Abnormal Development of Hyalomma Marginatum Ticks (Acari: Ixodidae) Induced by Plant Cytotoxic Substances.

Alicja Buczek,Weronika Buczek,Katarzyna Bartosik,Alicja M Buczek,Dorota Kulina

doi:10.3390/toxins11080445

Abstract

The increasing application of toxic plant substances to deter and fight ticks proves the need for investigations focused on the elucidation of their impact on the developmental stages and populations of these arthropods. We examined the course of embryogenesis and egg hatch in Hyalomma marginatum ticks under the effect of cytotoxic plant substances. The investigations demonstrated that the length of embryonic development of egg batches treated with 20 μL of a 0.1875% colchicine solution did not differ significantly from that in the control group. Colchicine caused the high mortality of eggs (16.3%) and embryos (9.7%), disturbances in larval hatch (8.1%), and lower numbers of normal larval hatches (65.6%). In 0.2% of the larvae, colchicine induced anomalies in the idiosoma (67.6%) and gnathosoma (22.5%) as well as composite anomalies (8.5%). The study demonstrates that cytotoxic compounds with an effect similar to that of colchicine can reduce tick populations and cause teratological changes, which were observed in the specimens found during field studies. Since there are no data on the toxic effects of active plant substances on other organisms and the risk of development of tick resistance, a strategy for the use of such compounds in tick control and the management of plant products should be developed.

Highlights

It is advisable that such investigations should be undertaken, since some chemical compounds in the environment that are commonly used for plant protection and control of parasitic arthropods or industrial waste may impede the development of living organisms
The aim of the study was to examine the effect of microtubule inhibitors on the embryonic development and larval hatch in H. marginatum illustrated by the action of colchicine
The anomalies found in tick specimens collected in natural conditions and in those from the experimental investigations suggest that they may have been caused by chemical compounds

Summary

Introduction

The great medical and veterinary importance of these ticks and the forecasts of an increase in their spread range [11,12] have been arousing increasing interest in the various aspects of the harmful effects exerted by ticks on the host and the impact of chemical and environmental factors on tick development and population size. Toxins 2019, 11, 445 development of various stages [5], and the course of embryogenesis and larval hatch [18,19]. Little is known about the effect of chemical factors on ticks in the non-parasitic developmental stages, including the embryonic development and larval hatch. It is advisable that such investigations should be undertaken, since some chemical compounds in the environment that are commonly used for plant protection and control of parasitic arthropods or industrial waste may impede the development of living organisms. The use of plant materials may be an alternative method for reducing tick populations in contrast to the application of commercial acaricides, to which ticks may develop resistance

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