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1.
The Nelson Environmental Study Area (NESA) is maintained by the University of Kansas for experimental research in ecology. Since 1983, benthic and emergent aquatic macroinvertebrates have been collected as part of several research projects. In this paper, we present the taxonomic composition and emergence phenologies of Chironomidae collected at NESA. Emergence traps, artificial substrate samplers, light traps and hand-picked specimens from D-nets yielded a total of 123 species, 41 of which are new records for Kansas. Chironominae was the most species rich subfamily with 79 species, while Tanypodinae and Orthocladiinae were represented by 25 and 19 species, respectively. Emergence phenologies from small, replicated, experimental ponds were determined by quantitative sampling in 1988 and 1989. In both years, many taxa showed patterns of seasonal emergence, being restricted to one of the three seasons sampled, while 9 (1988) and 12 (1989) taxa emerged over most or all of the sampling periods.Cladotanytarsus spp. andPsectrocladius vernalis were the most abundant taxa in 1988 and 1989, respectively. Chironomid distribution patterns at NESA and their relevance to patterns across the state are discussed. Annotations are provided for selected taxa and new records for the state are indicated.  相似文献   

2.
To understand the mechanisms driving species diversity is central to community ecology. Here, we explored if habitat partitioning is associated with a species‐rich ectoparasite community in small rodents from a tropical dry forest in western Mexico. We trapped 199 mice in three 0.5 ha‐plots from eight small rodent species for every two months, from July 2011 to April 2012, and collected their ectoparasites. We identified 17 species of mites, two sucking lice species, two phoretic species, and one commensal species. The most abundant ectoparasite species was Steptolaelaps liomydis, representing 42 percent of all ectoparasites collected; seven ectoparasite species had < 10 individuals. Eighteen ectoparasite species (of 22 species) were collected from the most abundant rodent Liomys pictus. C‐score and the number of checkerboard species pairs were significantly higher against a random expectation. Ectoparasite species in L. pictus mice showed host microhabitat partitioning; Fahrenholzia ehrlichi and Fahrenholzia texana were found only in the anterior dorsal area, Ornithonysus sp. occurred along the dorsal part, Ixodes species were restricted to the ears, and Steptolaelaps liomydis was found throughout the body. We also identified ectoparasite communities with distinct species composition in two rodent species that use contrasting macrohabitats (L. pictus, strictly terrestrial; Peromyscus perfulvus, mostly arboreal). The remaining and low abundant rodent species showed a species‐poor ectoparasite community composition. We conclude that habitat partitioning at both macro and microhabitat scales appeared to characterize the species‐rich ectoparasite community. Conversely, most rodent host species with low abundances showed a species‐poor ectoparasite community.  相似文献   

3.
Adult rove beetles (Staphylinidae) were sampled every 7–14 days from one winter wheat field located in each of the four major wheat growing regions of Oklahoma during the 1999–2000 and 2000–2001 growing seasons. The number of cereal aphids per tiller, wheat plant growth stage, and wheat tiller density also were estimated. A total of 12 genera representing 13 species of beetles were collected from the field. The density of rove beetles was generally low, ranging from 0.003 beetles per m2 in fall to 0.106 beetles per m2 in spring. Rove beetle communities differed among seasons. After accounting for the effect of season, there was no statistically significant association between rove beetle community structure and field location, aphid density, wheat plant growth stage, or wheat plant density. Most rove beetle species showed no association with a particular season, however, Aleochara notula Erichson, Lathrobium sp., and Oxypoda sp. were present predominantly in fall, while Bisnius inquitus Erichson was associated with winter. Oxypoda sp. was the most abundant rove beetle in winter wheat fields in spring and was relatively abundant in winter, but was not collected from wheat fields in fall. Tachyporus jocosus Say was present in wheat fields during all seasons. T. jocosus was the most abundant rove beetle species in the winter wheat fields in fall and winter and was the second most abundant species during spring.  相似文献   

4.
We investigated the effects of different environmental factors on the distribution and abundance of 6 species of dasyurid marsupials using a multiple‐scale analysis. Data collected in the spinifex dunefields of the Simpson Desert, Australia, were analysed at 3 spatial scales spanning more than 5 orders of magnitude: “metasite” (covering an area of 1000–2000 km2), site (2–12 km2) and grid (0.01 km2). Temporal variability was also investigated, using data collected in March, April, and May in 4 consecutive years from 1997 to 2000. Both abiotic and biotic factors influenced the capture rates of different species at different times and spatial scales. At the coarsest spatial scale, Dasycercus cristicauda (mulgara) was consistently limited in its distribution by the intensity of rainfall, probably as an indirect result of increased grazing pressure from pastoral activity and a higher density of feral predators in high rainfall areas. However, at the finest spatial scale, this partly carnivorous species was scarce in areas of dense spinifex, perhaps because such habitats yield lowest returns during foraging, and was more common in areas where small invertebrate prey were abundant. Factors affecting the distribution of the most abundant dasyurid species in the study area, Sminthopsis youngsoni (lesser hairy‐footed dunnart), could not be identified at any scale; we conclude that this reflects the opportunistic foraging strategies and flexible habitat requirements of this insectivorous species. Both Ningaui ridei (wongai ningaui) and Sminthopsis hirtipes (hairy‐footed dunnart) were less abundant throughout the study region. For N. ridei, a spinifex specialist, predictors of occurrence could be identified only at the finest scale of analysis; at the grid level, a close positive association was detected in 2 of the 4 study years between capture rate and spinifex cover. For S. hirtipes, all 3 levels of spatial analysis revealed a negative association between capture rate and both rainfall and spinifex density. For the rarely‐caught S. crassicaudata (fat‐tailed dunnart) and Planigale tenuirostris (narrow‐nosed planigale), no clear results were obtained at any spatial scale, and we interpret this to indicate that the study region represents sub‐optimal habitat for these species. Given that different factors affected the distribution and abundance of dasyurids at different spatial scales over time, we conclude that a multiple‐scale approach to population and community analysis is vital to accurately identify which environmental processes shape population and community dynamics. Understanding the interplay between regional and local processes will be crucial for management of existing species populations and for prediction of their distributions and abundances in future.  相似文献   

5.
The paper presents for the first time important information regarding population structure, growth rate, length‐weight relationships and reproductive aspects of the Neretvan nase, Chondrostoma knerii, a fish species endemic to the Neretva River. Chondrostoma knerii is mainly distributed in the lower parts and delta of the Neretva River wetlands and its tributaries (Krupa River, Hutovo Blato wetlands) shared between Croatia and Bosnia Herzegovina. Samples were collected between 2000 and 2001 during the reproduction period of the species in the Hutovo Blato wetlands area. Population structure analysis indicates that all ages appear, from 0 to 7+. Longevity was estimated at 7.5 years. Main age classes were 3, 4 and 5 years, totalling 91.00% of all individuals. Males ranged between 2 and 5+ years of age, and females between 1 and 7+ years of age. Maximum length was 28.04 cm and maximum weight, estimated from the length‐weight relationship, as 206.8 g. Found scattered in streams of high water velocity, eggs were attached to the substrate (aquatic plants or solid objects). Correlation between egg number and length and weight was extremely low. The gonad‐somatic index distribution showed an inverse proportionality with total length. Main length classes for reproduction ranged from 20 to 24 cm, while fecundity ranged between 2000 and 16 000 eggs per female.  相似文献   

6.
Invasive plants and urban run‐off constrain efforts to restore sedge meadow wetlands. We asked if native graminoids can self‐restore following the removal of Typha × glauca (hybrid cattail), and if not, what limits their recovery? After we harvested Typha and depleted its rhizome starch reserves, Carex spp. expanded vegetatively (approximately 1 m over 2 years) but not by recruiting seedlings. A seedling emergence experiment showed that seed banks were depleted where Typha had eliminated the sedge meadow over a decade ago (based on aerial photo analysis). Carex seedling emergence was 75–90% lower where Carex was absent than where it remained in the plant community, and at least 17 species that were abundant 30 years ago were absent from the seed bank and extant vegetation. By varying hydroperiod, we showed that prolonged flooding prevented emergence of Carex seedlings and that a fluctuating hydroperiod reduced emergence and ultimately killed all Carex seedlings. In contrast, Typha seedlings emerged and survived regardless of hydroperiod. Thus, slow vegetative expansion by Carex, depauperate seed banks, and altered hydroperiods all constrain self‐restoration. To compensate for multiple constraints on self‐restoration, we recommend a long‐term management approach that capitalizes on flooding and the capacity of Carex spp. to regrow vegetatively. We suggest annually harvesting swaths of Typha at the edges of clones, before or during flood events, to allow gradual, vegetative self‐restoration of Carex spp.  相似文献   

7.
A significant increase in the number of reported cases of La Crosse virus (LACV) infections in eastern Tennessee has occurred in the last ten years. The objective of this study was to determine the abundance and habitat preferences of the potential vectors of LACV in this region. Adult host‐seeking mosquitoes were collected using CO2‐baited CDC light traps and a series of human‐landing catches in eastern Tennessee from 2004 to 2006. A total of 4,200 female mosquitoes of 23 species was collected by CO2‐baited CDC trapping at ten sites during the study period. Aedes albopictus (Skuse) was the most abundant mosquito collected at all sites and vegetation types, with the ratios of total Ae. albopictus to Ae. triseriatus (Say) females collected being 2.1:1 in 2004, 3.8:1 in 2005, and 4.9:1 in 2006. Ten species were collected during a series of human‐landing catches made at four different sites; one probable and three confirmed case sites of LACV infections, totaling 528 female mosquitoes. Aedes albopictus was the most abundant species collected, with a 4:1 ratio of Ae. albopictus to Ae. triseriatus females. Aedes albopictus exhibited two clear peaks of “landing” activity, one in the early morning and one in the late afternoon or early evening. Simple and multiple regression analyses of the predictors of the number of mosquitoes collected showed that populations of Ae. albopictus were three times more likely to be collected overall than Ae. triseriatus. Species (Ae. albopictus), vegetation (residential), and the previous cumulative precipitation for the four weeks prior to collection were significantly (P < 0.05) associated with the number of mosquitoes collected by CO2‐baited CDC trapping. Aedes albopictus was also more likely to be collected than Ae. triseriatus at confirmed cases of LACV infections.  相似文献   

8.
Abstract. Vegetation and soil seed banks of a threatened Atlantic fen meadow community were studied using recent phytosociological records and seedling emergence from soil samples. Similarly managed but differently degraded stands that suffered different levels of species impoverishment were compared. The actual vegetation was related to a set of phytosociological references representing the subassociations of the community. DCA positions of reference relevés from the different subassociations were overlapping, suggesting that in all references many common species occur. Recent records were positioned in‐between the seed bank samples and the references. The soil seed banks of all stands were dominated by ordinary species. Most character species had at most sparse seed banks and no seedlings of locally extinct character species, mentioned in historic floristic records, were detected. In contrast species of pioneer and small‐sedge communities as well as those of heathlands were abundant in the seed banks. Based on the vertical distribution of seeds in the soil layers most fen meadow species were classified into transient or short‐term persistent seed bank types. We concluded that complete restoration of the Cirsio dissecti‐Molinietum without reintroduc‐tion is only likely in stands that were degraded only a few years ago. On the other hand, the presence of viable seeds of Nanocyperion and Parvocaricetea species is promising for the restoration of these communities even after decades. Recreation of pioneer habitats by sod cutting will preserve these species.  相似文献   

9.
Abstract In late 2001 a category 3 cyclone impacted forest plots that were established in Tonga in 1995, and additionally, one plot was accidentally burned by an escaped land‐clearing fire. Subsequent surveys provide observations of 10 years of forest dynamics in this poorly studied region, and the first reported observations of large interannual variation in juvenile (seedling and sapling) abundance in the western tropical Pacific. The severely disturbed (burned) plot was initially colonized by a non‐native early pioneer, Carica papaya L., but 3.5 years later a native pioneer, Macaranga harveyana (Muell. Arg.) Muell. Arg., was the most abundant tree species. The seedling layer included some long‐lived pioneers and shade‐tolerant species. Two mature forest plots affected only by the cyclone changed very little over a decade. Late‐successional shade‐tolerant species that dominated the overstory were also abundant as seedlings and saplings. This is in contrast with a 30‐ to 40‐year‐old, formerly cultivated, secondary forest plot that still shows no recruitment of late‐successional dominants, in spite of the proximity of remnant forest patches. This study suggests differing pathways of succession following shifting cultivation versus cyclone and fire disturbances in Tonga. Land use legacies appear to have a long‐lasting effect on community composition.  相似文献   

10.
Fire is the most important disturbance factor in Cypress (Austrocedrus chilensis) forests in Patagonia, Argentina. This ecosystem recovers poorly after fire, and direct sowing could be a potentially useful restoration practice. To evaluate the effect of season of sowing, post‐fire plant cover (PC), and climatic variability on seedling emergence and survival, three direct sowing studies were established in two burned cypress stands: Trevelin (xeric conditions) and El Bolsón (mesic conditions). Two studies were conducted in winter (2000 and 2001) and one in spring (2001). Precipitation was higher than the mean during the 2000–2001 growing season and lower during 2001–2002. At both sites, emergence and survival were much higher for winter‐ than for spring‐sown seedlings. In the xeric stand, emergence and survival of winter‐sown seedlings increased with medium and high PC values, after the humid and dry summers, respectively. However, most spring‐sown seedlings did not emerge, and those that did were short‐lived. Because of the more favorable growing conditions in the mesic stand, PC had no effect on emergence and only favored first year survival of winter‐sown seedlings after the dry summer. Spring‐sown seedlings showed no association with PC in the mesic site, probably because the first summer was exceptionally humid. We speculate that shading plants exert a positive effect on cypress seedling establishment, likely by reducing the stress from high temperatures and low water availability. Sowing of small patches under the protection of understory vegetation could be useful in restoring burned cypress stands.  相似文献   

11.
We examined long‐term responses of an Amazonian bird assemblage to wildfire disturbance, investigating how understory birds reacted to forest regeneration 1, 3, and 10 years after a widespread fire event. The bird community was sampled along the Arapiuns and Maró river catchments in central Brazilian Amazonia. Sampling took place in 1998, 2000, and 2008 using mist‐nets in eight plots (four burned, four unburned sites). Species richness did not change significantly in unburned sites. In burned sites, however, we found significantly lower richness in 1998, higher richness in 2000, and similar richness in 2008. Multi‐dimensional scaling ordination showed consistent differences in bird communities both within burned sites sampled in different sampling years, and between burned and unburned sites in all years. Of the 30 most abundant species, 12 had not recovered 10 years after the fires, including habitat specialists such as mixed flocks specialists and ant‐followers. Fire‐disturbance favored three species (two hummingbirds and a manakin) in the short term only. All other species were either favored throughout the study (seven species of omnivores and small insectivores) or did not show a clear response (eight species). In burned sites, we also found significantly lower abundance of species sensitive to disturbances and habitat specialists over the entire study period. Although the bird community seems to be recovering in terms of richness, the overall community composition and abundance of some species in post‐burned and unburned sites remain very different, and have not recovered after 10 years of forest regeneration.  相似文献   

12.
1. Four alien cynipid gall wasps of the genus Andricus are established and still spreading in the British Isles. The order, according to the northerliness of their distribution boundary, is: A. corruptrixA. quercuscalicisA. lignicolaA. kollari. All four aliens have a sexual generation in spring on Quercus cerris (introduced to Britain) and an agamic generation in autumn on native oak species. 2. For 2 years 1994 and 1995, galls of both generations of the four alien species were sampled at eight sites from the south of England to the north of Scotland to determine the parasitoid and inquiline species that attack the new galls. The spring generations of the invading species shared a parasitoid complex of four pteromalid species. Five species of inquilines and 11 species of parasitoids emerged from the autumn galls. 3. Two colonisation events were recorded for A. lignicola and A. corruptrix. On both occasions, the spring generations were found first at the new sites, indicating that the agamic generation provides the colonisers for these invading species. After colonisation, the galls of both species were attacked by parasitoids in their first season. 4. In spring, the invading species were among the most abundant cynipids at all eight sites. By sampling the whole local community of cynipid galls, it was found that the parasitoid species attacking the spring galls of the invaders seemed to have shifted their attack to the new hosts. 5. The secondary sex ratios of the parasitoid species emerging from the sexual galls of A. quercuscalicis (the smallest of the four) showed a strong and significant male bias at all sites and in both years. Parasitoid emergence from the galls of the sexual generations of the other three species (all about equal in size) was between 60 and 70% male, and variable among sites and between years.  相似文献   

13.
Abstract 1 Native natural enemies have the potential to control fall armyworm Spodoptera frugiperda (Smith) in tropical maize grown in Mexico, where this insect pest causes severe economic losses to farmers. It has been proposed that enhancing herbivore‐induced volatile emissions in maize plants may help to increase the effectiveness of natural enemies, which use these volatiles to locate their prey. This will only be of immediate benefit to farmers if the activity of the natural enemies results in a direct reduction in herbivory. Here we report on field surveys for the most common natural enemies in a tropical maize‐growing region in Mexico and the potential effects of these enemies on herbivory by fall armyworm. 2 Caterpillars were collected in maize fields near Poza Rica in the state of Veracruz during January and February 1999, 2000 and 2001. Plants were either naturally infested by S. frugiperda, or artificially infested with laboratory‐reared larvae. Ten species of parasitoids emerged from the collected larvae and eight species of predators that are known to feed on larvae and eggs were observed on the plants. Campoletis sonorensis (Cameron) (Hymenoptera: Ichneumonidae) was the dominant parasitoid species, in 1999 and 2001. 3 Of the nine larval parasitoids collected, six (all solitary) are known to reduce herbivory, whereas one causes the host to eat more (for two species this is not known). This implies that enhancing the effectiveness of solitary endoparasitoids may benefit subsistence farmers in developing countries by immediately reducing herbivory. The overall benefit for the plant resulting from parasitoid activity also has important implications for the evolutionary role of parasitoids in contributing to selection pressures that shape indirect defences in plants.  相似文献   

14.
We monitored survival of seedlings in 216 1‐m2 quadrats in lowland rain forest in tropical north Queensland between December 2001 and December 2002. During this time, the region experienced severe drought associated with an El Nińo Southern Oscillation event. The 2001 census recorded 124 species and 2912 individuals. In late November 2002 (2 wk prior to the second census), a low intensity fire passed through approximately half of the study site removing all evidence of seedlings from 110 plots. Only 482 (17%) individuals and 64 (52%) species recorded in 2001 survived the 12‐mo period. In 96 quadrats not affected by fire, mortality was high, but considerably variable between species. Six of the 20 most abundant species in 2001 experienced mortality rates higher than the community average and two of the most abundant species showed rates lower than average. Overall, conditions experienced during 2002 caused significant changes in the rank abundances of species between censuses. Mortality due to fire was less severe and mortality more uniform across species, resulting in significant concordance between pre and postfire rankings, once the effects of drought had been considered. Our results provide the first indication of how differences in survival after a perturbation predicted to become more frequent in future global climates may alter the size and species composition of the seedling bank in Australian tropical rain forests.  相似文献   

15.
Ecological investigations of long-legged flies (Dolichopodidae) were carried out in wet meadow wetlands near České Budějovice, Czech Republic. Sampling was performed during the adult flies’ seasonal activity (March–October) in 2002, 2003 and 2004 using yellow pan traps, Malaise traps, emergence traps, and by sweeping. Altogether 5,697 specimens of 78 species of Dolichopodidae were collected, identified and analysed. The study examined community structure, species abundance, and diversity (Shannon-Weaver’s index - H’; Sheldon’s equitability index - E). Chrysotus cilipes, C. gramineus and Dolichopus ungulatus were the most abundant species in all three years. Species richness and diversity seem strongly affected by soil moisture.  相似文献   

16.
Community structures of aphids and their parasitoids were studied in fruit crop habitats of eastern Belgium in 2014 and 2015. Quantitative food webs of these insects were constructed separately for each year, and divided into subwebs on three host‐plant categories, fruit crop plants, non‐crop woody and shrub plants and non‐crop herbaceous plants. The webs were analyzed using the standard food web statistics designed for binary data. During the whole study period, 78 plant species were recorded as host plants of 71 aphid species, from which 48 parasitoid species emerged. The community structure, aphid / parasitoid species‐richness ratio and trophic link number varied between the two years, whereas the realized connectance between parasitoids and aphids was relatively constant. A new plant–aphid–parasitoid association for Europe was recorded. Dominant parasitoid species in the study sites were Ephedrus persicae, Binodoxys angelicae and Praon volucre: the first species was frequently observed on non‐crop trees and shrubs, but the other two on non‐crop herbaceous plants. The potential influence, through indirect interactions, of parasitoids on aphid communities was assessed with quantitative parasitoid‐overlap diagrams. Symmetrical links were uncommon, and abundant aphid species seemed to have large indirect effects on less abundant species. These results show that trophic indirect interactions through parasitoids may govern aphid populations in fruit crop habitats with various non‐crop plants, implying the importance for landscape management and biological control of aphid pests in fruit agroecosystems.  相似文献   

17.
Two diel emergence patterns (April and October 1990) of chironomids from a hyporhithral site (4th–5th order) in the Aude River are described. In April, 62 species were collected with a mean hourly richness of 31 (±4). The Orthocladiinae (91%) largely dominated the emergence. The total number of exuviae captured by one drift-net varied from 1300 to 11600 per one hour period. There was a clear bimodal pattern with peaks post dawn (07.00–09.00 hrs) and around sunset (18.00 hrs).In October, the total number of exuviae captured was much lower and varied from 150 to 540 per one hour period with post dawn (06.00–08.00 hrs) and post sunset (18.00 hrs) peaks. Nevertheless, the total species richness (65) was higher as was the mean hourly richness (37±4). The Orthocladiinae (68%) dominated less because of increases in the Tanytarsini (15%) and Chiromini (14%). A diel rhythm appeared in autumn emergence. Most of the Orthocladiinae exuviae were collected during daylight hours, whereas most of the Chironomini and Tanytarsini were sampled during darkness. A majority of the exuviae with a length below 3 mm emerged during daylight, but most of the exuviae above 5 mm length emerged during darkness. The exuviae with an intermediate length (3–5 mm) had an amodal diel emergence pattern. In spring and autumn, the majority of species had a bimodal emergence pattern either by day (Orthocladiinae) or by night (Chironominae). But the smallest species had either an unimodal (Thiennemaniella vittata) or bimodal (Neozavrelia fuldensis) daytime emergence. The diel emergence patterns of 10 of the most frequently recorded species are presented.  相似文献   

18.
Temporal variation in the helminth parasite communities of the Pacific fat sleeper, Dormitator latifrons, from Tres Palos Lagoon, Guerrero, Mexico, was studied at the component community and infracommunity levels. In total, 185 host specimens were collected between April 2000 and March 2001. Eight parasite species were identified: Clinostomum complanatum, Echinochasmus leopoldinae, Ascocotyle (Phagicola) longa, Pseudoacanthostomum panamense, Saccocoelioides sp., Parvitaenia cochlearii, Neoechinorhynchus golvani, and Contracaecum sp. The communities had low numbers of parasite species and diversity, and contained only generalist parasites. Nested (nonrandom) species composition was observed in the infracommunities during all climatic seasons. The variation in nestedness intensity was attributed to a process of sequential colonization by the most common parasite species, because some were more abundant in the dry season, and others were more abundant in the rainy season.  相似文献   

19.
The diversity of mosquito arbovirus vectors was investigated to define regional risk of arbovirus transmission in Kenya. Mosquitoes were sampled between April, 2007 and December, 2010 at thirteen sites across seven administrative provinces and ecological zones. CDC light traps were used to collect mosquitoes while human‐landing collection was conducted in five of the sites to target day‐feeding Aedes (Stegomyia) species. Over 524,000 mosquitoes were collected and identified into 101 species, 30 of them known vectors of arboviruses endemic to Kenya. Ae. (Neomelaniconion) mcintoshi and Ae. (Aedimorphus) ochraceus were most abundant in Garissa in the arid northeastern province, and Mansonia uniformis and Mn. africana in semi‐arid Baringo in the Rift Valley Province. Ae. ochraceus, Mn. africana and Mn. uniformis were also significant in Nyanza Province, while Ae. (Neomelaniconion) circumluteolus predominated in Budalangi, Western Province. Aedes (Stegomyia) aegypti was predominant in Rabai in the Coast Province but insignificant in the western and Nyanza sites. Culex pipiens was abundant in Rift Valley and Nyanza Provinces around the lake shores. This study highlights the potential for emergence and re‐emergence of arboviral diseases among vulnerable populations. This calls for comprehensive mapping of vector distribution and abundance for planning focused vector control measures.  相似文献   

20.
1. Following its recent global spread, Harmonia axyridis (Coleoptera: Coccinellidae), an aphid predator of East Palearctic origin, dominated local coccinellid communities. While long‐term trends in this change are well documented, little is known about seasonal changes. 2. Seasonal changes in communities of adult Coccinellidae were investigated in central Europe (Prague), from April to November in 2010–2014. The beetles were collected at 2‐weekly intervals by net‐sweeping particular stands of trees (Tilia spp., Acer spp. and Betula sp.). The numbers of beetles caught were recalculated per unit effort, and average species abundance and community richness, dominance and diversity were calculated for each 2‐week period. 3. Frequencies of 21 established species varied throughout the vegetative season and general trends in this variation were similar in each of the 5 years of this study. In May–June the abundant species was Adalia decempunctata, which was later replaced by Harmonia axyridis as the most abundant species in late summer. Coccinella septempunctata colonized trees occasionally in summer. This sequence of species substitution occurred every year and was reset during winter. Species richness decreased and dominance increased during the course of each vegetative season. The diversity of the coccinellid community (Shannon index H′) significantly decreased during the course of the vegetative season. This was caused by a gradual increase in the dominance of H. axyridis, the abundance of which explained 88% of variation in H′. 4. The existence of a significant seasonal difference indicates that it is important to take this into consideration when comparing coccinellid communities.  相似文献   

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