–by Raymond Cloyd – Horticultural Entomologist
Have you noticed the leaves on your sunflower, Helianthus annuus, plant being fed upon by caterpillars (Figure 1)?
Figure 1. Gorgone checkerspot caterpillars on leaf of sunflower (Raymond Cloyd, KSU)
If so, the caterpillar is the gorgone checkerspot, Chlosyne gorgone. The caterpillar ranges in color from black to orange, with a black head and spines or barbs covering the body (Figures 2 and 3).
Figure 2. Gorgone checkerspot caterpillars (Raymond Cloyd, KSU)
Figure 3. Gorgone caterpillar (Raymond Cloyd, KSU)
The caterpillars feed on sunflowers and other related plants. The caterpillars initially feed in groups (Figure 4)
Figure 4. Gorgone caterpillars feeding on sunflower leaf (Raymond Cloyd, KSU)
whereas later on the mature caterpillars, which are approximately 1.0 inch in length, feed individually (Figure 5). Third instar larvae eventually searches for a place to overwinter.
Figure 5. Mature gorgone caterpillar (Raymond Cloyd, KSU)
If you see caterpillars feeding on sunflower leaves and your plants can tolerate some feeding damage, then just leave them alone as the caterpillars will eventually develop, by means of complete metamorphosis, into beautiful butterflies.