Preconditioning of the generalist herbivore Trialeurodes vaporariorum to greenhouse monocultures and its subsequent performance on wild polycultures

Abstract

Generalist herbivores can face many challenges when choosing their host plant. This can be particularly difficult if their choice and performance are affected by host experience. Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is an invasive generalist herbivore, which has established in year‐round greenhouses at northern latitudes where it cannot overwinter outdoors. It mainly uses crops such as cucumber (Cucumis sativus L.), tomato (Solanum lycopersicum L.), and ornamentals as host plants. However, every summer the insect escapes greenhouses and is exposed to natural vegetation. We evaluated the performance of T. vaporariorum on diverse vegetation outside greenhouses after prolonged experience of greenhouse crops. First, we surveyed the vegetation near infested greenhouses. Development success of the insect differed among wild hosts. We identified five new hosts among 12 plant species that bore pupae and were thus considered suitable as the insect's host plants. Members of the Urticaceae and Onagraceae were the most preferred and frequently inhabited by all insect life stages. The highest abundance of insects occurred in plots with low plant species richness, independent of plant family in these habitats. We then studied experimentally the impact of 1 year of preconditioning to one of three common greenhouse crops, cucumber, tomato, or poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch), on the performance of the preconditioned adults and their progeny on four wild plants. Adults from tomato and poinsettia preferred the novel host species over the species to which they were preconditioned. The whitefly population preconditioned to cucumber was the most fecund on all offered hosts. We conclude that generalist herbivores can have large variation in performance, despite polyphagy, on novel hosts as shown by the variable abundance of T. vaporariorum pupae among outdoor hosts. Furthermore, performance of whiteflies on natural vegetation was affected by experience on greenhouse crops. Based on our observations, we provide insights and recommendations for pest management.

Reproductive Behavior of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) Relative to Different Host Plants in an Intensive Tomato Crop Region of Chile

“…Our results from the performance test conducted under controlled conditions showed that weeds such as Bidens aurea exhibited higher populations than commercial crops. However, this behavior was not observed under field conditions in the study area; this is in contrast to Ovčarenko et al [29], who argued that whiteflies prefer weeds surrounding crops rather than the crops inside greenhouses. The factors that could affect the performance of the insect depend on the physical and chemical properties of the plant, such as trichome density [36,38], secondary metabolites [39], and thick cuticles [1].…”

“…Luciana, 7742, and Mistral. No preadaptation conditions of the whitefly according to Ovčarenko et al [29]. To avoid possible selection bias, the variety of tomatoes was changed in the test.…”

“…About 249 host plant species have been reported, which are distributed in 80 families, among which Asteraceae represent the highest register with 44 species, followed by Solanaceae (22) and Malvaceae (18) [27,28]. In Finland, Ovčarenko et al [29] identified five new host plant species outside greenhouses containing whiteflies once the main crops were harvested. In this case, plants surrounding the production systems acted as natural reservoirs for the insect, allowing its survival until a new crop appeared both inside and outside the greenhouses [30].…”