松嫩草地牛粪中大型节肢动物种类组成及种群动态变化

研究并分析了松嫩草地牛粪中大型节肢动物种类组成及动态变化.结果表明,在草地牛粪中共调查到大型节肢动物7目20科43种,以鞘翅目、膜翅目和双翅目为主.依其食性不同,分为粪食性型(8科19种)、腐食性型(4科4种)、植食性型(4科6种)、捕食性型(5科11种)、杂食性型(2科5种)、尸食性型(1科1种)和寄生性型(1科1种).根据鞘翅目金龟总科中营粪食性型生活的粪甲虫对牛粪利用方式的不同,分为外生粪甲虫(6种)、内生粪甲虫(5种)、远生粪甲虫(2种)和偷窃寄生粪甲虫(1种).除了双顶嗡蜣螂,牛粪中大型节肢动物数量与鲜牛粪重量具有显著正相关关系(p＜0.01).粪食性型种类数和个体数量随鲜牛粪堆置时间的延长而迅速减少,7d后消失,其个体总数量与鲜牛粪堆积时间呈显著的负相关关系(p＜0.01),而与牛粪含水量呈显著正相关关系(p＜0.01),各种大型节肢动物因其食性不同在鲜牛粪中占据不同的生态位.鲜牛粪中大型节肢动物以粪食性型占绝对优势,而干牛粪中则以捕食性型和杂食性型为主.牛粪中大型节肢动物种群季节动态变化受温度、降水量与牛粪含水量影响,鲜牛粪中大型节肢动物优势种为直蜉金龟(69.25%)和肖秋家蝇与东方角蝇幼虫(25.12%).4、5、6月份和9月份,优势种为直蜉金龟,7月和8月份,优势种为蝇幼虫.     

Biological and chemical assays of pyrethroids in cattle dung

Bioassays were developed in Zimbabwe to measure pyrethroid in cattle dung. These and chemical assays then estimated concentrations in dung from treated oxen and elucidated risks to dung fauna. Laboratory bioassays with adult beetles (Histeridae and Scarabaeinae, including Copris, Digitonthophagus, Onitis and Sisyphus spp.) and muscoid larvae (Musca lusoria Wiedemann) indicated that the LC50 of pyrethroids, as ppm in the wet weight, averaged 0.04 for deltamethrin pour-on, 0.25 for deltamethrin dip, 0.22 for alphacypermthrin pour-on, 0.10 for cyfluthrin pour-on, 0.23 for cypermethrin dip and 0.63 for flumethrin dip. Field bioassays involved artificial dung pats of 800 g, deployed in woodland and inspected after 24 h to record insects dead and alive. Beetles were most abundant in the wet season. Muscoid larvae were less seasonal. The LC50 of insecticides in the field confirmed laboratory indications. Adult Diptera (muscoids and Sgifidae) were not repelled or killed until the deltamethrin concentration reached 10 ppm. Pat dispersal by dung fauna and termites (Microtermes spp.) was halved by deltamethrin at 0.1-1 ppm. Scavenging of dead beetles by ants was greatest with small beetles (< 15 mm long) uncontaminated with insecticide. Dips and pour-ons of deltamethrin on cattle gave residues of about 0.01-0.1 ppm in dung produced in the fortnight after application. About 1.6% of the deltamethrin applied was transferred to dung. Deltamethrin and alphacypermethrin in dung showed no detectable degradation in 64 days. Contamination levels threaten populations of slow-breeding beetles.     

Abundance and reproductive strategy of the dung beetle Aphodius rufipes (L.) (Scarabaeidae)

Abstract. 1. Adult A.rufipes invade fresh dung pats (mainly in August) and stay for a few days in each pat to feed and oviposit; maximum abundances: 0–100 beetles per cattle dung pat. Larval growth is completed within 40–55 days.
2. The dispersion of beetles is contagious or seemingly random. In sunny weather, with rapid crust formation on the dung, pats deposited in the afternoon are invaded by more beetles than those deposited in the morning.
3. In the field, the total number of eggs per pat is significantly less variable than the number of adult beetles; this might indicate a density-dependent, regulatory, rate of oviposition. The subsequent larval mortality is probably density-independent.
4. Experiments confirmed that the number of eggs laid per female-day in the pats was density-dependent.
5. The non-opportunistic reproductive strategy of A.rufipes may have evolved as an adaptation to life in dung pats: at excessive population densities pats might disappear before completion of larval growth.
6. Finally, A.rufipes in dung pats is compared with blowflies breeding in carrion.     

半干旱草原大中型土壤动物在畜粪分解中的作用

土壤动物是陆地生态系统的重要组分, 在有机质分解过程中具有重要作用。目前有关土壤动物在生态系统分解中的作用研究主要聚焦于植物凋落物的分解, 而对动物粪便分解的研究稀少。本研究在内蒙古典型草原设置了马粪和牛粪分解原位实验, 使用不同孔径的金属隔离网排除不同体型大小的土壤动物, 通过测定大中型土壤动物对畜粪分解过程中质量损失、碳氮含量和微生物呼吸以及土壤养分动态变化的影响, 解析其在分解中的作用。设置5个处理, 即CK, 仅土壤, 无粪; T0, 粪添加+0.425 mm隔离网(排除了粪居型和掘洞型粪金龟和中型土壤动物); T1, 粪添加+1 mm隔离网(排除了粪居型和掘洞型粪金龟); T2, 粪添加+2 mm隔离网(排除了掘洞型粪金龟); T3, 仅粪添加(不排除土壤动物)。结果表明: (1)在畜粪分解60天内, 土壤动物对畜粪的干质量损失没有显著的促进作用(P > 0.05); 相反, 在畜粪分解360天, 不隔离土壤动物处理(T3)显著地提高了牛粪干质量损失(P < 0.05), 而降低了马粪干质量损失(P < 0.05)。(2)在畜粪分解的60天内, 畜粪中碳和氮含量下降速度在有土壤动物存在的情况下(T3)快于隔离土壤动物(T0和T1)。(3)两种畜粪添加增加了土壤微生物的呼吸, 且这种增加趋势在实验的第15天和第30天在土壤动物存在时(T3)最明显。(4)与对照(CK)相比, 马粪添加处理提高了土壤速效氮、有机碳的含量和土壤含水量, 且这种增加趋势在排除掘洞型粪金龟(T2)和不排除土壤动物(T3)条件下表现更显著(P < 0.05), 而牛粪添加处理没有明显改变这些指标(P > 0.05)。研究表明, 分解初期粪金龟的取食和活动会改变畜粪的理化性质, 进而影响分解后期土壤生物在畜粪分解中的作用。     

Use of food and space by tunneler dung beetles (Coleoptera; Scarabaeinae) during reproduction

At two temperate pasturelands in northern Mexico, we explored possible competition for food and space under pats during the simultaneous nesting periods of the univoltine species Dichotomius colonicus (Say), Phanaeus quadridens (Say), and Copris sierrensis Matthews. To simulate unlimited resources, 50 5-kg cow dung pats were placed at regular distance intervals in each pastureland. After building trenches around the pats, the number and depth of each nest, as well as larval development status, were documented once for a period of 1-8 mo. Analyses of variance and association tests were used to make a between-site comparison of dung pat occupation, nests occupied per species, nests per dung pat, and nest depth below each pat. The proportion of pats occupied by each species differed significantly between sites. C. sierrensis colonizing most pats at one site and D. colonicus at the other. There were no differences between sites in the frequency of pats occupied by more than one species. The association test and Ochiai index showed that each species colonized dung pats independently. The results suggest that pat occupation depended on their location by beetles and the relative abundance of each species. The species tended to dig nests at different depths, possibly reducing interspecific competition for space. It can therefore be concluded that, when food resources seem to be unlimited, they are shared following a "lottery dynamic" model if there is spatial differentiation among species.     

Spatial distribution, resource utilisation and intraspecific competition in the dung beetle Aphodius ater

Competitive interactions in northern temperate dung beetles are poorly understood. This investigation therefore comprises a series of field and experimental work on a dung beetle species common in northern Europe, Aphodius ater, with special focus on intraspecific competitive interactions. The between-pat distribution of adult A. ater in relation to the age of sheep dung pats was studied in the field. The distribution of both sexes was contagious in the fresh pats but became more regular with increasing pat age. The successional occurrence of males and females did not differ, but immature females tended to occur in fresh pats while mature females were mainly found in older pats. With increasing age of pats, the egg load of females also increased. Egg-laying behaviour of the beetles was studied in laboratory experiments. The mean number of eggs laid per female per dung pat decreased with increasing beetle density. Thus, density-dependent processes seem to regulate resource utilisation with regard to breeding behaviour, resulting in equal exploitation of the available pats. Survival and weight of recently hatched beetles decreased with increasing initial density of eggs. Hence, in A. ater, competition between larvae for food within pats does occur. Received: 4 February 1998 / Accepted: 20 April 1998     

Establishment of pasture species on cattle dung: the role of endozoochorous seeds

Abstract. The process of colonization of cattle dung patches and its relation to endozoochorous dispersal is analysed in a Mediterranean pasture. Dung pats dropped in spring and winter were marked, and the vegetation developing on them during the first two years of colonization was followed. The influence of endozoochorous seeds on dung colonization is assessed through the study of: (1) the vegetation on spring and winter dung pats and the seed contents of both, which is abundant in the former and negligible in the latter; and (2) the vegetation on spring dung pats compared with that of the surrounding pasture. The origin of plants growing on dung (either seeds in the manure or in the soil seed bank) was traced by studying dung colonization under controlled conditions in pots with manure put on seed-free sand, and on pasture turf. The results indicate that endozoochorous seeds germinate in manure; they are the main source of recovery in gaps generated by dung pats. The micro-succession involved is independent of the type of pasture. A small-scale spatial pattern results in which gaps of old dung are dominated by endozoochorous species. Thus, dung patches enhance the similarity between grazed communities, and the variation within communities.     

Differences in temporal utilization patterns of dung pats among three scarabaeid dung beetles

1. Differences in the temporal utilization patterns of dung pats were investigated among three dung beetle species, Aphodius haroldianus, Onthophagus lenzii and Liatongus phanaeoides, and density effects of three species on emigration from a dung pat were compared.
2. A. haroldianus preferred fresh dung pats, immigrated to fresh pats and then emigrated from those pats quickly (mean duration of residence 48.4 h), whereas L. phanaeoides immigrated to older dung pats (over 7 days after deposition) as well as fresh ones and remained in the pats for the longest time (165.6 h).O. lenzii showed intermediate behavior in this respect (63.3 h).
3. In A. haroldianus, the presence of conspecifics induced faster emigration than presence of the other two species. L. phanaeoides showed the opposite relationship. In O. lenzii, the response to conspecifics was intermediate to those of the other two species.

     

Aggregated distribution of resources creates competition refuges for rainforest dung beetles

This study examines the effects of resource distribution on colonisation, intra- and interspecific aggregation, and the occurrence of low-density, competition refuges for tropical dung beetles. In field experiments from central Peru, using dung pats (resource patches) of different volumes, the numbers of interacting species and total beetle biomass at individual pats increased with increasing pat volume. In two of three separate experiments (including an experiment that also varied patch density), this represented a decrease in the biomass of beetles per unit volume (biomass-density) at larger patches. The numbers of interacting tunneller species and tunneller biomass-density were also related to the distance between pats (patch density) in one of two experiments with constant numbers of pats. Closely positioned pats had generally fewer interacting species and a lower biomass-density of beetles. For the most abundant Dichotomius species, interspecific associations increased as distances increased between dung pats. The numbers of interacting species and biomass-density declined linearly under the combined effects of increasing patch density and local patch abundance in 25 m² plots. In experimentally placed grids with large numbers of pats, colonisation of pats at the edge of the grids was generally higher than at the centre of the grids for tunnellers and Eurysternus spp. but not for ball rollers; however, at least tunnellers did not readjust to avoid patches with high densities of competitors. These results indicate that an aggregated distribution of dung and natural variability in patch size contribute to species coexistence by creating low-density refuges for weaker competitors.     

Cattle dung and the fate of Biserrula pelecinus L. (Leguminosae) in a Mediterranean pasture: seed dispersal, germination and recruitment

Seed dispersal of Biserrula pelecinus via cattle dung in a semiarid pasture is analysed by quantification of the viable seed content of cattle dung, assessment of the percentage of readily germinable seeds in growth chamber of seeds collected from the plant and from dung, monitoring of the on-field frequency of the species in dung pats and in surrounding (control) pasture plots the four springs after dung deposition, and quantification of the pasture area occupied by dung pats. Large amounts of seeds of the species are dispersed by cattle (up to 4 seeds g^-1 of dry manure in June 1991), and the germinability of the seeds increases significantly following their passage through the cattle gut (from 2.5% to 9.5%). In the first three springs after deposition, the frequency of adult plant of the species on dung almost tripled that found in the surrounding pasture. The effect on the pasture is scale-dependent and varies considerably between zones depending on the area covered by dung. Thus, presence on dung may explain an average of 8% of the frequency of the species in the pasture at a 10 times 10 cm scale, and up to 20% in some areas. The results are the first evidence of a herbaceous species being greatly favoured in a plant community by its dispersal through herbivore dung, a process that may have profound implications for the interpretation of plant-herbivore relations and on the evolution of plant traits.     

Effects of adding exotic dung beetles to native fauna on bush fly breeding in the field

Egg to pupal survival of bush fly,Musca vetustissima Walker, under field conditions was examined during 1987/88 in an area of south-eastern Australia that had not been colonised by exotic dung beetles. In pads of cattle dung containing only the native fauna, fly survival ranged from 0.3% to 12.5%. The addition of 2 species of exotic dung beetles,Euoniticellus fulvus (Goeze) andOnthophagus taurus (Schreber) to field pads, in numbers similar to those observed at the collection site, reduced fly survival to between 0.3% and 4.4%. Fly survival in the presence of the native and exotic dung fauna was sufficiently low to keep fly breeding below their mean replacement level of 3% for most of the season. Widespread dispersal and establishment of exotic dung beetles in south-eastern Australia, alongside the native fauna, should lead to long-term reduction of the bush fly problem.      

Reduced splash dispersal of bovine parasitic nematodes from cow pats by the dung beetle Diastellopalpus quinquedens.

From a thoroughly mixed portion of cattle feces with Cooperia sp. eggs, 1-kg artificial pats were placed in 6 buckets containing 6 kg of soil each. Ten dung beetles, Diastellopalpus quinquedens, were added to each of 3 buckets. The remaining 3 buckets served as controls without beetles. When infective parasite larvae (L3) had developed in the cow pats indoors, the following procedure was followed. During occasions of rainfall each bucket was placed outdoors in the center of a wider and higher container. When the rain stopped all buckets were brought indoors, and infective larvae spread by splash droplets during the rain were collected in the containers and counted. After 33 days, the remaining dung on the soil surface in buckets with dung beetles constituted only 38% of that in the controls. Moreover, the number of L3 in feces left on the soil surface in the buckets with beetles was reduced by 88%, presumably due to beetle activity. This may explain the 70-90% reduction in splash dispersal of L3 of Cooperia sp. from cow pats attacked by beetles. The dung-burying activity of the beetles did not result in increased numbers of L3 in the soil under the cow pats, suggesting that many of the parasites in buried feces were destroyed.     

Endozoochory by free-ranging, large herbivores: Ecological correlates and perspectives for restoration

Seed dispersal via ingestion and defecation by large herbivores provides a possible aid for ecological restoration of plant communities, by connecting source communities of target species with habitat restoration sites. It is also a possible threat due to invasion of weeds, grasses or exotic species. Insight into the factors determining internal seed dispersal could therefore improve the management of grazed ecosystems.

We recorded viable seed density in cattle, sheep and pony dung samples and monitored dung pat colonisation in the field. In addition, we counted the distribution of dung pats in plots spread over all habitat units in our study site.

The three herbivore species appeared to disperse large quantities of many species (61 in total) from a variety of plant families, monocots as well as dicots. The density of viable seeds in herbivore dung and the colonisation of dung pats were positively correlated with Ellenberg nitrogen indicator values and seed supply, but not with seed mass or shape.

The results imply that many seeds are dispersed from high productive to low productive parts of the grazed area. In free-ranging systems, we therefore recommend enclosure and separate management of plant communities on nutrient-poor soils with high conservation interest. For habitat restoration sites we recommend integrated grazing only with target plant communities on nutrient-poor soils and not with plant communities on nutrient-richer soils.     

Effect of population density on reproduction of two sympatric dung beetle species,Aphodius haroldianus andA. Elegans (Coleoptera: Scarabaeidae)

The effect of population density on reproduction as well as the oviposition modes of two sympatric dung beetle species, Aphodius haroldianus (a low fecundity/high parental effort species) and A. elegans (a high fecundity/low parental effort species) was studied at a pasture in central Japan from 1982 to 1986.

1. The adult population density of A. haroldianus was high (>40 per dung pat). The density of A. elegans was low (<5 per dung pat). Oviposition of A. haroldianus was suppressed above the density of about 10 adults of conspecifics but not affected by the density of other species. The intra- and interspecific density effects on oviposition were not detected in A. elegans.
2. The number of A. haroldianus adults per pat decreased with dung age, while that of A. elegans increased until sixth day after deposition and then decreased. The number of eggs laid per pat was not different between 1-day-and 3-day-old pats for A. haroldianus. However, more eggs of A. elegans were found in 3-day-old pats than in 1-day-old ones.
3. In the both species, the amplitude of population fluctuations was not remarkable; the maximum/minimum ratio for five years being 2.3 for A. haroldianus and 2.9 for A. elegans. Different density dependent processes were suggested to function for the small fluctuation of population density between the two species, i.e. intraspecific density effect on oviposition for A. haroldianus and contest type competition for food among larvae of A. elegans.

     

Reproductive properties of two sympatric dung beetles,Aphodius haroldianus andA. Elegans (Coleoptera: Scarabaeidae)

1. Reproductive properties of two sympatric dung beetles, Aphodius haroldianus and A. elegans, were studied at a pasture in the central Japan.
2. Overwintered adults of A. haroldianus came flying to dung pats from May to early August and bred from June to July. A. elegans overwintered as larvae, new adults came to dung pats from mid May to mid June. After aestivation, they reproduced from October to November.
3. A. haroldianus was a species with low fecundity and large food reserve for larvae. Female of this species had short duration of residence and laid fewer number of eggs in one dung pat. On the other hand, A. elegans was a species with high fecundity and small food reserve for larvae. Female of this species had long duration of residence and laid larger number of eggs in one dung pat.
4. The daily egg production in A. haroldianus reached a peak (0.40 eggs/female/day) at middle of oviposition period, but, that in A. elegans reached a peak (6.49 eggs/female/ day) at the beginning of oviposition period. The mortality of A. haroldianus female occurred after the daily egg production reached a peak and then rapidly increased, whereas that of A. elegans began soon after the beginning of oviposition and then gradually increased.

     

Seasonal abundance and reproductive output of the dung flies Neomyia cornicina and N. viridescens (Diptera: Muscidae)

The seasonal abundance and reproductive output of two common, but little studied, dung-breeding flies, Neomyia cornicina and N. viridescens, were examined in artificial cow pats in pastures in southwest England in 2001 and 2004. In 2001, the numbers of both Neomyia species increased slowly over summer to show a sharp seasonal peak in late August and early September. There was no significant effect of mean temperature, mean relative humidity or dung water content on abundance or seasonally de-trended abundance. High levels of aggregation were seen between pats and, when present, greater numbers of N. cornicina emerged than N. viridescens. Neomyia cornicina was present in 13% of 240 artificial standardized pats put out in 2001, at a median of 19 adults per colonized pat; N. viridescens was present in 8% of artificial pats at a median of three adults per colonized pat. In 2004, N. cornicina emerged from 46% of the 94 artificial pats put out at a median of three adults per colonized pat, while N. viridescens emerged from only 12% of pats at a median of one adult per colonized pat. Flies were also collected in 2004, using sticky-traps and hand nets. Again, free-flying N. cornicina appeared to be more abundant in the field than N. viridescens; 162 N. cornicina were caught compared to 44 N. viridescens over the same sampling period. The size of each adult female was recorded and ovarian dissection was used to determine the numbers of eggs matured. Female N. viridescens were significantly larger than the N. cornicina and matured significantly higher numbers of eggs. Gravid N. viridescens matured a mean of 37.1 (+/-16.9) eggs, whereas gravid N. cornicina matured a mean of 28.8 (+/-13.2) eggs. The reasons why the larger, more fecund, N. viridescens adults are less abundant in the field or emerging from pats than N. cornicina are unknown. Further work is required to identify the nature and cause of the mortality experienced by the larvae of these species and the ecological differences and functional specialisation which allows co-existence to be maintained.     

Respiratory loss and bulk export of organic matter from cattle dung pats: a field study

Respiratory loss and bulk transport of organic matter from dung pats in a Danish pasture were measured by a chromic oxide marker technique. Measurements covered the period until a dung age of 7-8 weeks. On average, respiration and transport contributed 46% and 54% of organic matter disappearance in three spring experiments: in three autumn experiments the corresponding values were 25% and 75%. Thus, both processes are important. The rate of transport was highest at the bottom of the pat, whereas the highest respiratory rate occurred in the top and periphery. During the first 10–14 days transport predominated, probably owing to the activity of dung insects, whereas respiration was remarkably low. During the remaining period, transport was probably affected mainly by earthworms. Respiration seemed to be mostly microbial and to proceed during dung pat decay in essentially the same way as did cellulolytic activity. Earthworms did not significantly affect the respiration of pats.     

Resource quality and the colonisation and succession of coprophagous dung beetles

In order to examine the degree of resource selectivity in a north temperate dung beetle assemblage und to identify major parameters that influence such selectivity, the occurrence of adult dung beetles ( Aphodius. Geotrupes and Sphaeridium ) in up to five different types of dung over a period of up to 25 d was examined in a series of field experiments using standardised dung pats. There were significant physical and chemical differences in dung quality between dung types and over time during succession. Dung beetle species showed distinct preferences for particular types of dung which were generally similar in data sets from both pitfall traps and dung pat samples. Species also showed distinct patterns of successional occurrence. Ordinations produced by Canonical Correspondence Analysis, based on species occurrences in dung types and over time, usually selected dung pat age as the most important environmental variable influencing dung beetle assemblages. Dung quality parameters contributed a significant element of structure to the species ordinations but ordinations using dung types or dung quality parameter values as the environmental variables were very similar in terms of sample and species placement within the ordination for each data set. Most importantly the CCA ordinations clearly grouped species according to their breeding behaviour. Early-successional species laid eggs in the soil, or in silken egg cocoons, which allowed them to exploit wet dung. Mid and late-successional species laid eggs in the dung pat: late-successional species could exploit normally wetter dung types than mid-successional species, probably due to increased crust formation and drying as the dung pat ages. Thus, species appear to be differentially adapted to exploit varying types of dung microhabitats. Therefore, where two or more species of large herbivores are present, dung quality preferences probably constitute an important niche dimension.     

Some effects of rearing the yellow dung fly Scatophaga stercoraria in cattle dung containing invermectin

Invermectin was added to cattle dung in controlled concentrations like those found in the pats of injected cattle, and the medium was used to rear larvae of the dung fly Scatophaga stercoraria. Ivermectin at 0.036 ppm (wt/wet weight) debilitates 50% of the larvae within 48 h. At 0.015 ppm, 50% of the larvae are unable to pupariate, while at 0.001 ppm, 50% of the larvae fail to reach the adult stage. Adults produced from larvae reared in pats containing 0.0005 ppm invermectin show high levels of fluctuating asymmetry in wing characteristics as well as deformities in the wing veins themselves. The data are discussed in relation to the effects of excreted ivermectin on pastureland biology.     

Area-wide impact of macrocyclic lactone parasiticides in cattle dung

Following the treatment of cattle with veterinary parasiticides and insecticides, residues are excreted into the dung in concentrations that may be toxic to functionally important dung-colonizing insects. In the dung, these residues cause a range of well-studied lethal and sub-lethal effects, the magnitudes of which vary with the compound used, mode of administration and concentration, and the insect species in question. Particular concern has been associated with the use of macrocyclic lactones in this context. Loss of insect colonizers may delay pat decomposition, but field studies report contrasting results that reflect confounding factors such as weather conditions, pat moisture content, pat location, time of year and dung insect species phenologies. The question of fundamental concern is whether the impacts seen in experimental or laboratory studies are likely to have a functional impact on insect populations, community interactions and the economically important process of dung decomposition. Recent studies which have attempted to address these wider, landscape-level impacts in temperate ecosystems are reviewed here. These show that the extent to which chemical residues may have any sustained ecological impact will depend on both a range of farm management factors, such as the temporal and spatial patterns of chemical use, the number of animals treated and the choice of active ingredient, and a range of insect-related factors, such as abundance, population dynamics and dispersal rates. However, they also demonstrate that considerable uncertainty remains about the likely extent of such effects and that current data are insufficient to support firm conclusions regarding sustained pasture-level effects. More large-scale, longterm field experiments are required, particularly in relation to insect dispersal and functional interactions within the dung insect community.