Diversity Of Leafhoppers Research Articles

Inventory of leafhoppers in irrigated rice in Tamil Nadu

Leafhoppers diversity was studied in irrigated rice ecosystems of Cauvery Delta Zone, High Rainfall Zone and Western Zone. Leafhopper assemblage comprised 14 species of Cicadellidae and among them Maiestas dorsalis (Motschulsky) was found to be the most abundant species (35.02%), followed by Cofana spectra (Distant) (23.15%). The order of species diversity in the observed districts were Western Zone (13 species) > High Rainfall Zone (8 species) > Cauvery Delta Zone (4 species). Shannon Weiner Index revealed a higher diversity in High Rainfall Zone and Western Zone (H'= 1.77 > 1.76). Margalef's Index of species richness was observed highest in Western Zone (a = 1.93). Pielou's Evenness Index was found to be almost similar for Western Zone (0.30) and Cauvery Delta Zone (0.29) while High Rainfall Zone exhibited highest evenness (0.37). Jaccard index of similarity of 50% (highest) was observed between Western Zone and Kanyakumari, Cauvery Delta Zone and High Rainfall Zone. Berger-Parker Index of dominance (D) revealed M. dorsalis to be the most dominant in Western Zone (0.25) and Cauvery Delta Zone (0.66) while High Rainfall Zone showed a high dominance of Nephotettix nigropictus (Stål) (0.27). Among the leafhoppers studied Balclutha incisa (Matsumura), Cicadulina bipunctata (Melichar), Empoascanara maculifrons (Motschulsky), Exitianus sp., Thomsonia porrecta (Walker) were recorded for the first time in rice ecosystem of Tamil Nadu. The present study will be a baseline information on the diversity of leafhoppers in irrigated rice of Tamil Nadu and will complement the data collected in the future to gain a holistic understanding on the leafhopper diversity of Tamil Nadu.

Rapid response of vascular plants and insects to restoration of montane grasslands

IntroductionIndustrialization has ushered in massive changes in agriculture. Particularly in low mountain ranges, large-scale afforestation with Norway spruce on traditionally managed, semi-natural grasslands has caused a severe decline in biodiversity. Tree removal, hay transfer and resumption of grazing or mowing are typical measures to re-create species-rich grasslands. The aim of this study was to use vascular plants and three insect taxa (leafhoppers, true bugs, and grasshoppers) as bioindicators to evaluate the success of montane grassland restoration on former spruce forests in Central Europe. In addition, we intended to identify the drivers of species richness within the studied grasslands in order to derive suitable recommendations for habitat management.MethodsWe analyzed two different treatments: (i) grazed restoration sites where trees had been cut and species-rich green hay had been applied (N = 9) and (ii) target sites with a long continuity of low-intensity grazing (N = 9).Results and DiscussionOur study revealed that all studied taxa responded rapidly to the restoration measures. After a development period of 3 to 5 years, we found no differences in species richness and diversity of leafhoppers, true bugs and grasshoppers (all, target and threatened species). In addition, non-metric multidimensional scaling showed a large overlap in species composition between restoration and target grasslands. Among target and threatened species, vascular plants displayed the same pattern as insects and reached similar values when comparing the two treatments. However, total species richness and diversity of vascular plants were still higher on the target sites and species composition overlapped only partially. Grazing intensity was the predictor with the highest explanatory power in multivariable (Generalized) Linear Mixed-effects Models, being negatively related to species richness of leafhoppers and true bugs. We conclude that the measures implemented were effective in re-establishing target communities of different taxa. The transfer of seed-containing hay enabled or accelerated the development of the vegetation. Insects, on the other hand, were able to recolonize the restored grasslands on their own, given that these sites were embedded in a network of species-rich grasslands. With regard to insects (e.g., leafhoppers and true bugs), it should be ensured that grazing is applied at low intensity.

Brochosomes and Other Bioaerosols in the Surface Layer of the Atmosphere of Moscow Metropolis

The paper presents the results of the morphological study of aerosol particles in the urban air of Moscow (Russia) in 2019–2022 by scanning electron microscopy (SEM). Our monitoring revealed mineral and anthropogenic particles, and also primary bioaerosols (PBA), such as pollen, spores, plant fibers, etc., typical for the urban environment. Moreover, in July 2021, brochosomes, lipid secretions of semi-hard-winged insects Cicadellidae (or leafhopper), were found in several aerosol samples. They are quasi-spherical hollow porous semi-regular polyhedra (truncated icosahedra) of 0.2–0.7 microns in size, consisting mainly of carbon and oxygen. Despite the prevalence and diversity of leafhoppers, identification of their secretions in atmospheric aerosols in situ is rather rare: single articles from South Korea, Spain, the Himalayas, and the United States. In this sense, the results obtained are interesting and novel. PBA particles cover a wide size range and have a complex and diverse shape, which determines the distance and efficiency of their atmospheric transport. Pollen and fungal spores have a high allergenic potential and can have harmful effects on human health. Any new information about PBA can be useful for studying the development and dynamics of ecosystems.

Diversity of leaf hoppers on fruit crops and weeds in North Kashmir

This study analyses the diversity of leafhopper fauna at six locations (Wadura, Arampora, Dangiwacha, Imberzalwari from District Baramulla and Chogul and Chetkak from District Kupwara) occurring on various fruit crops and weeds. Diversity indices such as species diversity index, evenness index, richness index and abundance were computed. These reveal that six species infest these, of which those infesting fruit trees include Empoasca decipiens, Empoasca fabae, Agallia spp., Aconeurella erebrus and Exitianus indicus; and Stirellus spp., Maiestas dorsalis, Macrosteles quadrilineatus, Exitianus indicus and one plant hopper species viz., Laodelphax striatellus infest weeds. Maximum abundance was observed to be of A. decedens on fruit trees and Stirellus spp. on the weed flora.

Effects of Habitat Fragmentation on the Population Structure and Genetic Diversity of Erythroneurini in the Typical Karst Rocky Ecosystem, Southwest China.

Simple SummaryIn this article, based on satellite imagery, field survey collection, and molecular sequencing data, the habitat fragmentation, species diversity, and genetic diversity of Erythroneurine leafhoppers in three typical karst areas (the Shibing Yuntai Mountain Nature Reserve, the Bijie Salaxi Demonstration Zone, and the Zhenfeng-Huajiang Demonstration Zone) in southwest China were explored. The results of the study show that the fragmentation degree of Erythroneurine leafhopper habitat is affected by the degree of rocky desertification in the area, and there is a positive correlation between them. The species diversity and genetic diversity of Erythroneurine leafhoppers in the study area and its various plots are all affected by habitat fragmentation, and there are certain differences in species, quantity, and gene-flow among different fragmented populations. The weaker the degree of habitat fragmentation in the region, the higher the species diversity and genetic diversity. In order to better protect the species diversity and genetic diversity of other organisms such as the Erythroneurine leafhopper species and their host plants, the following measures can be taken based on the background of the study area. (1) Strengthen the control of rocky desertification; (2) Enhance farmers’ awareness of ecological protection; (3) Increase the continuity of suitable habitats; (4) Improve the stability of the ecosystem; and (5) Improve management policies for protected areas.Karst rocky desertification is one of the main causes of habitat fragmentation in Southwest China. Guizhou Province is located in the center of the karst area in southern China and is a typical karst ecological environment fragile area. Many studies have shown that habitat fragmentation is the main factor leading to the loss of biodiversity and species extinction, and it is also one of the important factors that threaten the survival of natural organisms. This study initially explored the habitat fragmentation degree, species diversity, and genetic diversity of leafhoppers in three typical karst areas in Guizhou. The study was combined with the general situation of the study area, understanding the main factors affecting habitat fragmentation, and putting forward reasonable protection suggestions for species resources. Based on satellite imagery, field survey collection, molecular sequencing data, and related index measurement methods, we measured the habitat fragmentation degree, species diversity index, and genetic diversity index of Erythroneurine leafhoppers of Shibing Yuntai Mountain Nature Reserve, Bijie Salaxi Demonstration Zone, Zhenfeng-Huajiang Demonstration Zone. Moreover, we compared the differences in the three study areas, carried out correlation analysis with relevant environmental factors, and discussed the main factors that formed the results. The results of the study show that the species diversity and genetic diversity of Erythroneurine leafhoppers in the study areas are affected by habitat fragmentation, and the weaker the degree of habitat fragmentation in the region, the higher the species diversity and genetic diversity, which is specifically manifested in species, quantity, and gene-flow. Understanding the status of biodiversity in karst areas is conducive to the sustainable development of biological resources. In order to better protect the diversity of such insects and their host plants and other biological diversity, combined with the background of the research area, we propose corresponding protection measures for reference.

Restoration measures foster biodiversity of important primary consumers within calcareous grasslands

Despite great efforts in European nature conservation, semi-natural habitats such as calcareous grasslands are still suffering considerable declines due to abandonment. Shrub cutting and subsequent grazing or mowing are effective restoration measures to counteract the adverse effects of management cessation. Here, for the first time, we used leafhoppers (Auchenorrhyncha) as bioindicators to assess the conservation value of restored calcareous grasslands.We compared environmental conditions and leafhopper assemblages of 21 restored grasslands and 21 regularly managed sites (control) within the largest area of calcareous grasslands in the northern part of Germany. Furthermore, we applied Generalised Linear Mixed-effects Models (GLMM) to assess the effects of environmental parameters on species richness of leafhoppers within the restored grasslands.After a period of three to eight years, the restoration measures had led to species-rich leafhopper assemblages, including both habitat specialists and threatened species. However, we still found clear differences in leafhopper composition compared to the control. Within the restored grasslands, a pronounced field layer and an increased number of host plants positively affected species richness.In conclusion, the restored grasslands form open fringe-like habitat structures that clearly enhance the conservation value of calcareous grasslands by (i) harbouring numerous exclusive (indicator) species leading to a higher leafhopper diversity at the habitat level and (ii) by providing habitats for several habitat specialists which occurred only rarely on control grasslands. In order to maintain or even increase the biodiversity of calcareous grasslands, we recommend a combination of traditional grazing and small-scale shrub cutting.

Low conservatism of leafhopper communities in remnant and reconstructed prairie sites in a working agroecological landscape

Leafhoppers (Hemiptera: Cicadellidae) form a large, diverse insect family that contributes significantly to trophic interactions and pathogen transmission in grasslands. We compared leafhopper communities of five remnant prairies and five prairie reconstructions in northeastern Kansas, USA. We hypothesized that leafhopper communities would be more conservative (i.e., greater dependence on prairies) and diverse on remnant as compared to reconstructed prairies, and that remnants would support more grass-feeders. We also predicted that sites surrounded by natural/semi-natural landscapes would have greater leafhopper diversity. We found grass feeders represented a higher proportion of leafhoppers on remnants. We found, however, no difference in mean conservatism between remnants and reconstructions, and overall levels of conservatism were lower than other grassland data sets. Mean conservatism was greater in the mid-summer than in early summer, where migratory pests such as Macrosteles were abundant. Although remnants and reconstructed prairies didn’t differ in leafhopper diversity, diversity increased with forb percent cover. The amount of natural and semi-natural land cover around sites had complex relationships with leafhopper diversity and composition. For future studies, we encourage coordinated studies on leafhopper communities across the tallgrass prairie region, with a particular focus on conservatism. Deciphering the effect of survey times, and grassland size and management, on prairie-dependent leafhoppers is important. We predict that large numbers of migratory species may lead to greater homogeneity in leafhopper communities across sites early in the season. Over time, site types and landscape features may progressively filter species and amplify local specialists, resulting in more late-season variation among sites.

Diversity of Leafhoppers (Hemiptera: Cicadellidae) Associated with Border Grasses and Maize During the Wet and Dry Seasons in Mexico.

Leafhoppers constitute one of the largest groups of pests causing damage to crops worldwide. Edge grasses, which are border crops (also known as border grasses), contain diverse plant species and maintain large populations of leafhoppers during the tropical dry and wet seasons. However, little is known about the diversity of leafhoppers on these grasses. The objective of this study was to characterize the diversity of leafhoppers on maize and on surrounding border grasses during the dry and wet seasons. Leafhopper adults were collected with a sweep net from border grasses during the dry season, when maize is absent. During the wet, maize-growing season, leafhoppers were collected in both the maize fields and their surrounding edge grasses. A highly diverse (H' = 1.97 ± 2.03) leafhopper population was seen on the edge grasses during the dry season, and during the wet season, leafhopper diversity was higher in the edge grasses (H'= 1.79 ± 1.72) than in the maize fields themselves (H'= 1.67 ± 1.12). Throughout the wet season, the most abundant leafhopper species in border grasses were Stirellus bicolor (Van Duzee) (Hemiptera: Cicadellidae), Graminella sonora (Ball) (Hemiptera: Cicadellidae), and Balclutha incisa (Matsumura) (Hemiptera: Cicadellidae), whereas Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae) was the most abundant species in maize fields. All of these species were from the subfamily Deltocephalinae. Canonical Component Analysis showed that leafhopper abundance of Sibovia compta (Fowler) (Hemiptera: Cicadellidae), Graphocephala aurolineata (Fowler) (Hemiptera: Cicadellidae), D. maidis, and S. bicolor was associated with abiotic factors such as relative humidity, soil moisture, temperature, and pluvial precipitation. Nevertheless, for most leafhopper species, abundances were not significantly correlated with the abiotic variables measured.

Local and Landscape Constraints on Coffee Leafhopper (Hemiptera: Cicadellidae) Diversity.

The intensification of agriculture drives many ecological and environmental consequences including impacts on crop pest populations and communities. These changes are manifested at multiple scales including small-scale management practices and changes to the composition of land-use types in the surrounding landscape. In this study, we sought to examine the influence of local and landscape-scale agricultural factors on a leafhopper herbivore community in Mexican coffee plantations. We sampled leafhopper (Hemiptera: Cicadellidae) diversity in 38 sites from 9 coffee plantations of the Soconusco region of Chiapas, Mexico. While local management factors such as coffee density, branches per coffee bush, tree species, and density were not important in explaining leafhopper abundance and richness, shade management at the landscape level and elevation significantly affected leafhoppers. Specifically, the percentage of low-shade coffee in the landscape (1,000-m radius surrounding sites) increased total leafhopper abundance. In addition, Shannon’s diversity of leafhoppers was increased with coffee density. Our results show that abundance and diversity of leafhoppers are greater in simplified landscapes, thereby suggesting that these landscapes will have higher pest pressure and may be more at-risk for diseases vectored by these species in an economically important crop.

Rewilding with large herbivores: Direct effects and edge effects of grazing refuges on plant and invertebrate communities

Natural grazing refuges can contribute significantly to plant and animal diversity in grazed ecosystems, particularly when herbivore densities are high. When natural grazing refuges are absent, artificial refuges could be created, for example by means of fencing. It remains, however, unclear how grazing refuges affect the diversity of various taxa in their surroundings. Edge effects can be expected to be positive for biodiversity because at these edges minimal disturbance is combined with beneficial light conditions for plant diversity. This can be expected to decrease with increasing distance and to differ between matrix vegetation types.Here, we investigated the impact of herbivore exclusion through fencing on communities of plants and various invertebrate taxa in a rewilding area on very productive soil, the Oostvaardersplassen, The Netherlands. The area is grazed year round by Heck cattle, konik horses and red deer, at a combined density of approximately 2.4animalha−1. Ten exclosures (13×12m) were erected in 2010 and plant communities were monitored for three years. In the third year, pitfall trapping, earthworm counts and plant surveys were performed in the centre, at the edge, at 10m and at 20m distance from each exclosure.Plant species richness declined strongly at the centre of the exclosures, but remained high outside the exclosures and at their edges. Earthworm, isopod, myriapod and ground beetle diversity increased in the exclosures, but showed small or no differences in species composition, while weevils showed a decrease. Spider, true bug, and leafhopper diversity did not differ, but showed large changes in species composition. For leaf-, dung and click beetles, neither diversity nor species composition differed systematically between treatments. For all taxa, diversity at the exclosure edges was as high as in the most diverse treatments, thus, combining all taxa to calculate multidiversity showed species richness to peak at the edge of the exclosures, but this positive edge-effect extended less than 10 metres.We conclude that when natural grazing refuges are not present, the creation of grazing refuges may thus be an effective management tool to increase diversity. Because exclosure edges support the highest multidiversity, maximising the edge length will have most beneficial effects for grassland flora and fauna, which can be achieved by creating many small, rather than few large refuges, or by creating serrated rather than straight edges. Such positive effects can be expected to be beneficial to higher trophic levels such as birds and other vertebrates.

Diversity of Leafhoppers during the Winter Dry Season on Perennial Grasses Bordering Harvested Fields of Maize

Leafhoppers are efficient vectors of plant pathogens, but their diversity during the off season in perennial grasses bordering harvested fields of maize has not been studied. The objective of this study was to document the diversity of leafhoppers on grasses that grow during the winter dry season when harvested fields of maize, Zea mays L. ssp. mays, are fallow. Green perennial grasses at Jalisco, Mexico, were sampled with a sweep net every 2 weeks from November 2012 through June 2013. The Shannon-Wiener index showed a diversity of H´= 1.86 and the Pielou index showed a lack of evenness (J´= 0.58) in abundance of all species. In total, 25 taxa from 22 genera were collected, identified, and illustrated. The subfamily Deltocephalinae was most abundant and diverse, with 17 taxa in 14 genera. Greatest species diversity was found during the first 4 months of the winter dry season. The Deltocephalinae Stirellus bicolor, Graminella sonora, and Dalbulus elimatus were most abundant and found throughout the winter.

Diversity of leafhoppers (Hemiptera: Cicadellidae) in experimental rice lots and associated weeds in Buenos Aires province, Argentina

We identified the species of Cicadellidae associated with rice fields from an agricultural experimental station of La Plata city, Argentina, and explored the diversity pattern of the leafhopper assemblage. Insects were obtained from rice and surrounding weeds between 2006 and 2010. Syncharina argentina (Berg) and Agalliana ensigera Oman were the most abundant species in rice and weeds, respectively. Diversity (H′), heterogeneity (D) and evenness (J) indices were estimated. There was a significant effect of crop cycle (2006 to 2010) and host plant (rice and weeds) on H′ and D, with the interaction between them being not significant. Evenness was similar in rice lots and weeds, but differed between crop cycles. The pattern of abundance of species within rice lots and weeds followed the logarithmic model. Possible explanations for this pattern are discussed. The importance of the presence of some species as vectors of plant pathogens is highlighted.

Effects of Montane Heathland Restoration on Leafhopper Assemblages (Insecta: Auchenorrhyncha)

AbstractAt the beginning of the 20th century, many montane heathlands were abandoned and became subject to natural succession or afforestation by humans. Thus, the formerly large montane heathlands slowly degraded into small and isolated patches. In this study, we evaluate the influence of restoration measures on leafhopper (Auchenorrhyncha) assemblages of montane heathland ecosystems in Central Europe. Our analyses comprised three different site types that were adjacent to each other: (1) montane heathlands, (2) restoration sites, and (3) control sites. Leafhoppers showed a clear response to montane heathland restoration. Thus, after 4–5 years since implementation of restoration measurements restoration sites were characterized by the highest species richness. However, detailed analyses of leafhopper diversity, species composition, and environmental parameters on the three site types revealed that restoration sites were rather similar to control sites and significantly differing from montane heathlands. We conclude that leafhoppers are excellent bioindicators for restoration measurements because they reflected environmental differences between the three site types. Restoration measurements might only be a useful instrument to promote typical montane heathland leafhopper communities in the long run. Colonization by leafhoppers is, however, dependent on many different factors such as leafhopper mobility, vegetation structure, microclimate, and the establishment of ericaceous dwarf shrubs. Practitioners should establish a management regime (grazing and sod‐cutting) that creates a mosaic of different habitat structures and increases typical heathland vegetation, thus, favoring the colonization of typical heathland leafhoppers.

Diversity and Abundance of Leafhoppers in Canadian Vineyards

Leafhoppers (Hemiptera: Cicadellidae) are pests of many temperate crops, including grapevines (Vitis species). Uncontrolled populations can induce direct and indirect damage to crops due to feeding that results in significant yield losses and increased mortality in infected vineyards due to virus, bacteria, or phytoplasmas vectored by leafhoppers. The main objective of this work was to determine the diversity of leafhoppers found in vineyards of the three main Canadian production provinces, i.e., in British Columbia, Ontario, and Quebec. Approximately 18,000 specimens were collected in 80 commercial vineyards from 2006 to 2008. We identified 54 genera and at least 110 different species associated with vineyards, among which 22 were predominant and represented more than 91% of all the leafhoppers. Species richness and diversity were estimated by both Shannon's and Pielou's indices. For each province, results indicated a temporal variation in species composition. Color photographs provide a tool to quickly identify 72 leafhoppers commonly associated with vineyards.

Disentangling direct and indirect effects of experimental grassland management and plant functional-group manipulation on plant and leafhopper diversity

BackgroundPlant biodiversity can affect trophic interactions in many ways, including direct bottom-up effects on insects, but is negatively affected by agricultural intensification. Grassland intensification promotes plant productivity, resulting in changes in plant community composition, and impacts on higher trophic levels. Here, we use a novel grassland management experiment combining manipulations of cutting and fertilization with experimental changes in plant functional group composition (independent of management effects) to disentangle the direct and indirect effects of agricultural management on insect herbivore diversity and abundance. We used leafhoppers as model organisms as they are a key insect taxon in grasslands and react rapidly to management changes. Leafhoppers were sampled between May and September 2010 using standardized sweep netting and pan traps.ResultsPlant diversity, functional group composition and management regime in grasslands affected leafhopper species richness and abundance. Higher cutting frequencies directly led to decreasing leafhopper species richness, presumably due to the higher disturbance frequency and the reduction in food-resource heterogeneity. In contrast, fertilizer application had only a small indirect negative effect via enhanced aboveground plant biomass, reduced plant diversity and changes in functional group composition. The manipulated increase in grass cover had contrasting direct and indirect effects on leafhopper species richness: grass cover directly increased leafhopper species richness, but negatively affected plant diversity, which in turn was positively related to leafhopper species richness. In conclusion, insect diversity is driven in complex direct and indirect ways by grassland management, including changes in functional group composition.ConclusionsThe availability of preferred food sources and the frequency of disturbance are important direct and indirect drivers of leafhopper species richness, interacting in complex ways with plant diversity and food resource heterogeneity.

Diversity and abundance of leafhoppers in Canadian vineyards.

Leafhoppers (Hemiptera: Cicadellidae) are pests of many temperate crops, including grapevines ( Vitis species). Uncontrolled populations can induce direct and indirect damage to crops due to feeding that results in significant yield losses and increased mortality in infected vineyards due to virus, bacteria, or phytoplasmas vectored by leafhoppers. The main objective of this work was to determine the diversity of leafhoppers found in vineyards of the three main Canadian production provinces, i.e., in British Columbia, Ontario, and Quebec. Approximately 18,000 specimens were collected in 80 commercial vineyards from 2006 to 2008. We identified 54 genera and at least 110 different species associated with vineyards, among which 22 were predominant and represented more than 91% of all the leafhoppers. Species richness and diversity were estimated by both Shannon’s and Pielou’s indices. For each province, results indicated a temporal variation in species composition. Color photographs provide a tool to quickly identify 72 leafhoppers commonly associated with vineyards.

High Plant Richness in Prairie Reconstructions Support Diverse Leafhopper Communities

AbstractA primary reason for restoring plant communities is to increase biodiversity to previous levels. It is expected that restoring land with greater plant diversity will increase biodiversity at higher trophic levels, but high diversity seed mixes are expensive. In this study, we used one insect family, leafhoppers (Hemiptera: Cicadellidae) to assess the difference in leafhopper communities that result from establishing high compared with low plant richness restorations. We tested the hypotheses that: (1) the added effort of a high richness restoration leads to measurable increases in both diversity and richness of leafhoppers; and (2) that leafhopper community composition is more similar to remnant prairies in high richness than in low plant richness restorations. We found that higher plant richness led to 3‐ to 7‐fold increases in leafhopper and prairie‐dependent leafhopper diversity and richness in restorations. Leafhopper communities in high richness restorations were not more similar to remnant prairies, rather they were distinct among high and low richness restorations and prairie interior. Leafhopper richness and diversity correlated with plant richness, and leafhopper community composition differed among plant community assemblages, but not with the occurrence of single plant species. For our sites, species‐rich restorations provided better quality habitat for leafhoppers that was comparable to remnant prairie. Our results suggest that restorations with high plant species richness better support animal food webs.

Diversity of Cicadellidae in agricultural production areas in the Ovens Valley, north‐east Victoria, Australia

AbstractThere is a paucity of data on the distribution of Cicadellidae (leafhoppers) in Australia. This study quantifies the relative abundance, seasonal activity and diversity of leafhoppers in the Ovens Valley region of north‐east Victoria, Australia. Species diversity and abundance was assessed at four field sites in and around the field borders of commercially grown tobacco crops using three sampling techniques (pan trap, sticky trap and sweep net). Over 51 000 leafhopper samples were collected, with 57 species from 11 subfamilies and 19 tribes identified. Greater numbers and diversity of leafhoppers were collected in yellow pan traps. The predominant leafhopper collected was Orosius orientalis (Matsumura). Twenty‐three leafhopper species were recorded for the first time in Victoria and eight economically important pest species were recorded. Seasonal activity of selected leafhopper species, covering two sampling seasons, is presented.

Diversity and abundance of leafhopper species (Homoptera: Cicadellidae) among red maple clones

A survey was conducted in the 2001 growing season to examine the leafhopper diversity and abundance among trees of 17 red maple (Acer rubrum) clones. Yellow sticky traps were used to qualify and quantify the number of aerial leafhoppers from 1 May 2001 until 4 September 2001. A total of 45 species from eight different leafhopper subfamilies, for a total of 6055 individuals, were considered in this study. The mean number of leafhoppers collected, mean species richness, diversity and evenness were significantly lower on traps of trees for ‘October Glory’ than for the other clones. Yet, none of the leafhopper species dominated the weekly samples. Species similarity among clones ranged from 56 to 90%. No two clones had complete similarity. ‘Franksred’ and trees of a controlled cross between ‘October Glory’ × ‘Autumn Flame’ shared the highest degree of species similarity, while clones from PA, USA and RI, USA were the least similar. The development of new clones did not create new pest problems, but suppressed populations of damaging pests, and maintained the diversity of low abundance species.

Plant succession in perennial grass strips and effects on the diversity of leafhoppers (Homoptera, Auchenorrhyncha)

The biodiversity of agroecosystems may be enhanced by increasing species richness and structural diversity of vegetation by creating perennial strips. Aims of the study were (1) to describe the plant succession of perennial strips in northern conditions; (2) to clarify the difference in insect fauna between cereal fields and perennial strips; (3) to determine the effect of succession on leafhoppers in perennial strips; and (4) to compare the leafhopper fauna of perennial strips with that of other uncultivated biotopes. Three perennial grass strips (12 m wide, 420 m long) were sown in the middle of cereal fields (15 ha) in 1991 with a seed mixture of timothy ( Phleum pratense), meadow fescue ( Festuca pratensis), red clover ( Trifolium pratense) and white clover ( Trifolium repens). The perennial strips were not mown or renewed after the establishment. In 1992 and 1993 barley and in 1994 spring wheat were grown in the surrounding fields. The composition of plant cover in the grass strips changed over four seasons. The total number of plant species decreased from 23 species in 1992 to 10 in 1995. The change resulted from the dramatic decrease of annual weeds after the first year. Furthermore, the total plant cover declined slightly. The cover of P. pratense increased, whereas that of T. pratense and T. repens decreased. The plant species typical of early succession were annual weeds including Tripleurospermum inodorum and Thlaspi arvense. In the last year, perennial weeds such as Cirsium arvense and Elymus repens became common. Leafhopper abundance and species number were higher in perennial grass strips than in cereal fields. Furthermore, the species composition varied between habitats. Year-to-year fluctuations in leafhopper catches were large. Leafhopper abundance and diversity (Shannon index) were highest in 1993 when 192 sweep net samples contained a total 4680 specimens belonging to 37 species. The plant species richness of the grass strips did not correlate with the abundance and species richness of leafhoppers, which seemed to be more dependent on other factors. Although the plant species number in grass strips decreased clearly during succession, changes in species richness of leafhoppers were not so great. Factors affecting the leafhopper community are discussed.