Residual toxicity of insecticides used in Tunisian citrus orchards on the imported parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae): Implications for IPM program of Ceratitis capitata (Diptera: Tephritidae)

Abstract

Citrus agro-industry is globally harshened mainly by Ceratitis capitata (Wiedemann), the most worldwide destructive tephritid fruit fly species. Citrus agro-industry is one of the pillars of Tunisia economy, and by hence, harshened by this species. Tunisia has established an Integrated Pest Management (IPM) programme against citrus pests, including C. capitata, that rely on the structured use of pesticides, on the application several trapping protocols, along with pilot-scale sterile insect technique program and, since 2013, with pilot-scale releases of the braconid parasitoid Diachasmimorpha longicaudata Ashmed (Hymenoptera: Braconidae). Insecticide sideeffects on parasitoids and other natural enemies are being requested for a successful implementation of biological control within any IPM programme. However, these data are almost scarce for the braconid species D. longicaudata. To this end, we have determined the side-effects of malathion, methidathion, acetamiprid, azadiractin, abamectin, deltametrin+thiacloprid and spinosad, as the most popular insecticides used in Tunisia either as fresh residues or at several aged time points, on the parasitoid D. longicaudata according the IOBC pesticide harm-classification. IOBC classification evolution of residues over time had allowed determining the best combination of pesticide applications in a structured fashion with the viable releases of D. longicaudata for the control of C. capitata in Tunisian citrus agro-ecosystems.

Side Effects of Pesticides on the Olive Fruit Fly Parasitoid Psyttalia concolor (Szépligeti): A Review

“…Phosmet exhibited high toxicity in glass residual contact laboratory tests, but it was harmless when the substrate was treated parasitized C. capitata pupae (Table 1) [64]. Toxicity of organophosphates has been reported for other braconids, such as Aphidius gifuensis Ashmead [65] or Diachasmimorpha longicaudata Ashmead [66].…”

“…Beta-cyfluthrin, lambda-cyhalothrin, alpha-cypermethrin, zeta-cypermethrin, and deltamethrin greatly compromised P. concolor survival when females were exposed to residual contact and ingestion tests, but emergence was not affected when parasitized pupae were treated (Table 1) [64,68]. Short-term mortality of adults due to pyrethroids [65,66,[69][70][71][72] and negative sublethal effects on larval and pupal development, fecundity, sex-ratio or oviposition [70,[73][74][75] have been well documented in families Aphelinidae, Encyrtidae, Braconidae, Mymaridae, Trichogrammatidae, and Scelionidae. Pyrethroids can interfere with the mobility and orientation of parasitoids searching for food sources or host plants [76].…”

“…This revealed that ecological selectivity may result through the use of bait treatment. High toxicity of imidacloprid and moderate toxicity of acetamiprid have been reported with residues of up to 28 days in other braconids [65,66,72,75].…”

Enhancing "Psyttalia concolor" (Szépligeti) (Hymenoptera: Braconidae) in olive groves to increase biological control of the olive fruit fly = Incrementar la presencia de "Psyttalia concolor" (Szépligeti) (Hymenoptera: Braconidae) en los olivares para mejorar el control biológico de la mosca del olivo

“…This toxicity of organophosphates has been reported for other braconid parasitoids, e.g. Aphidius gifuensis Ashmead (Ohta and Takeda, 2015) and Diachasmimorpha longicaudata Ashmed (Harbi et al, 2017).…”

Watermelon-infesting Tephritidae fruit fly guild and parasitism by Psyttalia phaeostigma (Hymenoptera: Braconidae)

“…Reliability for internal branch values though a LRT test are shown levels of insecticide residues (Essumang et al 2013), reflecting the extreme pest pressure on the crop in West Africa. The compatibility between insecticides and natural enemies is vital for biological control, hence the current fruit fly management method is a problem for the use of parasitoids as biological control agents (Harbi et al 2017). Non-specific tephritid insecticides, incompatible with natural enemies, risk destroying any arthropod, including biological control agents (Roubos et al 2014;Biondi et al 2012).…”