Biology subjects

Laszlo, Z.

Publications and source records attributed to Laszlo, Z..

10 recordsLinked to original sources

bioRxiv2026

From chambers to communities: gall architecture shapes parasitoid network stability in Diplolepis (Cynipidae, Diplolepididae) rose galls

1. Gall-inducing insects create structurally distinct microhabitats that mediate their interactions with associated parasitoid communities, and variation in gall architecture is recognized as an important driver of the composition and organization of these communities. 2. In cynipid gall wasps of the genus Diplolepis, galls range from single-chambered to multichambered structures, and this variation has previously been linked to differences in parasitoid attack rates and community composition, yet its consequences for the topology and stability of the resulting ecological networks remain unexplored. 3. We compiled 17 empirical Diplolepis-parasitoid interaction networks spanning seven host taxa and used dynamical (non-normalized return time) and structural (robustness) measures of stability, together with network topology and diversity metrics, to test whether gall architecture shapes the organization of the resulting parasitoid networks. We hypothesized that networks associated with multichambered galls would be more stable, more connected and more unevenly structured than those associated with single-chambered galls. 4. Multichambered-gall networks showed significantly higher robustness at the species level and lower species-level non-normalized return times under intermediate and weak self-regulation, together with higher species-level connectance and clustering coefficients. In contrast, gall architecture reduced rather than increased Shannon diversity after accounting for network size, and had no detectable effect on the Gini index. Most effects weakened after aggregation to the genus level, highlighting the sensitivity of gall-associated network descriptors to taxonomic resolution. 5. These results indicate that gall architecture leaves a measurable signature on the organization and stability of associated parasitoid networks that extends beyond simple differences in community composition, adding a network-level perspective to the study of gall morphology as an ecological filter of natural-enemy communities.

ecology↗

bioRxiv2026

Method for maintaining translocated wild roses under laboratory conditions for controlled gall induction by Diplolepis rosae and D. mayri

O_LIPlant-gall wasp systems provide unique models for studying multitrophic interactions and unique developmental processes, yet standardized laboratory protocols for maintaining wild rose hosts (Rosa spp.) and sustaining gall inducers (Diplolepis spp.) are lacking. C_LIO_LIWe developed and tested a method for growing and maintaining translocated individuals of Rosa canina, R. rubiginosa, R. spinosissima, R. gallica, R. tomentosa, and R. pendulina under laboratory conditions over three consecutive years (2023-2026) to provide a continuous source of host plant material for experimental gall induction by D. rosae and D. mayri. C_LIO_LIThe protocol integrates soil and substrate composition, photoperiod and humidity regimes, pruning, dormancy management, and controlled exposure to gall-inducing wasps. More than 75% of rose individuals survived the full 3-year period, with consistent annual gall induction achieved in several host species. C_LIO_LIThis work represents the first reproducible laboratory method for long-term maintenance of wild rose hosts and controlled gall induction by Diplolepis species. The framework also provides a broadly applicable approach for maintaining perennial woody hosts and experimentally manipulating specialized plant-insect interactions under laboratory conditions, thereby supporting ecological, physiological, and evolutionary research across comparable systems. C_LI

ecology↗

bioRxiv2023

Successful gall induction by Diplolepis rosae and D. mayri on the sweet briar (Rosa rubiginosa) under laboratory conditions

O_LIPlant galls are unique outgrowths caused by various organisms, including insects, serving as nourishment for the inducers larvae. Despite the taxonomists and ecologists attempts to elucidate the mechanisms behind plant gall formation, its understanding is still incomplete. Modern genetic techniques allow in depth analysis of the molecular processes, but variations across species entangle the analysis. Establishing laboratory-friendly plant-gall inducer communities is crucial, yet past attempts have faced challenges. C_LIO_LIOur study aimed to create a sustainable laboratory community involving wild roses (Rosa sp.) and as gall-inducing insects rose gall wasps belonging to the genus Diplolepis. Controlled indoor conditions were optimized for plant growth. Wild roses were transplanted, then exposed to gall inducers, and monitored. C_LIO_LISuccessfully initialized gall growth was measures and analysed, revealing insights into the impact of plant vigour on gall size. C_LIO_LIOur study successfully established a novel laboratory community for further research on gall formation mechanisms. C_LI

ecology↗

bioRxiv2020

Increasing network stability towards large food webs

Stability is a key attribute of complex food webs that has been for a long time in the focus of studies. It remained an intriguing question how large and complex food webs are persisting if smaller and simple ones tend to be more stable at least from a mathematic perspective. Presuming that with the increasing size of food webs their stability also grows, we analyzed the relationship between number of nodes in food webs and their stability based on 450 food webs ranging from a few to 200 nodes. Our results show that stability increases non-linearly with food web size based both on return times after disturbance and on robustness calculated from secondary extinction rates of higher trophic levels. As a methodologic novelty we accounted for food web generation time in the return time calculation process. Our results contribute to the explanation of large and complex food web persistence: in spite of the fact that with increasing species number the stability of food webs decreases at small node numbers, there is a constant stability increase over a large interval of increasing food web size. Therefore, in food web stability studies, we stress the use of food web generation times.Competing Interest StatementThe authors have declared no competing interest.View Full Text

ecology↗

bioRxiv2020

A new species of Mesopolobus Westwood (Hymenoptera, Pteromalidae) from black locust crops

A new species of the genus Mesopolobus Westwood, Mesopolobus robiniae sp. n., is described and illustrated from east-central Europe (Romania and Hungary). The species was reared from black locust (Robinia pseudoacacia) seedpod samples, where it most likely parasitizes the black locust’s seed predator Bruchophagus robiniae Zerova, 1970. Here we present the new species and report on its ecological relationships within the European seed predator community of black locust. We also give details regarding type material and type locality, a detailed description with images, a differential diagnosis of the new species, and a modification to the identification key published by Graham (1969), that distinguishes this new species from closely related species. In addition, we provide information on the distribution, biology and results of barcoding analysis. We also provide the DNA sequence data to complement the morphological taxonomy.Competing Interest StatementThe authors have declared no competing interest.View Full Text

zoology↗

bioRxiv2020

Interneuronal mechanisms underlying a learning-induced switch in a sensory response that anticipates changes in behavioural outcomes

How an animal responds to a particular sensory stimulus will to a great extent depend on prior experience associated with that stimulus. For instance, aversive associative learning may lead to a change in the predicted outcomes, which suppresses the behavioural response to an otherwise rewarding stimulus. However, the neuronal mechanisms of how aversive learning can result in the suppression of even a vitally important innate behaviour is not well understood. Here we used the model system of Lymnaea stagnalis to address the question of how an anticipated aversive outcome can alter the behavioural response to a previously effective feeding stimulus. We found that aversive classical conditioning with sucrose as the CS (conditioned stimulus) and strong touch as the aversive US (unconditioned stimulus) reverses the decision so that the same salient feeding stimulus inhibits feeding, rather than activating it. Key to the understanding of the neural mechanism underlying this switch in the behavioural response is the PlB (pleural buccal) extrinsic interneuron of the feeding network whose modulatory effects on the feeding circuit inhibit feeding. After associative aversive training, PlB is excited by sucrose to reverse its effects on the feeding response. Aversive associative learning induces a persistent change in the electrical properties of PlB that is both sufficient and necessary for the switch in the behavioural output. In addition, the strong touch used as the US during the associative training protocol can also serve as a sensitizing stimulus to lead to an enhanced defensive withdrawal response to a mild touch stimulus. This non-associative effect of the strong touch is probably based on the facilitated excitatory output of a key identified interneuron of the defensive withdrawal network, PeD12.

neuroscience↗

bioRxiv2019

ABHD4-dependent developmental anoikis protects the prenatal brain from pathological insults

In light of the astronomical number of cell divisions taking place in restricted neurogenic niches, brain malformations caused by ectopic proliferation of misplaced progenitor cells are surprisingly rare. Here, we show that a process we term developmental anoikis distinguishes the abnormal detachment of progenitor cells from the normal delamination of daughter neuroblasts in the developing mouse neocortex. By using in vivo gain-of-function, loss-of-function, and rescue manipulations together with correlated confocal and super-resolution imaging, we identify the endocannabinoid-metabolizing enzyme abhydrolase domain containing 4 (ABHD4) as an essential mediator for the elimination of abnormally detached cells. Consequently, rapid ABHD4 downregulation is necessary for delaminated daughter neuroblasts to escape from anoikis. Moreover, ABHD4 is required for fetal alcohol-induced apoptosis, but not for the well-established form of developmentally controlled programmed cell death. These results suggest that ABHD4-mediated developmental anoikis specifically protects the embryonic brain from the consequences of sporadic delamination errors and teratogenic insults.

developmental biology↗

bioRxiv2019

Landscape scale terrestrial factors are also vital in shaping Odonata diversity of watercourses

Habitat loss and fragmentation causes decline of insect populations. Odonata (both dragonflies and damselflies) are especially threatened, because they are notably influenced by both aquatic and terrestrial environment. We explored the relative importance of local and landscape variables for Odonata assemblages (species richness, assemblage composition, population abundance) revealing differences in the sensitivity of Zygoptera and Anisoptera on the selected variables. Our study took two years and was placed along 11 lowland watercourses. We sampled the specimens using 500 m long transects from May to September. Landscape variables (length of watercourses, forest patch proportion, and farmland patch size) were calculated at three scales to better account for fragmentation. Our findings show that local variables influence damselflies, but dragonflies are more sensitive to landscape variables. Damselflys diversity decreased with the increasing macrovegetation cover, while dragonflys diversity decreased with the increasing degree of land use intensification, but increased with the length of watercourses. Our findings, both on local and landscape scales demonstrated the importance of terrestrial environment on Odonata. Based on our findings we stress the importance of partial watercourse clearing, and maintenance of traditional farm management based on small parcel farming near watercourses to maintain diverse and healthy Odonata assemblages.

ecology↗

bioRxiv2019

Phylogeny of Holarctic gall wasps of the genera Diplolepis and Periclistus (Hymenoptera: Cynipidae) based on DNA barcodes

Rose gall wasps Diplolepis induce structurally distinct galls on wild roses, which provide gallers with food and shelter. These galls are attacked by a wide variety of micro-hymenopterans including another cynipid Periclistus that act as inquilines. Both Diplolepis and Periclistus are difficult to distinguish based on adult morphology, instead the structural appearance of galls is often used to distinguish species. Using the mitochondrial gene COI, we built phylogenies of both Diplolepis and Periclistus, while also estimating the ancestral host use of the inducers. Our phylogeny recovered the monophyly of Diplolepis, which have likely diverged from single-or multi-chambered leaf gallers to other plant organs. Periclistus exhibits a divide between the Palearctic and Nearctic clades, and ranges from specialists to generalists in terms of host specificity. The molecular results have largely supported the validity of species described in the literature, with notable exceptions in four species groups. While it is premature to enact any taxonomic changes without additional molecular markers, this incongruence between morphological and molecular data indicates these groups need taxonomic revision and gall morphology alone may be inadequate to delimit species.

zoology↗

bioRxiv2018

Biased parasitoid sex ratios: Wolbachia, functional traits, local and landscape effects

Adult sex ratio (ASR) is a demographic key parameter, being essential for the survival and dynamics of a species populations. Biased ASR are adaptations to the environment on different scales, resulted by different mechanisms as inbreeding, mating behaviour, resource limitations, endosymbionts such as Wolbachia, and changes in density or spatial distribution. Parasitoid ASRs are also known to be strongly biased. But less information is available on large scale variable effects such as landscape composition or fragmentation. We aimed to study whether the landscape scale does affect the ASR of parasitoids belonging to the same tritrophic gall inducer community. We examined effects of characteristics on different scales as functional trait, local and landscape scale environment on parasitoid ASR. On species level ovipositor length, on local scale resource amount and density, while on landscape scale habitat amount, land use and landscape history were the examined explanatory variables. We controlled for the incidence and prevalence of Wolbachia infections. Parasitoid ASR is best explained by ovipositor length: with which increase ASR also increases; and available resource amount: with the gall diameter increase ASR decreases. On large scale the interaction of functional traits with habitat size also explained significantly the parasitoid ASRs. Our results support the hypothesis that large scale environmental characteristics affect parasitoid ASRs besides intrinsic and local characteristics.

ecology↗