CIHEAM- Mediterranean Agronomic Institute of Bari. Biological Control of Insect Pests Prepared by: Hamid El Bilali and Vito Simeone. Contents. Main non-pesticides control tools: micro-organisms, macro-organisms, natural products and semiochemicals; Definition of biological control;
CIHEAM- Mediterranean Agronomic Institute of Bari
Biological Control of Insect Pests
Prepared by: Hamid El Bilali
and Vito Simeone
In organic agriculture, crops protection is based first of all on a good deal of knowledge on agroecosystem (biocenocis and biotope) and information about the target pest, prevention, interactions plant- environment-pest and finally on the use of the allowed pesticides (Annex II-B of the E.C.R. N° 2092/91).
tolerant or resistant cultivars;
barriers- insect-proof net; floating row covers;
plastic tunnels, reflective mulches (aphids)…
In “The Manual of Biocontrol Agents” (Copping, 2004) there are 373 entries of which:
Natural products especially plant- and microorganisms- derived ones
growth regulator, anti-oviposition,
reduces adults fecundity and
cinerariaefolium and T. cineum.
There are six different active ingredients (pyrethrins) resulting from the combination of two acids and 3 alcohols
Semiochemicals: Reppelents, attractants and sex, alarm, and aggregation pheromones.
Mass trapping: Attract&Kill method
Definition of biological control
Biological control can be defined as the use of natural enemies to reduce the damage caused by a pest population. Biological control is an approach that fits into an overall pest management program, and represents an alternative to continued reliance on pesticides.
Basic biological control theories: populations dynamics, density-dependance and alternative theories.
Illustration of natural control: the population number is fluctuating over time it is bounded within a range. The population's "characteristic abundanc“, the long term expected number of individuals in the population, is represented by the yellow.
Example of a factor that acts in a density-dependent fashion
Biological control objectives: reduction, prevention or delay of infestation
This objective is similar to prevention, in that both require early intervention, before a population exceeds a threshold. However, delay means that the population will eventually build up to a high level, but it does so at a time when the species is no longer considered a pest.
Biocontrol approaches: The tactical approach taken to achieve the objectives, which may be conservation, augmentation or importation.
Examples of hedge species planted in organic orchards
Mastic Tree, Evergreen Pistache: Pistacia lentiscus
Gum arabic tree: Acacia spinosa
Jujube berries: Zizyphus sativa
Poet’s Cassica hosts many beneficial insects against olive moth (Prays oleae) like Chelonus eleaphilus. Furthermor, they are also some alternative preys of this beneficial insect living on Poet’s Cassia.
Biological control agents: parasitoids, predators and pathogens.
Number of parasites’ progenies that emerge from the host :
Number of parasites’ progenies :
Number of parasites’ progenies :
Generally speaking the most common features of insect predators are:
Frequency of individual prey items in the diet may be influenced by:
Strategies used by predators to locate and capture preys include the following:
The major groups of predaceous insects belong to the following orders: Coleoptera, Dermaptera, Diptera, Hemiptera, Hymenoptera, Mantodea, Neuroptera, Orthoptera and Thysanoptera.
The most relevant Hemiptera predatory families are: Miridae (plant bugs); Nabidae (damsel bugs), Anthocoridae (insidious flower bugs), Reduviidae (assassin bugs), Phymatidae (ambush bugs), Lygaeidae and Pentatomidae (stink bugs).
The sequence of behaviours used by predators to locate prey is similar to that for parasitoids. In general, behaviours are not as clearly defined for predators as for insect parasitoids.
Genetic diseases may be classified as:
Insect pathogens are used in biological control in at least three different ways: inundative applications, inoculative releases, management of naturally occurring pathogens, and introduction of exotic pathogens as classical biological control agents.
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