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The European tent caterpillar, Malacosoma neustria Linnaeus (Lepidoptera: Lasiocampidae), is a worldwide known pest that causes significant losses by feeding on many woody and shrub-like plants during the larval period. In this study, a Beauveria bassiana strain isolated from M. neustria larvae and characterized according to its morphological and molecular properties. Its insecticidal activity was tested on M. neustria larvae. Sequence results of partial ITS (ITS1-5.8S-ITS2) gene region identified the isolate (named as Mn1) as a B. bassiana strain. Phylogenetic analysis showed that Mn1 strain displays close similarity to B. bassiana ARSEF 1848 and ARSEF 751 isolates. According to the concentration-responce tests performed using 1 × 10 3  - 1 × 10 9 conidia per mL concentrations, LC 50 value of the new strain was calculated as 1 × 10 5 conidia per mL within 7 days against the larvae of M. neustria in the laboratory conditions. B. bassiana Mn1 strain, characterized in this study, is recorded as the first entomopathogenic fungus isolated from M. neustria, and the results showed that new strain of B. bassiana has a serious potential to be utilized as a good biocontrol agent against M. neustria., (© 2023. Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.)

Plants produce secondary metabolites for defense against herbivorous insects. In this study, the effects of different concentrations of quinine, nicotine, and tannic acid on food consumption and pupal parameters of the larva of a severe pest, Malacosoma neustria L. (Lepidoptera: Lasiocampidae), were investigated in 2007. Artificial diets containing 0.125%, 0.25%, and 0.5% concentrations of quinine or nicotine were prepared. In addition, diets containing 1.25%, 2.5%, and 5% tannin and a control diet without secondary metabolite were prepared. The feeding experiments revealed that the food consumption and pupal parameters of male and female larvae were different, and all parameters of female individuals were higher than those of male larvae. It has been determined that tannins cause more reductions in food consumption and pupal parameters than alkaloids in male and female individuals. We observed an increase in male larvae's pupal mass with increased concentration of nicotine to 0.5%. Nicotine did not cause a decrease in pupal parameters of larvae compared to quinine. In addition, all parameters of female individuals decreased with the addition of secondary metabolite. Although food consumption in alkaloid-containing diets was less than in the control group, there was a positive relationship between food consumption and pupal lipid and protein content. However, quinine had a more significant effect on triggering protein storage than nicotine. In diets containing tannins, more lipids were stored. A decrease was observed in the food consumption and pupal parameters of all individuals in the tannin-containing diets compared to the other diets. [ABSTRACT FROM AUTHOR]

Malacosoma neustria is a pest for many plant species. Instead of chemical control, eco-friendly biological control methods should be used to combat this species. The purpose of this study was to evaluate the efficacy of isolates of two entomopathogenic fungi, Metarhizium brunneum (ORP-18) and Beauveria bassiana (GOPT-331), used as both oral and spray application on the 4th instar larvae of M. neustria under laboratory conditions. In addition, it was determined how the infection affected the amounts of malondialdehyde, NADPH oxidase and glutathione of the larvae. Both fungal isolates were placed in separate containers at 2 ml for each concentration (1x105, 1x106, 1x107 and 1x108 conidia/ml) in the oral group and contaminated all over the Elaeagnus rhamnoides leaves and then the contaminated leaves were offered to ten larvae in each container. For the spray group, 2 ml of spray was applied to every ten larvae placed in the containers for each concentration. As a result, it was found that both isolates killed the larvae. The ORP-18 isolate caused higher mortality rates than the GOPT-331 isolate. The spray application was more lethal than the oral application. With increasing conidial concentrations of both isolates, the amounts of malondialdehyde and NADPH oxidases increased, while the glutathione amounts decreased, which indicated the adverse effects of reactive oxygen species (ROS) on larval survival. On the basis of the results, it is recommended to use the ORP-18 isolate for the control of larvae of M. neustria. [ABSTRACT FROM AUTHOR]

The larval parasitoids and larval diseases of Malacosoma neustria (L.) (Lepidoptera: Lasiocampidae) in various host plants were investigated in Erzurum Province, Turkey, during 2004 and 2005. The larval parasitoids were reared in a laboratory, and a total of 29 parasitoid species were established in association with the larvae of M. neustria in the families Tachinidae (Diptera), Braconidae, Ichneumonidae, and Chalcidoidea (Hymenoptera). Of the 6 tachinid parasitoids, Pales pavida (Meigen) was the most prevalent species and accounted for 25% of the tachinid records. Among the tachinids, there were 2 new records for the Turkish fauna: Exorista amoena Mesnil and Palesisa nudioculata Villeneuve. Exorista amoena was reared from M. neustria for the first time. The braconid species Meteorus lionotus Thomson and Cotesia vanessa (Reinhard) were also reared from M. neustria for the first time. Among the 10 chalcidoid species reared, Monodontomerus aereus Walker and Brachymeria secundaria (Rusc.) were the most prevalent species. Five chalcidoid species, Asaphes suspensus (Nees), A. vulgaris Walker (Pteromalidae), Brachymeria secundaria (Ruschka) (Chalcididae), Eupelmus urozonus Dalman (Eupelmidae), and Eurytoma verticillata (F.) (Eurytomidae), were reared from M. neustria for the first time. Of the 10 species of ichneumonids reared, Exeristes roborator F. was the most abundant and accounted for 35% of the total ichneumonid records. The total parasitism rate of all parasitoids was 33.7%. As disease agents of M. neustria, the nuclear polyhedrosis virus and 4 pathogenic bacteria, Brevibacillus agri, Alcaligenes xylosoxydans xylosoxydans (Achromobacter xylosoxidans), Bacillus lentimorbus, and Serratia fonticola, were diagnosed. All of the bacteria from M. neustria were recorded for the first time. The percentage of diseased larvae was low, about 3%. [ABSTRACT FROM AUTHOR]