Biological activity of zeolite-containing tripoli against some agricultural pests
Keywords:
zeolite-containing tripoli, Aulacorthum solani, Leptinotarsa decemlineata, Tetranychus urticae, different ages of pest insect, contact toxicity, phytotoxicityAbstract
The toxicity of zeolite-containing tripoli (siliceous sedimentary rock) of the Khotynetz deposit (Orel Oblast) was studied in the laboratory for the first time for aphid Aulacorthum solani Kalt., Colorado beetle Leptinotarsa decemlineata Say and spider mite Tetranychus urticae Koch. Using different treatment methods of processing test objects with a tripoli (dusting or dipping in suspension and supernatant of leaves, populated by aphids, or putting aphids on treated leaves), no ovicidal properties of the preparation were found. However, the larvicidal and moderate imagocidal action against sucking pests was found. Depending on the method of treatment, the obtained mortality rates of Aulacorthum solani (resistant and susceptible populations) and Tetranychus urticae fluctuated within the range 70.4–83.0 % and 46.6–80.4 %, accordingly. Study of the effect of tripoli on the Leptinotarsa decemlineata, showed the larvicidal activity decreasing with age: the highest rates (60–100 %) were estimated for larvae of younger pest ages, and absence of efficacy was found for larvae of older ages and imagoes.The presence of phytotoxic properties in tripoli was not established. The results suggest that study of toxic effect of this unique natural substance on pests should be continued in field. At the same time, in order to obtain high toxic effect, the tripoli application rate and multiplicity of treatments can be increased by 2–3 times.