Kerria

The Kerria insect, commonly known as the lac insect (Kerria lacca), belongs to the order Hemiptera and the family Kerriidae. It is a specialized sap-sucking pest primarily recognized for its secretion of natural resin, which forms a hard covering over the insects, known commercially as lac or shellac.

This pest infests a variety of tropical and subtropical woody plants. Common host plants include species of Ficus, Acacia, Ziziphus, and other leguminous trees. The insects attach themselves to tender twigs and branches, where they aggregate in large, dense colonies that can cover entire sections of the tree.

The biological cycle consists of several stages: egg, crawler (nymph), and adult. Adult females remain sessile for their entire life, feeding continuously. The life cycle is temperature-dependent, often resulting in two or more generations per year depending on the geographic region and climate conditions.

Damage caused by Kerria lacca is primarily due to the extraction of large amounts of plant sap. This feeding activity significantly weakens the host tree, causing branch dieback, stunted growth, and a decrease in photosynthetic capacity. In severe cases, high infestation density can make the tree susceptible to secondary pathogen attacks.

Control measures involve a combination of cultural and chemical strategies. Sanitation pruning is the most effective cultural method to reduce population spread. During the crawler emergence phase, the application of systematic insecticides is often necessary to prevent new infestations. Integrated pest management should also consider the role of natural predators to maintain population stability.