Parasitoids

Parasitoids
    Parasite
    • An animal species, which lives on or in a larger animal, the host, feeding upon it, and frequently destroying it. A parasite needs only one or part of host to reach maturity.
    Parasitoid
    • An insect parasite of an arthropod; parasitic only in its immature stages, destroying its host in the process of its development, and free living as an adult.
    Types of parasitoids
    1. Based on the developmental site in the host
    a. Ectoparasitoid
    • An insect parasite which develops externally on its arthropod host.
    • (eg). Bracon brevicornis on coconut black headed caterpillars.
    b. Endoparasitoid
    • An insect parasitoid which develops within the body of its arthropod host.
    • (eg) Eriborius trochanteratus on coconut black headed caterpillar.
    2. Based on host specificity
    a. Monophagous parasitoid
    • Highly host specific attacking a single host species. E.g. Parasierola nephantidis (Goniozus) (Bethylidoe) on Opisina arenosella (coconut black headed caterpillars).
    b. Oligophagous parasitoid (Stenophagous): Attacking a group of related host species.
    c. Polyphagous parasitoid: Attack a wide variety of host species. (eg) Trichogramma Spp. (Trichogrammatidae) on eggs of
    many Lepidopteran species.
    3. Based on the host
    a. Primary parasitoid: A parasitoid parasitizing a pest. It is beneficial (eg) Trichogramma sp.
    b. Seconday parasitoids: A parasitoid attacking another parasitoid. It is harmful (eg.) Opisina arenosella (pest) Bracon brevicornis (Primary parasitoid) – Pleurotropis sp. (secondary parasitoid).
    c. Tertiary parasitoid: A parasitoid attacking secondary parasitoid. It is beneficial. (eg) Trichospilus coerulescens
    • All parasitoids whose hosts are parasitoids are called as hyperparasitoids (Parasitoids of Parasitoids).
    4. Based on the number of parasitoids developing from a single host insect
    a.Solitary parasitoid:
    • One progeny alone is capable of completing its development in or on its host (eg) Eriborus trochanteratus.
    b. Gregarious parasitoid:
    • Several progeny are capable of completing its development in or on a single host. (eg) Bracon breviconis.
    • A further extension of gregaiousness is Polyembryony in which several individuals develop from a single egg. (eg) Platygaster.
    5. Based on the stage of host insect attacked
    Order: Hymenoptera (90% of parasitoid coming under this order)
    I.Egg parasitoid
    a. Trichogramma chilonis: Trichogrammatidae – Eggs of sugarcane internode borer, cotton bollworm, rice leaf folder.
    b. T. japonicum: Trichogrammatidae – Eggs of rice stem borer
    c. Telenomus rowani : Scelonidae – Eggs or rice stem borer
    d. T.remus : Scelonidae – Eggs of tobacco caterpillar
    II. Egg-Larval parasitoid
    a. Chelonus blackburni: Braconidae – Eggs of cotton spotted bollworm.
    III. Larval parasitoid
    a. Bracon hebetor: Braconidae – Larvae of coconut black headed caterpillar
    b. B.brevicornis :Braconidae – Larvae of coconut black headed caterpillar
    c. Compoletis chloridae: Ichneumonidae – Larvae of H. armigera
    d. Cotesia plutella :Braconidae – Larvae of diamondback moth
    e. Eriborus trochanteratus: Ichneumonidae – Larvae of coconut black headed caterpillar
    f. Goniozus nephantidis : Bethylidae – Larvae of coconut black headed caterpillar
    g. Platygaster oryzae: Platygasteridae – Larvae of rice gall midge.
    IV. Larval – Pupal parasitoid
    a. Isotima javensis: Ichneumonidae – Pre – pupal parasite of top shoot borer of sugarcane.
    V.Pupal parasitoid
    a. Brachymeria nephantidis; Chalcidae – Pupae of coconut black headed caterpillar.
    b. Tetrastichus israeli: Eulophidae – Pupae of coconut black headed caterpillar.
    c. Trichospilus pupivora: Eulophidae – Pupae of coconut black headed caterpillar.
    d. Xanthopimpla punctata : Ichneumonidae
    VI. Nymphal and adult parasitoid
    a. Aphelinus mali : Aphelinidae – Aphids
    b. Encarsia formosa: Aphelinidae – Cotton whitefly
    Order: Diptera (10% of parasitoid coming under this order)
    I. Larval parasitoid
    a. Sturmiospsis inferens: Tachinidae: Larvae of sugarcane early shoot borer.
    b. Spaggossia bassiana: Tachinide: Larvae of coconut black headed caterpillar.
    II. Larval – pupal parasitoid
    a.Eucelatoria bryani: Tachinidae : Larvae of H.armigera

Last modified: Friday, 24 February 2012, 10:06 PM