Dispersal of single‐ and double‐brood populations of the European earwig, Forficula auricularia: a mark‐recapture experiment

Abstract

Quantitative information on dispersal of insects should be taken into consideration for making efficient pest management decisions. Such information was not available for the European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), an important biocontrol agent in fruit orchards. A mark‐recapture experiment was carried out in Belgian orchards, where marked earwigs were released at a single point and recaptured after 1 month. Dispersal from this release point was analysed using an analytical formula of a simple diffusion model with disappearance (e.g., as a result of death) derived by Turchin & Thoeny (1993; Quantifying dispersal of southern pine beetles with mark‐recapture experiments and a diffusion model. Ecological Applications 3: 187). The cumulative number of recaptured earwigs as a function of the distance of release was used to fit the model and estimate parameters. A derived expression, in terms of these parameters, was used to estimate the frequency distribution of the population, as the radius of a circle enclosing various proportions of the earwigs’ dispersal distances. In Belgium, populations of the European earwig can have two life‐history strategies, single‐ (SBP) and double‐brood populations (DBP). Therefore, mark‐recapture experiments were carried out on both population types. We fitted data from SBP (n = 10) and DBP (n = 16) successfully in both the diffusion model and in an exponential curve. Because of the biological relevance, estimates of the diffusion model were used for calculating the frequency distributions. Males and females dispersed the same distances. No differences were found between orchards with different spatial structures (apple and pear). According to literature data, mobility of earwigs is very low compared with other arthropods, which has consequences for the efficiency of biocontrol interventions, like mass releases of earwigs or the use of hedgerows for the establishment of healthy (source) populations. Quantitative results revealed that earwigs of SBP dispersed four times further than earwigs of double‐brood populations. For instance, 95% of the population remained within a radius of 28.6 m in SBP and 7.54 m in DBP.

One clutch or two clutches? Fitness correlates of coexisting alternative female life-histories in the European earwig

“…life-history traits, ecology and fitness payoffs) used comparisons across taxa, related species or populations within species (references listed in Crespi and Teo 2002; Moerkens et al 2010). Only little empirical research was carried out on semelparous and iteroparous life-history tactics that coexist in a population (Grosberg 1988;Iguchi and Tsukamoto 2001;Leggett and Carscadden 1978;Seamons and Quinn 2010).…”

Microdot technology for individual marking of small arthropods

“…For pest control, measurements of pest insect dispersal are essential for establishing the scale over which management should operate, identifying suitable habitat and assessing connectivity between populations (Mahroof et al , 2010), whereas quantifying population densities and survivorship allows the effective monitoring of management outcomes. Data on the movement of introduced control agents for biological control of pests or weeds is also crucial for predicting their spread from release points (Corbett & Rosenheim, 1996; Bianchi et al , 2009; Moerkens et al , 2010), monitoring their populations and predicting impacts on nontarget species (Rudd & McEvoy, 1996; Chapman et al , 2009). Conservation of beneficial insects requires dispersal data to delimit management units and the movement of pollinator species is also becoming increasingly important for restoration of pollinator services in degraded ecosystems (Menz et al , 2010), as well as assessing the risks of engineered genes escaping from genetically‐modified crops (Ellstrand, 2003).…”

Communities of flower visitors of Uvariopsis dioica (Annonaceae) in lowland forests of Mt. Cameroon, with notes on its potential pollinators

“…This is due to their feeding behaviour; individuals sometimes spent hours on a single flower feeding. However, earwigs are considered ineffective pollinators because they are less common and known to be poor dispersers (Moerkens et al ., ).…”