Marcin Studnicki

The effects of age and past and present behavioral specialization on behavior of workers of the red wood ant Formica polyctena Först. during nestmate reunion tests

Social insect workers usually participate first in intranidal tasks and then switch to extranidal ones. However, foragers may switch again to intranidal brood care. This process is called the behavioral reversion. We applied dyadic nestmate reunion tests to explore behavioral differences between five groups of workers of the red wood ant Formica polyctena: callows (newly eclosed workers), nurses, reverted nurses (foragers that switched back to intranidal brood care in response to exposure to brood in absence of nurses), and two groups of foragers. Inter-group differences between the tested ants were related both to age and past and present behavioral specialization. Callows were the least active and their behavior was characterized by the lowest tempo. Nurses usually behaved in a way intermediate in respect to behavior of callows and the ants that had already passed the transition to extranidal tasks. The behavior of reverted nurses showed both similarities and differences with respect to behavior of foragers. Some traits of behavior of reverted nurses were similar as in the case of nurses, or intermediate in respect to both nurses and foragers. Behavioral reversion of workers of F. polyctena has thus other behavioral correlates besides the reappearance of intranidal brood care.

Validation of Individual-Based Markov-Like Stochastic Process Model of Insect Behavior and a “Virtual Farm” Concept for Enhancement of Site-Specific IPM

The paper reports application of a Markov-like stochastic process agent-based model and a “virtual farm” concept for enhancement of site-specific Integrated Pest Management. Conceptually, the model represents a “bottom-up ethological” approach and emulates behavior of the “primary IPM actors”—large cohorts of individual insects—within seasonally changing mosaics of spatiotemporally complex faming landscape, under the challenge of the local IPM actions. Algorithms of the proprietary PESTonFARM model were adjusted to reflect behavior and ecology of R. cerasi. Model parametrization was based on compiled published information about R. cerasi and the results of auxiliary on-farm experiments. The experiments were conducted on sweet cherry farms located in Austria, Germany, and Belgium. For each farm, a customized model-module was prepared, reflecting its spatiotemporal features. Historical data about pest monitoring, IPM treatments and fruit infestation were used to specify the model assumptions and calibrate it further. Finally, for each of the farms, virtual IPM experiments were simulated and the model-generated results were compared with the results of the real experiments conducted on the same farms. Implications of the findings for broader applicability of the model and the “virtual farm” approach—were discussed.

Correlation of Alzheimer’s Disease Death Rates with Historical Per Capita Personal Income in the USA

Alzheimer’s disease (AD) is a progressive degenerating disease of complex etiology. A variety of risk factors contribute to the chance of developing AD. Lifestyle factors, such as physical, mental and social activity, education, and diet all affect the susceptibility to developing AD. These factors are in turn related to the level of personal income. Lower income usually coincides with lower level of education, lesser mental, leisure—social and physical activity, and poorer diet. In the present paper, we have analyzed the correlation of historical (1929–2011) per capita personal income (PCPI) for all states of the USA with corresponding age-adjusted AD death rates (AADR) for years 2000, 2005 and 2008. We found negative correlations in all cases, the highest one (R ≈ -0.65) for the PCPIs in the year 1970 correlated against the AADRs in 2005. From 1929 to 2005 the R value varies in an oscillatory manner, with the strongest correlations in 1929, 1970, 1990 and the weakest in 1950, 1980, 1998. Further analysis indicated that this oscillatory behavior of R is not artificially related to the economic factors but rather to delayed biological consequences associated with personal income. We conclude that the influence of the income level on the AD mortality in 2005 was the highest in the early years of life of the AD victims. Overall, the income had a significant, lifelong, albeit constantly decreasing, influence on the risk of developing AD. We postulate that the susceptibility of a population to late-onset AD (LOAD) is determined to a large extent by the history of income-related modifiable lifestyle risk factors. Among these risk factors, inappropriate diet has a significant contribution.

Ontogenetic-based sequential path analysis of grain yield and its related traits in several winter wheat cultivars

Studies that provide representative insights for determining yield through its related traits during the ontogeny of modern cultivars subjected to sources of environmental variation are limited for different crops, including wheat. Most of the empirical evidence on the relationships between the yield of small grain cereal crops and its contributing traits has been obtained under dry or semidry conditions. The aims of this paper were to (1) illustrate how an path analysis can be used to clarify and interpret the relationships between grain yield (GY), yield components, and other yield-related traits of 25 winter wheat cultivars subjected to sources of environmental variation and (2) determine how the yield-related traits contribute to the yield variation. The data used in this analysis were generated from multi-environment trials across wheat-growing areas in Poland. Using Ward’s clustering procedure was capable of identifying the most critical predictor traits of the yield components and their contributions to cultivar-focused GY variation. Our findings document, confirm, and improve the basic biological understanding of how to grow modern wheat cultivars for high GY through effectively stimulating the improvement of yield-related traits through the optimization of developmental stage-based agronomic strategies. Our results confirmed empirically that modern European wheat cultivars grown in a temperate climate require favorable conditions, the use of appropriate N fertilizer and growth regulators, and the application of fungicide to protect against leaf diseases and to provide conditions that effectively increase the time to anthesis, the Leaf Area Index per spike at anthesis, and the grain filling duration, and reduce plant height and flag leaf disease severity, thus leading to a high GY. A high yield level is obtained by the performance of preferred yield-related traits that can maintain the three yield components at relatively high levels.

Female age as a factor determining the patterns of tree canopy utilisation by the European cherry fruit fly, Rhagoletis cerasi

ABSTRACT The European cherry fruit fly, Rhagoletis cerasi is a univoltine, oligophagous pest of cultivated sweet cherries. The pest is closely associated with the canopy of its host tree, and its on-farm behaviour and mobility are determined by the crop structure and spatial arrangement of the farm. However, in spite of its relevance to integrated pest management, little is known about the within-canopy behaviour of R. cerasi, or the role of host and non-host canopy traits in local pest translocations. This paper reports the results of our exploratory studies, which reveal the modulating role of female age on various aspects of R. cerasi on-farm behaviour, such as diurnal and lifetime patterns of canopy utilisation and within-canopy activity, the propensity to undertake local explorative errands and the response to volatiles emanating from host and non-host canopies. The potential implications of our findings on the development of site-optimised IPM and/or pest-resilient agro-landscapes were also discussed.

The Calculator of Anti-Alzheimer's Diet. Macronutrients.

The opinions about optimal proportions of macronutrients in a healthy diet have changed significantly over the last century. At the same time nutritional sciences failed to provide strong evidence backing up any of the variety of views on macronutrient proportions. Herein we present an idea how these proportions can be calculated to find an optimal balance of macronutrients with respect to prevention of Alzheimer’s Disease (AD) and dementia. These calculations are based on our published observation that per capita personal income (PCPI) in the USA correlates with age-adjusted death rates for AD (AADR). We have previously reported that PCPI through the period 1925–2005 correlated with AADR in 2005 in a remarkable, statistically significant oscillatory manner, as shown by changes in the correlation coefficient R (Roriginal). A question thus arises what caused the oscillatory behavior of Roriginal? What historical events in the life of 2005 AD victims had shaped their future with AD? Looking for the answers we found that, considering changes in the per capita availability of macronutrients in the USA in the period 1929–2005, we can mathematically explain the variability of Roriginal for each quarter of a human life. On the basis of multiple regression of Roriginal with regard to the availability of three macronutrients: carbohydrates, total fat, and protein, with or without alcohol, we propose seven equations (referred to as “the calculator” throughout the text) which allow calculating optimal changes in the proportions of macronutrients to reduce the risk of AD for each age group: youth, early middle age, late middle age and late age. The results obtained with the use of “the calculator” are grouped in a table (Table 4) of macronutrient proportions optimal for reducing the risk of AD in each age group through minimizing Rpredicted−i.e., minimizing the strength of correlation between PCPI and future AADR.

A comparison of winter wheat cultivar rankings in groups of Polish locations

The grouping of locations from local-scale multi-environmental trials (METs) into mega-environments has been criticized. Some European countries, e.g. the Czech Republic, Poland and Germany, have been characterized as possessing homogeneous environmental conditions. For aligned environmental conditions, it has been assumed that cultivar rankings will be similar and consequently cannot be used to designate mega-environments. An example of METs at the local scale is the Polish Post Registration Variety Testing System. The objective of this study was to determine groups of test sites within 16 Polish regions which are characterized by similar yield ranking of 50 winter wheat cultivars over three growing seasons (2011–2013). The compatibility of these cultivar yield rankings across regions was evaluated using Pearson correlation coefficients. Thereby, the 16 regions were divided into six groups (mega-environments) of locations. Regions within each group have similar cultivar rankings, whereas between groups, we observed different cultivar rankings, indicating crossover interactions. Besides similar cultivar yield responses the regions within mega-environments were characterized also by similar environmental (soil and/or climate) conditions.

The effect of the presence of quiescent female nymphs, males and their spermatophores on spermatophore placement in two species of eriophyoid mites

Under sex dissociated sperm transfer, females seek spermatophores and pick up sperm without male assistance. In several species males adjust spermatophore deposition rate to the presence of conspecifics. It is not known, however, which factors could favor such elasticity in non-pairing males. In this paper, we compare male response towards conspecifics between the sex dissociated eriophyoid mites Aculus fockeui (Nalepa and Trouessart) and Aculops allotrichus (Nalepa). The species differ significantly in male reproductive strategies and, consequently, the intensity of male–male-competition. Aculus fockeui males deposit spematophores all over the leaves and occasionally leave single spermatophores beside quiescent female nymphs (QFNs). In contrast, A. allotrichus males guard QFNs and encircle them with spermatophores. In this study, males of both species deposited spermatophores close to and apart from the rival spermatophores. Aculops allotrichus males had similar spermatophore output whether they were kept alone or in a group of seven males. They did not change spermatophore output in the presence of five rival spermatophores, a QFN or a QFN and varying number of rivals, either. In contrast, A. fockeui males increased spermatophore output in the presence of rival spermatophores or when on the arena with a QFN the male number increased to eight males. They did not respond, however, to the presence of a QFN and one rival or a QFN alone. The possible effect of the species-specific intensity of male–male competition, population density, the availability of receptive females and the rate of spermatophore output on the flexibility of eriophyoid spermatophore deposition is discussed.

Assessing grain yield and quality traits stability of spring wheat cultivars at different crop management levels

Eleven spring wheat cultivars were compared in terms of the stability of their grain yield and grain quality. The cultivars’ stability was evaluated separately at two different crop management levels – moderate-input management and high-input management. Three stability models were used for the two crop management levels based on a linear mixed model framework with restricted maximum likelihood. The Shukla model was the most appropriate for the evaluation of stability of tested spring wheat cultivars. The thousand-grain weight, starch content, Zeleny sedimentation value and test weight were characterized, and the stability ranking cultivars at moderate-input management level was mostly consistent with the rank of cultivars 24 for high-input management level. For grain yield, grain protein content and wet gluten content, the stability rankings were not consistent. Cultivars ‘Monsun’ and ‘Parabola’ are the most stable cultivars for grain yield in moderate-input management and high-input management, respecti...

Response of winter wheat cultivars to crop management and environment in post-registration trials

Mądry W., Derejko A., Studnicki M., Paderewski J., Gacek E. (2017): Response of winter wheat cultivars to crop management and environment in post-registration trials. Czech J. Genet. Plant Breed., 53: 76−82. In order to deliver essential information related to flexible cultivar recommendations, the cultivars which have been released have to be evaluated under different crop management treatments across agro-ecosystems using two-factorial post-registration multi-environment trials. The objective of this study was to evaluate the yield adaptive patterns of 24 winter wheat cultivars tested across 20 trial locations and three consecutive cropping seasons. The evaluated winter wheat cultivars from many Western European countries and Poland showed different adaptive responses to the Polish agro-ecosystems under each of the crop management intensities. Under the high-input management, the cultivars Rapsodia, (UK) Bogatka and Nadobna (Poland) showed a wide adaptation. The cultivars Alcazar (France), Anthus (Germany), Batuta (Poland) and Boomer (UK) were the best adapted to lower-productive environments and poorly adapted to highly productive conditions under both management treatments.