Alien Invader – or Native Species?

                            

 

I was thrilled when my friend Cheryl sent me a photo of something unusual that had landed on her front step. What could it be?

 

Actually, I could see right away it was a fat green caterpillar. But I had never seen one like this before. It was close in size to the large striped caterpillars that eat all the leaves off the frangipani trees, but was mostly green, except for a dark band across its face that expanded to look like one big eye in the center of its forehead. Below that was something that looked like a mouth, but wasn’t. Weird.  

 

Its green body looked similar to a horned caterpillar I once saw on a sugar apple tree, but this one had a smoother shape and only a tiny little horn on its butt.   

 

                                    

 

After some late-night internet research, I found a photo that seemed like a match – a sphinx moth caterpillar called Erinnyis alope.

 

Cheryl brought me the caterpillar in a box so I could check it out. I wondered if it was invasive, however it turned out to be a local species that eats the leaves of various tropical plants, including papaya, cassava, jatropha and allamanda. 

 

I put it in a large plastic crate with some fresh papaya leaves, but it wasn’t interested in eating. Whenever I came by it puffed up its head to make its false eye spot stick out. That’s its way of scaring off predators, and it definitely gave me the creeps. 

 

I decided to keep the caterpillar inside and see what it would look like when it turned into a moth. At other times I have raised monarch butterflies, as well as frangipani caterpillars, which turn into large gray Pseudosphinx tetris moths. It has been amazing for me to see the different cycles of their transformation. 

 

The alope caterpillar kept running around the inside of the crate, and not eating. Given its size, I concluded that it was done eating and was getting ready to transform into its pupa stage. That’s probably why it dropped out of the papaya tree near Cheryl’s door – it was looking for some leaf litter to hide in as it entered its next phase. I picked some dead leaves off the papaya tree in my yard and put them in the crate. After that, the caterpillar stopped running and settled down. 

 

After a couple of days, the caterpillar looked shrunken, and its color had faded. 

                                

 

 

By nighttime, it had made its transformation into a pupa state. Next to it lay the remains of its caterpillar skin, which it had slipped out of. 

 

                                     

 

 

Outside, under ordinary conditions, the pupa would be hidden in the leaf litter on the ground until it turned into a moth. The pupa forms a hard shell on the outside, while inside the former caterpillar body develops into a new winged creature. It is not completely hard, and it can twitch in an alarming way if it is disturbed. 

 

The pupa lay in the crate under the kitchen table for 17 days. I’ll admit that towards the end I occasionally moved the crate a bit to see if there was any reaction. It was reassuring to see small signs of life. 

 

Then one morning I woke up and saw that the pupa shell was empty. The moth must have come out, but where did it go? The crate was not covered, and there was a lot of stuff around the room. It had to be there somewhere.   

 

After a while I decided to think like a newly emerged moth. It would need to let its wings stretch and dry out. So, it probably didn’t get far. I got down on the floor and spotted it on the edge of a chair leg. 

 

                                

 

The moth hung on the chair leg all day, even after I moved the chair out onto the screened-in deck. By the next morning it had managed to fly over to the ledge and sit on a stick.

 

I took a few photos, and managed to catch it showing off the orange on the inside part of its wings. Otherwise, it looked pretty dull and grey.

   

 

                              

 

 

After the photo shoot, I took it outside (riding on the stick) and set it on some of the dead papaya leaves hanging from our tree. It was perfectly camouflaged so I hoped it wouldn’t be picked off right away by a bird. 

 

By the end of the day, it was gone. I hope it flew off to find a mate and successfully continue the cycle of alope caterpillar life.  

Bees Search for Flowers During the Dry Season

 

A Centris bee and large black carpenter bee

 As the dry days of April dragged on there were few flowers to be seen, and many hungry bees and birds. 

 

One of the native trees blooming in early April was the Caribbean Dogwood (Piscidia carthagenensis), though the pale pinkish flowers were hard to spot on the tree’s high, bare branches. It drops its leaves before flowering. 

 

When I stopped along the road to get a photo of one of these trees, I noticed that there were some bees that had also found the flowers. I easily recognized the native female carpenter bees (Xylocopa mordax) because they are large, black, and shiny. After some research I concluded that the smaller one nearby was probably a type of Centris bee, which would be in the same family as the carpenter bees. 

 

Not too far down the road, there was another tree with light purple flowers, an ornamental pea tree, Gliricidia sepium. There were a few large carpenter bees on this one too, including a male one, which is a surprising burnt orange color, not black. 

Male carpenter bee

 

It was exciting to see the male carpenter bee – a first for me. They are not around very much because they die quite soon after hatching and mating. The females are more visible as they go around collecting pollen and nectar. They put a mash of pollen and nectar into small holes they make in trees as nests for their eggs. Then when the larvae develop, they will have the pollen mash for food before they break out of their tiny nesting spaces. 

 

Carpenter bees are important pollinators for open-faced flowers, but some flowers hide their nectar and pollen deep inside, where the big carpenter bees don’t fit. A hungry carpenter bee will sometimes slit open the bottom of a tubular flower and ‘steal’ the nectar, bypassing the pollen and reducing the flower’s pollination possibilities. 

A female carpenter bee taking nectar from the bottom of a Ginger Thomas flower.

 

A few carpenter bees (and some hungry ants) also found flower buds on a Morinda citrifolia, which is originally from Asia and known locally as painkiller tree. The leaves are reportedly useful for easing muscle aches. In some places it is called ‘noni’ and the green fruits valued for their health benefits. Here they are called ‘starvation fruit’, maybe because the trees grow quickly and produce fruit even under adverse conditions, like after hurricanes. Another idea about the name is that the pale, ripe fruits are stinky and unappetizing, something no one would eat unless they were starving. Or a fruit bat.   

A female carpenter bee on a Morinda citrifolia

 The native bees looking for nectar have to compete with the European honeybees, which were introduced to the islands by colonists. In some situations, honeybees can become so numerous that they dominate the available nectar supplies. 

A honeybee on a black mangrove flower

 

Carpenter bees are solitary, while honeybees live in hives, and communicate with each other about where to find nectar and pollen. Also, local bees tend to have special relationships with a few trees that they pollinate, and may not go to just any flower. Honeybees are not so discriminating. 

 

Honeybees can also be quite aggressive. One morning when I put out sugar water for the bananaquits, a bunch of honeybees came by and tried to take over the feeder. The next day there were even more. I put out several bowls and tried to get the birds and bees to use different ones, but there was still conflict.    

 

A bananaquit annoyed by honeybees at the feeder

 

At the end of April, enough showers came to encourage a few of the lovely lavender wattapama trees (Poitea florida) to bloom. These trees are special because they are native only in Puerto Rico and the Virgin Islands. Unfortunately, their flowers only last for a few days. 

A honeybee and a Centris bee attracted to the wattapama flowers 

  

When I went to take some photos, I found honeybees visiting the flowers, as well as attractive native Centris lapines bees.  

 

Centris lapines bees have orange butts

When the islands are parched, it’s nice to help the bees and birds by offering them bowls of water, or sugar water. But it’s also important to keep the bowls clean, so they don’t spread germs, especially as some of the birds might decide to use the water for a quick bath.