The relationship between the Passion Flower (Passiflora) and the Zebra longwing butterfly (Heliconius chaithonia)

Figure 1. Photo of a Zebra longwing
 butterfly (Heliconius charithonia)
Photo by: C. Quigley.

The zebra longwing butterfly (Heliconius charithonia) (Figure 1) is a species of butterfly that uses the leaves of the Passion flower (Passiflora) plants to feed its larvae (figure 2) (Williams & Gilbert, 1981). To do so, the butterfly will lay its eggs directly on the leaves of the plant, and when the eggs will hatch they will simply feed on them (Williams & Gilbert, 1981). So obviously this is a great way for the butterfly to ensure the surviving of its offspring, but on the other hand the plant loses a part of its leaves each time an egg hatches. 

Figure 2. Photo of two larvae of the
 Zebra longwing butterfly (Heliconius
 charithonia), feeding on the Passion
 flower (Passiflora) leaves.
Photo by: H. Nendick-Mason.

Figure 3. Photo of the Passion Flower
(Passiflora) leaves imitating the Zebra
 long wing (Heliconius charithinia)
butterfly eggs.
Photo by: G. Dimijan & M. B. Dimijan.

This competition between the Passion flower plant and the longwing butterfly has pushed the plant to evolve and develop an effective defense mechanism. The passion flower will indeed mimic eggs on the top of its leaves so the butterfly will automatically think that the leaves have already been used by another butterfly for its young. Therefore, it will look for another available plant to make sure there will be enough available resources for its offspring (Williams & Gilbert, 1981). According to Williams & Gilbert (1981) this mimicry significantly decreases the number of eggs on the leaves and consequently reduces the herbivory by the larvae.

Reference list

Dimijan, G. & Dimijan, M. B. (n.d.).  Passion Flower (Passiflora) leaves imitating the butterfly eggs [Image]. Retrieved from: http://adarwinstudygroup.org/biology-culture-psychology/mimicry/

Nendick-Mason, H. (n.d.). Photo of 2 larvae of the Zebra longwing butterfly (Heliconius charithonia), feeding on the Passion flower (Passiflora)[Image]. Retrieved from: http://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/zebra_longwing.shtml

Quigley, C. (n.d.). Photo of a Zebra longwing butterfly (Heliconius charithonia) [Image]. Retrieved from: http://my.chicagobotanic.org/events/zebra-longwing-the-friendliest-butterfly-around/

Williams, K. S. & Gilbert, L. E. (1981). Insects as Selective Agents on Plant Vegetative Morphology: Egg Mimicry Reduces Egg Laying by Butterflies. Science, 212(4493), 467-469.