Biocontrol Science and Technology (1998) 8, 289-299

J. Romeis and T.G. Jyothirmayi, K.N.S. Shanower (1998)
Constraints on the use of Trichogramma egg parasitoids in biological control programmes in India
Biocontrol Science and Technology 8 (2), 289-299
Abstract: The use of Trichogramma (Hymenoptera: Trichogrammatidae) egg parasitoids for the biological control of several insect pests, including the pod borer Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), is being promoted in India. Several companies supply these parasitoids to farmers, but no evaluation of product quality has been made. Low product quality is recognized as being one of the most important reasons for the failure of these biocontrol agents. In this study, Trichogramma chilonis Ishii egg-cards were obtained from eight producers in southern India. Product quality was evaluated using the following parameters: number of eggs/card, percentage parasitism, percentage emergence, progeny sex ratio and percentage of deformed females. In addition, producers were asked for the average values of these parameters in their production systems and for their recommendations for the use of T. chilonis to control H. armigera in cotton. The quality of the egg-cards was highly variable and was much lower than that stated by the producers. The recommended frequency and interval of releases, and the number of parasitoids to be released, differed greatly among producers. The low product quality results in up to 85% fewer parasitoids being released than is recommended by the producer. The effect of the low product quality and the highly variable release recommendations on applied biological control programmes is discussed. Suggestions for more effective use of Trichogramma spp. are given.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jörg Romeis

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
rearing/culturing/mass production

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa armigera	Cotton (Gossypium)	India
Trichogramma chilonis (parasitoid)	Helicoverpa armigera	Cotton (Gossypium)	India