Field Guide of Discovery-based Exercises for - Aseanipm ...

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Field Guide of Discovery-based Exercises for Organic Vegetable Production
• Predators. A group of organisms that is free-living throughout their entire life cycle. Each
predator consumes many pests, called preys, in its lifetime. It is generally bigger than
its prey. In vegetable areas, spiders, predatory bugs, ants, earwigs, dragonflies, and some
ladybird beetles are organisms identified eating both larval and adult stages of insect pests.
• Parasitoids. These are insects, mostly wasps and flies that lay eggs on eggs or larvae
of insect pests of vegetables. Upon hatching, parasitoid larvae feed on hosts, either
internally or externally and kill hosts slowly during their development. Adult parasitoids
feed mostly on flowers. Some examples are Diadegma sp., Cotesia sp., Diadromus sp.,
and Trichogramma sp.
5 Pathogens. These are parasitic microorganisms used to control insect pests of vegetables.
Some insect pathogens infecting various insect pests are viruses, bacteria, and fungi. Both
viruses and bacteria infect their host when eaten. Fungal pathogens can infect their hosts by
penetrating directly through surfaces of host’s body. A few examples are nucleo-polyhedrosis
virus (NPV), Nomurea sp., Beauverea sp., and Cordecyps sp.
Pollinators. These insects pollinate flowers of some vegetable crops like cucumber, chayote,
snap bean, green pea, bell pepper, and tomato. Wild bees and honeybees are most predominant
pollinators of vegetables.
Rodents, on the other hand, are one of the most consistent and serious pests of agricultural crops.
The main problem in rodent management is that it must be undertaken through community-based
actions, but organizing communities is not an easy task. Thus, a sub-section, will guide us to
study rodent biology, baiting and rodent burrow digging, but mostly, we will learn activities that are
helpful in organizing communities for more effective rodent management 126 .
126 Sumangil, J.P. 1990. Control of ricefield rats in the Philippines. In Quick, G.R. (ed). 1990. Rodents and Rice. Report and Proceedings of an Expert Panel
Meeting on Rice Rodent Control held on 10-14 September 1990 at international Rice Research Institute, Los Baños, Laguna, Philippines. pp35-48.