Have you ever found small white worms inside litchi fruits? Well, these worms are called fruit borer and are harmless. These worms are produced by a type of moth in the Gracillariidae family.
Adult moth lay eggs on the underside of a leaf or near the pedicel of litchi fruit. After a few days, milky white larvae with brown heads develop from the eggs and start to bore inside the fruit. The larvae entrance is not easily seen due to outer rough covering of litchi fruit. Only a small black dot is visible when examined closely. Otherwise, the fruit appears normal and fresh from outside while the larva develops inside. The larva is the most damaging stage; it bores into the upper seed side and feeds on the fruit pulp. This is the litchi fruit borer, litchi fruit insect. Rain and humid weather favor larval growth. Fully grown larvae emerge from the fruit and pupate on older leaves, forming a spindle around them. After some time, adults emerge from the cocoon.
fig: Litchi fruit borer (Conopomorpha sinensis) damage symptoms on litchi fruit ( Photo source: my own)
Control measures
Additionally, control measures target litchi fruit borer, litchi fruit insect and related pests.
- Field sanitation should be practiced by removing and destroying damaged fruits and seeds.
- Fruit wrapping or bagging can be done if the infestation becomes severe.
- Neem-based pesticides can be sprayed.
- For bio-control, Trichogramma chilonis can be used.
Other interesting larvae: Larvae: Some beautiful, Some ugly, creepy things eating your plants – Think Like A Plant
It would be so disappointing to cut into a litchi fruit and find the fruit borer. I have t say, though, the adult borer is a beautiful insect with its complex wings and textured torso.
You can’t see any signs of larvae from outside without peeling the pericarp, so, have to observe carefully while eating.