Important Natural Enemies and Their Hosts
Biological insect suppression in its original or classical sense involves the directed use of beneficial organisms. These beneficial organisms fail into several categories or groups. The broad-based categories of biological control agents/natural enemies are (according to function involved).
1. Parasites and Parasitoids
2. Predators
3. Micro-organisms
On the other hand, the categorization may also be done as:
1) Vertebrates: These include predatory animals like:
A) Fishes (Pisces)
B) Amphibians (Amphibia):- Tadpoes, frogs, toads etc.
C) Birds (Aves):- King crows, Starling, Quail partridges, Mynah, House crow, Indian roller.
D) Mammals (Mammalia):- Bats, mice, Snakes, Lizards, Squirrels, Mongoose etc.
2) Invertebrates: (Arthropods)
A) Predators: Spiders, Mites, Hydra, Planaria.
B) Parasites: Arthropod parasites, Insects.
3) Namathelmithes: Nematodes
4) Protozoan: – Protozoa.
5) Pathogenic microorganism: Bacteria, Viruses, Fungi.
All or most of these categories have yielded successful examples of insect pest suppression, either single or in concert. Among these natural enemies, from the point of view of biological control three groups of arthropods are important i.e.
1. Spiders
2. Mites and
3. Insects.
1. Spiders:
The spiders universally live a predatory life and are constantly look out for insect as their food. They catch them directly or with the help of various types of snares made out of webs. The important species found actively feeding on sugarcane pyrilla in India are Clubiona atwali and Clubiona drassodes be to the family Clubionidae.
2. Mites:
Many mite species have acquired a parasitic life on insect pest, Allothrombium spp. lives as an ectopara site on many small insects and Entrombidium spp. on egg of locust and grass hoppers.
3. Insects:
Insects form the single largest and the most important group of predators and parasites. They suppress population of known or potential pests. They belong to 15 orders and more those 240 families. Spraying mantids devour a large number of insects of all sorts. The green lace wing, Chysoperia spp. feed voraciously on aphids and other soft bodied insects @ 160 individuals per day. Tiger beetle, Cicindela spp. is very common in Northern and Western India. The lady bird beetles form a group of predators of aphids in the larval stage as well as in adult stages. The vast majority of the parasites belong to Hymenoptera, Diptera and Strepsiptera orders. Trichogramme spp. which are more or less universal parasites of eggs of Lepidotera.