Flight directionality of Tribolium castaneum soon after take‐off under glasshouse and field conditions

Abstract

Flight directionality of the rust-red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), was investigated under glasshouse and field conditions using sticky traps placed around dense experimental infestations of T. castaneum derived from field-collected samples. Although beetles of this species are known to fly quite readily, information on flight of beetles away from grain resources is limited. Under still glasshouse conditions, T. castaneum does not demonstrate strong horizontal or vertical trajectories in their initial flight behaviour. Flight was significantly directional in half of the replicates, but trapped beetles were only weakly concentrated around the mean direction of flight. In the field, by contrast, emigration of T. castaneum was strongly directional soon after flight initiation. The mean vector lengths were generally >0.5 which indicates that trapped beetles were strongly concentrated around the calculated mean flight direction. A circular-circular regression of mean flight vs. mean downwind direction suggested that flight direction was generally correlated with downwind direction. The mean height at which T. castaneum individuals initially flew was 115.4 AE 7.0 cm, with 58.3% of beetles caught no more than 1 m above the ground. The height at which beetles were trapped did not correlate with wind speed at the time of sampling, but the data do indicate that wind speed significantly affected T. castaneum flight initiation, because no beetles (or very few; no more than three) were trapped in the field when the mean wind speed was above 3 m s À1 . This study thus demonstrates that wind speed and direction are both important aspects of flight behaviour of T. castaneum, and therefore of the spatio-temporal dynamics of this species.

Phosphine fumigation and the ecology of the rust red flour beetle, Tribolium castaneum: the effects of phosphine resistance genes and sublethal exposure

“…Selection for resistance to phosphine, as an evolutionary process, is often assumed to be accompanied by changes in the fitness of the organism in the absence of phosphine exposure (Daglish et al, 2015, Pimentel et al, 2007, which are referred to as "fitness costs". Such costs generally result from allocating the energy of a basic biological process to the protective behavioural mechanisms that work against the activity of the insecticide, and this may lead to the impaired performance of that particular biological process (Groeters et al, 1994).…”

“…Some factors involved in T. castaneum taking flight have been examined, for example, temperature (Cox et al, 2007), population density (Perez-Mendoza et al 2011a, b) and aspects of the physiological state of the insects (Fedina andLewis 2007, Perez-Mendoza et al, 2011a, b), Also, the influence of wind direction in the field on the orientation of their flight, which is largely downwind, has been quantified, and it is clear they do not fly when wind speed is too high (> ~ 3 m/s) (Rafter et al, 2015). The role of genes in emigration of the beetles by flight, and the colonization of new resources remains unclear, but the previous study showed that genes associated with resistance to phosphine are associated with a reduced propensity to fly, as well as a decrease in velocity and more turning whilst walking towards a food resource (Malekpour et al, 2016).…”

“…Also, it is suitable for use on a wide range of commodities and in a range of storage situations (Ahmedani et al, 2007;Nayak & Collins, 2008). The long history of phosphine use (since the 1970s) and its often poor application have contributed to selection of phosphine resistance in a range of storage pests in many countries (Lorini et al, 2007, Opit et al, 2012, Daglish et al, 2015. Detailed genetic analysis has identified two major autosomal genes that are linked to the expression of phosphine resistance, but which are incompletely recessive (Jagadeesan et al, 2012).…”

“…Some studies, using the population cage approach, show no evidence of any fitness cost associated with weak resistance (Daglish et al, 2015), and others suggest that resistance alleles do not affect the mobility of insects (Kaur et al, 2013). Clarification of the degree to which phosphine resistance alleles impose fitness costs should enhance the prospects for improving resistance management strategies (Lockwood et al, 1984).…”

Characterisation of variables associated with the flight behaviour of the rust-red flour beetle (Tribolium castaneum)

“…More recently, the field studies of Rafter et al (2015) demonstrated that wind speed and direction are important features in the flight behaviour of T. castaneum. They found that T. castaneum generally flies downwind in the absence of any olfactory stimulus such as the aggregation pheromones of this species.…”