Integrated Management Tactics for Frankliniella Thrips (Thysanoptera: Thripidae) in Field-Grown Pepper

Abstract

In a 2-yr study, the impacts of different plastic soil mulches, insecticides, and predator releases on Frankliniella thrips and their natural enemies were investigated in field-grown peppers. Ultraviolet light (UV)-reflective mulch significantly reduced early season abundance of adult thrips compared with standard black plastic mulch. This difference diminished as the growing seasons progressed. Late season abundance of thrips larvae was higher in UV reflective mulch compared with black mulch plots. The abundance of the predator Orius insidiosus (Say) was significantly lower in UV-reflective mulch compared with black mulch treatments. Infection of plants with tomato spotted wilt virus, a pathogen vectored by Frankliniella occidentalis (Pergande), was <6%. In the year with the higher disease incidence (2000), UV-reflective mulch plots had significantly less disease (1.9%) compared with black mulch plots (4.4%). Yield was significantly higher in UV-reflective mulch (24,529 kg/ha) compared with black mulch (15,315 kg/ha) during this year. Effects of insecticides varied with species of thrips. Spinosad reduced abundance of F. occidentalis, but not Frankliniella tritici. In contrast, esfenvalerate and acephate reduced numbers of F. tritici and Frankliniella bispinosa, but resulted in higher populations of F. occidentalis. Spinosad was the least disruptive insecticide to populations of O. insidiosus. Releases of O. insidiosus and Geocoris punctipes (Say) reduced populations of thrips immediately after releases; naturally occurring predators probably provided late season control of thrips. Our results suggest that UV-reflective mulch, combined with early season applications of spinosad, can effectively reduce abundance of thrips in field-grown pepper.

The Influence of Crop Habitat and Control Strategies on Pepper Viruses in Andalusia (Spain)

“…These agrosystems could be considered ecological communities in which plant pathogens have their own dynamics, defined for example by host suitability, climate, and vectors [1]. In the case of plant viruses that are transmitted by vectors, their management can involve conventional (chemical) control and/or integrated (including biological) control [2]. The use of virus-resistant cultivars constitutes an important means to control virus diseases [3].…”

Management strategies for western flower thrips in vegetable greenhouses in Iran: a review

“…A number of cultural control methods can only suppress the population density and are generally utilised in the IPM programs for F. occidentalis. These practices include: sanitation such as removing weeds (specifically, a number of species of the Solanaceae and Compositae families as reservoirs of viruses) and old plants, use of compost for pupae control, use of UV-reflective mulch to decrement thrips populations due to disruptions in host-finding behaviour, manipulating the greenhouse microclimate conditions, placing a weed fabric barrier underneath benches to prevent pupating in the soil (Kisha 1977;Helyer & Brobyn 1995;Shipp & Zhang 1999;Stavisky et al 2002;Reitz et al 2003;Cloyd 2009). Also, the application of fertilizers is an effective method with a major effect on the abundance and distribution of F. occidentalis growing on chrysanthemum and agricultural crops (Reitz 2002b;Chau et al 2005).…”

Management Strategies for Western Flower Thrips and the Role of Insecticides

“…As large populations can develop on non-crop hosts, mass dispersal into crops occurs, whether open field crops (Pearsall & Myers, 2001;Puche et al, 1995;Ramachandran et al, 2001) or crops in protected environments (Antignus et al, 1996). The potential for continual recolonization of crops limits the observed field efficacy of insecticides (Eger et al, 1998;Reitz et al, 2003). This ongoing dispersal means that even repeated insecticide applications have little utility in reducing pest damage, especially in high value crops with low damage thresholds (Bauske, 1998;Kontsedalov et al, 1998).…”

“…Similar results have been observed in crop fields where two-thirds or more of thrips in untreated or spinosad-treated pepper are the native species. Yet, the demographics differ in pyrethroid treated plots, where western flower thrips predominant (Hansen et al, 2003;Reitz et al, 2003). Because the native species F. tritici and F. bispinosa do not cause the economic damage that western flower thrips do, and because they outcompete western flower thrips, their conservation contributes to overall pest management.…”

“…Populations of the invasive western flower thrips likely arrived in Florida with resistance to most classes of broad-spectrum insecticides (Immaraju et al, 1992). Further, flaring of the populations of the western flower thrips and other pests is possible when any broad-spectrum synthetic insecticide is used (Funderburk et al, 2000;Reitz et al, 2003). For this reason, growers are encouraged to move to newer, safer, and more selective insecticides in different chemical classes that are becoming available.…”