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In most of the tropical countries including Sri Lanka beetles attack store seeds and is a major cause of serious post harvest losses. In order to protect the stored product from insects not only pesticides but a formulation of plants and their products as powders, volatile oils, non volatile oils and extracts could be effectively used. An overview of available literature on use of plant products against the storage beetles in tropical regions is presented in order to highlight the importance, safe use, and effective control. Seed beetles cause an important part of the total insect damage to seed crops. The potential efficacy of a plant product can depend on the plant species, the plant part, and the time and way of harvesting. The mere fact that the natural products are used, implies that considerable variation is to be expected. Many of the tested plants do show effects against the seed beetles. The most effective plants or methods of application are not known, but results are promising and plant material can be an effective weapon in the battle against the beetles. Plants can be an effective replacement for chemical insecticides to protect stored seeds

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Plant oils obtained from leaves and other parts of 20 different plant species were bioassayed under laboratory conditions for their ability to protect stored legumes from damage by cowpea weevil (Callosobruchus maculatus) and adzuki bean seed weevil (Callosobruchus chinensis). Three plant oil extracts showed some bioactivity, nine plant oil extracts caused significant adult mortality in both species and eight had none. Six plant oil extracts, black pepper, lemon grass, clove seeds, neem, custard apple, and sacred basil inflicted between 41 to 100% egg mortality in both species in the order of 60, 60-67, 70, 90, 91 and 100% respectively.

Cinnamon (Cinnamomum verum Presl., Syn. Cinnamomum zeylanicum Blume) is an important spice crop grown in Sri Lanka and some other countries in Southeast Asia. Although cinnamon is a hardy plant, it is subjected to attack by a variety of insects and microbes. The major insect and mite pests reported in Sri Lanka and other Southeast Asian countries include, a jumping plant louse Trioza cinnamoni (Homoptera: Triozidae), a plant feeding mite Eriophyes boisi (Acarina: Eriophyiidae), Synanthedon spp (Lepidoptera: Sesiidae). The minor insect pests reported are the lepidopteran caterpillars Chilasa clytia, Graphium sarpedon, Orthaga vitialis, Dasychira mendosa, the fruit borer Alcides morio, and the leaf miner Acrocercops spp. The important diseases of cinnamon reported are leaf spot/blight caused by Colletotrichum gloeosporioides and grey leaf spot/blight caused by Pestalotia cinnamomi. Phytopthora cinnamomi causing stripe canker and the pink disease caused by Corticium salmonicolor affecting stems of cinnamon and Phellinus lamaensis causing brown root rot have also aroused some attention by the researchers. The Identification and management strategies adopted for the above pests and diseases are reviewed.