Larval and adult food preferences of the poinsettia thrips Echinothrips americanus Morgan, 1913 (Thysanoptera: Thripidae)

Abstract

Numerous occurrence of Echinothrips americanus Morgan, 1913, a relatively newly established pest in European greenhouses, on a wide spectrum of cultivated plants throughout Slovakia has encouraged us to present current data on its food ecology. Analysing 1,650 plant species, the poinsettia thrips was found on 106 species (48 families) including 19 showing sporadic, 75 moderate and 17 high infestation. Larvae were detected on 25 plant taxa from 13 families, most of them being new hosts. Mature clusters of Acalypha hispida, showing moderate to high infestation level and carrying both larvae and adults, were selected for more detailed statistical evaluation. Preference of adults for upper and lower leaf surface tends to be without statistical significance, the larvae on the contrary were strongly related to the lower side (Pearson's v 2 = 13.3552, P = 0.0013). Concerning the age, increased occurrence was apparent on younger leaves for both larvae and adults. For larvae the nonparametric test gives the statistical difference between three age categories of leaves with the following values: Kruskal-Wallis v 2 = 6.6384, P = 0.03618. The statistical significance of age seems to be more crucial for younger shoots, as proved by the statistics for both larvae (Kruskal-Wallis v 2 = 8.4852, P = 0.0144) and adults (Kruskal-Wallis v 2 = 7.1049, P = 0.0287). Different food preferences of larvae and adults may result in specific approach when applying an effective biological or chemical control. Narrower tolerance of larvae could make them more manageable target in plant protection instead of efforts to control the whole thrips population.

Effective factors on host choice of phytophagous thrips and possibilities of use for control

“…Thripslerin popülasyonlarını devam ettirmesi tek konukçu bitki türünün farklı fenotip ve genotipleri arasında farklılıklar gösterebilmektedir ve bu durum tarımsal üretimde thripslere dayanıklı bitkilerin belirlenmesinde önem taşımaktadır (Varga et al, 2010). Söz konusu dayanıklılıkla yaprağın epidermal kalınlığı arasında güçlü bir ilişki olduğu bilinmektedir.…”

Biological control of Echinothrips americanus by phytoseiid predatory mites and the effect of pollen as supplemental food

“…This thrips species is native to eastern North America (Oetting 1987), but it has spread rapidly across Europe since 1995 (Vierbergen et al 2006) and more recently, it also established in China (Li et al 2014). The poinsettia thrips is also highly polyphagous and causes serious damage in various vegetable and ornamental crops through extensive foliage feeding (Ramakers et al 2000;Varga et al 2010;Vierbergen et al 2006).…”

Non-Parametric Statistical Methods and Data Transformations in Agricultural Pest Population Studies

“…This occurrence is understandable considering that individuals have better life conditions in this plant stratum because they are less exposed to the action of natural enemies and sun radiation. Besides, there are leaves in this level that, given their age, could be more adequate to guarantee food for the insect in larval stages (Suris and Plana, 2001;Tobing, 2007;Varga et al, 2010). …”