Hyenism in Ants: Non-Target Ants Profit From Polyergus rufescens Raids (Hymenoptera: Formicidae)

The presence of slavemaker ants alters the structure of the ant community. The influence of slavemakers on non-host ants is believed to be indirect, via changing competitive interactions among the ants. According to my observation Myrmica sabuleti (and probably also Lasius alienus) profited from a Polyergus rufescens raid against a Formica fusca nest. Both non-host species collected F. fusca corpses. These carcasses were used as food in the case of M. sabuleti at least. M. sabuleti profited substantially from the Polyergus raid because the dry biomass weight of the collected F. fusca carcasses was approximately half of the dry biomass weight of all M. sabuleti workers

Myrmica scabrinodis as a possible host of Myrmica hirsuta (Hymenoptera: Formicidae)

In a previous study most males of the Glanville fritillary butterfly (Melitaea cinxia) were caught in valleys, whereas almost all females were distributed on slopes in the Tianshan Mountains, northwestern China. To help understand this phenomenon, male mate location behaviours were observed in different landscapes of the Tianshan Mountains. In valleys, males exhibited perching behaviour. On slopes, spatial distribution of males showed patrolling behaviour on meadows, but intermediate behaviour between perching and patrolling at forest edge. The temporal distribution of males also varied, being found on slopes from 7:00 to 18:00, but in valleys from 8:00 to 13:00 each day. Ambient temperatures were higher on slopes than those in valleys between 8:00 to 13:00. Males exhibited lower tolerance to high temperature than females, leading to the conclusion that valleys are more likely to be used by males as thermoregulation sites, rather than for mating

Records of host ant use of Phengaris Doherty, 1891 (Lepidoptera, Lycaenidae) in the Czech Republic

The specificity of the specialisation of Phengaris Doherty, 1891 caterpillars to their host ants is still not fully understood. In this report, we summarize all available records of Phengaris in ant nests from the Czech Republic. P. alcon (Denis & Schiffermüller, 1775) was found exclusively in nests of Myrmica scabrinodis Nylander, 1846 at four sites, and one P. nausithous (Bergsträsser, 1779) caterpillar was found in a nest of M. scabrinodis. According to published records, P. nausithous may use M. scabrinodis at the edges of its range but should be adapted exclusively to M. rubra (Linnaeus, 1758) in the centre of its range. No records of P. arion (Linnaeus, 1758), P. teleius (Bergsträsser, 1779) and P. alcon populations feeding on Gentiana cruciata (Gentianaceae) ("P. rebeli") are available from the Czech Republic

A Comparison of Selected Modifications of the Particle Swarm Optimization Algorithm

We compare 27 modifications of the original particle swarm optimization (PSO) algorithm. The analysis evaluated nine basic PSO types, which differ according to the swarm evolution as controlled by various inertia weights and constriction factor. Each of the basic PSO modifications was analyzed using three different distributed strategies. In the first strategy, the entire swarm population is considered as one unit (OC-PSO), the second strategy periodically partitions the population into equally large complexes according to the particle’s functional value (SCE-PSO), and the final strategy periodically splits the swarm population into complexes using random permutation (SCERand-PSO). All variants are tested using 11 benchmark functions that were prepared for the special session on real-parameter optimization of CEC 2005. It was found that the best modification of the PSO algorithm is a variant with adaptive inertia weight. The best distribution strategy is SCE-PSO, which gives better results than do OC-PSO and SCERand-PSO for seven functions. The sphere function showed no significant difference between SCE-PSO and SCERand-PSO. It follows that a shuffling mechanism improves the optimization process

The Twin Challenges to Separation of Powers in Central Europe: Technocratic Governance and Populism

Separation of institutions, functions and personnel – Checks and balances – Hungary, Poland, Czechia, Slovakia – Short tradition of separation of powers in Central Europe – Fragile interwar systems of separation of powers – Communist principle of centralisation of power – Technocratic challenge to separation of powers during the EU accession – One-sided checks on the elected branches and empowering technocratic elitist institutions – Populist challenge to separation of powers in the 2010s – Re-politicising of the public sphere, removing most checks on the elected branches, and curtailing and packing the unelected institutions – Technocratic and populist challenges to separation of powers interrelated more than we thought