Caterpillar of Gulf Fritillary Butterfly, on Passion Flower. 16 September 2015. Sonora Ca. Caterpillar of Gulf Fritillary Butterfly, on Passion Flower. 16 September 2015. Sonora Ca. Caterpillar of Gulf Fritillary Butterfly, on Passion Flower. 16 September 2015. Sonora Ca. Caterpillar of Gulf Fritillary Butterfly, on Passion Flower. 16 September 2015. Sonora Ca.