Sunday, June 17, 2012

Differences

After discovering our first Zebra Longwing caterpillars ever in My Florida Backyard a few weeks ago, we're now noticing clutches of eggs on the passionvine too. Passionvine (Passiflora spp.) is a popular host plant. In Central Florida, it's used by Gulf Fritillaries and Zebra Longwings. Further south, it's used by Julia Longwings, and to the north by Variegated Fritillaries. (Learn more about all these butterflies and caterpillars here.)

The eggs of Zebra Longwings and Gulf Fritillaries look very similar, but due to the laying habits of the butterflies, you can actually tell them apart pretty easily. Zebra Longwings lay eggs in clusters at the ends of vines, while Gulf Fritillaries lay their eggs singly, often on the upper sides of leaves. (The pictures below aren't of the greatest quality, but they help explain the point.)

Zebra Longwing Eggs

Gulf Fritillary Egg

Once hatched, the caterpillars have similar feeding habits. It takes them about two weeks to grow full-size and pupate to chrysalis. They then spend about two weeks hanging in chrysalis before emerging as butterflies. Gulf Fritillaries round out the life cycle by spending about two weeks feeding and mating before they die, but Zebra Longwings are actually much longer lived as adults. They are one of the few butterflies that possess the ability to digest pollen in addition to nectar, allowing them to expand their lives as butterflies to as much as six months or more. The pollen collects on their proboscis and is digested externally (click here to see a picture of a Zebra Longwing with collected pollen) - a cool and unusual process in the insect world.

We love nature of all sizes in My Florida Backyard, but we're especially fond of it on a small scale. It's endlessly fascinating to flip a leaf and see what's beneath!

1 comment:

  1. Thank you for this explanation! I just found some eggs on a wild Yellow Passionvine - this helped me determine that they're Gulf Fritillary and not Zebra Longwing eggs.

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