The coconut hispine beetle, Brontispa longissima Gestro (Coleoptera:Chrysomelidae) is potentially one of the most serious insect pests of coconut and ornamental palm plants in Southeast Asia. According to report, it is endemic to Indonesia and Papua New Guinea and was only accidentally introduced into continental Southeast Asia, including the Philippines. Larvae and adults of the beetle feed on tissues of unopened leaf buds of the coconut palm. Infestations of the beetle turn the leaves brown and decrease fruit production. Successive severe defoliations will lead to death of the tree that appears like severely burned.
The Caraga Region in Mindanao Island of the Philippines is still considered by the Philippine Coconut Authority (PCA) a Brontispa-free region, as to date. With that, a continuous monitoring of coconut farms and ornamental palm plants is conducted by the PCA. Recently, in our center, one farmer who has availed project from the PCA, and had lots of training from PCA including the identification of Brontispa infestation, observed a seemingly Brontispa-like infestation in two of our coconuts. Checking the plants, I thought it was only some abnormalities or maybe bud rot or caused by some beetle. Since it was still around 3 or 4 years old and an aromatic kind of coconut, is quite low, I climb to its top checking the bud and found it still intact. I smelled the center, nothing unusual smell that might indicate a bacterial infection. Checking deeper inside the still unopened leaves, I saw an insect definitely a beetle. I doubted then that it might be Brontispa. I checked in the internet how Brontispa looks like. It looked like one! I thought Manong might be right, after all. I took its picture and immediately reported to PCA. After some minutes, a representative identified it tentatively as Plesispa – a family of the Brontispa. Yet, they still scheduled a visit to verify the infestation. Indeed, it was Plesispa. They recommended to just drench the bud with insecticide to eliminate the insect.
Plessispa is not as threatening as Brontispa, I later knew from PCA because it only attacks coconut seedlings. Brontispa could severely destroy seedlings and mature and aged coconut trees, alike. Looking at the insects, the red to orange color at the back of the Brontispa extends to the small part of the base to almost 1/3 of its wing while for Plesispa its red to orange color is only confined to its pronotum, and does not extend to its wing. Brontispa’s structure is more slender than Plesispa. The pronotum is broad in Brontispa while it is narrowed in Plesispa. The antenna in Brontispa is filiform while antennal segments in Plesispa are distinct. And lastly, the patterns on elytra of Brontispa are finer while on Plesispa has deeper punctuations.
Last June, the PCA has intercepted hundreds of coconut seedlings from Davao to be planted in one municipality of Agusan del Sur. Fortunately, it was taken with appropriate action, as it turned out, there was indeed Plesispa in the seedlings. Farmers or stakeholders must respect the regulatory action of concerned agency related to quarantine laws. Being intercepted or was not allowed to plant a crop that is under the watch of quarantine bodies maybe disappointing today, but this is for the protection of greater masses, including you.
Let us help continue make Caraga a Brontispa-free Region!