The effect of sublethal concentrations of deltamethrin and alphacypermethrin on the fecundity and development of Ixodes ricinus (Acari: Ixodidae) eggs and larvae

Alicja M. Buczek,Alicja Buczek,Weronika Buczek,Paweł Kuczyński,Katarzyna Bartosik

doi:10.1007/s10493-019-00381-5

Alicja M. Buczek, Alicja Buczek + Show 3 more

Open Access

https://doi.org/10.1007/s10493-019-00381-5

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Abstract

Two pyrethroids, deltamethrin (D) and alphacypermethrin (AC), have been used as commercial products for tick control worldwide. However, the effects of sublethal doses of these compounds on various tick species and their developmental stages have not been fully explored yet, although such knowledge could contribute to a more effective application of both pyrethroids and simultaneous reduction of their costs and undesirable side effects, including the harmful impact on other organisms and environmental contamination. This study investigates the effect of sublethal concentrations of D and AC applied to engorged females on the fecundity, development of eggs and larvae, and the number of offspring in the Ixodes ricinus (L.) tick, which is the most important vector of tick-borne diseases of humans in Europe. After detachment from rabbit’s skin, fully engorged I. ricinus females were treated with 20 μl of pyrethroid solutions at five concentrations from 0.01562 to 0.25% and kept at 28 °C and 75% relative humidity. The impact of the pyrethroids on maturation and development of eggs as well as development of larvae was assessed based on parameters of the preoviposition and oviposition periods and the course of embryogenesis and egg hatch. The investigations have shown that both tested acaricides reduce the reproductive rate in I. ricinus females by inhibition of egg development and disturb embryonic development and larval hatch. Females did not lay eggs at concentrations higher than 0.0625% AC and 0.125% D. The lower concentrations of both pyrethroids disturbed or inhibited the embryogenesis and egg hatch in I. ricinus.

Highlights

Given the direct effects of their parasitism and ability to transmit numerous pathogens, ticks represent arthropods with the greatest medical and epidemiological importance
Eggs were laid by I. ricinus females treated with 0.01562–0.125% deltamethrin and 0.01562–0.0625% alphacypermethrin solutions (Figs. 1, 2)
At the highest concentrations of deltamethrin and alphacypermethrin that did not deprive the females of the oviposition ability, only 42.9 and 14.3% of females, respectively, laid eggs (100% in the control group)

Summary

Introduction

Given the direct effects of their parasitism and ability to transmit numerous pathogens, ticks represent arthropods with the greatest medical and epidemiological importance. The use of an appropriate acaricide dose is important for the control of sympatric tick species, e.g. Ixodes ricinus (L.) and Dermacentor reticulatus (Fabricius) (Hubálek et al 2003; Széll et al 2006; Buczek and Bartosik 2011; Švehlová et al 2014; Hofmeester et al 2016; Stańczak et al 2016; Olivieri et al 2017; Radzijevskaja et al 2018) and for minimisation of their harmful effects on other organisms present in the same ecosystem (Soderlund et al 2002; Bradberry et al 2005; Anadón et al 2009; Antwi and Reddy 2015)

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