Coconut leaf beetles are also known as red-breasted leafworms, coconut goldenrods, and coconut bristle leafworms. It is a pest of coleoptera, the general family of leaf beetles, the family Lycaenidae, and the subfamily Ofcody. Native to Indonesia and Papua New Guinea, the coconut leaf beetle is now widely distributed in the Pacific Islands and Southeast Asia and other regions, is a devastating pest, is China's prohibited entry of international class II plant quarantine objects, endangering betel nut, coconut and other palm plants, larvae eat young flesh tissue, resulting in leaf drying, plant weakness and death. In 2007, the harm area of palm plants in Hainan Province reached 6.59 million mu, covering 18 cities and counties, causing great damage to hainan's special palm plant industries such as betel nut and coconut, and seriously threatening Hainan's natural ecological environment.
【Life habits】Coconut leaf beetles occur in 4-5 generations per year, and the generations overlap. The egg stage is 3-6 days, the hatching rate is 92.5%, the larval stage is 30-40 days, the expected 30-40 days, the pre-pupal stage is 3 days, the pupal stage is 6 days; the adult stage can reach 22 days. Female adults lay about 1-2 months before spawning, and each female can lay about 100 eggs. It takes about 50 days from egg to adult. 18 days before spawning, adult worms lay eggs every day, some lay eggs every 1-5 days, and most of them lay 1-2 eggs per day, up to 6. The eggs are laid in the worm tunnel formed by feeding on the heart leaf, 3-5 in a longitudinal column, and the egg and leaf surface adhesion are fixed.
【Hazard symptoms】Endanger the youngest heart leaves of betel nut, eat the leaf flesh tissue, excrete fine insect feces, the affected leaves become dry and withered, and the plant dies when the heart leaves are seriously damaged. Adults have the ability to fly, flying morning and evening or by means of air currents for 300-500 meters of natural diffusion. Each insect form can be planted to operate long-distance transmission.
【Control method】 Quarantine is implemented in the newly planted area to prevent pests from being transferred into the betel nut coconut seed seedlings or introduced with other palm plant materials. Chemical control: Seriously damaged plants are first sprayed with high-efficiency cypermethrin, cypermethrin, chlorpyrifos or imidacloprid and other chemical agents 1000 times liquid whole plant spray to kill adult insects, prevent adults from escaping after being disturbed, cut off dead leaves and burn them centrally, and then spray regularly 2-3 times, once a month. Use the insecticidal single and acetamidine compound of coconut nail powder, "coconut insect net" and other hanging bag method control: on the inside of the young leaves at the base of the heart leaf, stuff 1-2 packets, and fix the petiole of the heart leaf with the hanging bag line, so that the agent naturally flows with rain or artificial water to the pest damage site to kill the pest. The duration of effectiveness is up to 8-10 months.
(Luo Daquan, Institute of Environment and Plant Protection, Chinese Academy of Tropical Agricultural Sciences.)
Li Zengping, College of Environment and Plant Protection, South China University of Tropical Agriculture)