The Plesispa Beetle Attack to Young Coconut Plants
Cultivators should be aware of the coconut plants at very young stage. When it has been two or three years old, they can see yellow spots on leaves. If you look carefully down side of such leaves, you can see small beetles there. these beetle are known as Plesispa, The beetle of Both adults and larvae of the pest live in between the folded blades of leaves and in very early buds. The larvae and adults feed themself on tissues of the young bud.
Spots damaged by the pest can be seen when the leaves are unfolded. However, if you neglect it will spread to other plants. Even, the plant will be died if all the leaves are become yellow and then brown. As per my experience, I found above mention disease symptoms in three or four plants initially, then three or four weeks later, I noticed such symptoms in more plants in the land.
According to CDO’s advice, cultivator has to use M-20 (Marshal 20) to spray to leaves by more concentrating on down side of the effected leavesat this stage. For this purpose, cultivator has to use sprayer for more effective. chemical users should be more careful when they use it.
Black and Red Beetle Attack to Coconut Plants
As my experience, beetles’ damage is the worst one that can be happened in new coconut plantation. Until the tree is collapsed to ground, identification is very difficult. Therefore, within very short time period, a large number of plants can be destroyed due to identification is very difficult. Every planter takes care of their coconut plants personally. There are two types of beetles, Red beetle and Black beetle. Red beetle attack is more serious than Black one. Red beetle goes through the inside of stem through the damage place of the tree and build cells for their young creatures by eating inside of the plant. Due to such huge damage, the plant is fallen down to ground. If you remove debrief one by one you can see lot of cell with larva inside. After the mature of young beetles, they fly and attack adjoining plants.
Black beetles normally attack to the leaves. You can notice broken young coconut leaves which have been fallen down. If you can look at them carefully, you will notice places eaten by someone. That may be black beetle damage.
When you are at the plantation at about 4 o’clock in the afternoon, you can see beetle movements with some sounds. If there is a fire place those flies come towards to fire. However, when beetle are attacking to the tree, it seem that some leaves are withered. It will be last stage of the tree. Some will be fallen without any sign.
Some suggested to keep naphthalene in between coconut bile in the plants to avoid beetle coming. We did the same, but we have not seen success of this method. Next, other suggested rubbing used engine oil on the stems of the coconut plants. We did the same too, but we could not see a better progress. Some proposed to inject pesticide (eg. Monocrotophos) to plants to kill attackers, but it is not suggested as it is danger to human.