Evaluation of Potential Insectary Plants for Conservation Biological Control of Cabbage Insect Pests
Sheela Sharma*, Sundar Tiwari2,3
1Entomology Division, Nepal Agriculture Research Council, Khumaltar, Kathmandu Nepal
2Bio-Protection Research Centre, Lincoln University, Lincoln 7647, New Zealand
3Department of Entomology, Agriculture and Forestry University, Bharatpur 44200, Nepal
Habitat manipulation is an important pest management strategy in sustainable agriculture. Deployment of floral resources in and off-farm, trap cropping, cover cropping, intercropping etc are the major pest management options in habitat manipulation. The current agricultural pest management approaches are mostly relied on synthetic fossil-fuel based compounds such as insecticides, fungicides, herbicides etc. These anthropogenic practices are directly linked to human health, biodiversity loss and environment. The rapid decline of pollinators and beneficial arthropods such as predators and parasitoids are the most potent impact of pesticides in agricultural fields. Hence, a study was proposed to increase the fitness of natural enemies such as predators and parasitoids by the provision of floral resources to them and promote conservation biological control of cabbage pests. Insectary plants or floral resources supply shelter, nectar, alternative food and pollen (SNAP) to pestís natural enemies and supply these resources to them at adverse conditions. Buckwheat (Fagopyrum esculentum), coriander (Coriandrum sativum), marigold (Tagetes spp), mustard (Brassica spp.) had deployed in cabbage fields as potential insectary plants of cabbage pests. All of these insectary plants were compared with the cabbage (Brassica oleraceae) strips. The results confirmed that coriander, buckwheat and marigold significantly increase the population of syrphid fly and ladybird beetle (Coccinella septempunctata) and reduce the population pressure of aphids (Brevicoryne brassicae) and diamondback moth (Plutella xylostella) in cabbage fields. It is also suggested that the population of beneficial arthropods were higher in floral strips and declined their numbers with distance. The lower aphid population in the proximity of flower strip suggested that conservation biological control has the potential to reduce pest population in cabbage fields. This informationís are important to develop an integrated pest management protocol of cabbage pests in cabbage fields.
Keywords: insectary plants; conservation biological control; cabbage aphids; diamondback moth; syrphid fly
Int. J. Grad. Res. Rev.Vol-5, Issue-1: 67-75