Research on the efficacy of three application techniques of entomopathogenic nematodes against the Colorado potato beetle [Leptinotarsa decemlineata (Say), (Coleoptera: Chrysomelidae)] under greenhouse conditions

Abstract

Colorado Potato Beetle [Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae)] (CPB) is one of the most destructive pests of potatoes. CPB is a polyphagous pest that damages every stage of the potato. Although entomopathogenic nematodes (EPNs) in the world have been demonstrated by many laboratories and field/garden studies activity against many harmful groups, very few studies have been conducted on CPB in our country (Türkiye). In the scope of work intended to be used EPNs against CPB. The main objective of the study is to reveal greenhouse-pot applications (soil, green limbs, and cadaver applications) of EPN [Steinernema feltiae (isolate 09-31) and Heterorhabditis bacteriophora (isolate 09-43)], which are present in our laboratories in our stocks. For the first time in Türkiye, greenhouse-pot applications studies have been carried out against this harmful group. There is also a lot of work in the world about the use of aqueous concentrations of EPNs against harmful effects. In recent years, efforts have been made to use EPNs in cadavers instead of aqueous concentrates. This application (cadaver applications) against CPB is the first working. The results revealed that EPNs performed better in soil applications, and the highest mortality rate was obtained from S. feltiae (65.23±4.45 and 77.33±2.59). Other applications (green limbs and cadaver applications) are seen to have a low level of efficacy. In trials, the mortality rate in cadaver applications did not exceed 40%, and the lowest mortality rate in H.bacteriophora was 37,40±8,88%. In the case of green devices, the mortality rate did not exceed 30%, and the highest mortality rate was 29.14±6.09 in H.bacteriophora. According to EPN greenhouse-pot experiments results, soil applications of S. feltiae (isolate 09-31) should be included within the scope of field trials.