Breeding Butterflies

Recently, Life Sciences manager Sarah Moore attended the International Conference of Butterfly Exhibitors and Suppliers. This conference is held in a different location each year. In the past it has been held in Costa Rica, Switzerland, Malaysia and Ecuador. The locations may sound exotic, but to the people hosting them, they are home. The 2011 conference was held at Niagara Falls. Here is Sarah’s report.

Most of the time, when I tell people I work with butterflies, they are curious or a bit perplexed; but not the attendees of the International Conference of Butterfly Exhibitors and Suppliers. So it was a treat to spend a week with people who shared the job, duties, concerns, and joys of working with these delicate organisms.

During my visit, I was able to view a facility that raises many of their own butterflies through their entire life cycle. Since I am frequently asked why Pacific Science Center does not breed butterflies on site, I was especially curious to see the process and learn how much additional resources were involved. As it turned out, becoming a butterfly farmer is a serious endeavor.


The Butterfly Conservatory at Niagara Park has a state of the art butterfly breeding area adjacent to it. I spent so much time looking at this facility that I had to hurry through the wonderful butterfly house itself.

Butterflies never meet their offspring, but they put great care into securing appropriate food and habitat for them. A female butterfly will only lay her eggs on the correct plant material, at the correct stage of growth. There were several large, open rooms where host plant material is raised.


These plants are kept in semi-tropical temperatures – a big deal in chilly Niagara. Although to protect the butterflies, pesticides are never used, the plants were nevertheless in great shape and appeared free from any kind of unwanted insect.


Once the plant is large and strong, it is placed in a smaller flight cage where female butterflies are introduced. The butterflies mob the plants, laying eggs for 24 to 48 hours. The plants are then removed to another netted room, where once the eggs hatch out, additional plants are offered to the caterpillars as they grow.

These giant birdwing swallowtail caterpillars are especially hard to raise. They eat plants rich in toxic substances, which they use to make their own bodies distasteful. However, they can become sick from eating too much of the toxin.


In the wild, the caterpillars would chew around the base of the plant, girdling it, to prevent the flow of toxins up the branch. Then they would eat the leaves, and that section of the plant would die. In captivity, the plants are cut, aged in water and then supplied to the larvae. The stems are wrapped with netting to protect them from being chewed through.

But in the end, the birdwing butterflies are worth it. I hope to be able to order some of these spectacular butterflies in time for the holidays!


A good conference always leaves the participant’s head buzzing with possibilities. Could Pacific Science Center breed its own butterflies? Not with our current permits, and probably not with the resources available to us. Could we breed a few specimens to demonstrate the life cycle? This is a more realistic possibility, and one I will be exploring further. Read more!

Leave Them Alone!

They march across sidewalks and appear on the trunks of trees. Plump, fuzzy, caterpillars, often appearing sluggish, confused, and far from anything they could possibly eat. Along with spiders, changing leaves and ripe pumpkins, the sudden appearance of caterpillars seems to be a sign of fall in Seattle.




Pacific Science Center’s Life Sciences department gets its share of calls about these larvae. Most callers are at once charmed by their cuteness and anxious about their fate, as they seem to have lost all interest in taking care of themselves.

Much of the worry is unnecessary. Most caterpillars that become obvious in the fall belong to species that overwinter as larvae. Banded woollybears, Pyrrharctia isabella, are a famous example. These rust-red and black larvae have been fattening up during the summer. As the days grow shorter, they lose interest in eating and become restless. They leave the plants that feed them, and wander about, hunting for safe places to hide. Once they find the right spot, they go into diapause - delayed or suspended development.

Their bodies are amply prepared for the cold weather ahead. The liquid in their body is able to cool below freezing. Their instincts help them burrow into soil and dead leaves, where they will be further protected from weather extremes.

In late winter, they will resume development, pupate, and emerge as grown moths. One of the concerns about climate change is that the timing for these sensitive developments may become confused, as temperatures warm sooner but day lengths are still short in spring. In general, adapting to changes in climate is easier for species that have multiple generations per year, and have cycles that are less strongly linked to the changes in season.

In past articles, this blog recommends against raising caterpillars found in the fall. At best it is frustrating, and at worst, can lead to serious timing problems for the insect, which may complete its life cycle at a time of year that is inappropriate for feeding or finding mates. Not only that, but their soft-looking coats can be irritating to the skin and eyes, and are best not touched! It may seem like a cold, cruel world for such a tiny animal, but trust these little bears’ instincts and let them fend for themselves this winter.

Read more!

Unwanted Visitors

Notice anything missing in the Tropical Butterfly House? If you answered, “The umbrella plant is gone,” you must be visiting us a lot! Give yourself a pat on the back! This week our Horticulture staff removed that tall, willowy sedge plant, Cyperus alternifolius that loomed over the south goldfish pond.

Why?



During routine plant grooming on March 16th, horticulturist Maida Ingalls noticed several caterpillars of different instars on the fronds of the umbrella plant. These odd looking creatures were easily recognizable as the caterpillars of Owl butterflies, Caligo memnon.


Unfortunately, this wasn’t the first infestation of Caligo caterpillars. Several years ago some had been found on the same umbrella plants. Those larvae were removed and destroyed. The Tropical Butterfly House is a controlled environment with strict USDA permitting requirements that forbid us from growing caterpillars on our premises. Because of our permit restrictions, we have been carefully watching this plant and others for signs of butterfly larvae.


After a short consultation, Maida and Horticulture Supervisor Jeff Leonard cut down and removed all of the umbrella plant foliage and stalks, placing it in the freezer for a minimum of 72 hours. Next, they will completely dig up the plants’ roots with hopes that some day they can install a waterfall that will run into the pond below.

Maida reminds us, “Caterpillars are masters of camouflage. It’s hard for the casual observer to see them on a plant because they easily blend in with the stems and mimic the veins of the leaves.”

Even though we select only plants that will not stimulate the butterflies to lay eggs, it’s not unusual for Science Interpreters or Life Sciences staff to come across tiny Lepidoptera eggs every now and then. As Life Sciences manager Sarah Moore explains:

“The pressure on female butterflies to lay their eggs is pretty strong. They pick up on scents, and on visual cues; color, texture, and reflectivity of objects can all trigger egg laying. We’ve had the most problems with Caligos. Besides plant foliage, we’ve found them laying eggs on guests’ clothing, walls, glass and once, a butterfly laid eggs on my plastic eyeglass frames!”

The Life Sciences staff is ever vigilant, looking for the tell-tale signs of chewed foliage and caterpillar frass among the plantings. The continual monitoring of our garden to allow only butterflies – not their offspring – keeps us in compliance with the USDA permitting requirements and makes a more pleasant environment for all.

Read more!

Raising Butterflies

Future biologists often enjoy raising caterpillars at home or in class, and watching them turn first into chrysalides and then to butterflies. The hands-on experience of feeding, tending and observing butterflies throughout the life cycle can spark a love of learning. Furthermore, kids get a frame of reference when they visit Pacific Science Center’s Tropical Butterfly House.




Be aware, there are complications raising butterflies! We hope that those of you who wish to try raising butterflies yourself can learn from the many calls we get. We want you to have the best chance possible to bring caterpillars safely to adulthood.



To begin - the most common problem is timing. People may receive butterfly kits as a gift during times of year when rearing them is problematic. We recommend against starting raising caterpillars in the late summer, fall or winter. An entire life cycle can take as little as six or eight weeks, so you could end up with butterflies that can’t be safely released outside.

Pacific Science Center is always available to take in butterflies in this situation. Give us a call or e-mail first, so that we know you are coming. But a little planning can help you avoid the problem altogether.



If you find a caterpillar in the fall, it is best to leave it where it is. Left outside, the chrysalis will naturally adapt itself to changing temperatures and can survive even freezing weather. It can use temperature and day length to assess the time of year, and will not emerge until the season is ready. Inside, the temperatures may shock it into developing too quickly and emerging while it is still wintery outside.

Classrooms must plan not only around the seasons but around weekends and breaks. Pupae must be monitored daily, and planning ahead for weekends will help prevent the sorrow of coming in to a bunch of butterflies that emerged but had nothing to eat.



Not all butterflies emerge in good condition from their pupae. In an average batch of ten or twelve, you might have a few butterflies with crumpled wings, butterflies that die shortly after emerging, or even some pupae that do not mature into butterflies at all.

For some, this is a learning moment; for others it can be upsetting and sad. If you work with kids, plan for how you will approach the idea of death and physical damage. Be ready for some strong feelings and open discussion.



For most people, it makes sense to release native butterflies into the outdoors, and bring purchased ones to Pacific Science Center for flight in our exhibit. But once they have raised butterflies, some people choose to keep them in confinement, providing artificial nectar in the form of sugar water. The original kit for the caterpillars may have come with a small amount of food which will be gone. At some point, butterflies may breed and produce eggs. If you wish to carry on the life cycle, know what your butterfly species eats, and have that food available immediately! If you do it in advance, researching and finding plants is fun. Not so when hungry mouths are waiting.



Caterpillars and butterflies do not represent the same time commitment, either in years or in hours per day, as a dog or a cat. But they are completely dependant on us while we care for them. Still, we can become very attached and caught up in the outcome. Please take the time early in the process to plan ahead for the entire life cycle. It will maximize the educational value and cut down on the stress.

Sarah Moore, Life Sciences Manager

Read more!