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Baculoviruses, especially prevalent in Lepidoptera, have attracted the most attention as biological insect control agents. Infection with baculoviruses is usually fatal and therefore can affect the host population density, especially if virus transmission increases with host density. Lepidoptera larvae show a strong dose-dependent response to pathogens such as baculoviruses, so their response to various pathogen exposures was studied in this work. Models of virus exposure to insect hosts are usually judged by whether or not they generate cyclical population dynamics of multiple host generations. However, the existing theoretical models based on systems of differential equations are of little use for practical application due to the large number of variables and free parameters. In this regard, the possibility of using a mathematical model for describing the epizootic Malacosoma neustria L. and Lymantria dispar L. under the influence of the nuclear polyhedrosis virus is considered. To assess the sensitivity of insects to the effects of baculoviruses, laboratory experiments were carried out on the mortality of caterpillars under various infectious loads. In this paper, we consider the possibility of constructing a model for the lifetime of insects after exposure to baculoviruses as an analog of a second-order phase transition in physical systems and give estimates of the model parameters for two insect species at different titers of baculoviruses and at different ages of caterpillars. The dependence of the parameters of the proposed model on the nuclear polyhedrosis virus strains is shown. The importance of the applied parameters for the organization of forest protection measures is substantiated. [ABSTRACT FROM AUTHOR]

The lackey moth, Malacosoma neustria (Linnaeus, 1758), a worldwide pest, causes extensive economic losses on particularly hazelnut, Prunus, Quercus, Populus, and Salix trees. In this study, a local nucleopolyhedrovirus (NPV) was isolated from the larvae of M. neustria in the northeast of Turkey. It was named ManeNPV-T2. Electron microscopic observations showed that the polyhedra of the new isolate contain several virions with multiple nucleocapsids packaged within a single viral envelope. Restriction endonuclease analysis of ManeNPV-T2 DNA indicated that it has a different restriction profile compared to the previous Turkish and Latvian isolates. The phylogenetic analysis of the amplified polh sequence of ManeNPV-T2 showed its relation to the other NPVs from Malacosoma species. Mortality values for third instar M. neustria larvae ranged from 48% to 100% according to the concentration of polyhedral occlusion bodies. Based on screening tests, the LD50 value of the new isolate was calculated as 1.34 x 104 occlusion bodies per larvae. Consequently, ManeNPV appears to be a promising microbial control agent for biocontrol 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]