By Mulopi Joseph; Mayuge
Most farmer enjoy planting and eating avocado in their homes because it has a higher nutrient values. The problem is that some end up harvesting avocado fruits with brown patches or spots on the fruit skins. This may be due to the damage done by thrips. But in most cases the farmer is un aware.
Thrips belong to the insect order of Thysanoptera which means fringe wings, and there are many species of thrips known of which just 1% are pests.
Thrips is a Latin word from the Greek for wood louse; and they are typically small, slender bodied insects a round 0.5-15cm in length. Although winged, thrips are poor fliers; they can be transported long distances by winds or storms. The majority of thrips feed on plant juice, some species are predators, and others feed on pollen, fungi, decaying vegetations or are omnivorous.
Thrips have usual mouth parts in that they only have one mandible and this single mandible is used like a needle to puncture plant tissue from which food and liquids are siphoned into the mouth through a straw like structure which is formed from moveable appendages around the mouth.
Female thrips lay eggs in the incision made into soft plant tissue with the ovipositor and eggs are kidney shaped and whitish – yellow color; the predator thrips type lays eggs on leaf surfaces. Following egg hatch, thrips pass through two actively feeding immature stages called larvae and all thrips species have more than one pupil stage.
The first pupil stage is the propupa and the second is the pupae and thrips don’t feed as pupae and many drop into the soil and leaves. Adult thrips move back onto the host plant to commence feeding and reproduction.
When they are disturbed they run to the leaf edges and move to the leaf under surface and larvae’s are most commonly found on the underside of the leaves. Avocado thrips larvae and adult feed on developing fruits while hiding under. This destroys the fruits.