Mean annual first arrival dates (FAD) of 45 migratory bird species recorded in Moravia (Czech Republic, c. 49º N) in 109 spring seasons between 1881 and 2007 were correlated with the preceding winter (December to March) North Atlantic Oscillation (NAO) index. The arrival of birds occurred significantly earlier following high NAO winter index values (those result in spring warmer than normal in central Europe) in all short-distance migratory species with a European or North African winter range, whereas the arrival timing did not correlate significantly with the seasonal NAO index in long-distance migrants having sub-Saharan winter range. When the values of Pearson coefficient between NAO and FAD were correlated with the migration distance of all 45 bird species, the correlation was remarkable and significant (p<0.001): r = 0.848 for the distance to central locations of winter range, and r = 0.822 for the northern limits of the wintering area. The migration distance was thus responsible for 68–72 % of variation in the regression of birds’ arrival on NAO winter index in central Europe. The data are robust (this is the longest avian phenological record analyzed for correlation with NAO in Europe), and indicate different mechanisms that govern timing between short-distance and long-distance migrants in their departure from wintering areas.
1_The maritime pine bast scale, Matsucoccus feytaudi Ducasse (Hemiptera: Matsucoccidae), occurs in the western part of the Mediterranean basin and is a sap sucking insect that feeds only on maritime pine (Pinus pinaster Aiton). It causes damage in SE France and Italy, where it was accidentally introduced. In Spain information is scarce and, moreover, almost nothing is known about the predators of this species. This study was designed to determine the seasonal trends in abundance of M. feytaudi and its major predators, which might help to improve the biological control of this pest in other areas. Natural P. pinaster stands in the Valencian Community (Spain) were surveyed in 2004. In addition, the seasonal trends in abundance of M. feytaudi and its natural enemies were monitored in three stands over a period of three years (2002, 2005 and 2006). The monitoring was carried by wrapping sticky tapes around tree trunks and using delta traps baited with sexual pheromone. The maritime pine bast scale was detected in all the stands surveyed. At almost all the sites surveyed, three species of predators were captured: Elatophilus nigricornis Zetterstedt (Hemiptera: Anthocoridae), Hemerobius stigma Stephens (Neuroptera: Hemerobiidae) and Malachiomimus pectinatus (Kiesenwetter) (Coleoptera: Malachiidae). The presence of M. pectinatus is noteworthy as this is the first record of this species as a possible predator of M. feytaudi. The results show that M. feytaudi, although differing in its phenology depending on the location, is univoltine in the study area. The prepupae, pupae and adults of M. feytaudi appeared between December and March in colder areas and between October and February in warmer areas. E. nigricornis nymphs are important predators of M. feytaudi, and were abundant when the scale insect (crawlers, prepupae, pupae, male and female adults) was present., 2_The flight period of E. nigricornis and the hemerobiid H. stigma ranged from May to October. However, these flight patterns did not correlate with the presence of the different stages of the bast scale (crawlers, prepupae, pupae, male and female adults) on the surface of tree trunks. The presence of M. pectinatus in large numbers in some stands suggests it might be an important natural regulator, which helps to keep M. feytaudi populations at low densities in the areas of Spain studied. This malachiid shows a strong kairomonal attraction to the sexual pheromone of M. feytaudi and its flight activity is significantly correlated with the presence of crawlers of bast scale., Eugenia Rodrigo ... [et al.]., and Obsahuje seznam literatury
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 experience important selection pressures from their parasitoids, which affect both their population dynamics and their evolutionary responses. The interaction between the egg parasitoid Oomyzus galerucivorus Graham (Hymenoptera: Eulophidae) and its chrysomelid host Galeruca tanaceti L. (Coleoptera: Galerucinae) was investigated with the particular aim determining whether the chrysomelid host can escape its parasitoid by ovipositing late in the year as early as September. Although the leaf beetle and its parasitoid emerge in April, G. tanaceti starts to oviposit after spending the summer in reproductive diapause. The objective was to determine, whether the small parasitic wasp can parasitise its host's eggs even at the end of its host's reproductive season in December, when temperatures are low. Beetle oviposition, parasitism rates and temperatures were measured on three comparable mesoxerophytic grassland sites over the coarse of a season. Beetle oviposition, but not parasitism, was significantly positively dependent on temperature. Rate of oviposition decreased over the oviposition period with decrease in temperature. In contrast, after a lag phase of 1-2 weeks at the beginning of the oviposition period in September beetle egg clutches were parasitised at a constant rate until the end of the season in December. Host eggs were parasitised even at mean daily temperatures of 0-6°C. Thus the tansy leaf beetle does not escape from egg parasitism by ovipositing late in the season in central Germany.
The univoltine leaf miner Chromatomyia fuscula Zetterstedt is a Scandinavian cereal pest. We wanted to compare the phenology of C. fuscula in southern Norway with that of its most important natural enemies: 15 parasitoids of the families Eulophidae and Pteromalidae (Hymenoptera: Chalcidoidea). The use of two Malaise traps in an organically-grown spring barley field and its boundary through 6 seasons (1992-1997) also allowed us to compare these two habitats and to observe the effect of harvesting on the parasitoid activity without interference from pesticides. C. fuscula overwinters as an adult and oviposits in May/June. Few specimens of the next generation, emerging in the crop, were caught in the boundary traps, suggesting the fly hibernates elsewhere. In contrast, the F1 generation of the parasitoids was caught in considerable amounts both in the crop and boundary. The abundance of parasitoids was highest in July/August; in the crop it usually started decreasing well before harvesting; in the boundary it peaked two weeks or more after harvesting. The results suggest that many parasitoids (especially females) move from the crop to the boundary (or beyond) before harvesting. In both habitats parasitoid species richness usually increased until harvesting, and thereafter decreased. The pooled parasitoid female proportion was 0.36; in crop and boundary it was 0.30 and 0.66, respectively, and the majority of species had a higher proportion of females in the boundary than in the crop. The phenology of two of the most common parasitoids is presented: The pupal parasitoid Cyrtogaster vulgaris Walker (Pteromalidae) had a high activity in the boundary, also very early (females only) and late (both sexes) in the season. The larval parasitoid Diglyphus begini (Ashmead) (Eulophidae) was less active early and late in the season, and had a much smaller boundary activity than C. vulgaris. Both sexes were present throughout the season. The annual sex ratio of D. begini was density dependent, being highly male biased in the two years with highest catches. In C. vulgaris neither density nor habitat explained the sex ratio. D. begini probably overwinters inside the mine as a preadult, having one generation on C. fuscula in the crop and another one in an alternate host away from the habitats sampled here. C. vulgaris overwinters as fertilized females in the border habitat.
The effects of photoperiod on pre-imaginal development and reproductive maturation of adult females of the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), were investigated at 20°C and at photoperiods from 10L : 14D to 18L : 6D. Experiments were conducted on a laboratory strain that originated from the Russian Far East. Larvae and adults were fed on the green peach aphid Myzus persicae. Under short day conditions the pre-imaginal development was faster than under long day conditions. The acceleration of pre-imaginal development occurred when day length was shorter than 16 h and the threshold day length was ca 14 h. The rate of reproductive maturation of adult females, in contrast, was twice as high under long day conditions, with the threshold between 14L : 10D and 12L : 12D, although even under short day conditions ca 10% of the females show a tendency to mature more quickly. This difference between the thresholds of these two photoperiodic reactions indicates they are relatively independent of one another. and Sergey Ya. Reznik, Nina P. Vaghina.
Plants’ abilities to function are difficult to evaluate directly in the field. Therefore, a number of attempts have been made to determine easily measurable surrogates – plant functional traits (PFTs). In particular, the value of PFTs as tools for predicting vegetation responses to management (i.e., grazing and mowing) is the focus of a large number of studies. However, recent studies using PFTs to predict the effect of pasture management in different regions did not give consistent predictions for the same set of PFTs. This lead to the suggestion that more specific traits better suited for a specific region be used in the future. We consider the identification of the most adaptative traits for surviving grazing and mowing in different biomes an important goal. Using temperate grasslands in Europe as an example, we show that (i) plant height, often considered as the best predictor of species response to grassland management, is coupled with other more relevant functional traits, and that (ii) clonal traits have important, often neglected functions in the response of species to grassland management. We conclude that single traits cannot be the only basis for predicting vegetation changes under pasture management and, therefore, a functional analysis of the trade-off between key traits is needed.
Dung beetle assemblages were monitored using baited pitfall traps from January to December 2006 in Northern Tunisia. 4,965 beetles belonging to 37 species were trapped. Aphodius lineolatus and Onthophagus taurus dominated the assemblages. Results showed a significant seasonal variation in assemblage composition, and diversity. There were four periods of activity during the course of the year. Temporal turnover was highest in October and in February. Temporal distribution of species shows seasonal segregation and opposite patterns in the two dominant guilds (Aphodiinae-dwellers and Scarabaeidae-tunnelers). Aphodiidae-dwellers were active from autumn to spring, although they were affected by summer drought. The Aphodius-dweller showed high temporal plasticity and phenological segregation. In contrast, Scarabaeidae-tunnelers were active all year round but mainly in the spring-summer period and less so in winter. Species in this guild showed a high degree of phenological overlap and a short ecological length. Our results suggest that coexistence in dung beetle guilds is facilitated by their phenological patterns, which reflect distinct ecological requirements and biogeographical origin of species. Geotrupidae-tunnelers and Scarabaeidae-rollers were rare and occurred mainly in the summer-autumn period, when individuals of the two other guilds were rare.
Long-term spring phenological instants of 57 migratory bird species, i.e. arrival in summer visitors and departure in winter visitors, were recorded in South Moravia (Czech Republic) from 1952 through 2001 and evaluated for annual correspondence with the North Atlantic Oscillation (NAO) weather system. The migration instants occurred significantly earlier following positive winter/spring NAO index values (causing periods warmer than normal in Europe) in a number of short-distance migrants with a European winter range (e.g., Alauda arvensis, Columba palumbus, Corvus frugilegus, Motacilla alba, Phoenicurus ochruros, Phylloscopus collybita, Serinus serinus, Sturnus vulgaris, Vanellus vanellus), whereas they did not correlate with NAO in most long-distance migrants having a sub-Saharan winter range (e.g., Acrocephalus spp., Anthus trivialis, Apus apus, Cuculus canorus, Delichon urbica, Ficedula albicollis, Hippolais icterina, Hirundo rustica, Jynx torquilla, Lanius collurio, Locustella spp., Muscicapa striata, Oriolus oriolus, Phylloscopus sibilatrix, Riparia riparia, Streptopelia turtur, Sylvia spp.). The winter/spring (especially February and March) NAO conditions thus affect the migration timing of short-distance migrants that winter in western or southern Europe, and could explain their earlier than normal arrival that had been observed in Europe since the 1980s.
1_Insects feeding on the foliage of oak were studied on a mountain where species of Mediterranean deciduous and evergreen oak coexist. There were 58 insect species (54 Lepidoptera, 1 Coleopteran and 3 Hymenoptera) belonging to twenty families in the assemblage feeding on eight species of Quercus, two of which are introduced from nearby regions. The overlap in occurrence in time and of feeding niches of the insects feeding on the foliage of the different species of oak was determined using the: (a) Poole-Rathcke method, which tests phenological overlap and (b) Petraitis method, which tests niche overlap. This indicated that insect families partition seasonal time in a random and the entire assemblage in a regular way. All groups of insects partitioned season randomly except for the pairs of monophagous-oligophagous and Palearctic-Eurosiberian species, which partition season regularly. Oak folivorous insects correctly perceive the three subgenera of oaks with the exception of the planted Q. robur pedunculiflora. The folivorous insects recorded on the Mediterranean evergreen oaks (subgenus Sclerophyllodrys) differ from those on the other two subgenera (Quercus and Cerris) and co-occurring deciduous trees. The hypothesis of complete general overlap is rejected for groups based on feeding specialization, zoogeographical categories and taxonomic families. The same was the case when the entire insect assemblage was considered. The percentage of specific niche overlap of the folivorous insects is low and greatest among the monophagous species (13.8%) and those with a Mediterranean distribution (15.4%). Voltinism is not very important for this assemblage and only seven species are bivoltine of which four fed on a different species of oak in the second generation., 2_The overall conclusion is that the co-occurrence in space of these species is possible because they occur regularly at different times during the season whereas that of insect groups based on zoogeographical, taxonomic or feeding specialization are randomly dispersed in time., Maria Kalapanida, Panos V. Petrakis., and Obsahuje seznam literatury