Steps in Establishing Biological Control Programmes
Steps in Establishing Biological Control Programmes
Following program may be followed for introduction for beneficial organism:
1) Exact Identification of Pest:
For identification of pest first recognize the occurrence of damage. Then determine the specific cause of damage and undertake precise taxonomic identification. The species names give access for availability of literature and explore the possibilities of utilizing the natural enemy of related species.
2) Origin, Geographic Distribution and Ecological Requirements:
Examine the degree of damage of the pest in homeland indicating existence of natural enemy and their importation. Determine pests’ potential important information. If the species has been the subject of successful programme earlier elsewhere, employ similar procedure e.g. Vedalia beetle used against cottony cushion scale in California. If no work has been done on the target pest, then the techniques of other related natural enemy available from similar work may be followed.
3) Host Parasitoid Lists and Other Faunal Surveys:
a. If target species is not an important pest in its place of origin it may be a god reason that density dependent natural enemy is present these to regulate population size.
b. If the species is pest its potentially useful natural enemy may have moved to new environment free from hyperparasites.
c. Search literature for previous specific studies and its natural enemies. Refer lists/catalogues/area-wise faunistic surveys for diseases, parasitoids and predators present.
4) Field Study of both Target Insect and Beneficial Organisms:
a. From literature survey, find information on location/native habitat, pest status, ecology and its natural enemies.
b. Undertake field studies in native habitat for collecting sufficient natural enemies for shipment and locate most suitable area for collection of natural enemies in large quantity.
5) Prediction of Success and Efficacy:
a. Collection preliminary information on ecology compatibility and effect of natural enemy on pest density, its behavior synchronization biotypes etc.
b. Predict certainty in the outcome of Biological insect pest suppression before. It is carries out. Success in introducing natural enemy which has proven itself before against the same target pest in a similar environment elsewhere.
6) Collection of Beneficial Organisms:
a. Collection of natural enemies for importation in short possible time. Employ minimum possible techniques to the specific pest and its natural enemy.
b. Hand collection of natural enemies of host is feasible method. But artificially dense population of host is encouraged or created in controlled area subject to exposure to the desired parasitoid.
c. Collection site need not to be at remote, exotic or inaccessible.
7) Shipment of beneficial organisms:
a. Most critical step in introduction of natural enemy programme is transportation from origin to place of introduction.
b. Necessity of providing food and water to sustain life during journey sometimes need living host/prey insects on potted plants.
c. Permit for the agencies for importation of organisms.
d. Shipment of material in a series of small shipment rather than in a single large one.
e. Containers should be strong enough to survive rough handling and prevent escape during shipment route.
f. There are wooden containers or cardboard mailing tubes, aerated plastic containers, Vacuum flasks or foam insulated containers with suitable labels for cautions of temperature extremes or adverse condition.
g. Shipment during development stages becomes easier.
h. As a part of each shipment, attack information sheet indicating, identity source, number of natural enemies and dates of collection of shipment.
8) Quarantine:
a. The purpose of quarantine is twofold. The procedure prevents the premature escape of the imported insects, and it prevents the contamination of entomophage culture by native species.
b. Adequate screening of the shipment before release to eliminate hyper parasitoids. It may be done by rearing the imported species for one or more generations under controlled conditions.
c. Admittance is usually restricted authorized personnel only.
9) Propagation:
a. Introduce large number of natural enemies.
b. Synchronies entomophage and pest life cycles with carefully timed propagative output, rearing of natural enemy all year round and storing the progeny until release.
c. Complete knowledge of life cycle, biology and behaviors, proper rearing condition and a suitable laboratory host may be factitious (unnatural) host or artificial diet.
10) Release and colonization:
a. A current trend toward the earliest possible attempt is field release.
b. Extensive laboratory propagation minimal colonization efforts.
c. Incomplete understanding of the host-parasitoid or prey-predator relationship may lead to poor adaptation of natural enemy.
d. Alternate host, required food supplies of nectar or polled for the adults may be missing for the introduced natural enemy which eater establishment of entomophage.
e. Proper time of introduction of natural enemy against target pest of univoltine type.
f. Predators should be released with greatest assurance of mate and early reproduction.
g. Select promising site for introduction based on preceding information for easy and natural spread.
h. Colonization by installation of field cages i.e. for predators to minimize initial spread / dispersal and protect against native competitor species.
i. Predict weather conditions like frosts, heat waves, heavy rains / winds, bright sunshine which causes high mortality of colonized natural enemy.
j. Release are best made in early mornings or late evening when light levels are subdued, temperatures are lower and humidity is high.
k. Release larger colonies at few point, multiple induction quickly regulate pest spectrum.
l. Greatest success with smallest individual releases in the stable environment.
11) Follow-up Recoveries:
a. Determination of establishment of introduced natural enemy and its rate of dispersal.
b. Carry out making field observation and collection in and near the sites of release or by visual determination in the field after the sites or release or by visual determination in the field after one generation or dissect parasitized host or by rearing of adults from field collected host material.
c. Recoveries:The first instance of recovery indicate temporary or initial establishment of natural enemy. The second or third instance indicate permanent establishment only if it is recovered in three successive year after its release.
12) Evaluation:
Assessment of effectiveness of natural enemy by careful and continuous monitoring of increase and spread of introduced entomophages.
It involves 3 ways.
a. Qualitative analysis:
By frequent extensive sampling observation of the progress and spread of introduced species and apparent cause effect relationship to decline pest populations.
b. Experimental exclusion procedure:
By comparing the population density of the pest in the absence of newly introduced natural enemy with that in presence of the introduced natural enemy with that in the presence of the introduced species.
c. Quantitative mathematical analysis:
It is best proof of success or failure. it involves development of extensive life tables of pest both before and after the introduction of natural enemy.