A New Invasive Coconut Pest in Malaysia: The Red Palm Weevil (Curculionidae: Rhynchophorus ferrugineus)

Abstract

The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) is currently the most severe pest of major cultivated palms, including coconut palms. Red palm weevil infestation was first detected in 2007 by the Department of Agriculture (DOA) in all seven Terengganu districts. An intensive 3-month survey in 2011 throughout Terengganu in over 800 ha of coconut plantations, villages, parks and in the Federal Land Development Authority (FELDA) plantations in all districts indicated that red palm weevils infested as many as 55 000 coconut trees, showing a drastic increase and rapid spread of red palm weevil population. The symptoms and damages of each attacked part (shoot, cabbage, petiole and trunk) of infested coconut palms where different growth stages of the insect lived is discussed in this paper. However, symptoms of attack at an early stage of infestation were difficult to detect as the red palm weevil is a concealed tissue borer. The severely infested coconut palms showed signs of wilting, drooping of dried leaves like an umbrella-shaped or skirting-shaped leaves. By the time the presence of the weevil is realised, it is already too late to save the palm. A total number of 1 208 red palm weevils which consists of 12 eggs (1.0%), 392 larvae (32.5%), 677 pupae (56.0%) and 127 adults (10.5%) were collected from this study. Higher numbers of red palm weevils were found in petioles (770 individuals), followed by cabbages (194 individuals), trunks (142 individuals) and the least was shoots (102 individuals). Various stages of red palm weevil (egg, larvae, pupae, adult) co-existed in the same infested coconut palm, until the total death of the palm, where the adults move to another host plant. The larvae were found starting from the top of the palm, moving inside the palm making tunnels and large cavities, even at the base of the trunk. This is the first report on the onslaught of R. ferrugineus on coconut palms in this country. This invasive weevil will be a threat to the coconut industry and, could threaten the survival of oil palm plantations, which represents the backbone of Malaysia’ s commodities market. An early action is needed to prevent further spread of the pest in other states of the region and to protect the coconut industry in Malaysia. Keywords: Red palm weevil, Rhynchophorus ferrugineus, invasive, coconut pest, symptoms, growth stages.