Optimisation of a semiochemical slow-release alginate formulation attractive towards Aphidius ervi Haliday parasitoids

• Published in: Pest management science Vol. 68; no. 1; pp. 127 - 136
• Main Authors: Heuskin, Stéphanie, Lorge, Stéphanie, Godin, Bruno, Leroy, Pascal, Frère, Isabelle, Verheggen, François J, Haubruge, Eric, Wathelet, Jean-Paul, Mestdagh, Michèle, Hance, Thierry, Lognay, Georges
• Format: Journal Article Web Resource
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.01.2012; Wiley; Wiley Subscription Services, Inc; John Wiley & Sons Ltd
• Subjects: alginate beads; Alginates - chemistry; Animals; Aphidius ervi; aphids; Aphids - drug effects; Aphids - physiology; Biological and medical sciences; biological control; Chemistry; Chemistry, Pharmaceutical - methods; Chimie; Delayed-Action Preparations - chemistry; Delayed-Action Preparations - pharmacology; Entomologie & lutte antiravageur; Entomology & pest control; Female; Fundamental and applied biological sciences. Psychology; Glucuronic Acid - chemistry; Hexuronic Acids - chemistry; Insects; Life sciences; Optimization; Parasites; Pest control; Pest Control, Biological; Pesticides; Pheromones - chemistry; Pheromones - pharmacology; Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; Phytopathology. Animal pests. Plant and forest protection; Sciences du vivant; semiochemical; Sesquiterpenes - chemistry; Sesquiterpenes - pharmacology; slow release; Wasps - drug effects; Wasps - physiology; Aphidoidea; Insecta; Biological control; Aphidius ervi; Alginates; Parasitoid; Homoptera; Arthropoda; Formulation; semiochemical; Braconidae; Hymenoptera; Invertebrata; alginate beads; aphids; Semiochemicals; slow release
• ISSN: 1526-498X; 1526-4998; 1526-4998
• DOI: 10.1002/ps.2234

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E‐β‐farnesene and E‐β‐caryophyllene) slow‐release devices in biological control approaches by attracting predators and parasitoids of aphids. Various formulation criteria were optimised with respect to semiochemical encapsulation capacity. Moreover, the optimised formulation was characterised by texturometry and confocal microscopy. The slow‐release rates of semiochemicals were calculated in laboratory controlled conditions. The attractiveness of semiochemical formulations towards Aphidius ervi was demonstrated by olfactometry. RESULTS: Two major parameters were highlighted in encapsulation optimisation: the type of alginate (Sigma L) and the type of crosslinker ion (Ca2+). Other formulation parameters were optimised: ionic strength (0.5 M), Ca2+ (0.2 M) and alginate (1.5%) concentrations and the maturation time of beads in CaCl2 solution (48 h). After physical characterisation of beads, semiochemical slow‐release measurements showed that alginate formulations were efficient sesquiterpene releasers, with 503 µg of E‐β‐farnesene and 1791 µg of E‐β‐caryophyllene totally released in 35 days. The efficiency of semiochemical alginate beads as attractants for female parasitoids was demonstrated, with high percentages of attraction for semiochemical odours (88 and 90% for E‐β‐farnesene and E‐β‐caryophyllene respectively) and significant statistical results. CONCLUSION: Semiochemical alginate beads can be considered as efficient slow‐release systems in biological control. These formulations could be very useful to attract aphid parasitoids on crop fields. Copyright © 2011 Society of Chemical Industry