Interesting article describing the laboratory techniques for raising butterflies.
Nathan Brockman, butterfly wing curator
for Reiman Gardens, sorts chrysalises shipped
from Costa Rica in the Butterfly Laboratory on Nov. 18.
Iowa State Daily
November 30, 2004
Come fly with me
Reiman Gardens perfects technique of butterfly rearing
Flowers aren’t the only thing that grow at Reiman Gardens.
Thousands of butterflies also bloom within the gardens’ butterfly wing.
Nathan Brockman, Reiman Gardens’ insect-rearing specialist, raises
the butterflies flown at Reiman Gardens and works to develop better
ways to raise the insects.
"In the wild, approximately 90 percent would die, considering all
the steps from eggs to adult," Brockman said. "But a small percentage
can make it to adulthood and then lay lots of eggs."
Caterpillars develop into cocoons, and, when butterflies emerge,
their wings are small. Their bodies pump fluid into their wings to make
them bigger before they dry out and harden. Brockman said the
butterflies sometimes have problems coming out because their wings can
He said about 90 percent survive in the lab because Reiman Gardens has top-quality butterfly houses and emergence cages.
"We can slow or speed up growth depending on temperature," Brockman
said. "If it’s too hot, butterflies can emerge too early. And, if it’s
too cold, they can freeze in their chrysalis, especially if it’s too
cold too fast."
The temperature, humidity and lights in the emergence cages are on
timers to stimulate morning and night and can be altered in order to
change the times butterflies emerge.
The emergence cages were custom-built by Percival Scientific Inc.,
an Iowa-based company, which normally builds laboratory incubators.
"This was the first kind of emergence cages that they had built like
this," Brockman said. "Now they have a product line catering these to
butterfly facilities like Reiman."
Reiman Gardens is the only facility of this kind with such an emergence cage, Brockman said.
The emergence cages are also completely sealed so that parasites and diseases don’t get out or in.
The only way a parasite can get into the emergence cage is by being
inside the cocoon itself, Brockman said. A female parasitic wasp can
sting the caterpillar and lay eggs inside it before it develops into a
cocoon. The caterpillar will keep developing into a cocoon with the
parasite eggs growing inside it, and the parasitic wasps will eat the
cocoon from the inside out and emerge from it instead of a butterfly.
"We generally see more of this in the tropical shipments," Brockman
said. "But sometimes the U.S. shipments will have infected chrysalises."
Butterflies come from their cocoons in the emergence cages and are
taken into the butterfly wing twice a day — morning and night — via a
net-covered box called a sleeve.
Another way to better raise the butterflies is to collect the eggs before they hatch into caterpillars.
Elizabeth Nelson, butterfly wing docent, said workers put passion
flower vine in the butterfly wing as a place for the butterflies to lay
eggs. She said the butterflies’ eggs stick to the plants like adhesive.
Brockman and his three part-time students go on "egg hunts" to find
the tiny white eggs. The eggs will change colors from white to dark
brown before the caterpillar emerges.
Most of the caterpillars and eggs are raised on host plants inside
small cubic glass cages, but others are raised inside plastic cups on
an artificial diet. Artificial diets are mixtures of plant matter,
vitamins and juices from their actual host plant.
"Sometimes it’s better to raise them off an artificial diet because
we don’t need space in the greenhouse to raise host plants," Brockman
said. "And it takes up less space in the lab because they’re raised in
cups, not glass cages."
All butterflies raised here are flown in the butterfly wing. They
supplement the butterflies received from suppliers, Brockman said. The
amount released fluctuates every day, but evening numbers are usually
less because the majority of butterflies emerge in the morning.
Brockman said, on average, they release about 64 butterflies a day.
"Sometimes they bring in 100 butterflies," Nelson said. "And other days they’ll only bring in seven."
The lab at Reiman Gardens is USDA-certified for 500 different species, but it can fly any amount of each species.