Red-humped caterpillar

The Red-humped caterpillar (Schizura concinna) is an insect belonging to the order Lepidoptera and the family Notodontidae. As an adult, it is a moth with a wingspan of approximately 35–40 mm, possessing mottled brown coloring that serves as excellent camouflage against the bark of host trees during the daytime.

This pest is a significant defoliator, widely found in North America. It feeds on a broad range of host plants, predominantly fruit trees such as apple, pear, cherry, and plum. Additionally, it frequently attacks various deciduous species including willow, poplar, and walnut. Young saplings are particularly vulnerable and can be stripped of their leaves in a short period.

The biology of this species is marked by gregarious behavior. Females deposit eggs in clusters on the underside of leaves. Upon hatching, the larvae stay together in colonies. The larvae are easily identified by their bright coloration—reddish-brown with white and black longitudinal stripes—and the distinct "hump" on their back, which they lift into a defensive posture when disturbed.

The primary damage is caused by the larvae consuming foliage. Younger instars skeletonize the leaf by feeding on the lower surface, while older larvae devour the entire leaf blade, leaving only the midribs and stems. Severe infestations can cause total defoliation, which severely taxes the tree's resources, impacts fruit development, and reduces the overall health and vigor of the specimen.

Effective management strategies rely on integrated pest management (IPM). Regular inspection of orchards is critical to identify egg masses or young larvae before they cause widespread damage. In home gardens, manual removal and destruction of the caterpillar clusters are highly effective. For larger infestations, applications of biological control agents like Bacillus thuringiensis or selective insecticides are recommended.

• Frequent monitoring of canopy foliage from early summer.
• Manual removal of colonized branches.
• Application of Bacillus thuringiensis (Bt) based bio-insecticides.
• Targeted chemical applications when larvae are in early instars.