Determination of mating status of Lobesia botrana (Denis & Shiffermuller, 1776) (Lepidoptera: Tortricidae) using the sentinel female technique

In Chile, Lobesia botrana is a pest submitted to a campaign of eradication/contention. Its management uses mating disruption (CS) as a fundamental control tool which is usually indirectly evaluated by the suppression of male captures in traps and/or by the fruit damage reduction in treated fields. However, the goal of mating disruption technique is to avoid mating. The current study provides the bases to use the "sentinel female" technique as a direct and alternative method to evaluate CS efficacy by measuring the percentage of mating in females. In studies conducted in laboratory, the age at post-emergence copulation from the pupa and the dimensions of the bursa copulatrix in virgin and mated females were evaluated in adult females. Additionally, two methods of virgin females' confinement (females with a tied wing or females in cages with restricted access) were evaluated, measuring the respective % copulation when exposed to virgin males, which was contrasted with unconfined virgin females. It was determined that the females mate before 48 hours after mating with a male. The bursa copulatrix of a virgin female measures 0.9 & PLUSMN; 0.03 mm long x 0.2 & PLUSMN; 0.01 mm wide, while in a mated female it measures 1.1 & PLUSMN; 0.5 x 0.5 & PLUSMN; 0.3 mm, which constitutes an objective criterion to determine the female mating status. Virgin females were able to mate in all treatments; 100% of the unconfined females copulated, 92% copulated with a tethered wing and 64% in cages. It is concluded that the method of confinement in cages works to directly evaluate the efficacy of CS.