Dispersal abilities of adult click beetles in arable land revealed by analysis of carbon stable isotopes

Abstract

1 The dispersal abilities of agrioted beetles, serious pests on a variety of crops, are poorly known under natural conditions. This hampers their control. We used, for the first time, a stable isotope approach to assess dispersal of adult Agriotes obscurus in arable land. 2 After a diet switch from a C3-to a C4-plant, carbon isotope ratios of A. obscurus larvae significantly changed towards the isotopic signature of the new diet. Moreover, the larval ␦ 13 C signatures were transferred to the wing covers of the adult beetles with little distortion. 3 To assess the dispersal abilities under natural conditions, pheromone traps, lured for Agriotes sp., were installed at two study sites in Western Austria. Each site comprised a maize field (= C4-plant) and adjacent C3-grasslands with traps established along a transect of increasing distance to the maize. 4 ␦ 13 C signatures of wing covers revealed that adult male A. obscurus were able to migrate at least 80 m, which was the maximum distance that dispersal could be traced in the present study. The dispersal behaviour might have been influenced by site-specific factors. 5 The results obtained demonstrate a higher potential of adult male Agriotes to disperse than previously assumed. Moreover, the combination of pheromone trapping and stable isotope analysis proved to be an effective approach to study insect movement and dispersal in arable systems harbouring C3-and C4-crops.

Movement of three aphidophagous ladybird species between alfalfa and maize revealed by carbon and nitrogen stable isotope analysis

“…The management of the environment may focus on the habitat, farm or landscape levels (Landis et al 2000), with scale-dependent effects on natural enemies (Tscharntke et al 2007). Stable isotope ratios have been proven to be suitable for tracking the plant origin of herbivorous and predatory insects Vialatte et al 2006;Traugott et al 2008;Schallhart et al 2009Schallhart et al , 2011Forbes and Gratton 2011;Ouyang et al 2012). Recently, this method has been used to determine the dispersal of pest predators between alfalfa and maize in the northeast of the Iberian Peninsula (Madeira et al 2014).…”

Influence of irradiation on dispersal ability and survival rate in the sugarcane click beetle Melanotus okinawensis Ôhira (Coleoptera: Elateridae)

“…The mark-recapture method is useful to estimate the abundance, survival rate, and dispersal ability of adult click beetles. Schallhart et al (2009) recently used the isotope ratio as a mark for estimating the dispersal of Agriotes beetles. Population parameters of M. okinawensis were first estimated by Kishita et al (2003).…”

Stable nitrogen and carbon isotope ratios in wild native honeybees: the influence of land use and climate

“…Since stable nitrogen ratios are influenced by human-induced environmental changes, stable carbon ratios may be useful to assess human cultivation of C 4 plants. One such study revealed that stable carbon ratios of target pests were able to indicate the distance from which cultivated C 4 plants could affect pests in habitats with uncultivated C 3 plants (Schallhart et al 2009). …”

“…For instance, A. cerana nests are often found in tree cavities in old growth forests (Oldroyd and Wongsiri 2006), and the workers are found near crop flowers in agricultural fields within mountainous and forested landscapes (Taki et al 2010). Apis cerana can also readily use holes in buildings, and populations are even found in highly disrupted human-dominant landscapes (Sasaki 1999). In the dense city of Hong Kong, A. cerana is often found and uses flowering plants for the majority of their food resources, and these plants are pollinated mainly by this honeybee species (Corlett 2001).…”

“…Stable carbon isotopic ratios have also been used to reveal the relative importance of different food resources in addition to the dispersal behavior of insect populations and communities. Previous studies on herbivores have been conducted to distinguish their dependence on C 3 and C 4 plants (Boutton et al 1978;Fry et al 1978;Schallhart et al 2009). Additionally, combined analyses of stable nitrogen and carbon isotope techniques have often been used to identify the effects of environmental changes on trophic positions and resource use (Hyodo et al 2010;Martins et al 2013;Ostrom et al 1997).…”