Have you ever spotted neat clusters of tiny, barrel-shaped pellets on a tree trunk or the underside of leaves? These formations are not random bits of debris—they are the eggs of the Lychee Stink Bug (Tessaratoma papillosa), a significant pest for fruit orchards, particularly lychee and longan trees.
Meet the Culprit: The Lychee Stink Bug
Belonging to the family Tessaratomidae, the adult lychee stink bug is a sizable insect, measuring about 25–30 mm (1 inch) in length. It has a shield-shaped, yellow-brown body with a distinctive white, waxy coating on its abdomen. While they might look unassuming, both the adults and their nymphs (juveniles) are destructive sap-feeders.
The Life Cycle: From Egg to Infestation
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Egg Stage: The female lays eggs in compact clusters of 10–40, often on the underside of leaves or on bark. These eggs resemble small, round, pale green to light brown pellets, arranged in orderly rows.
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Nymph & Adult Stage: After hatching, the nymphs undergo several molts. Throughout all life stages, they use piercing-sucking mouthparts to extract sap from young shoots, flower panicles, and developing fruit.
The Damage: Why This Bug Is a Major Pest
This feeding activity has severe consequences for the host tree:
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Direct Damage: Sap loss weakens branches, causes flowers and young fruit to drop, and leads to wilting and dieback of new growth.
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Indirect Damage: Their feeding punctures create entry points for fungal and bacterial pathogens.
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Economic Impact: Infestations result in significantly reduced fruit yield, misshapen fruit, and poor overall crop quality, posing a real threat to the livelihoods of lychee and longan farmers.
How to Identify an Infestation
Early detection is key to control. Look for these signs:
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Egg Clusters: The small, round, pellet-like eggs on leaves or bark.
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Insect Presence: Adults (large, shield-shaped, yellow-brown with white underside) or nymphs (smaller, often reddish or orange) gathering on shoots.
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Plant Symptoms: Wilting new growth, necrotic spots on leaves and fruit, and significant fruit drop.
