Behind the emerging window

Visitors to the Tropical Butterfly House often ask how the butterflies get out of the emerging window and into the exhibit. But have you ever wondered how the pupae get pinned up on the boards in the first place? It’s actually more complicated than it appears.



Once or twice a week, Pacific Science Center receives a box of carefully packaged pupae. These shipments come from Costa Rico, El Salvador, Suriname, The Philippines, or our broker in Los Angeles. All of our shipments are noted on our weekly “Fresh Sheet.” As soon as the shipment is delivered to the reception desk, Life Sciences staff gets to work. Color-coded labels are selected, a prepared checklist is assembled, pins, boards, handling trays are readied, and the hot glue guns are plugged in!

Wait! Did I say “hot glue guns?” Yep. Unfortunately, not every pupa arrives with a sufficient amount of silk to pin to the foam boards. We have found that in those instances, a little dab of hot glue on the pin will securely attach the abdomen of the pupae without any ill effects to the butterfly.

Inside the shipping box may be several smaller boxes that are all opened within our sleeve cage. This is a precaution in the event that a pupa in the shipment has been infected with a parasitic wasp. The sleeve cage prevents the tiny flying insects from escaping and contaminating the rest of the exhibit.

Each species is unwrapped from its cotton bedding, counted, and carefully inspected before being placed in a damp towel on a tray and given to a staff member for pinning. Pupae that are not viable or have already emerged are noted on the checklist. If a butterfly is in the process of emerging as it is being unpacked, we carefully place it in a “hospital,” a small cage that gives the butterfly netting to hang from while drying its wings. Pupae that are close to emerging are also placed in the hospital.

The entire process of unpacking and pinning a butterfly shipment can take two to three staff members two to three hours. So the next time you visit the Tropical Butterfly House, take a closer look at our pupae in the emerging window. The assemblage is meticulous and consistent. Yet it is also as lovely as the butterflies themselves. It’s just one more component in the process of maintaining a beautiful butterfly display.