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Background: The pine processionary moth Thaumetopoea wilkinsoni Tams, 1926 (Lepidoptera: Notodontidae), causes severe skin reactions to animals and humans. The insect also destroys pine ecosystems by feeding on pine leaves at its larval stage. Instead of chemical control, eco-friendly biological control methods should be preferred to combat this species. Results: The purpose of this study was to evaluate the efficacy of Beauveria bassiana isolate (GOPT-331) and Metarhizium brunneum isolates (ORP-13 and ORP-18) against the second and fourth larval instars of T. wilkinsoni under laboratory conditions. T. wilkinsoni eggs were collected from pine trees at Ondokuz Mayıs University in Samsun, Turkey, in 2021, and the second and fourth larval instars were used for the experiment. Two milliliters of a spray of the three fungal isolates was applied to the larvae for each concentration (1 × 105–1 × 108 conidia ml−1). The mortality rates of GOPT-331, ORP-13, and ORP-18 were changed between 91.1 and 100% for the second-instar larvae and between 86.6 and 97.7% for the fourth-instar larvae at 1 × 108 conidia ml−1. The ORP-13 isolate showed the lowest LC50 values. Conclusion: In conclusion, it is suggested that all the three isolates were virulent to T. wilkinsoni and can be used for biological control of this species. The promising results from the study were obtained from trials conducted under controlled laboratory conditions, and it will be critical to explore the potential of these promising entomopathogenic fungi in field conditions. [ABSTRACT FROM AUTHOR]

Background: The European tent caterpillar Malacosoma neustria Linnaeus, 1758 (Lepidoptera: Lasiocampidae), a worldwide pest, feeds on a wide variety of woody and shrub-like plants in its larval stage and causes extensive economic losses. In the fight against this species, environmentally friendly biological control methods should be preferred instead of chemical control. The aim of this study was to evaluate the efficacy of entomopathogenic fungi (EPF) Metarhizium brunneum (ORP-13) and Beauveria bassiana (GOPT-301-2) isolates against the fourth instar larvae of M. neustria under laboratory conditions. Results: M. neustria eggs were collected from the Kızılırmak Delta of Samsun Province, Turkey, and the fourth instar larvae were used in the experiment. Larvae in the control group were fed on sterilized leaves of Eleagnus rhamnoides. Both fungal isolates were applied onto the larvae at 2 ml for each concentration (1 × 106, 1 × 107, and 1 × 108 conidia ml−1). Ten larvae were placed in each group, and sterilized E. rhamnoides leaves were offered to the larvae. The study was carried out in 9 replicates for each group, and the larvae were observed for 14 days. As a result of the study, it was found that the survival rates of the larvae decreased as concentration increased. It was determined that both isolates caused 100% mortality at 1 × 108 conidia ml−1 concentration. The lowest LC50 value was found in larvae exposed to the ORP-13 isolate. Conclusion: It has been suggested that M. brunneum and B. bassiana isolates were virulent for M. neustria larvae and can be used for biological control of this species. [ABSTRACT FROM AUTHOR]

Background: The pine processionary moth, Thaumetopoea wilkinsoni Tams, 1926 (Lepidoptera/Notodontidae) is one of the most harmful insects that destroys pine ecosystems by feeding on pine leaves at its larval stage. Because of its urticating setae, the insect also causes severe skin reactions to animals and humans. Instead of chemical control, eco-friendly biological control methods are preferred to combat this species. Results: The purpose of this study was to evaluate the efficacy of five different Beauveria bassiana Vuill, 1912 (Hypocreales/Cordycipitaceae) isolates (TR-SM-10, TR-SM-11, TR-SM-2, TR-SK-1 and TR-D-1) and one B. pseudobassiana Rehner & Humber (Hypocreales/Cordycipitaceae) isolate (TR-SM-1) against the fourth instar larvae of T. wilkinsoni under laboratory conditions. T. wilkinsoni larvae were collected from the Ondokuz Mayıs University Kurupelit Campus in Samsun, Turkey, in 2021, and the fourth instar larvae were used in the experiment. Two ml of spray of the six fungal isolates were applied to every ten larvae at each concentration (1 × 107 and 1 × 108 conidia ml−1). The experiment was carried out in five replicates per group, and the larvae were observed for 10 days. As a result, all isolates of B. bassiana caused 100% mortality at 1 × 108 conidia ml−1 concentration. B. pseudobassiana isolate also caused 100% mortality at both concentrations. At 1 × 107 conidia ml−1 concentration, the larvae treated with the B. pseudobassiana isolate (TR-SM-1) had the lowest LT50 (2.89 days) and LT90 values (4.79 days), while the larvae treated with TR-SM-10 isolate had the highest LT50 (5.65 days) and LT90 values (9.39 days). At 1 × 108 conidia ml−1 concentration, the larvae treated with TR-SK-1 isolate had the lowest LT50 (2.89 days) and LT90 values (4.79 days), while those treated with TR-SM-10 isolate had the highest LT50 (3.95 days) and LT90 values (8.15 days). Conclusion: It has been recommended that the five different isolates of B. bassiana and B. pseudobassiana isolates were virulent to T. wilkinsoni larvae and can be used for biological control of T. wilkinsoni. [ABSTRACT FROM AUTHOR]