Prolonged slow release of (Z)‐11‐hexadecenyl acetate employing polyurea microcapsules

Abstract

The potential use of polyurea microcapsules, as Ôrelease carriersÕ for insect pheromones, has been demonstrated. (Z)-11-hexadecenyl acetate (Z11-16:Ac), the major sex pheromone component of several Noctuidae species, was used as the model molecule. The coating material's ability to release the pheromone was initially studied by the solid-phase micro-extraction technique. Polyurea microcapsules released Z11-16:Ac relatively slowly, with a duration of approximately 1 month, as it was determined under both laboratory and semi-field conditions. Preliminary laboratory bioassays revealed a satisfactory attraction of Sesamia males, at doses of 50 and 500 mg of dried microcapsules containing the aforementioned pheromone. Almost all male insects tested initiated flight and among them 40.2-49.4% successfully contacted the pheromone source. The preparation of polyurea microcapsules needs further refinement as to increase release duration; nevertheless, these results demonstrate strong potential for the future use of polyurea microcapsules as part of integrated insect control programmes.

Attract‐and‐kill strategy. Laboratory studies on hatched larvae of Culex pipiens

“…pipiens biotype molestus has also been confirmed 16. Recently, a slow‐release system has been developed that incorporates ( Z )‐11‐hexadecenyl acetate, the main component of the sex pheromone of several Noctuidae, by means of polyurea coating 17…”

Preparation and characterization of a novel imidacloprid microcapsule via coating of polydopamine and polyurea

“…8,9 In the eld of pesticides, pesticide microcapsule formulations for controlled release bring several advantages over the conventional formulations, such as protecting pesticides from rapid environmental wastage, increasing the performance level of pesticides efficiently, and reducing potential risks to the environment and humans. 10 Pesticide microcapsule formulations can be prepared by encapsulation of pesticides via different routes, including interfacial polymerization, 11,12 in situ polymerization 13 and condensation, 14 and solvent evaporation. 15,16 However, the preparation of imidacloprid microcapsule formulations is difficult due to the poor solubility of imidacloprid in common solvents at room temperature (e.g., 0.61 g L À1 in water, 50 g L À1 in 2-butanone).…”

Preliminary studies for the attract-and-kill strategy against Culex pipiens

“…These preliminary studies are the basic step for the implementation of attract-and-kill strategy. The following step will be the use of microencapsulated oviposition pheromone, a method used before for Sesamia males, (Mihou et al 2007) which will prolong the slow release capability of SP.…”