Variation in Preference and Performance of Frankliniella occidentalis (Thysanoptera: Thripidae) on Three Strawberry Cultivars

Abstract

Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major pest of strawberry, causing substantial yield loss through direct feeding on the flowers and fruit. Insecticides are the main method used for its control; however, F. occidentalis has developed resistance to insecticides from all major chemical classes. Chemical control is not a long-term strategy and integrated pest management is required. This study determined whether F. occidentalis damage could be reduced by host plant resistance or tolerance in three commercial strawberry cultivars (Fragaria X ananassa [Rosaceae]: 'Albion', 'Camarosa', and 'Camino Real'). Determination of resistance or tolerance to F. occidentalis was based on olfactory response, feeding damage, ovipositional preference, and host suitability for reproduction on leaves. F. occidentalis adults preferred to feed on Camarosa; however, if leaves had been fed on previously by conspecifics, there was no difference in feeding preference. Camarosa was the most preferred cultivar for oviposition, and more eggs were laid by F. occidentalis on Camarosa than either Albion or Camino Real. More larvae hatched and adults were reared from Camarosa than either Albion or Camino Real. The percentage of unhatched eggs, larvae, and pupae that died was highest on Camino Real. Survival rate was highest on Camarosa. Egg incubation, prepupation, pupation, and total developmental periods were shortest on Camarosa, but the larval period was longest on Camarosa. Camarosa was the most favorable cultivar for F. occidentalis population growth on leaves.

Effect of spinosad and predatory mites on control of Frankliniella occidentalis in three strawberry cultivars

“…As our previous study showed that strawberry cultivars (cvs) can affect thrips survival (Rahman et al, 2010), we also evaluated the effect of strawberry cultivar (cv.) We evaluated the effectiveness of three predatory mites against F. occidentalis by integrating with spinosad.…”

“…We evaluated the effectiveness of three predatory mites against F. occidentalis by integrating with spinosad. As our previous study showed that strawberry cultivars (cvs) can affect thrips survival (Rahman et al, 2010), we also evaluated the effect of strawberry cultivar (cv.) on F. occidentalis control.…”

Nuevos registros de <i>Frankliniella occidentalis</i> (Pergande) (Thysanoptera: Thripidae) y de <i>Tetranychus urticae</i> Koch (Acari: Tetranychidae) en fresas cultivadas en Venezuela

“…Las características morfológicas y composición química (fenoles, taninos, entre otros) presentes en las diferentes estructuras de las plantas de fresa de los distintos cultivares, pueden asociarse con la susceptibilidad y/o resistencia a los ataques de F. occidentalis y T. urticae. Al respecto, Rahman et al (2010) observaron que F. occidentalis mostró mayor preferencia alimenticia, tasa de oviposición y supervivencia, sobre Camarosa que sobre 'Albión' y 'Camino Real'. Afifi et al (2010) confirmaron que 'Camarosa' resultó más susceptible a T. urticae que la variedad Sweet Charlie, argumentando que tal diferencia se debió a la menor cantidad de fenoles y aminoácidos, mayor cantidad de azúcar, y menor cantidad de tricomas en las hojas de Camarosa que en las de 'Sweet Charlie'.…”

Predatory mites double the economic injury level of Frankliniella occidentalis in strawberry

“…Published economic injury levels (EILs) vary considerably for strawberry, from 3 to 24 thrips per flower, according to thrips stage monitored (i.e. adults only or adults and larvae combined) (Steiner and Goodwin 2006), cultivar (Rahman et al 2010) and sale price (Coll et al 2007). …”

“…Some strawberry cultivars are more tolerant than others to thrips damage (Kitamura and Kashio 2004), and differences could be used to select for resistance to thrips. Other cultivars are more favourable for F. occidentalis population growth (Rahman et al 2010), so the relationship between thrips density and bronzing damage needs to be quantified under local conditions in order to develop EILs. The limited data on the susceptibility of different strawberry fruit stages to bronzing appear contradictory.…”