Ipid bark beetle population assessment and threats to weaken pine stands in Central Russia

The data on the ipid bark beetle population growth in pine plantations of Central Russia in 2020 was recorded. The formation of favorable weather conditions for the development of this depredator in some regions was recorded, which greatly influenced the successful development of the insect population in plantations, in particular in the Pskov, Vladimir, Moscow, Bryansk, Lipetsk, and Ryazan regions. In some areas, a medium and low spread of the bark beetle was revealed. The influence of meteorological conditions on the flight activity of the insect and the probability of the mass reproduction foci formation under the 2020 weather conditions were analyzed. The results of the study formed the basis for the forecast preparation of the sanitary and forest health state. It is recommended to use the materials of the article to determine the optimal period for carrying out measures to protect pine plantations from the ipid bark beetle.

The RELATIVE EFFICACY OF DIFFERENT CONCENTRATIONS OF MINT (MENTHA LONGIFOLIA) AGAINST TRIBOLIUM CONFUSUM (COLEOPTERA: TENEBRIONIDAE).

Present study aimed to examine the effect of different concentrations of mint, Mentha longifolia (2.00 %, 1.50 %, 1.00 %, and 0.50 %) on Tribolium confusum in wheat under laboratory conditions. All the concentrations of mint exhibited the potential to cause mortality of T. confusum and their effectiveness against T. confusum increased with time. Although, no significant difference was recorded among various mint materials to elicit mortality of T. confusum after 24 hours of application. However, a rise in mortality was recorded after 48 hours of application with the highest mortality of T. confusum also recorded in 2.00% concentration followed by 1.5 %, 1 %, and 0.5 % concentrations. The mortality of beetles showed further rise afterward and at the end of the week of the mortality experiment, 2.00% mint concentration cause maximum mortality. No mortality of beetles was recorded in the control. Population fluctuation results showed a significant difference in population growth at monthly intervals as a steady growth was observed in the 2%, 1.5% 1%, and 0.5% concentration, but, rapid growth was recorded in the control. At the end of the third month, the highest population of T. confusum was recorded in control (88.00±3.79 beetles), whereas, the beetle population observed in 0.50%, 1.00%, 1.50%, and 2% concentrations were (71.33±1.45 beetles), (63.00±3.46 beetles), (53.67±2.91 beetles) and (30.00±3.61beetles) respectively. The overall weight and grain loss were significantly higher in control, whereas, 2% of mint concentration suffered the lowest loss. Therefore, 2% of mint concentration is recommended to be used to manage the population of T. confusum in wheat.

RELATIVE EFFICACY OF DIFFERENT CONCENTRATIONS OF MINT (MENTHA LONGIFOLIA) AGAINST TRIBOLIUM CONFUSUM (COLEOPTERA: TENEBRIONIDAE)

Present study aimed to examine the effect of different concentrations of mint, Mentha longifolia (2.00 %, 1.50 %, 1.00 %, and 0.50 %) on Tribolium confusum in wheat under laboratory conditions. All the concentrations of mint exhibited the potential to cause mortality of T. confusum and their effectiveness against T. confusum increased with time. Although, no significant difference was recorded among various mint materials to elicit mortality of T. confusum after 24 hours of application. However, a rise in mortality was recorded after 48 hours of application with the highest mortality of T. confusum also recorded in 2.00% concentration followed by 1.5 %, 1 %, and 0.5 % concentrations. The mortality of beetles showed further rise afterward and at the end of the week of the mortality experiment, 2.00% mint concentration cause maximum mortality. No mortality of beetles was recorded in the control. Population fluctuation results showed a significant difference in population growth at monthly intervals as a steady growth was observed in the 2%, 1.5% 1%, and 0.5% concentration, but, rapid growth was recorded in the control. At the end of the third month, the highest population of T. confusum was recorded in control (88.00±3.79 beetles), whereas, the beetle population observed in 0.50%, 1.00%, 1.50%, and 2% concentrations were (71.33±1.45 beetles), (63.00±3.46 beetles), (53.67±2.91 beetles) and (30.00±3.61beetles) respectively. The overall weight and grain loss were significantly higher in control, whereas, 2% of mint concentration suffered the lowest loss. Therefore, 2% of mint concentration is recommended to be used to manage the population of T. confusum in wheat.

Lightning Damage Facilitates Beetle Colonization of Tropical Trees

Lightning is a common agent of disturbance in many forest ecosystems. Lightning-damaged trees are a potentially important resource for beetles, but most evidence for this association is limited to temperate pine forests. Here, we evaluated the relationship between lightning damage and beetle colonization of tropical trees. We recorded the number of beetle holes on the trunks of trees from 10 strike sites (n = 173 lightning-damaged trees) and 10 matching control sites (n = 137 control trees) in Panama. The trunks of lightning-struck trees had 370% more beetle holes than control trees. The abundance of beetle holes increased with increasing total crown dieback among both control and lightning-damaged trees, and with larger tree diameter among lightning-struck trees. Beetle holes also were more abundant in trunk sections of lightning-damaged trees located directly below a damaged section of the crown. The results of this study suggest that lightning damage facilitates beetle colonization in tropical forest trees and provide a basis for investigations of the effects of lightning-caused disturbance on beetle population dynamics and assemblage structure.

Ecological and Faunistic Structure of Ground Beetle Population (Coleoptera, Carabidae) of Forest Belts in the Tambov Region (Russia)

The article presents the analysis of ground beetle population in forest belts of different types. The ecological structure of ground beetle complexes of forest belts is determined by soil and moisture conditions. Differences in the diversity of ground beetle populations depending on a complex of soil and plant conditions and the nature of anthropogenic impact are found. The increase in steppe formation and xerophytism conditions in forest belts leads to a decrease in species diversity of the genera Carabus, Poecilus, Pterostichus, Calathus, Amara and Harpalus.

Bark Beetle Population Dynamics in the Anthropocene: Challenges and Solutions

Tree-killing bark beetles are the most economically important insects in conifer forests worldwide. Yet  despite >200 years of research, the drivers of population eruptions or crashes are still not fully understood, precluding reliable predictions of the effects of global change on beetle population dynamics and impacts on ecosystems and humans.  We critically analyze potential biotic and abiotic drivers of population dynamics of the European spruce bark beetle (Ips typographus) and present a novel ecological framework that integrates the multiple drivers governing this bark beetle system. We call for large-scale collaborative research efforts to improve our understanding of the population dynamics of this important pest; an approach that might serve as a blueprint for other eruptive forest insects.

Fungal Frequency and Mite Load Trends Interact with a Declining Mountain Pine Beetle Population

The mite and fungal biota associated with the mountain pine beetle (MPB) (Dendroctonus ponderosae Hopk.) may not be stable throughout an irruptive event. In congeneric beetles, variations in the frequency of their associated organisms affect population trends and similar effects may occur in MPB. We studied fungi and mite trends in a declining irruptive MPB population as it attacked three different pine hosts in the Colorado Front Range. During the study, we found two new associates including one biologically relevant mite and one beneficial blue-stain fungus. Fungi hyperphoretic on mites were also documented. This included beneficial and potentially detrimental species to the MPB. The frequency of several organisms varied between some years or pine hosts but not within male or female beetles. A large increase of Trichouropoda sp. and T. ips mites trended inversely with the declining beetle population, while a decrease in the beneficial blue-stain fungi trended similarly to the declining beetle population. We discuss the interactions and potential effects of phoretic biota in relation to (1) the MPB associates’ population trends, (2) the MPB incursions into cooler areas, and (3) the redundancy of blue-stain fungi carried by the MPB holobiont. These findings increase our knowledge of the mechanisms that influence MPB populations.

PENDUGAAN PERKEMBANGAN POPULASI ORYCTES RHINOCEROS L. (COLEOPTERA: SCARABAEIDAE) DI PERKEBUNAN KELAPA SAWIT (ELAEIS GUINEENSIS JACQ.)

Approximately 1.000 species of insects are associated with coconut worldwide. Over 40 species of coleopteran pests have been recorded – most are under effective natural control but some require interventions. In view of the increasing and devastating damage by coconut beetle (Oryctes rhinoceros) to coconut palms in the many countries, many efforts are made to find appropriate method to forecast its population. The basic procedures of these monitoring programs are outlined together with forecasting method. A study to forecast coconut beetle population has been carried out in palm oil estate, near Palembang. Study was aimed to estimate population after several observations of beetle population. Another aim was to assess the influences of environmental factors, i.e. temperature, relative humidity and rainfall intensity, which could affect to the beetle population fluctuation. Results showed beetle population could 65.12 percent in average due to unsuitable environmental factors. At first observation temperature was recorded 26 – 30 0C and 1185 larvae werefound. At last observation larvae population decreased to 392 larvae at temperature 29 – 33 0C. It was found that relative humidity and rainfall intensity also played important role in decreasing beetle population.Keywords: coconut beetle, time series analysis, population estimation, environmentalfactors