Grassland leafhoppers (Hemiptera: Auchenorrhyncha) as indicators of habitat condition - a comparison of between-site and between-year differences in assemblage composition

The Auchenorrhyncha (leafhoppers) show great potential as indicators of grassland habitat quality, which would make them useful as a conservation tool. However, they are known to have labile populations. The relative importance of site identity and the year of sampling in the composition of leafhopper assemblages on chalk grassland are assessed for two sets of sites sampled twice. The study included a total of 95 sites (one set of 54, the other of 41), and demonstrated that for both sets the vegetation community and geographical location had high explanatory value, while the influence of year was small. The conclusion is that, notwithstanding population fluctuations, the leafhopper assemblages are a good indicator of habitat quality, and represent a potentially valuable tool in grassland conservation and restoration.

Community associations of chalk grassland leafhoppers (Auchenorrhyncha): conclusions for habitat conservation

Due to their confinement to specific hostplants or restricted habitat types, Auchenorrhyncha have the potential to make suitable biological indicators to measure the quality of chalk grassland under different management practices for nature conservation. The Auchenorrhyncha data from a study designed to identify the factors influencing the invertebrate diversity of chalk grasslands in southern England was used to evaluate the potential use of this group of insects as biological indicators. Between 1998 and 2002 altogether 81 chalk grassland sites were sampled. Vegetation structure and composition were recorded, and Auchenorrhyncha were sampled at each site on three occasions in each of two seasons using a ‘Vortis’ suction sampler. Auchenorrhyncha assemblages were then linked to the different grassland plant communities occurring on chalk soils according to the British National Vegetation Classification (NVC). Altogether 96 Auchenorrhyncha species were recorded during the study. Using data on the frequency and dominance of species, as is commonly done for plant communities, it was possible to identify the preferential and differential species of distinct Auchenorrhyncha assemblages. Significant differences between the Auchenorrhyncha assemblages associated with the various chalk grassland plant communities of the NVC were observed down to a level of sub-communities. We conclude that data on Auchenorrhyncha assemblages can provide valuable information for the setting of conservation management priorities, where data on floristic composition alone may not be sufficient, providing additional information on aspects of vegetation structure and condition.

Novel margin management to enhance Auchenorrhyncha biodiversity in intensive grasslands

Agricultural intensification, including changes in cutting, grazing and fertilizer regimes, has led to declines in UK and NW European grassland biodiversity. We aimed to develop field margin management practices that would support invertebrate diversity and abundance on intensively managed grassland farms, focusing on planthoppers and leafhoppers (Auchenorrhyncha). Replicated across four farms in south-west England, we manipulated conventional management practices (inorganic fertilizer, cutting frequency and height, and aftermath grazing) to create seven treatments along a gradient of decreasing management intensity and increasing sward architectural complexity. Auchenorrhyncha were sampled annually between 2003 and 2005. Auchenorrhyncha abundance and species richness was highest in the most extensively managed treatments. Abundance was lowest with frequent cutting, while species richness was lowest where cattle grazing occurred. Unexpectedly, application of inorganic fertilizer had no effect on Auchenorrhyncha abundance or species richness. Management options that enhance invertebrate diversity, while allowing the remainder of the field to be managed conventionally, represent a potentially important conservation tool for many lowland improved grasslands. Extensification of conventional management in field margin areas of such grasslands are likely to benefit this numerically dominant component of grassland invertebrate fauna. These management practices have the potential to be incorporated into existing UK and European agri-environment schemes.

Female reproductive system of the sugarcane spittlebug Mahanarva fimbriolata (Auchenorrhyncha): Vitellogenesis dynamics and protein quantification

The present study aimed describing the ovaries of the sugarcane spittlebug Mahanarva fimbriolata which are meroistic telotrophic with nurse cells and oocytes located in the tropharium. SEM revealed paired ovaries located dorsolaterally around the intestine, and oocytes exhibiting shapes ranging from round (less developed) to elliptic (more developed), suggesting a simultaneous, although, asynchronous development. Based on histological data we classified the oocytes in stages from I to V. Stage I oocytes exhibit follicular epithelium with cubic and/or prismatic cells, fine cytoplasmic granules. Stage II oocytes present intercellular spaces in the follicular epithelium due to the incorporation of yolk elements from the hemolymph. Small granules are present in the periphery of oocytes while larger granules are observed in the center. Stage III oocytes are larger and intercellular spaces in the follicular epithelium are evident, as well as the interface between follicular epithelium and oocyte. Yolk granules of different sizes are present in the cytoplasm. During this stage, chorion deposition initiates. Stage IV oocytes exhibit squamous follicular cells and larger intercellular spaces when compared to those observed in the previous stage. The oocyte cytoplasm present granular and viscous yolk, the latter is the result of the breakdown of granules. Stage V oocytes exhibit a follicular epithelium almost completely degenerated, smaller quantities of granular yolk and large amounts of viscous yolk. Based on our findings we established the sequence of yolk deposition in M. fimbriolata oocyte as follows: proteins and lipids, which are first produced by endogenous processes in stages I and II oocytes. Exogenous incorporation begins in stage III. In stages I and II oocytes, lipids are also produced by follicular epithelial cells. The third element to be deposited is polysaccharides, mainly found as complexes. Therefore, the yolk present in the oocytes of this species consists of glycolipoproteins. Molecular weights of proteins present in M. fimbriolata oocytes ranged from 10 to 92 KDa, differently from vitellogenin, the most common protein present in insect oocytes, weighing approximately 180 KDa. (c) 2006 Elsevier Ltd. All rights reserved.

Meiotic chromosomes and nucleolar behavior in testicular cells of the grassland spittlebugs Deois flavopicta, Mahanarva fimbriolata and Notozulia entreriana (Hemiptera, Auchenorrhyncha)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relacionamento filogenético entre espécies pertencentes às famílias Belostomatidae, Gelastocoridae, Gerridae, Notonectidae, Veliidae (Hemiptera: Heteroptera) e Cercopidae (Hemiptera:Auchenorrhyncha)

Pós-graduação em Genética - IBILCE

Monitoramento de cigarrinhas (Hemiptera: Auchenorrhyncha) em acessos de coqueiros-anão e gigante.

2016

Espécies de Cercopoidea (Hemiptera: Auchenorrhyncha) coletadas em pomares de ameixeira em Santa Catarina, Brasil.

2011

The first assess of the haplotypes from COI gene sequences in species of spittlebugs (Cicadomorpha: Hemiptera) and aquatic true bugs (Gerromorpha and Nepomorpha: Hemiptera) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Does organic grassland farming benefit plant and arthropod diversity at the expense of yield and soil fertility?

Organic management is one of the most popular strategies to reduce negative environmental impacts of intensive agriculture. However, little is known about benefits for biodiversity and potential worsening of yield under organic grasslands management across different grassland types, i.e. meadow, pasture and mown pasture. Therefore, we studied the diversity of vascular plants and foliage-living arthropods (Coleoptera, Araneae, Heteroptera, Auchenorrhyncha), yield, fodder quality, soil phosphorus concentrations and land-use intensity of organic and conventional grasslands across three study regions in Germany. Furthermore, all variables were related to the time since conversion to organic management in order to assess temporal developments reaching up to 18 years. Arthropod diversity was significantly higher under organic than conventional management, although this was not the case for Araneae, Heteroptera and Auchenorrhyncha when analyzed separately. On the contrary, arthropod abundance, vascular plant diversity and also yield and fodder quality did not considerably differ between organic and conventional grasslands. Analyses did not reveal differences in the effect of organic management among grassland types. None of the recorded abiotic and biotic parameters showed a significant trend with time since transition to organic management, except soil organic phosphorus concentrations which decreased with time. This implies that permanent grasslands respond slower and probably weaker to organic management than crop fields do. However, as land-use intensity and inorganic soil phosphorus concentrations were significantly lower in organic grasslands, overcoming seed and dispersal limitation by re-introducing plant species might be needed to exploit the full ecological potential of organic grassland management. We conclude that although organic management did not automatically increase the diversity of all studied taxa, it is a reasonable and useful way to support agro-biodiversity.

Plant and arthropod community sensitivity to rainfall manipulation but not nitrogen enrichment in a successional grassland ecosystem

Grasslands provide many ecosystem services including carbon storage, biodiversity preservation and livestock forage production. These ecosystem services will change in the future in response to multiple global environmental changes, including climate change and increased nitrogen inputs. We conducted an experimental study over 3 years in a mesotrophic grassland ecosystem in southern England. We aimed to expose plots to rainfall manipulation that simulated IPCC 4th Assessment projections for 2100 (+15 % winter rainfall and −30 % summer rainfall) or ambient climate, achieving +15 % winter rainfall and −39 % summer rainfall in rainfall-manipulated plots. Nitrogen (40 kg ha−1 year−1) was also added to half of the experimental plots in factorial combination. Plant species composition and above ground biomass were not affected by rainfall in the first 2 years and the plant community did not respond to nitrogen enrichment throughout the experiment. In the third year, above-ground plant biomass declined in rainfall-manipulated plots, driven by a decline in the abundances of grass species characteristic of moist soils. Declining plant biomass was also associated with changes to arthropod communities, with lower abundances of plant-feeding Auchenorrhyncha and carnivorous Araneae indicating multi-trophic responses to rainfall manipulation. Plant and arthropod community composition and plant biomass responses to rainfall manipulation were not modified by nitrogen enrichment, which was not expected, but may have resulted from prior nitrogen saturation and/or phosphorus limitation. Overall, our study demonstrates that climate change may in future influence plant productivity and induce multi-trophic responses in grasslands.