SummaryThe tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a very challenging pest that causes economical losses in tomato production. This devastating pest originated from South America was the first time detected in İzmir province of Turkey in August 2009. The efficacy of the infective juveniles (IJs) of four native entomopathogenic nematode (EPN) species, Steinernema affine (Bovien) (isolate 46), S. carpocapsae (Weiser) (isolate 1133), S. feltiae (Filipjev) (isolate 879) and Heterorhabditis bacteriophora (Poinar) (isolate 1144) was investigated against the larvae of T. absoluta in the field during the tomato production seasons of 2012-2013 in Çanakkale. Individuals of T. absoluta were collected from infested tomato fields in Çanakkale and mass produced on tomato plants in a climate controlled room. EPNs were isolated from different parts of Turkey and mass produced by using Galleria mellonella larvae in the laboratory. The tomato leaf miners were exposed to each nematode species at the rate of 50 IJs/cm 2 on tomato plants in cages. T. absoluta were susceptible to all EPNs tested but the degree of susceptibility of the larvae to EPN infection varied according to the species. The most effective nematode species on T. absoluta larvae was S. feltiae (isolate 879) with 90.7% and 94.3% mortality in 2012 and 2013, respectively, whereas the least effective species was S. affine (isolate 46) with 39.3% and 43.7% mortality in 2012 and 2013, respectively. EPNs can be potential canditates to control tomato leafminer, so the integration possibility of these biological agents into the T. absoluta management programme is discussed.

The definition biological control has been used in different fields of biology, most notably entomology and plant pathology. It has been used to describe the use of live predatory insects, entomopathogenic nematodes EPNs or microbial pathogens to repress populations of various pest insects in entomology. EPNs are among one of the best biocontrol agents to control numerous economically important insect pests, successfully. Many surveys have been conducted all over the world to get EPNs that may have potential in management of economically important insect pests. The term entomopathogenic comes from the Greek word entomon means insect and pathogenic means causing disease and first occurred in the nematology terminology in reference to the bacterial symbionts of Steinernema and Heterorhabditis. EPNs differ from other parasitic or necromenic nematodes as their hosts are killed within a relatively short period of time due to their mutualistic association with bacteria. They have many advantages over chemical pesticides are in operator and end-user safety, absence of withholding periods, minimising the treated area by monitoring insect populations, minimal damage to natural enemies and lack of environmental pollution. Improvements in mass-production and formulation technology of EPNs, the discovery of numerous efficient isolates and the desirability of increasing pesticide usage have resulted in a surge of scientific and commercial interest in these biological control agents.

This study was conducted to determine the efficacy of native entomopathogenic nematodes (EPNs);

In this study conducted in 2020, three concentrations (1, 5 and 10 µM) of 24-epibrassinolide were applied to seedlings of Lycopersicon esculentum Mill. (Solanales: Solanaceae) cv. H2274, which is susceptible to root-knot nematodes, by immersion, spray and irrigation, and its effects against root-knot nematode Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (Tylenchida: Meloidogynidae) were investigated. One-thousand second stage juveniles of M. incognita, collected from cucumber roots in a greenhouse located in Çardak, Çanakkale were inoculated on the roots of the plants per pot. After eight weeks, stem fresh weight, stem dry weight, root diameter and longest root length values, in addition to the stem length and stem diameter measured at the beginning and end of the experiment, were recorded. 24-Epibrassinolide, applied by an immersion method, gave similar or better results than the control even in the presence of nematodes. Distilled water plus nematode application showed the highest gall index whereas 5 µM 24-epibrassinolide plus nematode application gave the lowest gall index. The lowest number of egg mass was also obtained from the same concentration of 24-epibrassinolide applied by immersion. As a result, 24-epibrassinolide showed a beneficial effect in terms of reducing the damage caused by the nematodes in tomato plants, depending on the concentration and application method.

In this study, the efficacy of Turkish isolates of four entomopathogenic nematodes (EPNs) against the last instar larvae of the potato tuber moth, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae) were investigated under laboratory conditions. Potato moths were collected from infested potato fields in Derinkuyu (Nevşehir Province) in June 2019. The four EPN species used were Steinernema affine Bovien, S. carpocapsae Weiser, S. feltiae Filipjev and Heterorhabditis bacteriophora Poinar. Efficacy experiments were carried out in 9 cm diameter plastic Petri dishes with doses of 50 IJs / larva at 25 o C. Mortalities were recorded after 24, 48, 72 and 96 hours. The mortality of P. operculella larvae caused by EPN species increased over time. From 24 h to 96 h, mortality increased from 40% to 66.6%, 83.3% to 100%, 93.3% to 100% and 96.6% to 100%, respectively. On the second day after S. feltiae application, there was 100% mortality of the pest larvae. All EPN species used in the experiment caused time-dependent, high mortality of P. operculella larvae. These promising results for the efficacy of four Turkish EPN isolates against the major potato pest, P. operculella warrant detailed field investigations of their potential use for the control of this pest in commercial potato production.