Entomophaga maimaiga – New entomopathogenic fungus in the Republic of Serbia

The higher mortality rate of the older gypsy moth larval instars was reported in the forest complexes of Belgrade and Valjevo region, in the culmination phase of the new outbreak of the gypsy moth in Serbia. By field and laboratory studies of the causes of their death, the presence of conidia and resting spores of the entomopathogenic fungus Entomophaga maimaiga was reported in the dead caterpillars. This has been the first report of occurrence of this species in Serbia, that is, Serbia is the third European country in which this fungus has been reported. It showed to be a powerful reducer of the population size of the gypsy moth, and in both regions it caused the collapse of the outbreak in 2011.Keywords: Entomophaga maimaiga, Lymantria dispar, gypsy moth, biological control, epizootic

Pine Pitch Canker and Insects: Regional Risks, Environmental Regulation, and Practical Management Options

Producción CientíficaPine pitch canker (PPC), caused by the pathogenic fungus Fusarium circinatum (Nirenberg and O’ Donnell), is a serious threat to pine forests globally. The recent introduction of the pathogen to Southern Europe and its spread in Mediterranean region is alarming considering the immense ecological and economic importance of pines in the region. Pines in forests and nurseries can be infected, resulting in severe growth losses and mortality. The pathogen is known to spread in plants for planting and in seeds, and results from recent studies have indicated that F. circinatum may also spread through phoretic associations with certain insects. With this review, we aim to expand the current understanding of the risk of insect-mediated spread of PPC in different parts of Europe. Through the joint action of a multinational researcher team, we collate the existing information about the insect species spectrum in different biogeographic conditions and scrutinize the potential of these insects to transmit F. circinatum spores in forests and nurseries. We also discuss the impact of environmental factors and forest management in this context. We present evidence for the existence of a high diversity of insects with potential to weaken pines and disseminate PPC in Europe, including several common beetle species. In many parts of Europe, temperatures are projected to rise, which may promote the activity of several insect species, supporting multivoltinism and thus, further amplifying the risk of insect-mediated dissemination of PPC. Integrated pest management (IPM) solutions that comply with forest management practices need to be developed to reduce this risk. We recommend careful monitoring of insect populations as the basis for successful IPM. Improved understanding of environmental control of the interaction between insects, the pathogen, and host trees is needed in order to support development of bio-rational strategies to safeguard European pine trees and forests against F. circinatum in future.European Cooperation in Science and Technology (COST Action FP1406 PINESTRENGTH)Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-69370-R)Portuguese Foundation for Science and Technology (contract IF/00471/2013/CP1203/CT0001)Russian Foundation for Basic Research (grant 17-04-01486)Saint Petersburg State Polytechnical University (project 2019-0420

Effect of host plant on gypsy moth diet and biological efficacy of Btk preparations

The effect of two host plants, Turkey oak (Quercus cerris L) and black poplar (Populus nigra L) on gypsy moth (Lymantria dispar L) development was researched. The effect of host plant was determined based on the parameters which characterize the diet, growth and efficacy of conversion of ingested food of the third instar caterpillars. Along with the effect on development, the effect of host plant on the efficacy of biological preparation based on the bacterium Bacillus thuringiensis var. kurstaki in gypsy moth caterpillar suppression was also researched. The differences in parameters characterizing the diet, growth, and efficacy of ingested food between experimental groups of caterpillars grown on poplar and Turkey oak leaves are explained by the differences in the chemical composition of the leaves of these tree species. The efficacy of Btk preparation is conditioned by the mechanism and content of different groups of defense substances in the leaves of the applied tree species

Gypsy moth outbreaks in forest complexes of the Belgrade region in the period 1996-2011

The paper presents the results of investigation of a gypsy moth population density level in the forest area of the Belgrade region, in the period 1996-2011. The characteristics of three over-proliferations were analyzed, two of which had a character of an outbreak (2003-2005. and 2009-2011.)

Gypsy moth outbreaks in forest complexes of the Belgrade region in the period 1996-2011

The paper presents the results of investigation of a gypsy moth population density level in the forest area of the Belgrade region, in the period 1996-2011. The characteristics of three over-proliferations were analyzed, two of which had a character of an outbreak (2003-2005. and 2009-2011.)

Biological efficacy of the ecotoxically favourable insecticides and their mixture in the control of gypsy moth

Forest certification is one of the ways of adapting forestry to modern ideas of "sustainable management", by meeting demands of Forest Stewardship Council (FSC) standard. By joining this process, Serbia obligated to follow FSC pesticides policy. Almost all insecticides registered in Serbia and applied for control of the most dangerous outbreaking defoliating species in forests, are on the list of prohibited ones. In certificated forest ecosystems in Serbia, microbiological insecticides (active ingredient: Spores and protein-crystals of the bacterium Bacillus thuringiensis ssp. kurstaki) are most widely used pesticides for the control of one of the most important economically harmful defoliators - gypsy moths, in progragation phase, when the number of pests is relatively small. When the number is greater, it is assumed that the so-called "soft" ecotoxicologically favourable preparations Avaunt (R), Alverde (R), Coragen (R), registered for application in agriculture, but not in forestry can be used for inhibition of multiplication. Studies of biological efficacy of the aforementioned preparations and their mixtures with biological insecticide Foray (R) showed that they have preconditions for application in forest ecosystems. The high biologic efficacy, mechanism of action, resistance to water rinsing, high selectivity, and small quantities of application, anticipated a bright future for them. Since results of researches of biological efficacy of insecticides in laboratory and field conditions are statistically different, studies done in natural conditions should be favored

Biological efficacy of the ecotoxically favourable insecticides and their mixture in the control of gypsy moth

Forest certification is one of the ways of adapting forestry to modern ideas of "sustainable management", by meeting demands of Forest Stewardship Council (FSC) standard. By joining this process, Serbia obligated to follow FSC pesticides policy. Almost all insecticides registered in Serbia and applied for control of the most dangerous outbreaking defoliating species in forests, are on the list of prohibited ones. In certificated forest ecosystems in Serbia, microbiological insecticides (active ingredient: Spores and protein-crystals of the bacterium Bacillus thuringiensis ssp. kurstaki) are most widely used pesticides for the control of one of the most important economically harmful defoliators - gypsy moths, in progragation phase, when the number of pests is relatively small. When the number is greater, it is assumed that the so-called "soft" ecotoxicologically favourable preparations Avaunt (R), Alverde (R), Coragen (R), registered for application in agriculture, but not in forestry can be used for inhibition of multiplication. Studies of biological efficacy of the aforementioned preparations and their mixtures with biological insecticide Foray (R) showed that they have preconditions for application in forest ecosystems. The high biologic efficacy, mechanism of action, resistance to water rinsing, high selectivity, and small quantities of application, anticipated a bright future for them. Since results of researches of biological efficacy of insecticides in laboratory and field conditions are statistically different, studies done in natural conditions should be favored

Gypsy Moth in Central Serbia Over the Previous Fifty Years

The gypsy moth, Lymantria dispar L., after an unusually long latency period (30 years), has demonstrated all the characteristics of an outbreak in the forests of central Serbia three times since 1994. During the first outbreak (1994-1998), 24.8% of the broadleaf forests were endangered by the gypsy moth, during the second one (2002-2005), 18.8% of the broadleaf forests were endangered, and during the third one, which still ongoing, 2% of the broadleaf forests were endangeted. The average number of eggs in an egg mass ranged from 191.7 to 654.1. The percentage of vital and parasitized eggs in the total number of eggs ranged on average from 79.2 to 98.7 and from 0.5 to 20.0 respectively. During the observed period, in the gypsy moth populations, the activity of 56 natural enemies of this insect - 19 predators, 28 parasites, 7 parasites or saprophages and 2 pathogens - was reported. A higher mortality rate of the older gypsy moth larval instars was reported in the forest complexes of Belgrade and Valjevo region, in the culmination phase of the new outbreak. By field and laboratory studies of the causes of their death, the presence of conidia and resting spores of the entomopathogenic fungus Entomophaga maimaiga was reported in dead caterpillars. During every year of an outbreak, the gypsy moth was suppressed in the egg stage, and in the larval stage during the culmination phases

Influence of Heavy Metals on Seed Germination and Growth of Picea abies L. Karst

This paper presents the influence of heavy metals on the process of seed germination and the survival rate of Picea abies L. Karst spruce seedlings. The experiments were conducted in laboratory conditions by adding solutions of compounds of zinc, copper, lead, and cadmium at three different concentrations (3 ppm, 33 ppm, and 100 ppm) to the media. The observed heavy metals affected the germination of the spruce seeds in different ways. Although the seed was tolerant to the presence of all metals, the percentage of germinated seeds depended on the type of metal and its concentration. The lower concentrations of the heavy metals (3 and 33 ppm) partially inhibited seed germination, and the highest concentrations (100 ppm) of all metals caused total inhibition. The P. abies L. Karst seedlings were very tolerant to the presence of all metals. The highest concentrations of cadmium and copper had a significant influence on the decrease of the number of the seedlings that survived, as well as on the decrease of biomass in comparison with lead. Zinc had the least adverse effect on the growth and survival of seedlings

Same physiological characteristics of the three ectomycorrhizal fungi from Suillus genus

The aim of this paper is to present the results of the study of the same physiological characteristics of the three species of ectomycorrhizal fungi from Suillus genus (S. luteus (L. ex Fr.) S.F.Gray, S. bovinus (Fr.) O.Kuntze and S. granulatus (L. ex Fr.) O. Kuntze. S. granulatus is an excellent edible mushroom. S. luteus and S. bovinus are both edible but they are both of an inferior quality. Three different media (Melin-Norkans, MMN, Potate Dextrose Agar, PDA and Malt Extract Agar, MEA) were used for the study of the influence of the type of medium on the rate of growth and morphological shape of mycelium of fungi. The interaction between mycorrhizal fungi was examined in the laboratory conditions by the "mixed cultures". The assessment of the interaction between certain mycorrhizal species and the inhibitions of growth was determined as the ratio between their growth in the mixed culture and the controlling isolate growth on the nutritive medi