temporarily lost track of the spiderlings once they left the leaf, within minutes I began finding new spider webs stretched along the ficus hedge.

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

Long live the queen butterfly

Although one encounter with a parasitoid wasp ended without incident, the queen caterpillars (Danaus gilippus) were not out of danger.  As I was looking over my pictures from the previous day, I noticed another wasp -- sitting on top of the largest of the queen caterpillars.

A queen caterpillar (Danaus gilippus) and a parasitoid wasp.

If you have trouble finding the wasp in the picture above, look between the 5th and 6th yellow stripes from the left, or just look at the close-up below.

A close-up of the parasitoid wasp on the queen caterpillar.

In the subsequent pictures that I took (which unfortunately are not focused on the wasp), the wasp's abdomen is curved down and the wasp appears to be ovipositing (laying eggs) into the caterpillar.  After inspecting this series of pictures, I decided to monitor the caterpillar closely for any sign that it was indeed parasitized.  However, the next morning, the caterpillar had disappeared from the milkweed.  By searching the surrounding area, I eventually located the caterpillar in a sheltered spot where it was beginning its transformation into a pupa.

The queen caterpillar preparing to pupate.

One day later, there was a very healthy-looking chrysalis where the caterpillar had been.

The chrysalis of the parasitized(?) queen caterpillar.

Over the next few days, the chrysalis continued to look as it should, without any dark discoloration to suggest that there were a couple hundred wasps developing inside instead of a butterfly.  I left Florida before I could be sure what the result would be, but I have been informed that in the end the wasp's attempt failed and it was a butterfly that emerged from the chrysalis.

This is a different queen butterfly (Danaus gilippus), since I didn't get to see the one that emerged from the chrysalis.