Biological control agentsd

1. Muhammad Irfan Shan
Department of Entomology
College of Agriculture
University of Sargodha

2. Trichogramma brassicae
https://ajxywn0wn.cloudimg.io/cdn/n/n/https://res.cloudi
nary.com/agrimag/image/upload/f_auto,w_450,h_450/v15
16618611/products/trichogramma-brassicae/623.jpg

3. • Trichogramma brassicae is a species of parasitiod
wasps from the Trichogrammatidae family.
• It mainly parasitizes Lepidopteran hosts in
agricultural fields. They
are entomaphagous parasitoids that deposit their
own eggs inside the host's eggs, consuming the
host egg material and emerging upon full
development.
• They are a common biological control species that
have been used commercially since the late 1970s.
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tps://res.cloudinary.com/agrimag/image/u
pload/f_auto,w_450,h_450/v1516618610/
products/trichogramma-brassicae/622.jpg

4. Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Trichogrammatidae
Genus: Trichogramma
Species: T. brassicae

5. Identification
• Adult wasps are yellow or yellow and
black with bright red eyes, short
antennae, and compact bodies.
• They look like gnats (tiny flying
insects).
• A small hole in the host egg is visible if
the wasps have emerged.
https://fitogest.imagelinenetwork.com/it/insettiutili/trichogramma
-brassicae/10039

6. Biology and Life cycle
• Females lay one or more eggs in the egg of a
host insect.
• The larvae pupate inside the host egg, and
adult wasps emerge seven to ten days after
the egg is laid.
• Over fifty wasps can emerge from one egg. In
warm weather many generations can be
produced.
• Hosts include corn, cotton, cabbage, peas,
tomatoes, soybeans, rice, citrus, ornamental
plants, pecans, and forests.
https://www.researchgate.net/profile/Malick_BA/publicat
ion/335978434/figure/fig15/AS:806259192246287@1569
238579824/Life-cycle-of-Trichogramma-spps.ppm

7. Target Pests
• T. brassicae - for use on vegetable, orchards, gardens and field crops
• Over 200 pests moth species eggs can be destroyed by Trichogramma
(armyworms, borers, cutworms, fruit worms, leaf worms, leaf worms, leaf
rollers, loopers etc.)
• Ephestia kuehniella
• Ostrinia nubilalis
• Helicoverpa armigera
• Lobesia botrana
• Mamestra brassicae
https://ajxywn0wn.cloudimg.io/cdn/n/n/ht
tps://res.cloudinary.com/agrimag/image/u
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products/trichogramma-brassicae/619.jpg

8. Mechanism of Action
• The Trichogramma egg hatches inside the eggs of the antagonist and the
small larva that comes out of it feeds, attack the embryos of the eggs from
the inside (endoparasitism) destroying them.
• After 8-10 days of feeding and development, the new adult Trichogramma
individual breaks the shell of the host egg and begins the search for a
similar one of the opposite sex and then mates then begins to look for
fresh eggs in which they deposit their own eggs.

9. Related Articles
1) Efficiency of spinosad, Bacillus thuringiensis and Trichogramma brassicae against the tomato leafminer in
greenhouse.
2) Demography and life history of the egg parasitoid, Trichogramma brassicae, on two moths Anagasta
kuehniella and Plodia interpunctella in the laboratory.
3) Inundative release of Trichogramma brassicae bezdenko (Hymenoptera: Trichogrammatidae) for control of
European corn borer in sweet corn
4) Age-specific Functional Response of Trichogramma brassicae (Hymenoptera: Trichogrammatidae)
Parasitizing Different Egg Densities of Ephestia kuehniella (Lepidoptera: Pyralidae)
5) A comparative study on the functional response of Wolbachia-infected and uninfected forms of the
parasitoid wasp Trichogramma brassicae
6) Augmentation of Trichogramma brassicae for control of cruciferous Lepidoptera
7) Field Assessment of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) and Bacillus
thuringiensis for Control of Ostrinia nubilalis (Lepidoptera: Pyralidae) in Sweet Corn
8) Assessment of Trichogramma species for biological control of forest lepidopteran defoliators
9) Parasitism of different Trichogramma species and strains on Plutella xylostella L. on greenhouse
cauliflower
10) Mass rearing and release of Trichogramma for biological control of insect pests of corn in China

10. Diaeretiella rapae
https://www6.inrae.fr/encyclopedie-pucerons_eng/Aphids-
and-agriculture/Crop-plants/Poaceae/Parasitoid-key

11. History and Background
• Diaeretiella rapae (Hymenoptera: Braconidae, Aphidiinae) was described
as Aphidius rapae by McIntosh in 1855. In 1960, Stary described a new
genus Diaeretiella and put the species under it
• Diaeretiella rapae is a species of cosmopolitan parasitoid wasp.
• D. rapae was reported as the most effective natural enemy against the
cabbage aphid, Brevicoryne brassicae.
• It is the only species in the genus Diaeretiella.

12. Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Superfamily: Ichneumonoidea
Family: Braconidae
Subfamily: Aphidiinae
Genus: Diaeretiella
Species: D. rapae

13. Identification
• The adult female parasitoid was bigger than male. Adult female measured
2.13 mm in length while male 1.78 mm in length.
• Antenna with 14 segments in females, more rarely 13 or 15
https://www.researchgate.net/figure/The-aphid-
parasitoid-Diaeretiella-rapae-attacking-the-peach-
potato-aphid-Myzus-persicae_fig4_264118928
https://en.wikipedia.org/wiki/Diaeretiella_rapa
e#/media/File:Diaeretiella_rapae_larvae_1.jpg

14. Eggs Larva Pupa
Mummy with emergence hole on the upper side Adult female Adult male
GAZMER, R., Gupta, M. K., & Singh, M. D. (2015). Biology of Diaeretiella rapae (Mc Intosh)(Hymenoptera: Aphidiidae) on cabbage aphid (Brevicoryne brassicaeLinnaeus) and
influence of host age on the developmental duration. Journal of Biological Control, 29(1), 3

15. Life Cycle
• Koinobiont endoparasitoids
• The fecundity of Diaeretiella rapae was 120-140 eggs per female.
• Eggs were transparent white but appeared light brownish under high
magnification. Average incubation period was 1.90 days
• Larvae of D. rapae underwent four moults. The first instar larva was
transparent white, second instar larvae were creamy white and curved
slightly, third instar larvae were light yellow in colour, fourth instar larvae
measured 2.76 mm in length and 0.87 mm in width. The average total
larval duration of D. rapae was 7.50 days.
• Pupa measured 2.0 mm in length and 0.80 mm in width with average
pupal duration was 5 days.

16. • Under laboratory conditions, egg-to-adult development ranges from 9 to
15 days. Adult females live for 10-15 while males live for 7 to 10 days
• Females live significantly longer than males at constant temperatures
http://evolves.massey.ac.nz/Images/D.rapa.jpg
https://www6.inrae.fr/encyclopedie-
pucerons_eng/Species/Parasitoids/Braconidae-
Aphidiinae/Diaeretiella-rapae

17. Target Pests
• D. rapae was reported as the most effective natural
enemy against the cabbage aphid, Brevicoryne
brassicae
• Other host aphids include Aphis craccivora, Aphis
fabae, Aphis gossypii, Aphis nasturtii, Aphis pomi, Aphis
rumicis, Brachycolus asparagi, Brachycaudus
helichrysi, Brachycaudus rumexicolens, Capitophonis,
Dactynotus sp., Diuraphis noxius, Hayhurstia atriplicis,
• Hyadaphis foeniculi, Lipaphis erysimi, Macrosiphum
euphorbiae, Myzus certus, Myzus persicae, Protaphis
sp. Rhopalosiphum fitchii, Rhopalosiphum
maidis, Rhopalosiphum padi and Schizaphis graminum.
http://entnemdept.ufl.edu/creatures/veg/
aphid/Brevicoryne_brassicae01.jpg
Cabbage Aphid

18. 1) Use of the parasitoid Diaeretiella rapae (to control the cabbage aphid Brevicoryne brassicae (L.)
2) The delay in arrival of the parasitoid Diaeretiella rapae influences the efficiency of cabbage aphid
biological control
3) Systematics, distribution and host range of Diaeretiella rapae (Mcintosh) (Hymenoptera: Braconidae,
Aphidiinae)
4) Biological control of the turnip aphid (Lipaphis erysimi K.) using the braconid wasp (Diaeretiella rapae ).
5) Microsatellite isolation and characterization in the beneficial parasitoid wasp Diaeretiella rapae (M’Intosh)
(Hymenoptera: Braconidae: Aphidiinae)
6) Parasitization of mustard aphid, Lipaphis erysimi Kalt. by Diaeretiella rapae M'lntosh in mid hill zone of
Himachal Pradesh (India)
7) Effects of host age on two closely related parasitoid species Diaeretiella rapae (McIntosh) and Aphidius
colemani (Viereck)(Aphidiidae: Hymenoptera)
8) Seasonal fluctuations of population density of the cabbage aphid,Brevicoryne brassicae (L.), in the
Netherlands, and the role of its parasite,Aphidius (Diaeretiella) rapae (Curtis)
9) Behavioural responses of the aphid parasitoid Diaeretiella rapae to volatiles from Arabidopsis
thaliana induced by Myzus persicae
10) Influence of different stages of Diaeretiella rapae on development of Pachyneuron aphidis
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