Non-target effects of the exotic generalist parasitoid wasp Fopius arisanus (Sonan) estimated via competition assays against Doryctobracon areolatus (Szepligeti) on both native and exotic fruit fly hosts

Authors: PARANHOS, BEATRIZ - Embrapa; PONCIO, SONIA - Instituto Federal De Educação Ciência E Tecnologia; MORELLI, RENATA - Proinsecta P&d; NAVA, DORI - Embrapa; NOGUERIA DE SA, L - Embrapa; Manoukis, Nicholas

Submitted to: BioControl
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2020
Publication Date: 10/22/2020
Citation: Paranhos, B.A., Poncio, S., Morelli, R., Nava, D.E., Nogueria De Sa, L., Manoukis, N. 2020. Non-target effects of the exotic generalist parasitoid wasp Fopius arisanus (Sonan) estimated via competition assays against Doryctobracon areolatus (Szepligeti) on both native and exotic fruit fly hosts. Biocontrol. 66:83-96. https://doi.org/10.1007/s10526-020-10057-4.
DOI: https://doi.org/10.1007/s10526-020-10057-4

Interpretive Summary: Biological control of the invasive pest fruit fly Bactrocera carambolae in Brazil through the introduction of a parasite wasp, Fopius arisanus, has been proposed. Before release of this exotic wasp, we conducted laboratory and field cage experiments to ensure that it will not have negative effects on native parasitoid wasps. Experiments focused on competitive tests with native fruit fly hosts and the introduced Medfly. Results suggest that F. arisanus will not have a negative impact on native wasps primarily because it is only marginally able to parasitize the native fruit fly that the native wasps depend on. We conclude that F. asrisanus will not have a significant effect on native parasitoid wasps or fruit flies.

Technical Abstract: Biological control by the generalist egg-parasitoid Fopius arisanus (Sonan) (Hymenoptera: Braconidae) has been proposed against Bactrocera carambolae (Drew & Hancock) (Diptera: Tephritidae) in northern Brazil. This study assessed possible effects of F. arisanus on native parasitoids by focusing on competition with the native wasp Doryctobracon areolatus (Szépligeti) (Hymenoptera: Braconidae) on two hosts, Anastrepha fraterculus (Wiedemann), a native tephritid, and Ceratitis capitata (Wiedemann), an introduced pest tephritid. Lab and greenhouse cage studies showed that F. arisanus parasitized <5% of the native host under choice or no-choice conditions compared to 26-65% for C. capitata. The host origin of F. arisanus did not affect subsequent parasitism rates on native or exotic hosts. However, when reared on C. capitata, F. arisanus had higher parasitism on C. capitata than on A. fraterculus. Lab and greenhouse competition studies showed that F. arisanus had no measurable detrimental effect on the native parasitoid in either the native or introduced host, suggesting that F. arisanus interfered minimally with the native parasitoid. Based on these results and other relevant studies showing non-preference of F. arisanus for the native fruit fly species, as well as the non preference of native parasitoids for exotic fruit flies, we infer that the release of F. arisanus against exotic tephritids such as C. capitata and B. carambolae in Brazil would not cause major disruption of the native populations of fruit fly parasitoids.