Early progress of work on the biology and control of the pepper [Piper nigrum] weevil, Lophobaris piperis Marshl. (Coleoptera: Curculionidae)
1986
Mohd Anuar Abbas (Institut Penyelidikan dan Kemajuan Pertanian Malaysia, Kluang, Johor. Stesen Penyelidikan)
The pepper weevil, Lophobaris piperis Marshl. is a major pest of pepper, Piper nigrum L. in Johore, Peninsular Malaysia and is slowly gaining prominence in Sarawak. A study of its life history showed that the egg to adult cycle can be completed in 48-71 days. The larva passes through five instar stages before the prepupa stage. Adult weevils are fairly long-living with a mean adult lifespan of 327.9 days. In a fecundity study, egg production was found to be strongly linear for young female weevils. The relationship is described by the equation, Y = 1.596 + 0.1580 X. Egg production for the longest living female was 0.24 eggs/day. Observation in the field showed that certain natural control factors help to regulate larvae number. Heavy rain kills young larvae in their tunnels. Wasps also provide some biological control of the weevil. The braconids, Spathius apicalis Westwood and Rhaconotus sp. as well as the Eupelmid, Eupelmus sp. have been found to be ectoparasites on the larvae of the pepper weevil. These parasites are persistent in the field. Some insecticide screenings have been carried out in the laboratory and in the field. Monocrotophos at 0.1% a.i. have shown good potential for larvae control, while 0.058% a.i. chlorpyrifos or 0.073% ai. endosulfan can be used for adult control.
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