Behavioural responses to potential dispersal cues in two economically important species of cereal-feeding eriophyid mites

Agnieszka Kiedrowicz,Anna Skoracka,Lechosław Kuczyński,Mariusz Lewandowski,Heather Proctor

doi:10.1038/s41598-017-04372-7

Agnieszka Kiedrowicz, Anna Skoracka + Show 3 more

Open Access

https://doi.org/10.1038/s41598-017-04372-7

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Abstract

Passively dispersing organisms should optimise the time and direction of dispersal by employing behaviours that increase their probability of being successfully transported by dispersal agents. We rigorously tested whether two agriculturally important passively-dispersing eriophyoid species, wheat curl mite (WCM) and cereal rust mite (CRM), display behaviours indicating their readiness to depart from current host plants in the presence of potential dispersal cues: wind, an insect vector and presence of a fresh plant. Contrary to our expectations, we found that both species decreased their general activity in the presence of wind. When exposed to wind, WCM (but not CRM) significantly increased behaviour that has previously been considered to facilitate dispersal (in this case, standing vertically). Our study provides the first sound test of the function of what have been interpreted as dispersal-related behaviours of eriophyid mites. The low proportion of WCM exhibiting dispersal behaviour suggests there may be predisposed dispersers and residents in the population. Moreover, we found that WCM was generally more active than CRM, which is likely a contributing factor to its high invasive potential.

Highlights

Dispersal is a fundamental biological process that has consequences for population dynamics, population genetic structure, and geographical distribution of species[1,2,3,4,5]
Higher probabilities of feeding in cereal rust mite (CRM) (83.3%, 95% CI = 76.1–89.2%) and wheat curl mite (WCM) (37.2%, 95% CI = 29.4–45.5%) but lower probabilities of walking in CRM (14.1%, 95% CI = 9.1–20.3%) and WCM (55.0%, 95% CI = 47.3–62.5%) were observed in the presence of wind when compared to other treatments
The probability of WCM standing erect in the presence of wind was low (4.0%, 95% CI = 3.1–5.2%), but was significantly higher when compared to the proportion standing erect in other treatments (Fig. 2, see Supplementary Table S2)

Summary

Introduction

Dispersal is a fundamental biological process that has consequences for population dynamics, population genetic structure, and geographical distribution of species[1,2,3,4,5]. Existence of directed dispersal in passively dispersing organisms has recently been proposed for plants[9] As another example, ‘pre-ballooning’ behaviours in spiders increase the probability of their being picked up by the wind, and include raising the abdomen, producing silk and jumping[10]. Behaviours that have been interpreted as facilitating dispersal in these mites include standing up on their anal lobes, arching their bodies and moving their legs rapidly, raising the hind part of the body while standing on their forelegs (all of which have been termed ‘take-off postures’), as well as forming groups of attached individuals (chains)[23,24,25,26] (Fig. 1c and d) These ‘take-off postures’ have been observed in eriophyoid mites when on an unsuitable host plant species and have been interpreted as indicating host-rejection and intent to disperse[27].

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