Time allocation ofOrius sauteriin attackingThrips palmion an eggplant leaf

Abstract

Orius sauteri (Poppius) (Heteroptera: Anthocoridae) is a polyphagous predator used as a biological control agent of palm thrips, Thrips palmi (Karny) (Thysanoptera: Thripidae). We studied O. sauteri' s searching efficiency, time allocation on a leaf, leaving tendency, and attacking of prey. Approximately 78% of the encountered prey was eaten. Searching for prey was concentrated for 86% of the time on the lower leaf side, where palm thrips are usually found. Patch residence times on empty leaves were different from those on leaves with T. palmi larvae. Walking activity was not affected by the thrips density, and walking took place during 64% of the total search time. The leaving tendency of O. sauteri was affected by the time from patch entry and the presence or absence of palm thrips, but not by the thrips density. If prey were present, the leaving tendency decreased (multiplication factor 0.327), resulting in longer giving-up times than when no prey was present. The fact that the leaving tendency increases when patch exploitation lasts longer suggests that not much time is wasted on patches where encounters with prey are scarce.

Mode of overwintering of invasive Harmonia axyridis in the Netherlands

“…The data on the length of the pre-oviposition period were analysed using Cox's proportional hazards model (Yano et al 2005). The model permits estimation of the period until a particular event is likely to occur, and the effects of various factors on the length of the period can be analysed as well.…”

Scaling up from individual behaviour of Orius sauteri foraging on Thrips palmi to its daily functional response

“…Because we have experimental data on the behaviour of one individual predator foraging for prey on one egg-plant leaf with different numbers of prey items present, we have a good starting point from which to scale up. Our earlier findings concerning the foraging process and the patch-leaving behaviour of O. sauteri are that, irrespective of the actual density of prey items on a patch, the leaving tendency only decreased by a factor of about 3 on average because prey were present (Yano et al 2005). Moreover, the leaving tendency increases when patch exploitation lasts longer.…”

“…As we want to determine the number of 2nd instar larvae of T. palmi that one female adult of the species O. sauteri consumes in one foraging day, we have based our simulation model on studies where the patch-leaving behaviour was studied (Yano et al 2005; see ''Patch-leaving rate'' and ''Other rate parameters'' below) and where the distribution of thrips larvae is determined in greenhouses (Kawai 1986; see ''Parameterizing the clumped distribution of thrips over leaves'' below).…”

“…The rate parameters all describe exponentially distributed durations with mean equal to the reciprocal of the rate parameter value. All estimated parameter values were from data obtained at ambient temperature of approximately 25°C, according to the estimated encounter rate and patch-leaving rate from the experiments reported in Yano et al (2005).…”

Enhancing pest management in sweet pepper by the exploitation of zoophytophagy

“…The different behaviours of O. laevigatus on sweet pepper plants and the predator location were analyzed using three-way analysis of variance Previous studies on the behaviour of several species of Orius under different conditions (availability of prey and/or pollen, quality of the plant as a feeding and/or oviposition substrate, architecture of the plant) have been reported (Fritshe and Tamó, 2000;Yano et al, 2005;Jonathan and Fergen, 2006;Lundgren et al, 2008). However, to our knowledge, no other study has quantified the time that a specific Orius species spends feeding on sweet pepper.…”