How Trichogramma survives during soybean offseason in Southern Brazil and the implications for its success as a biocontrol agent

• Published in: BioControl (Dordrecht, Netherlands) Netherlands), 2015-02, Vol.60 (1), p.1-11
• Main Authors: Foerster, Marion R, Marchioro, Cesar A, Foerster, Luís A
• Format: Article
• Language: English
• Subjects: adults; Agricultural ecosystems; Agriculture; agroecosystems; alternative hosts; Animal Biochemistry; Animal Ecology; Anticarsia gemmatalis; Behavioral Sciences; Biological control; biological control agents; Biomedical and Life Sciences; Eggs; Entomology; Females; Food sources; Host-parasite interactions; Life Sciences; Life span; Linear equations; longevity; Natural enemies; Parasitism; Parasitoids; Pest control; Plant Pathology; Seasons; Soybeans; Statistical analysis; Survival; Temperature; Trichogramma; Trichogramma pretiosum; Winter
• ISSN: 1386-6141; 1573-8248
• DOI: 10.1007/s10526-014-9616-5

Trichogramma species are important natural enemies of Anticarsia gemmatalis Hübner, a key pest of soybean in new world agroecosystems. Development, longevity and parasitism rate of Trichogramma pretiosum Riley, Trichogramma acacioi Brun, Moraes and Soares and Trichogramma rojasi Nagaraja and Nagarkatti were investigated under natural conditions throughout fall and winter in order to determine how these parasitoids survive during the soybean off-season in southern Brazil. All species remained active along the experimental period. Over 90 % of the parasitoids emerged throughout the off-season, except for T. rojasi which showed lower percentage of emergence in April and May. The reproductive activity was not interrupted during fall and winter, indicating that the parasitoids depend on alternative hosts to survive. Parasitoids survived during the off-season combining slow developmental rate with an increase in adult life span, an important adaptation that improves their chances of finding alternative hosts and food sources.