Lenka Petrakova

• PhD
• Research Assistant at Masaryk University

Trophic specialists often follow unique evolutionary pathways, show potential applications in biological control, and suffer from increased ecological vulnerability. The myrmecophagous spider genus Zodarion, highly diversified across the Mediterranean, is among the few predatory groups showing strict stenophagy. Most Zodarion species display narrow...

Spiders are among the most diversified and abundant predators in terrestrial ecosystems across the world, but information on their prey is limited. Particularly, there is paucity of data for prey-specialised species, such as palpimanid spiders. Here we investigated the trophic strategy of four palpimanid species (Diaphorocellus biplagiatus, Otiotho...

Trophic interactions of cave arthropods have been understudied. We used molecular methods (NGS) to decipher the food web in the subterranean ecosystem of the Ardovská Cave (Western Carpathians, Slovakia). We collected five arthropod predators of the species Parasitus loricatus (gamasid mites), Eukoenenia spelaea (palpigrades), Quedius mesomelinus (...

Participants of the thirteenth Czech-Slovak Meeting on Hymenoptera carried out faunistic research in the Malé Karpaty Mountains (SW Slovakia). Occurrence of Symphyta, Aculeata and the selected Parasitica were examined in five localities during the vegetation season in 2017. On occasion they visited twelve additional localities in the Malé Karpaty M...

• Competition among closely‐related specialist predators has rarely been studied, and thus the mechanism of their coexistence remains enigmatic. Interspecific competition among specialised co‐occurring predators capturing termites should be high. • Here we investigated various niche dimensions, namely temporal, spatial and trophic, of a couple of j...

Among spiders, taxonomically the most diversified group of terrestrial predators, only a few species are stenophagous and feed on ants. The levels of stenophagy and ant-specialisation vary among such species. To investigate whether stenophagy is only a result of a local specialisation both fundamental and realised trophic niches need to be estimate...

Predators should be selected to maximize their fitness by catching the most profitable prey. As predators grow in size, they often shift their preferences to larger prey during the course of development. Alike generalist predators, specialized predators should also shift to larger prey within the pool of focal prey. Here, we have studied the natura...

In predators an ontogenetic trophic shift includes change from small to large prey of several different taxa. In myrmecophagous predators that are also mimics of ants, the ontogenetic trophic shift should be accompanied by a parallel mimetic change. Our aim was to test whether ant-eating jumping spider, Mexcala elegans, is myrmecomorphic throughout...

Phylogenetic hypotheses of the relationships of Diptera: Anthomyzidae (61 taxa) are discussed with special reference to the genera Fungomyza Roháček, 1999, Anthomyza Fallén, 1810, Epischnomyia Roháček, 2006 and Arganthomyza Roháček, 2009 based on the analysis of 7 combined mitochondrial + nuclear gene markers in comparison with results of the most...

1. Feeding behaviour of generalist and specialist predators is determined by a variety of trophic adaptations. Specialised prey‐capture adaptations allow specialists to catch relatively large prey on a regular basis. As a result, specialists might be adapted to exploit each item of prey more thoroughly than do generalists. 2. It was expected that o...

Specialised predators possess a variety of adaptations. In venomous predators this may include the size of the venom gland and venom composition. It is expected that due to different foraging strategies, predators with a wide trophic niche (generalists) should possess larger venom glands that contain more diversified components than predators with...

Most spiders are euryphagous predators. However, there are also a few species with a stenophagous diet, foraging on only a single prey taxon. This strategy could have resulted from ecological opportunity or from evolutionary specialization, which is typical for phylogenetically advanced species. In Zodariidae, myrmecophagy is considered a derived t...

The arms race between specialist predators and their prey has resulted in the evolution of a variety of specific adaptations. In venomous predators this can include venom composition, particularly if predators are specialised on dangerous prey. Here, we performed an integrative study using six species of highly specialised ant-eating spiders of the...

Short video footages showing Australian Myrmarachne species.

Artificially increased habitat complexity can improve the biocontrol service provided by generalist predators as it can reduce intraguild predation (IGP). However, several counteracting mechanisms can buffer the effect of reduced IGP. Here, we investigated whether the cardboard bands installed in pear trees in early winter improve the suppression o...

Specialist true predators are expected to exhibit higher capture efficiencies for the capture of larger and dangerous prey than generalist predators due to their possession of specialized morphological and behavioral adaptations. We used an araneophagous spider (Lampona murina) and a generalist spider (Drassodes lapidosus) as phylogenetically relat...

ELife digest Many animals use bright colours to warn a potential predator that they can defend themselves. Wasps, for instance, are armed with a harmful sting and advertise this fact via their distinctive yellow and black stripes. Predators often learn to heed such warnings and avoid these unpalatable animals in future. As a result, animals that mi...

Aim The European velvety tree ant (Liometopum microcephalum), forming large colonies defending territories, has specific habitat requirements and occurs in isolated populations irregularly distributed across its range. Its dispersal is slow and colony numbers have been declining in many areas. We aim to assess the origin of populations across the s...

Populations of many taxa are polymorphic as a result of interactions between different evolutionary processes. One such taxon is the salticid spider genus Myrmarachne, which is under strong selection for myrmecomorphy resulting in an accurate mimetic resemblance to various ant species. In revising eastern Australian Myrmarachne, we provide descript...

Generalist predators may provide biocontrol service if (1) they are abundant in an agroecosystem, (2) intraguild predation is low, (3) alternative prey is scarce, and (4) pest population increase is slow. These conditions are met in fruit orchards during winter and in early spring. Spiders of the genera Anyphaena and Philodromus remain active durin...

True predators are characterised by capturing a number of prey items during their lifetime and by being generalists. Some true predators are facultative specialists, but very few species are stenophagous specialists that catch only a few closely related prey types. A monophagous true predator that would exploit a single prey species has not been di...

Liometopum microcephalum (PANZER, 1798) is a rare arboricolous ant, which forms large colonies of high ecological importance and ranks at the top position in the hierarchy of ant assemblages. Many aspects of the species' biology remain unknown due to its scattered occurrence and bad nest accessibility. Published information is sometimes incon-siste...

The arboricolous dolichoderine ant Liometopum microcephalum (Panzer, 1798) is considered to be mainly predatory, although there are some reports of it tending aphids. The main objective of the present study was to confirm that this ant has a trophobiotic relationship with aphids and assess seasonal differences in its utilization of honeydew. We hyp...

Interactions of Liometopum microcephalum with other two territorial ants also nesting in or foraging on trees, Lasius fuliginosus and Formica rufa, were studied in South Moravia (Czech Republic), at the northwestern border of its range, in 2005-2009. L. microcephalum defends its nest and foraging trees. Its distribution area is fragmented and in th...