Biological control of fruit flies: When to use more than one parasitoid species

We tested if the combined use of the parasitoids Fopius arisanus (Sonan) and Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) provides higher efficiency in controlling C. capitata populations, rather than used alone, on acerola (Malpighia emarginata DC.), guava (Psidium guajava L.), and mango (Mangifera indica L.). The efficiency or parasitism rates for F. arisanus and D. longicaudata, used alone or sequentially, ranged from 2.02 to 56.37 % among the crops surveyed. However, we can obtain the real efficiency of these parasitoids if we consider how much they avoid the emergence of fruit fly host, which is called efficacy. When used alone, the efficacy rates of F. arisanus and D. longicaudata on C. capitata were respectively 41.95 and 72.81 % on acerola; 53.76 and 44.95 % on guava; and 40.29 and 8.40 % on mango. However, when both species were used together, the efficacy of C. capitata control was 71.42, 76.58, and 36.86 % on acerola, guava, and mango, respectively. Therefore, to better achieve improved biological control efficacy, we recommend using D. longicaudata alone on acerola; F. arisanus on mango, and the combined use of both species on guava.