With the recent publication of the second report of the Intergovernmental Panel on Climate Change the evidence has become more convincing that not only is world climate changing but that these changes are likely to be caused by human activities. Climate change will have important implications for insect conservation and pest status. Under these circumstances it may be time to put more effort into investigating actual climate induced changes. The types of evidence required and available for such studies are discussed, with particular reference to the Lepidoptera. Preliminary results are presented on moth phenology from the Rothamsted Insect Survey which suggest that changes, consistent with climate change, can already be detected.
Rainbow trout (Oncorhynchus mykiss) and other salmonids have been widely stocked into upland streams throughout the world to provide a basis for sport fisheries, but the effects of such introductions on indigenous and endemic aquatic insect assemblages are poorly documented. In this study, we examine the impact of rainbow trout on the indigenous and endemic entomofauna of upland streams in Kokee State Park, Kauai, Hawaii, with particular emphasis on the potential threat trout pose to populations of endemic damselflies in the genus Megalagrion. Rainbow trout were introduced into the upland streams of Kauai beginning in the 1920s, with over 60 years of subsequent restocking. This study indicates, however, that streams in this area still maintain diverse populations of Megalagrion damselflies and other indigenous and endemic aquatic insects, both in catchments containing naturally reproducing trout populations and in catchments lacking rainbow trout. Our results indicate that the indigenous and endemic aquatic insect communities in the streams under study compare favorably in terms of density and taxonomic richness with other isolated and unimpacted streams elsewhere in Hawaii, and retain high densities and relative percentages of indigenous and endemic aquatic insect taxa. Our results demonstrate that the threats posed by conspicuous introduced species such as trout should not simply be assumed a priori on the basis of postulated negative interactions, because this may divert limited resources from programs aimed at control of other, potentially more destructive introduced taxa such as inconspicuous poeciliid fishes.
Records for butterflies on Elba island in the last 120years have been summarized and examined. I assessed species occurrence
for six periods of twenty years by bibliographic, museum and field data. For five periods data appear complete and species
assemblage highly concordant. Nonetheless, a certain evolution of Elba butterflies seems to be occurring. Moreover, I assessed
the regression between frequency at sources and frequency on islands among species living on Italian islets and used the residuals
as a tendency to be less or more common on islands compared to mainland. By a successive regression, I verified that these
residuals are actually related to the number of periods each species has been recorded on Elba. Interestingly, the number
of record periods is not correlated with species appearance. I concluded that there is a large core of persistent species
and a few species that are occasionally reported on Elba. Such satellite species represent butterflies that are less likely
to occupy island biotas and may represent endangered populations.
For two consecutive years we registered the presence (or absence) of blue winged grasshoppers (Oedipoda caerulescens; Linnaeus, 1758) on 312 habitat patches of differing size in a region of more than 3000 ha. The data show that presence of grasshoppers on a habitat patch is dependent on patch size as well as on patch isolation. We used an ecological incidence model to describe the metapopulation dynamics of the regional population and derived the parameters for this model from presence-absence data and observations of Oedipoda dispersion. The analysis shows that local extinction of grasshopper populations is influenced by strong fluctuations of environmental conditions and that for a number of small patches in our region recolonization is important for the presence of O. caerulescens. Colonization probability, as derived using the incidence model, is in good agreement with estimates from a population genetical analysis.
Predation of insects by feral cats (Felis silvestris catus) on a heterogeneous oceanic island (La Palma, Canary Islands) was studied. A total of 127 invertebrates were identified in
the analysis of 500 scats (100 from each habitat of the Island). Invertebrates appear in 18.00% of the scats, representing
an insignificant percentage of the total consumed biomass by feral cats on La Palma Island (0.05%). Insects were the most
common invertebrate prey both in percentage of occurrence (90.6%) and invertebrate biomass (93.53%), with a total of 115 prey
items. Orthoptera, Lepidoptera and Coleoptera were the main prey groups. Among the five main habitats present in La Palma
Island, the temperate forest shows the lowest consumption of invertebrates, although insect consumption did not show statistical
differences. However Orthoptera and Lepidoptera were more frequently preyed on in the pine forest and in the xerophytic shrub,
respectively. Moreover, applying the Simplified Morisita index, a different insect composition of the diet was observed among
habitats. Although, none of insects predated by feral cats are threatened, the identification of invertebrate component of
the feral cats’ diet is an important tool for the correct understanding of predation significance and to prevent damage to
endangered insect species.
The habitat associations of the noctuid moth Double Line Mythimna turca (Linnaeus 1761) were studied in three areas in Britain by setting up light traps equidistant alon0g transects which passed through different habitat types. Counts were made of M. turca at each trap station and the results compared with the habitat present in the vicinity of each trap. The results using chi-square analysis indicate that the preferred habitats for M. turca are woodland and Pteridium aquilinum scrub, especially where the grasses Agrostis capillaris and Holcus mollis occur. The environmental factors affecting moth catches are discussed and chi-squared expectations are adjusted to take account of the different efficiency of light traps in open grassland and woodland situations. The light trap transect method is shown to be useful for moth species where little is known of their ecology and can be used to provide a straightforward insight informing additional targeted autecological studies. The methodology may be less suited to those species which occur at low density, are poorly attracted to light or are known to migrate.
Recording the insect species of hollow trees, particularly in larger cavities, presents a major methodological challenge.
A whole range of endangered saproxylic beetles and other wood-inhabiting species live together in this habitat. In order to
conduct preliminary surveys and monitor populations of the hermit beetle (Osmodermaeremita) in Natura 2000 areas designated for nature conservation according to the EU Habitats Directive, a vacuum cleaner has been
used for the first time. Sampling of 127 trees with cavities revealed 39 trees in which O.eremita was present and for which submission of a report is mandatory. A total of 35 species was found, including 17 species in the
German red data book as well as six species which are classified as relict species of ancient woodland. The method has therefore
proved itself to be very appropriate and is now routinely used in southern Germany.
Patch occupancy by Coenonympha tullia has been surveyed in 166 sites in Northumberland, UK. It was found in 117 of them and absent in 37. Weather conditions were too poor to determine its presence at a further 12 sites. Differences in habitat quality among sites account for patch occupancy as successfully (R2 = 48%) as isolation and patch size jointly (R2 = 46%). This finding has relevance for metapopulation studies as it demonstrates that greater attention should be given to differences in habitat quality among patches beyond their size and distance from one another. Together, habitat quality, patch size and isolation account for 61% of the variation in C. tullia occupancy of sites and discriminant analysis produces a correct classification for > 88% of sites. Habitat quality and patch size jointly account for much the same variance, and result in the same classification of the twelve sites excluded from analysis, as they do in conjunction with patch isolation. This result suggests that there is potential for predicting changes in occupancy of sites from site specific data in the face of changes to biotopes, such as planned exploitation and deterioration of sites from other causes including climate change and management practices.
The marsh fritillary, Euphydryas aurinia, has declined greatly in distribution across its range within Europe, resulting in its designation as a protected species
under Annex II of the 1979 Bern Convention and the EC Habitats and Species Directive. The decline has been linked to a marked
reduction in the extent of suitable calcareous and wet grassland habitats, habitats which have been lost through conversion
of land to agriculture or urban areas, or reduced in quality due to inappropriate management. The UK is now one of the major
strongholds for this butterfly in Europe, although much of the remaining habitat is small, isolated and highly fragmented.
E. aurinia populations fluctuate greatly due to the combined effects of biotic (e.g. parasitoids) and abiotic (e.g. climate change)
factors. We quantified the habitat associations of larval webs of E. aurinia on fragmented versus extensive (unfragmented) calcareous grassland habitat in southern England to test the hypothesis that
habitat requirements of E. aurinia are more constrained within fragmented landscapes. Within both fragmented and unfragmented landscapes the quality and quantity
of its main host plant in the UK, Succisa pratensis, was positively related to numbers of E. aurinia larval webs found. The sward height was also important at predicting the distribution of larval webs in both landscapes,
although the heights were greater within sites in the unfragmented (≈20cm) compared to fragmented (≈15cm) landscape. We
also found significant effects of elevation and the cover of bare ground on numbers of larval webs. Elevation was strongly
correlated with the availability of host plant, whilst bare ground was only significant on sites within the fragmented landscape,
showing a negative relationship with number of larval webs. Our results further emphasise the importance of not only maintaining
the habitat quality of extant calcareous grassland sites for E. aurinia in the UK, but also increasing the size and connectivity of these sites to increase the chances and rate of (re)colonisation
of unoccupied but suitable habitat. In addition, we show that the habitat requirements of E. aurinia on sites in a large unfragmented landscape may be less specific and thus require less extensive management than that required
to create optimal conditions necessary at smaller, more isolated sites in fragmented landscapes.
–Marsh fritillary–Calcareous grassland–Butterfly–Metapopulation–Habitat fragmentation–Salisbury plain
The marsh fritillary is widely distributed in Wales, with over 200 populations identified in the past 15years. However, agricultural
improvement, habitat fragmentation and changes in agricultural practices continue to impact on status and a decline in range
of 23.5% was recorded over a 10-year period. Solutions must be applied at the landscape scale to improve metapopulation viability
and, since 2000, surveys of habitat extent and quality have been carried out on 116,373ha of grassland surrounding 111 populations.
Analysis of the results for standard ‘core landscapes’ (based on circles of 1km radius around known populations) shows that
overall cover of suitable breeding habitat is 3.44%. However, only 11.85% of the grassland that was suitable for marsh fritillaries
was classified as being in Good Condition. The remainder was regarded as having sub-optimal vegetation structure and/or the
foodplant was at low density; 33% of the habitat resource that was not in Good Condition was regarded as inappropriately or
excessively managed and 67% was suffering from neglect. An Index of Landscape Quality is used to rank landscapes for evaluation.
Thirty-five ‘core landscapes’ (incorporating 98 marsh fritillary populations) were assessed and just four exceeded a threshold
value deemed to represent viable landscape configurations. The results have demonstrated that most marsh fritillary populations
in Wales exist within depauperate patch networks that lack sufficient breeding habitat of the right quality for long-term
persistence. Without targeted conservation action the marsh fritillary will continue to decline in Wales. This paper reports
on efforts to collect information on the quality of breeding habitat for marsh fritillaries across Wales in order to identify
priorities for conservation action.
The occurrence pattern of the marsh fritillary was studied within a patch network on the Baltic island Öland, Sweden. Presence/absence
was established for potentially suitable habitat patches (n=158) on calcareous moist grassland and analyzed in a multiple logistic regression model where patch area, patch isolation
and nine habitat quality variables were included as explanatory variables. Larval food plant density was positively, and patch
isolation negatively, correlated to the presence of Euphydryas aurinia. Area did not contribute to the explanation of the occurrence pattern. Significant interactions between larval food plant
density times patch isolation, and larval food plant density times vegetation height, show that with low food plant density
the butterfly primarily occurs in patches with a vegetation height of 4–10cm, within a distance of 250m from nearest occupied
patch. In patches with a high food plant density the butterfly occurs in patches where the vegetation height is higher, 4–16cm,
and the distance to nearest occupied patch can be longer, up to 1.4km. This study supports earlier findings in other regions,
suggesting that a network of adjacent patches with a high food plant density and a vegetation height within the preferred
threshold, despite their size, is an apparent conservation goal.
Ecological demands were studied in Elaphrus cupreus, a frequent species, and E. uliginosus, one of the most endangered carabids in Europe. Ecological experiments were performed in the laboratory and the field in
northern Germany. Abundance was measured using the mark-and-recatch method. Both species prefer sites with water content changes
lower than 25%. E. uliginosus prefers higher temperatures than E. cupreus and niche breadth was on average wider in E. cupreus than in E. uliginosus. E. uliginosus is restricted to grassland sites with a low fraction (>0 and 25%) of bare soil. E. cupreus was mainly found on sites having >75–100% bare soil. This preference of E. uliginosus can be referred to its high temperature demands using open regions for warming up and its predatory behaviour using hideouts
for a rapid predatory push. The wider niche structure and lower temperature demand of E. cupreus allows the inhabitation of cooler alder woods. It prefers large fractions of bare soil because its predatory behaviour is
to run randomly on the soil. Thus, E. uliginosus demands wet extensively grazed grassland where cattle produces low fractions of bare soil, while E. cupreus prefers intensively grazed sites in grassland or alder woods.
The distribution of the endangered species Boros schneideri was studied by checking the presence of larvae and adults under the bark of dead Pinus sylvestris trees in 13 pine forests in Lithuania. B.schneideri was found in 10 biggest pine forests, the area of which exceeded 20,000ha. However, it was not detected in smaller isolated
forests. In Kazlų Rūda, Šimonys, Pabradė and Rūdiškės forests this species was recorded for the first time. The part of localities
in which B.schneideri was found and the percentage of trees with B.schneideri were significantly higher in the main parts of the biggest forests than in satellite or smaller forests. Both these parameters
were significantly lower in forests located in the close vicinity of urban territories than in forests further from them.
Consequently, the forest size and the distance of the forest from urban territories were found to be of critical importance
for the survival and density of the B.schneideri population. These distribution regularities are important for the establishment of protected areas for this species conservation.
The occurrence of the froghopper Neophilaenus albipennis was surveyed in a network of 506 patches of its host plant Brachypodium pinnatum. The occupancy pattern largely depends on the size and isolation of the habitat patches. Together with the observed turnover this indicates a metapopulation structure. In order to simulate the dynamics of the metapopulation the incidence function model was used. The model was successfully fitted to the field data. Impacts on the metapopulation were simulated and the probability of survival of the whole metapopulation was estimated. Implications for conservation, especially the minimum viable metapopulation size, are discussed.
The Moroccan locust, Dociostaurus maroccanus (Thunberg), was traditionally considered as one of the most dangerous agricultural pests in the Mediterranean (s.l.) zone. Its broad polyphagy, extreme voracity, enormous fecundity and capability to migrate in swarms made it a major enemy of agriculturists from the Canary Islands to Afghanistan. However, outbreaks of the Moroccan locust seem to have been more frequent in the past and, in many regions, the species has become rare. Climatic factors, in particular the amount of spring rainfall, are critical for the developmental cycle of D. maroccanus. However, anthropogenic factors appear to have the most powerful effect on the locust's population dynamics. On the one hand, deforestation and overgrazing create the necessary prerequisites for colonization by the Moroccan locust. On the other hand, converting grasslands into croplands makes the habitat totally unsuitable for the insect because females can lay eggs into undisturbed soil. These two conflicting tendencies appear to govern the current evolution of Moroccan locust populations, their manifestations being different according to the geographical zone. Although in some regions (e.g. in many European countries) D. maroccanus has lost its formerly high economic importance, in others (North African and central Asian countries) the species continues to flourish and may even increase its pest status.
The transfer of hay from a donor site onto a receptor site is currently a widely accepted restoration procedure to establish grasslands with high biodiversity and rich in species. The impact of this procedure on vegetation has been well studied. However, its influence on the insect population has not been investigated. This study verifies that individuals of Metrioptera bicolor (Orthopteroidea: Tettigoniidae) were successfully transferred with hay. Three individuals transferred with the hay were still able to reproduce after the hay transfer. This result corresponds to 4.6% of the 65 marked individuals that were mapped on the donor site on the day of hay transfer. Of the estimated 1220–3013 individuals on the donor site (8300 m2), 56–139 reproductively able individuals were transferred with the hay. Suitable habitat structures presupposed, this number is sufficient to initiate a persistent colonisation of the species on the receptor site. The loss rate of M. bicolor due to grass cutting totalled 42%, which can be considered a very high mortality rate. Comparable studies on bush crickets show a medium loss rate of 21%, in relation to body size.
The conservation status of Attacus wardi, a large iconic moth endemic to north-western Australia, is reviewed based on new data. Available evidence on the spatial distribution, critical habitat and threatening processes suggests the species qualifies as threatened according to IUCN Red List Criteria, and that its conservation status nationally should be revised from Endangered to Vulnerable. The species depends on relatively large patches of wet and dry coastal tropical monsoon forest, and it has the potential to be an important flagship species for the conservation of these ecological communities. Further studies are needed to determine minimum patch size and spatial connectivity among patches to support viable populations of the moth.
Chorthippus lacustris is an endemic grasshopper (Orthoptera) species in Epirus, Greece. Its population status, habitat characteristics, and relation
to historical and current human land use are investigated. The species has a restricted and fragmented distribution pattern.
Five locations, four within Pamvotida Lake basin and one in Lake Paramythia, cover a total of 0.12 km2. It is strongly dependent on wet grasslands, flooded on a seasonal basis. The greatest population density is recorded in
the site with the greatest diversity of dominant plant species. Ch. lacustris is estimated to have lost 85–99% of its habitat during the last 50 years due to wetland drainage. The main threat to the
species survival is further habitat loss by urbanisation around Pamvotida Lake and by land conversion to agriculture in Paramythia
Lake, even though both sites belong to the Natura 2000 network. The species status is Critically Endangered and it should
be listed in Annex II of the Habitat Directive (92/43/EEC) as a priority species for conservation. Restoring wet grasslands,
protecting them from further urbanisation and drainage, and monitoring species population are the main measures proposed for
During 1993–1996, two teams (Schlicht, Swengels) surveyed the same Minnesota prairies, but without any coordination of sites,
routes, methods, dates, and results between teams. In 27 instances, both teams surveyed the same site in the same year between
30 June and 18 July. For the 18 most frequently recorded species, abundance indices (individuals/h per site) significantly
covaried between teams for 11 (61%) species, including 2/3 prairie specialists tested. No species significantly correlated
negatively, 17/18 species had positive correlations, and the preponderance of positive correlations was significant. Swengel
indices per hour (two surveyors; unlimited-width transect) averaged 2.42 times Schlicht indices (one surveyor; fixed-width
transect). These results demonstrate that transect surveys by different teams at the same sites but not the same routes produce
similar rankings of species abundance among sites. This approach to population monitoring (transect surveys during the season
that covers the most specialist species at once, not necessarily with fixed routes but recording all species seen) might also
be appropriate in other regions with high habitat loss and low human population density. Abundance indices from surveys by
seven teams spanning 1979–2005 were calculated for evaluating population trends. For the five analyzable specialist species,
25/30 population trend tests of a species at a site had a negative direction, a highly significant skewing (P<0.0001). By contrast, five “common” (most frequently recorded non-specialist) species had an even distribution of negative
and positive trends. While adjacent sites had similarly timed decline thresholds (last year when a higher rate or any individual
was recorded vs. first year when all subsequent indices were lower or zero) within species, these thresholds were not synchronized
among sites in different counties. All sites analyzed in this study were preserves managed primarily with fire. While the
ecosystem (or vegetative) approach to reserve selection has been validated in other studies to be effective at capturing populations
of associated specialist butterflies, butterfly declines after reserve designation will likely continue unless the ecosystem
approach to reserve management includes specific consideration of individual butterfly species’ required resources and management
Managers surveyed for sensitive butterfly species in the San Bruno Mountain Habitat Conservation Plan area between 1982 and
2000 using an opportunistic “wandering transect” method. To extract as much valuable information as possible from the data
collected by this method we analyzed patterns of surveys and butterfly presence and absence within 250m square cells gridded
across the area within a Geographic Information System. While estimates of butterfly abundance were not possible, the data
could be tested for trends in butterfly occupancy. For those cells surveyed during at least 10years, no trends in the total
number of occupied cells was evident for either Callippe silverspot or mission blue butterfly. There were cells, however,
that showed positive or negative trends (P < 0.20) in occupancy for each species (Callippe silverspot: 14 positive, 15 negative, 6 cells occupied all years; mission
blue butterfly: 40 positive, 40 negative, 2 cells occupied all years). We conclude that for the period 1982–2000 the population
of each species was stable in overall total distribution, but indicate geographic areas of concern for each, specifically
the edges of the northeast ridge for Callippe silverspot butterfly and the northwest of the study area for mission blue butterfly.
Vegetation composition analysis using orthophotography with field corroboration indicates that those areas with declines in
occupancy for these species experienced native coastal scrub succession and a corresponding loss in grassland butterfly habitat,
while positive trending and stable cells had stable grassland proportions. Habitat managers at San Bruno Mountain should therefore
incorporate programs for protecting grassland butterfly habitat not only from invasive weeds but also from succession to native
coastal scrub. This approach illustrates the feasibility of using occupancy as an indicator to track butterfly status in a
protected area even when suboptimal data collection methods are used, but the difficulties of using these data also reinforces
the need for managers to devise monitoring schemes appropriate for their objectives before implementing them.
Detailed knowledge of the biodiversity of spider communities on agricultural land is important both in terms of enhancing pest control and understanding the driving forces influencing nature conservation value. Pitfall traps were used to assess spider species diversity at 71 Scottish agricultural sites between May and September during 1996 and 1997. Land-use varied from intensive arable fields, grasslands and extensive heather (Calluna vulgaris) moorland. Spider species richness (S) was found to decrease significantly as farm management intensity increased. Several linear regression models based on the 1996 data (50 sites) and a selection of plant, soil and landscape variables explained up to 88% of the variation in species richness. Four of these models were used to estimate 1997 species richness (36 sites: 15 repeat and 21 new) and up to 58% of sites were correctly predicted to within four species of the actual number caught. As only 60% of the repeat 1997 sites had values of S within four units of their 1996 score, this suggested a relatively high level of model accuracy. Model accuracy increased to 64% when all four models were used for each site, suggesting the individual models should be targeted at specific land-use types. We discuss the relevance of these models for predicting the consequences of changes in agricultural land-use for spider diversity.
Slovenia has one of the most extensive Natura 2000 networks in Europe with 259 SAC’s covering 31.4% of the country. To determine
how well does the current network cover the areas of high butterfly diversity and/or aggregation of the butterfly species
of conservation concern, the data from the recent survey for a distribution atlas were used. Altogether 99,423 records of
173 species collated after 1979 were used. The data distribution is slightly biased towards SAC’s, with 44.8% of localities
within them, most likely due to sparsely sampled urban areas and intensive farmland areas which are found only outside SAC’s.
The diversity and distribution of red listed species was evaluated at a 5×5km grid square level. Additionally the importance
of the size of the SAC’s was compared to their butterfly species diversity. In general the high diversity areas also hold
the largest aggregation of red listed species with core areas concentrated in SW Slovenia. The SAC’s cover majority of areas
with high diversity and the distribution of all but one threatened butterfly species. That species is Colias myrmidone, which is now considered extinct in Slovenia with no records after 1993. The most prominent areas with high conservation
value in Slovenia not included in the SAC’s network are the Koroška region, Goriška Brda region, lower Sava River valley and
Slovenske Gorice region. The butterfly diversity in small SAC’s is relatively high with increases in size only gradually increasing
the species numbers, thus emphasizing the importance and conservation value of small SAC’s for sustaining high butterfly diversity
KeywordsLepidoptera–Butterflies–Distribution–SAC network–Habitat directive