[4][5] Both adults and nymphs of P. pictus feed extensively on poisonous Calotropis milkweeds, notably C. gigantea and C. procera, gaining their own toxins from the plants.

[6] However, both adults and nymphs of P. pictus may also feed on a wide range of other plants, including several that are important agricultural crops, and for this reason they are sometimes regarded as a serious pest.

[6] Upon slight pinching of the head or abdomen, the nymphs ejects liquid in a sharp and sudden jet, with a range of up to around 30 cm (1 ft) or more, from a dorsal opening between the first and second abdominal segments.

The liquid is pale and milky, slightly viscous with an unpleasant smell and taste,[4][5] containing cardiac glycosides that the insect obtains from the plant it feeds upon.

[7][8] In the adults, the discharge occurs under the tegmina and collects as viscous bubbly heap along the sides of the body, lacking the squirting effect seen in nymphs.