Performance of Tetranychus urticae and Neoseiulus californicus on strawberry cultivars and assessment of the effect of glandular trichomes

Abstract

The performance of Tetranychus urticae and its predator Neoseiulus californicus on ten strawberry cultivars was determined in the laboratory. Development time and survival of T. urticae from egg to adult were recorded on Albio´n, Aromas, Camarosa, Diamante, Festival, Kp, Sabrosa, Selva, Sweet Charlie, and Whitney. Fecundity of newly molted and mated females was recorded during the first 10 days of oviposition. Predation rate and fecundity of N. californicus were tested on Albio´n, Aromas, Festival, Kp, Sabrosa, and Whitney. Predator females reared on each cultivar were placed individually in experimental units, and the number of eggs per day was counted during 3 days. Cultivars with high hairiness (Albio´n, Aromas, and Festival) and cultivars with low hairiness (Sabrosa, Whitney and Kp) were identified, to assess the effect on the performance of both species. Development time, survival from egg to adult, and fecundity of T. urticae differed among cultivars. Festival was classified as moderately resistant, Aromas and Kp were moderately susceptible, and the others were intermediate. The number of prey consumed per day per female of N. californicus differed between cultivars and time. Fecundity of N. californicus did not differ among cultivars; however, it did over time. The development time and fecundity of T. urticae did not differ among high and low hairiness cultivars. The glandular hairiness affected neither consumption nor fecundity of N. californicus. According to detrimental and propitious effect on T. urticae and N. californicus performance, respectively, we concluded that Festival and Albio´n could be used along with this predator in T. urticae management programs.