Yurong H., Kewei C., Xiongfei P..
2004. Egg parasitoids of Plutella xylostella in South China.
In : Improving biocontrol of Plutella xylostella : Proceedings of the International Symposium, Montpellier, France, 21-24 October 2002. Kirk Alan A. (ed.), Bordat Dominique (ed.). CIRAD, USDA-ARS
Résumé : In South China 5 species of Trichogramma and Trichogrammatoidae parasitoids have been found to attack diamondback moth, Plutella xylostella (L.), (DBM) eggs at an ecological farm where non chemical control measures such as B. thuringiensis and pheromone traps have been used since 1994. Because of slow recovery from the wholesale destruction of beneficial insects very few black eggs of DBM were found and the parasitoid species responsible were unknown. However, Trichogramma confusum and T. bilingensis He et Pang, a new species, were initially found to attack DBM eggs in 1996 two years after ceasing use of insecticides. Subsequently, another 3 species, Trichogrammatoidea bactrae Nagaraja, Trichogramma ostriniae Pang et Chen and Trichogramma raoi Nagaraja were discovered in 1999 and 2001, respectively. Among the five species, T. confusum was predominant, followed by T. bactrae, T. ostriniae, T. raoi and T. bifingensis. The 5 species together contributed 15% of DBM egg parasitism on average and with 57.6% in the harvesting period in autumn. Three species, T. confusum, T. bactrae and T. ostriniae have established stable populations in the field. The total mortality of DBM eggs was composed of parasitism and egg mortality caused by feeding of female Trichogramma. Over a year, parasitism varied with season and achieved its maximum in autumn but dropped to virtually zero due to heavy rainfall in summer, In the field where insecticides were frequently applied few parasitised DBM eggs were found. The control test of Trichogramma on DBM was conducted by inundative releases of T. confusum at 2 million per hectare in the field. The results showed, that parasitism could reach 75.8% on average and T. confusum could effectively control DBM populations when Oomyzus sokolowsakii, a larval-pupa parasitoid, or Cotesia plutellae, a larval parasitoid were released at the same time.
Mots-clés Agrovoc : parasitoïde, Trichogramma, Trichogrammatoidea, Plutella xylostella
Mots-clés géographiques Agrovoc : Chine
Classification Agris : H10 - Ravageurs des plantes
Auteurs et affiliations
- Yurong H., SCAU (CHN)
- Kewei C., SCAU (CHN)
- Xiongfei P., SCAU (CHN)
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/512016/)
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