The ants and wasps, in their turn, feed upon the Heliconius caterpillars. This helps check the caterpillar population which, if left to its own devices, could devour the passion vine. Not surprisingly, reproducing a slice of tropical forest in the Reptile House presents a few problems. Condon explains that the number of butterflies in the exhibit depends on the availability of flowers and shoots for the butterflies to feed upon. But even the sunny work area on the second floor of the Reptile House does not provide the sunlight necessary to produce enough plants to support a large number of butterflies.
Insect pests are another problem.
Lantana, with its firework-like bursts of flowers, is a favorite food plant of these butterflies. Unfortunately for Condon, who is trying to grow lantana, it is also a special favorite of aphid-like whiteflies. They devour large amounts of lantana, reducing the quantity available to the butterflies. Rearing the insects from egg to butterfly is a project unto itself. With the help of Karen Vein, a FONZ intern, Condon collects the tiny butterfly eggs from the exhibit and places them in small, covered plastic containers.