Lecture 12: PEST MONITORING - PEST SURVEILLANCE AND
FORECASTING - OBJECTIVES, SURVEY, SAMPLING, TECHNIQUES AND
DECISION MAKING - ETL AND EIL. FACTORS INFLUENCING EIL AND
ETL.
Pest Monitoring
Monitoring phytophagous insects and their natural enemies is a fundamental tool
in IPM - for taking management decision
Monitoring - estimation of changes in insect distribution and abundance
- information about insects, life history
- influence of biotic and abiotic factors on pest population
Pest Surveillance
Refers to the constant watch on the population dynamics of pests, its incidence
and damage on each crop at fixed intervals to forewarn the farmers to take up
timely crop protection measures.
Three basic components of pest surveillance
Determination of
a. the level of incidence of the pest species
b. the loss caused by the incidence
c. the economic benefits, the control will provide
Pest Forecasting
Forecasting of pest incidence or outbreak based on information obtained from
pest surveillance.
Uses
- Predicting pest outbreak which needs control measure
- Suitable stage at which control measure gives maximum protection
Two types of pest forecasting
a. Short term forecasting - Based on 1 or 2 seasons
b. Long term forecasting - Based on affect of weather parameters on pest
Objectives of Pest Surveillance
to know existing and new pest species
to assess pest population and damage at different growth stage of crop
to study the influence of weather parameters on pest
to study changing pest status (Minor to major)
to assess natural enemies and their influence on pests
effect of new cropping pattern and varieties on pest
, Survey
Conducted to study the abundance of a pest species
Two types of survey - Roving survey and fixed plot survey
Roving survey
- Assessment of pest population/damage from randomly selected spots
representing larger area
- Large area surveyed in short period
- Provides information on pest level over large area
Fixed plot survey
Assessment of pest population/damage from a fixed plot selected in a field.
The data on pest population/damage recorded periodic from sowing till harvest. e.g.
1 sq.m. plots randomly selected from 5 spots in one acre of crop area in case of rice.
From each plot 10 plant selected at random. Total tillers and tillers affected by stem
borer in these 10 plants counted. Total leaves and number affected by leaf folder
observed. Damage expressed as per cent damaged tillers or leaves. Population of
BPH from all tillers in 10 plants observed and expressed as number/tiller.
Qualitative survey - Useful for detection of pest
Quantitative survey - Useful for enumeration of pest
Sampling Techniques
Absolute sampling - To count all the pests occurring in a plot
Relative sampling - To measure pest in terms of some values which can be compared
over time and space e.g. Light trap catch, Pheromone trap
Methods of sampling
a. In situ counts - Visual observation on number of insects on plant canopy
(either entire plot or randomly selected plot)
b. Knock down - Collecting insects from an area by removing from crop and
(Sudden trap) counting (Jarring)
c. Netting - Use of sweep net for hoppers, odonates, grasshopper
d. Norcotised collection - Quick moving insects anaesthesised and counter
e. Trapping - Light trap - Phototropic insects
Pheromone trap - Species specific
Sticky trap - Sucking insects
Bait trap - Sorghum shootfly - Fishmeal trap
Emergence trap - For soil insects
FORECASTING - OBJECTIVES, SURVEY, SAMPLING, TECHNIQUES AND
DECISION MAKING - ETL AND EIL. FACTORS INFLUENCING EIL AND
ETL.
Pest Monitoring
Monitoring phytophagous insects and their natural enemies is a fundamental tool
in IPM - for taking management decision
Monitoring - estimation of changes in insect distribution and abundance
- information about insects, life history
- influence of biotic and abiotic factors on pest population
Pest Surveillance
Refers to the constant watch on the population dynamics of pests, its incidence
and damage on each crop at fixed intervals to forewarn the farmers to take up
timely crop protection measures.
Three basic components of pest surveillance
Determination of
a. the level of incidence of the pest species
b. the loss caused by the incidence
c. the economic benefits, the control will provide
Pest Forecasting
Forecasting of pest incidence or outbreak based on information obtained from
pest surveillance.
Uses
- Predicting pest outbreak which needs control measure
- Suitable stage at which control measure gives maximum protection
Two types of pest forecasting
a. Short term forecasting - Based on 1 or 2 seasons
b. Long term forecasting - Based on affect of weather parameters on pest
Objectives of Pest Surveillance
to know existing and new pest species
to assess pest population and damage at different growth stage of crop
to study the influence of weather parameters on pest
to study changing pest status (Minor to major)
to assess natural enemies and their influence on pests
effect of new cropping pattern and varieties on pest
, Survey
Conducted to study the abundance of a pest species
Two types of survey - Roving survey and fixed plot survey
Roving survey
- Assessment of pest population/damage from randomly selected spots
representing larger area
- Large area surveyed in short period
- Provides information on pest level over large area
Fixed plot survey
Assessment of pest population/damage from a fixed plot selected in a field.
The data on pest population/damage recorded periodic from sowing till harvest. e.g.
1 sq.m. plots randomly selected from 5 spots in one acre of crop area in case of rice.
From each plot 10 plant selected at random. Total tillers and tillers affected by stem
borer in these 10 plants counted. Total leaves and number affected by leaf folder
observed. Damage expressed as per cent damaged tillers or leaves. Population of
BPH from all tillers in 10 plants observed and expressed as number/tiller.
Qualitative survey - Useful for detection of pest
Quantitative survey - Useful for enumeration of pest
Sampling Techniques
Absolute sampling - To count all the pests occurring in a plot
Relative sampling - To measure pest in terms of some values which can be compared
over time and space e.g. Light trap catch, Pheromone trap
Methods of sampling
a. In situ counts - Visual observation on number of insects on plant canopy
(either entire plot or randomly selected plot)
b. Knock down - Collecting insects from an area by removing from crop and
(Sudden trap) counting (Jarring)
c. Netting - Use of sweep net for hoppers, odonates, grasshopper
d. Norcotised collection - Quick moving insects anaesthesised and counter
e. Trapping - Light trap - Phototropic insects
Pheromone trap - Species specific
Sticky trap - Sucking insects
Bait trap - Sorghum shootfly - Fishmeal trap
Emergence trap - For soil insects
