Rainforest Caterpillars - Eva Varga

As a teacher, I’ve had some amazing opportunities over the years. For a while now, I have wanted to write a post about them here to share some insight into who I am – to describe how I came to be the person I am today. I wanted to share some of them with you in hopes that I might inspire you. Accordingly, some of the posts you see around here in the near future may be a bit of a departure from your garden-variety homeschool blog. Sometimes, I just like to get these things in print so I’ll remember that they actually happened. For today, here’s a snapshot of one of those teaching experiences that changed my life.

People are pretty jealous when I tell them I’ve recently returned from a trip to Ecuador. They immediately ask, “Did you go the Galapagos?” Did you stay at a beach resort?” I have to be honest and answer, “No, I collected caterpillars.” While this may seem a bizarre way to spend ones vacation, I really did venture into the rainforests of Ecuador for two weeks as part of an Earthwatch expedition.

Rainforest Caterpillars

The purpose of this particular expedition was to assist a team of scientists in their investigations of caterpillar defenses against their natural enemies, particularly parasitoids. The principal investigators, Dr. Lee Dyer (Assistant Professor at Tulane University), Thomas Walla, and Craig Dodson (Associate Professors at Mesa State College), had four major research goals. The first was to gain a better understanding of the effectiveness caterpillars have against their natural enemies. Secondly, to examine caterpillar diets (generalist versus specialist feeders), hoping to clarify to what extent plant chemistry and natural enemies affect the diet of herbivores (more specifically, caterpillars). The third goal was to relate the results to agriculture as an alternative to the current use of pesticides. The fourth goal was to inventory the biodiversity of an ecosystem that is disappearing at an alarming rate.

After several years of caterpillar study at La Selva Biological Station in Costa Rica, Dr. Dyer and his colleagues are pioneering a companion project in the lesser-known and threatened Ecuadorian rainforest. My expedition team was the first to work at Yanayacu Biological Station in Ecuador, a privately owned preserve on the eastern slope of the Ecuadorian Andes.

Caught between plants, predators, and parasites, caterpillars have been forced to develop a bizarre armory of survival skills. For the most part, while many butterflies are well known as adults, the details of their life as caterpillars (the longest part of their life), is poorly known, and many inter-related questions need to be answered. Getting data to provide answers for these questions is what the expedition was all about, and in order to obtain that data, many mundane chores and practical tasks needed to be carried out.

A typical day of research usually involved a lot of hiking. In order to study caterpillars, you need to find them first. We usually set out with our collecting kits, to scour the roadsides and other disturbed areas (prime caterpillar habitat) for these elusive creatures. Finding one elicited shouts of joy in the beginning. After a few days in the humidity and nearly constant drizzle of the forest, the excitement wore off (but it was always exciting to find a new or interesting species).

In the lab, another group of volunteers was ready to process the new arrivals. Essentially, each individual caterpillar was given a unique number, identified taxonomically, and the behaviors, coloration, and morphology were recorded. The caterpillar was then ready to be placed in the “zoo”. The caterpillar specimens are then cared for until they pupate and either emerge as adult Lepidoptera or a parasitoid emerges. Each day, volunteers cleaned the bags of frass (entomological term for caterpillar droppings) and condensation, and assured that each bag had fresh plant material. As we did so, we also checked the status of the caterpillar and noted any changes (presence of a parasitoid or pupa).

In the Classroom

So, how will I use all this in the classroom? As a fifth grade teacher, one of my favorite (also the most popular with students) thematic units is on invertebrate animals. Since caterpillars are considered to be one of the most serious pests of agriculture, it was only natural that part of the study included trying to find a more natural way to control their population. Using their natural enemies against them, parasitoids seem to be a logical solution. This would be something that my students could explore locally.

But much more important than any facts which I can teach my students are my experiences and adventures in the rainforest. One of the main things I have learned is that we need a new “law of the jungle.” Biodiversity and the interconnectedness of all the creatures of the rainforest show us that we must honor the balance of nature. These are the great lessons of the rainforest which I hope to pass on to my students: attitudes and perspectives which provide a new vision of the world, one celebrating life’s diversity and offering an alternative to the 19th century views which still persist. That’s my lesson plan.