Infrastructure is one of the main causes of landscape fragmentation, which results in isolation and loss of populations. Although the negative effect of roads on insects is well documented, only a minority of studies has focused on roads in the context of barriers to dispersal. Flying species in particular have been neglected. We investigated the effect of a four-lane motorway as a barrier to the movement of an isolated population of the threatened dragonfly Sympetrum depressiusculum in an agricultural landscape in Central Europe. Generalized additive models were used to assess the motorway's effect on (i) the distribution of adult dragonflies in patches of terrestrial habitat surrounding their natal site, and (ii) individual flight behaviour (i.e. willingness or unwillingness to cross the motorway). Movement patterns of marked adults throughout the landscape were also investigated. During one season, significantly fewer adults were found at patches located on the far side of the motorway, indicating it has a barrier effect. Observations on flight behaviour revealed no apparent effect of the motorway. The possible barrier effect for the species studied was therefore presumed to be a consequence of road mortality. Our results indicate that the motorway may influence the dispersal of this threatened species of dragonfly, which is a habitat specialist with particular requirements for its terrestrial environment. Negative effects on other species with similar behaviour and strategy can be presumed. When establishing new habitats, carrying out reintroductions or translocations, it is necessary to consider that roadways may reduce population size and affect population dynamics by limiting dispersal., Hana Šigutová, Filip Harabiš, Michal Hykel, Aleš Dolný., and Obsahuje bibliografii
We studied the demography, movement, behaviour and choice of nectar plants by adults of Aporia crataegi. This study was done in a dense network of different types of habitats (total size of study area 16.26 ha) from open landscape to shrubland, the latter being a result of abandonment of traditional agricultural practices such as extensive mowing and grazing. Total population size was estimated to be approximately 1700 and 2700 for females and males, respectively. Median and maximum distances moved by males were 134 and 3493 m, and by females 138 and 3165 m, respectively. The average lifespan was ca. 7.1 and 7.5 days, with maximum recorded lifespans of 21 and 17 days for males and females, respectively. The greater capture probability recorded for males indicates their high activity, as they spend most of their time in flight patrolling and searching for mates. A parabolic recruitment curve and protandry were also recorded. Both sexes are highly mobile. The spatial distribution of both sexes was roughly similar. The adult behaviour differed in different habitats, with more time spent feeding and resting when nectar plants were plentiful and more time spent flying when they were rare. Although adults utilized nine nectar sources, only two were recorded in over 80% of all the feeding occasions. In order to re-establish open grassland with some shrubland, traditional and mosaic management of the landscape should be revived at least to some extent., Jure Jugovic, Mitja Črne, Martina Lužnik., and Obsahuje bibliografii
The monotypic genus Silvispina M. Wang & Soulier-Perkins, gen. n. and new species S. changpotou M. Wang & Soulier-Perkins, sp. n. belonging to the family Lophopidae Stål, 1866, from Yunnan Province in China, is described and illustrated. The peculiarity of the first metatarsal segment of this genus is stressed and the taxonomic position of this new genus is discussed. The ornamentation and shape of metatibia and first tarsal segment (the characters that currently distinguish the subfamilies Menoscinae and Lophopinae) do not agree with either subfamily and the new genus is placed as incertae sedis in the Lophopidae. The genus Ridesa Schumacher, 1915 is removed from the family Lophopidae and placed in the Achilidae., Menglin Wang, Yinglun Wang, Adeline Soulier-Perkins., and Obsahuje bibliografii
A new progonocimicid bug named Cicadocoris parvus sp. n. is described from the mid-Jurassic Haifanggou Formation at Daohugou, Ningcheng County, Inner Mongolia, northeastern China. It differs from other species by being distinctly smaller, veins dSc, R1 and Rs run parallel to one another and are nearly evenly spaced on left tegmen, widest length of apical half/basal half of left tegmen is 1.1 and that of right tegmen is 1.0. Thus, there are at least three species of Cicadocoris (Progonocimicidae) described from Daohugou. All these species are relatively abundant in the Haifanggou Formation and are remarkable representatives of the early Yanliao biota., Jia-Qian Jiang, Di-Ying Huang., and Obsahuje bibliografii
We analyzed the abundance, distribution and niche overlap of species (Pianka's Ojk index) in tenebrionid beetle communities inhabiting different biotopes in Tyrrhenian and Adriatic sand dunes. The rank abundance distribution of the different species has the form of a geometric series in both communities as predicted by the niche preemption hypothesis for communities in harsh environments. Mean niche overlap values did not deviate significantly from null expectations, which indicates random interspecific interactions. These results, coupled with evidence of species habitat preferences, led us to conclude that the community organization of tenebrionid species inhabiting coastal dunes is determined more by habitat preferences than interspecific competition., Simone Fattorini, Davide Bergamaschi, Cristina Mantoni, Alicia T. R. Acosta, Andrea Di Giulio., and Obsahuje bibliografii
Climate change may facilitate shifts in the ranges and the spread of insect pests, but a warming climate may also affect herbivorous insects adversely if it disrupts the locally adapted synchrony between the phenology of insects and that of their host plant. The ability of a pest species to colonize new areas depends on its ability to adjust the timing of phenological events in its life cycle, particularly at high latitudes where there is marked seasonality in temperature and day length. Here we incubated eggs of three species of geometrid moth, Epirrita autumnata, Operophtera brumata and Erannis defoliaria from different geographical populations (E. autumnata and O. brumata from Northern Finland, E. autumnata and E. defoliaria from Southern Finland and all three species from Germany) in a climate chamber at a constant temperature to determine the relative importance of geographic origin in the timing of egg hatch measured in terms of cumulative temperature sums (degree days above 5°C, DD5); i.e. the relative importance of local adaptation versus phenotypic plasticity in the timing of egg hatch. In all three species, eggs from northern populations required a significantly lower temperature sum for hatching than eggs from southern populations, but the differences between them in temperature sum requirements varied considerably among species, with the differences being largest for the earliest hatching and northernmost species, E. autumnata, and smallest for the southern, late-hatching E. defoliaria. In addition, the difference in hatch timing between the E. autumnata eggs from Southern Finland and Germany was many times greater than the difference between the two Finnish populations of E. autumnata, despite the fact that the geographical distances between these populations is similar. We discuss how these differences in hatching time may be explained by the differences in hatch-budburst synchrony and its importance for different moth species and populations. We also briefly reflect on the significance of photoperiod, which is not affected by climate change. It is a controller that works parallel or in addition to temperature sum both for egg hatch in moths and bud burst of their host plants., Julia Fält-Nardmann, Tero Klemola, Mechthild Roth, Kai Ruohomäki, Kari Saikkonen., and Obsahuje bibliografii
Insects produce pigment and structural colours mainly for camouflage, signaling, physical protection or temperature regulation, and colour patterns can provide information about individual quality. Although the evolutionary function and nature of the variability in colouration are well known for many invertebrate taxa, there is little information on this topic for ants. We studied individual variation in the melanin-based colour traits of workers of the red wood ant, Formica rufa (Hymenoptera: Formicidae), from 20 colonies in Southern Finland and revealed the type of colouration in this species. First, using the threshold approach we distinguished between continuous and discrete variations. Furthermore, the analyses affirmed nine discrete morphs in terms of the colouration on the head and eight on the pronotum, while only continuous variation were found on the other body parts. Measuring the size of a particular colour pattern, the intensity of colour expression (degree of melanization) and statistical analyses allowed an assessment of the intra-individual variation in both discrete and continuous patterns. The results revealed substantial modularity in the above mentioned colouration traits. In workers of F. rufa there were individuals with a dark head and light coloured thorax and vice a versa. Size of the dark pigment colour patterns exhibited less modularity than the degree of melanization. Finally, the interrelation between colouration traits and individual body size revealed their size-dependent origin. Small individuals had relatively larger areas of colour on the head and thorax than big individuals. These results are likely to facilitate further taxonomical and ecological studies on red wood ants, as they show it is possible to assess colouration traits in ants. However, more studies are needed on the function of polymorphism and modular colouration in this group of ants., Oksana Skaldina, Jouni Sorvari., and Obsahuje bibliografii
The partial consumption of prey refers to when a predator does not consume all the digestible biomass of an animal it has killed. The frequency of partial consumption of prey by the polyphagous predator Macrolophus pygmaeus (Hemiptera: Miridae) was recorded for different species of prey and prey population structures, in single and mixed prey species patches. All the instars of the aphid, Aphis gossypii, were provided as prey alone or together with Myzus persicae or Macrosiphum euphorbiae. Numbers killed were determined when equal (10 nymphs of each instar, 40 in total) or unequal numbers (higher numbers of young nymphs but again 40 in total) of nymphs were placed on an eggplant leaf in a plastic Petri dish. In each dish a single 5th instar nymph of the predator was introduced and the numbers killed and numbers of partially consumed aphids were recorded after 24h, at 25 ± 1°C. The numbers of A. gossypii killed were higher than those of the other species of prey used. The frequency of partially consumed prey was highest when A. gossypii was offered alone in equal numbers of each instar, followed by when A. gossypii was provided together with M. persicae in unequal numbers of instars (23.6% and 11.2%, of the total mortality, respectively). Killed but not consumed prey was also recorded, at frequencies that reached 10.7% of the total mortality when A. gossypii was provided alone in equal numbers of each instar. For M. persicae and M. euphorbiae, these percentages were significantly lower. The higher frequency of this behaviour when A. gossypii was the prey may be related to its lower nutritional quality for the predator. The effect of prey instar was not significant. These results indicate that in determining the numbers killed by a predator, partially consumed prey may make up a significant part of the total kill and thus should be taken into consideration., Dionyssios Lykouressis, Dionyssios Perdikis, Ioannis Mandarakas., and Obsahuje bibliografii
Plant volatiles can synergize the response to moth pheromone. Synthetic pheromone analogs, in turn, have the opposite effect in reducing pheromone attractiveness. To determine how these two types of stimuli interact and influence male moth behaviour, we performed wind tunnel experiments on the grapevine moth, Lobesia botrana. We noticed that a blend of host plant volatiles [(E)-β-caryophyllene, 1-hexanol, (Z)-3-hexenyl acetate and 1-octen-3-ol in a 100:20:10:5 ratio] significantly increased the response of males to an optimized blend of sex pheromone [(7E,9Z)-dodeca-7,9-dienyl acetate (E7,Z9-12:Ac), (7E,9Z)- dodeca-7,9-dienol (E7,Z9-12:OH) and (Z)-9-dodecenyl acetate (Z9-12:Ac)] in a 100:10:2 ratio. However, the response of males to the natural attractant was significantly reduced by two analogs [(9E,11Z)-tetradeca-9,11-dien-2-one (MK 2) and [(9E,11Z)-1,1,1-trifluoro-tetradeca-9,11-dien-2-one (TFMK 3)], of the major component of the sex pheromone of the insect (E7,Z9-12:Ac). When both stimuli were tested on males at pheromone:analog:plant volatile blend 1:100:1000 ratio, the plant blend offset the inhibitory effect induced by TFMK 3 but not that of MK 2. Our results show for the first time that under laboratory conditions plant volatiles can prevent inhibition by a pheromone analog., Albert Sans, Miguel Morán, Magí Riba, Ángel Guerrero, Jaume Roig, César Gemeno., and Obsahuje bibliografii
Lygus lineolaris (Palisot de Beauvois, 1818) (tarnished plant bug) is a serious pest of cotton (Gossypium hirsutum L.) in the Delta region as compared to cotton in the Hills region of the state of Mississippi in USA. The reason for this is unclear but it was hypothesized that the plant cell wall degrading polygalacturonase enzyme system in the salivary glands of L. lineolaris from the Delta could be better adapted for cotton, which is grown more predominantly in the Delta region than in the Hills region. Expression analysis of three primary polygalacturonase genes (LlPG1, LlPG2 and LlPG3) was conducted in laboratory reared and field collected populations of L. lineolaris. Assay of polygalacturonase enzyme activity was also conducted to compare wild collected populations. Initial laboratory and field data revealed gene expression differences in sex, age, region, and host plant which guided the direction of our subsequent study during 2013 and 2014. Based on the results of this study, we propose that the three genes studied may not be reflective of the entire polygalacturonase enzyme system and may not be solely responsible for the observed adaptation of L. lineolaris to cotton in the Delta region than in the Hills region. Analyses also revealed that the expression of the three targeted polygalacturonase genes was affected by the host plant from which the insects were collected and that adults had higher polygalacturonase expression than nymphs. Taken together, our results provide strong evidence for developmental stage specific and host plant based change in expression of PG genes in the salivary glands of L. lineolaris. This, however, was not reflected in total polygalacturonase enzyme activity which was not significantly different between regions, hosts, sex, or developmental stage., Daniel Fleming, Natraj Krishnan, Fred Musser., and Obsahuje bibliografii