Larvae are pale green. They feed mostly on the underside of leaves, occasionally on the upper sides, skeletonizing the leaf superficially. They have an interesting predator avoidance strategy. When disturbed, the larva moves rapidly through an escape hole already chewed through the leaf (Rota and Wagner 2008). Usually there is more than one larva on a leaf, but the leaves of their host plants are very large, so the larvae are well spaced. The caterpillars build a thin, loose web in the area where they feed, leaving themselves exposed to potential parasitoids and predators. Parasitism is very high - 85% of B. monolychna larvae yield braconid wasps instead of moths (Rota 2008). Cocoons are usually spun on the underside of the leaf, and are composed of multiple layers, the inner layers being spindle-like. The outermost layer is a thin sheet of silk that covers the cocoon. Sometimes the cocoon creates a slight fold in the leaf. The adult emerges about ten days after the cocoon is completed. The adults of this species can be seen in the vicinity of their larval host plants during the day displaying their wings in a characteristic fashion, which makes them resemble jumping spiders (Rota and Wagner 2006). Occasionally, the adults of B. monolychna also come to lights.