Dung Beetle Activity Research Articles

Deforestation and biodiversity: effects of bushland cultivation on dung beetles in semi-arid Tanzania

Dung beetles provide important ecosystem services in the habitats where they occur. The activity of dung beetles enhances soil nutrient cycling and increases the soil’s ability to absorb and hold water. Consequently, these beetles are particularly important in semi-arid environments. This study analyses the importance of remaining wooded habitat patches (bushland) for the survival of a diverse dung beetle fauna in an otherwise cultivated landscape in semi-arid Tanzania. Dung beetles were sampled by pitfall trapping in maize fields and bushland habitats. In total, 6037 dung beetles (Scarabaeidae: Scarabaeinae), representing 77 species from 25 genera, were collected. Many species, particularly amongst the ball-rollers, showed a clear preference for wooded patches, species richness being significantly higher in the bushland patches than in the cultivated sites. The number of trapped specimens in bushland was also considerably higher than that found in maize fields, although the differences were not significant. In conclusion, bushland fragments appear to have an important conservation value as to maintaining a high diversity and abundance of dung beetles, thereby enhancing the ecosystem services provided by these beneficial insects.

Reproduction of the dung beetle ( Copris tripartitus) in the dung of cattle treated with cis-cypermethrin and chlorpyrifos

Fresh dung was collected from untreated cattle and cattle dosed with a spray-on formulation of high cis-cypermethrin and chlorpyrifos (2.1 g/cow), on days 1, 3, 5 and 7 post-treatment. The survival and reproduction of the dung beetle Copris tripartitus Waterhouse, when given this dung was assessed. Residues of high cis-cypermethrin and chlorpyrifos in dung collected 1 day after treatment were sufficient to inhibit oviposition by female C. tripartitus. However, there was no significant effect on egg-laying in dung collected at days 3, 5 or 7 days post-treatment. In a second generation of C. tripartitus, derived from beetles fed the dung from treated animals, residues in dung collected both 1 and 3 days after treatment were sufficient to inhibit oviposition, and residues in dung collected 1 day after treatment inhibited dung consumption by newly emerged adults of C. tripartitus. It is concluded that dung voided by cattle treated with a spray-on formulation of high cis-cypermethrin and chlorpyrifos have toxic lethal effects for 1 day post-treatment and sub-lethal toxic effects on ovarian condition and brood-ball production in dung voided at 1 and 3 days post-treatment. The potential ecotoxic effects of these compounds are discussed in terms of dung beetle activity and strategies for parasite control of cattle in the Korean environment.

The Contribution of Tunneling Dung Beetles to Pasture Soil Nutrition

The effect of dung beetle activity on soil nutrition was studied in three distinct soil types under laboratory conditions. Two tunneling dung beetles, Onthophagus gazella (Fabricius) and Onthophagus taurus (Schreber), were allowed to incorporate cattle dung, for brood production, into a piedmont Cecil clay soil, a coastal plain sandy-loam soil and commercially available play sand. Controlled treatments included soil alone and soil exposed to dung only. Soils were tested for primary nutrients (P and K), secondary nutrients (Ca and Mg), and micronutrients (Mn, Zn, and Cu), as well as other soil characteristics (pH, exchangeable acidity, etc.). Both O. gazella and O. taurus produced the most offspring in the piedmont clay soil; variable numbers of brood were produced in other soil types. Soils exposed to dung beetle activity were generally higher in nutrient content than both soils left untreated, and those that had been exposed to cattle dung only. In this manner, tunneling dung beetles can be considered vital to nutrient recycling and plant health in pasture systems.

Effects of deforestation on diversity, biomass and function of dung beetles on the eastern slopes of the Peruvian Andes

Dung beetles play a major role in nutrient cycling in the tropics. While a number of studies have indicated decreasing diversity of dung beetles as a result of deforestation, scant information exists on the implications of this for decomposition. This study compares dung beetle assemblages at forest and deforested sites on the eastern slopes of the Peruvian Andes and examines the importance of species richness and assemblage biomass in the decomposition of standardized dung pats. Results from pitfall trapping indicated that species richness, assemblage biomass and the number of beetles arriving at dung pats were greater at forest sites than at deforested sites. Although dung removal was generally faster at forest sites, between 50 and 100% of each 100 ml pat was removed within 3 days at all sites. Dung remained attractive to beetles for longer at forest sites, where it remained moister, than at the deforested sites. Dung beetle activity significantly reduced the number of flies emerging from dung. In an observation of decomposition of 96 separate dung pats, dung disappearance after 24 h was more frequently and more closely related to total assemblage biomass than to species richness. This study indicates that deforestation results in a reduced efficiency in decomposition by dung beetles that can be attributed mainly to reduced assemblage biomass at individual dung pats.

Seasonal Activity and Species Composition of Dung Beetles (Coleoptera: Scarabaeidae and Geotrupidae) Inhabiting Cattle Pastures in North Carolina

Species composition and seasonal distribution of dung beetles were studied on dairy and beef cattle pastures in North Carolina. Study sites included a dairy located in the piedmont region (North Carolina Department of Agriculture Piedmont Research Station, Salisbury, NC) and a combined dairy/beef facility in the coastal plain (North Carolina Department of Agriculture Center for Environmental Farming Systems, Goldsboro, NC). Dung beetles were trapped in cattle pastures from March 2002 through September 2003 by using dung-baited pitfall traps. Trapping yielded 4,111 beetles representing 14 species from the piedmont dairy, including Aphodius prodromus Brahm, a new record for North Carolina. Totals of 57,026 beetles representing 28 species and 28,857 beetles representing 26 species were trapped from the dairy unit and beef unit in the coastal plain site, respectively. Onthophagus gazella (F.), a second new record for North Carolina, was collected from the coastal plain. Beetles common to all collection sites include Aphodius erraticus (L.), Aphodius fimetarius (L.), Aphodius granarius (L.), Aphodius pseudolividus Balthasar, Onthophagus taurus Schreber, Onthophagus hecate hecate Panzer, and Onthophagus pennsylvanicus Harold. The introduced beetle O. taurus dominated the dung beetle population, accounting for >50% of the total beetles caught at either site. Beetle activity was greatest from March until November, with activity declining during the winter. Nine exotic species in the genera Onthophagus and Aphodius represented nearly 95% of the beetles trapped.

Diel flight activity and ecological segregation within an assemblage of tropical forest dung and carrion beetles

Temporal variation in activity of dung and carrion beetles in tropical forest is considered as a mechanism of ecological segregation between potentially competing species. We describe the diel flight activity of Scarabaeidae collected with baited pitfall traps at Les Nouragues field station in French Guiana. A total of 2663 individuals of 63 species was recorded, from the subfamilies Coprinae, Scarabaeinae and Aphodinae. Temporal guilds of diurnal, nocturnal and crepuscular species were identified. Diurnal species were about twice as numerous and abundant as either nocturnal or crepuscular species. Two main activity patterns characterize the diurnal species while nocturnal and crepuscular species show overlapping activity. The association of activity rhythm with the other niche variables, food selection, functional group, body size and relative abundance, was analysed using multiple correspondence analysis. Small diurnal coprophagous species were opposed to large crepuscular necrophagous species. Species packing is suggested but further analysis showed that the variables were independent of one another. The temporal differentiation of species combined with separation along multiple niche dimensions and resource gradients may facilitate the coexistence of species assumed to be strongly affected by interspecific competition.

Impact of the Activity of Dung Beetles (Coleoptera: Scarabaeidae: Scarabaeinae) Inhabiting Pasture Land in Durango, Mexico

In this study, I analyzed the diversity of the dung beetle community (Coleoptera: Scarabaeidae: Scarabaeinae) in relation to its bovine dung-removal efficiency in a cattle ranch with a load of 250 animals currently under holistic resource management. A total of 3,430 individuals of 8 Scarabaeinae species was collected, of which 5 species are abundant in the area: Euoniticellus intermedius (Reiche), Digitonthophagus gazella (Fabricius), Onthophagus mexicanus Bates, O. knulli Howden and Cartwright, and Canthon humectus (Say). Of these 5 species, E. intermedius, D. gazella, and C. humectus were dominant in terms of abundance and biomass. Cattle dung pats were exploited mostly within the first 48 h after deposition. The activity and abundance of dung beetles recorded in the study were insufficient to remove the amount of fresh dung deposited in cattle pastureland.

A limiting factor in the abundance of predatory phoretic mites (Acari: Macrochelidae): the seasonal abundance of their phorionts (dung beetles) in southern France

The effects of host (dung beetles; Coleoptera: Scarabaeoidea) activity on seasonal abundance of phoretic mites (predatory macrochelids) were investigated in experimental dung pads under Mediterranean climatic conditions. Macrocheles robustulus and Macrocheles merdarius were collected only in spring and autumn. The most abundant macrochelids (Macrocheles glaber group; >90%) were rare in the hottest days and during winter. Mite abundance and dung beetle activity were correlated. The distribution (aggregate or not) of macrochelids in both pads and beetle traps was interpreted as a consequence of the availability of carriers that were found greatly affected by unfavourable meteorological conditions (temperature and rainfall). By their abundance and because they are opportunistic in the choice of host, the M. glaber group species can be considered the most efficient in coprophilous fly control.

Dung beetle activity and the development of trichostrongylid eggs into infective larvae in cattle faeces

In the perspective to reduce the use of antiparasitic drugs, any interaction between the processes that control the development of parasite eggs into infective larval stages (L3) in dung and the activities of different dung-breeding organisms becomes of interest. The objective of the present study was to determine whether dung beetle activity affected the development of parasite larvae in cattle dung. Faeces containing eggs of parasites (predominately Cooperia spp.) were pooled according to high (250–600 epg) or low (approx. 100 epg) egg counts. Experimental dung pats were formed for each category of faeces and to half of these pats, dung beetles (20 Aphodius rufipes, 20 A. scybalarius syn. rufus) were added and kept for 12 days at 21 °C (±1 °C) and 90% RH (±5% RH). Beetles were then removed and the pats were divided in two where half the pat was incubated for an additional 12 days at 21 °C (±1 °C) and 90% RH (±5% RH) and the other half was immediately analysed. A greater number of L3 were recovered from the dung subjected to beetle activity compared with control dung ( P<0.001). However, following an additional 12 days incubation of the dung, similar numbers of L3 were recovered from beetle-affected dung with high egg counts, whereas there were significantly greater numbers of L3 derived from the control dung ( P<0.001). There was no significant difference in L3 recovery in the two categories of pats (i.e. high and low nematode egg counts). The results indicate that activity by Aphodius spp. in fresh dung can optimise conditions for nematode development to the infective larval stage if favourable environmental conditions prevail. Such synergistic effect may be due to the fact that dung beetles used in this study are dung dwellers, i.e. no substantial amount of the dung is removed or burrowed as these beetles feed, lay their eggs and the larval development takes place in brood chambers inside the dung.

Effects of dung presence, dung amount and secondary dispersal by dung beetles on the fate of Micropholis guyanensis (Sapotaceae) seeds in Central Amazonia

The study of seed fate is crucial for understanding fruit-frugivore interactions. One factor that can greatly influence the fate of seeds dispersed through mammal defecation, is the dung that accompanies the seeds. Dung attracts dung beetles and rodents; the former eat and bury dung, the latter feed on seeds. In this study the fate of Micropholis guyanensis subsp. guyanensis seeds surrounded by no dung and by 5, 10 and 25 g of howler monkey dung was followed until seedling establishment. The depths at which dung beetles bury the seeds were measured, and the effect of burial depth on seedling emergence was determined. Although initial seed fates differed among treatments, the same percentage of seedlings established from seeds without faecal material, and from seeds with 5, 10 and 25 g of dung. However, a significantly higher proportion of seedlings established from buried seeds when compared to seeds that remained on the surface. The percentage of seedlings establishing in a controlled germination experiment decreased significantly with increasing burial depth. The effect of dung beetle activity should be taken into consideration when assessing the role that mammal endozoochory plays on seed dispersal ecology of tropical plants. These results provide further evidence for the emerging realization that the study of secondary seed dispersal and post-dispersal events is crucial for a more complete understanding of plant regeneration.

Reproduction and Survival of the Dung BeetleOnthophagus binodis(Coleoptera: Scarabaeidae) Exposed to Abamectin and Doramectin Residues in Cattle Dung

Two groups of 50 heifers were given a subcutaneous injection of either abamectin (Avomec) or doramectin (Dectomax) at a dose rate of 200 μg/kg live weight. A third group of 50 heifers remained untreated. Dung samples were collected on 1, 3, 6, 9, 18, 24, 34, and 42 d after injection, and excreted residues were bioassayed using the dung beetle Onthophagus binodis Thunberg. Fewer newly emerged adults of O. binodis survived exposure to dung from cattle treated 3 and 6 d previously with abamectin or 9 d previously with doramectin than from dung of untreated cattle. Both compounds induced a range of sublethal effects on O.binodis. Abamectin residues excreted in dung up to 42 d after injection had a deleterious impact on ovarian condition, brood mass (egg) production, and larval survival. Doramectin residues only had a deleterious effect on these parameters at 3 and 6 d after injection relative to dung from control cattle. Analysis of the dung collected at each date after injection indicated that moisture content, pH, and percent nitrogen were not different from other physicochemical profiles conducted on cattle dung. Doramectin residues attained maximal concentrations of 101.1 μg/kg 3 d after injection followed by a linear decline with an elimination half-life estimate of 15 d. The bioassay data indicated that doramectin concentrations of <60 μg/kg have minimal impact on the mortality and reproductive potential of O. binodis and that deleterious effects to this species will be evident for only 1–2 wk after administration of the drug to cattle. The potential ecotoxic effects of these compounds are discussed in terms of dung beetle activity and strategies for parasite control of cattle in the Australian environment.

Survival and Reproduction in the Scarabaeine Dung Beetle Onthophagus binodis (Coleoptera: Scarabaeidae) on Dung Produced by Cattle on Grain Diets in Feedlots

Feedlotting cattle with dietary supplements of grain before market is becoming a widespread practice in Australia. Many farmers involved in this practice have noticed a minimal amount of dung beetle activity in the dung produced by cattle being fed grain diets. In this study, the dung from both feedlotted (grain-fed) and pasture-fed cattle was assessed as a food and reproductive resource for the dung beetle Onthophagus binodis Thunberg by bioassay in the laboratory. The diet of grain-fed cattle consisted of either 15% lupins, 20% oats, and 65% barley (50% grain) (grain 1) or 70% lupin grain and 30% hay (grain 2). There was no significant difference in either adult beetle mortality or the emergence pattern of F1 progeny when beetles were maintained on dung from either grain-fed or pasture-fed cattle. However, dung beetles reared on dung from pasture-fed cattle produced significantly more brood masses compared with beetles reared on dung from cattle fed on grain 2. A significantly greater number of F1 progeny survived to adulthood from brood masses produced by beetles reared on dung from pasture-fed cattle compared with dung from grain-fed cattle. The progeny emerging from brood masses produced with dung from pasture-fed cattle were significantly larger compared with progeny emerging from brood masses produced with dung from grain-fed cattle.

Dung decomposition and pedoturbation in a seasonally dry tropical pasture

Rates of dung decomposition and the associated accumulation of soil transported to the surface were compared for dung deposited during a dry and a wet season in a Costa Rican pasture. Average decomposition rates for the first 140 days after deposition were significantly lower for dung patches deposited at the beginning of the dry season than for patches deposited at the beginning of the wet season (0.73 vs. 1.50 g/day-1 on a dry weight basis). A strong linear relationship was found between dung removal and soil accumulation at the original soil surface, with an average of 2.0 g soil accumulated for every gram of dung which was removed. This relationship was not affected by deposition season. The lack of a seasonal difference, along with the relatively low decomposition rates during the wet season, were explained by the dominance of termites in the dung patches throughout the year. Evidence of dung beetle activity was never recorded during the dry season and was found in only 18 of the 45 dung patches recovered during the wet season.

Seasonal dung beetle activity and dung dispersal in selected South African habitats: implications for pasture improvement in Australia

Spatio-temporal variation in dung beetle distribution and cattle dung dispersal was quantified across a spectrum of summer rainfall habitat types in South Africa, i.e. grassland, open woodland and thickets on both sand and clay. This study facilitates the selection of further Afrotropical dung beetle species to optimize dung and fly control in similar Australian habitats. Substantial dung beetle activity and dung removal were recorded during the warm rainy season. However, there was considerable spatial variance for which soil type was primarily responsible. Differences between harder (clay) and softer soil types (sand) include, lower biomass of dung-burying and lower abundance of predatory dung beetles, lower rates and amounts of dung removal, and greater shredding of pad remnants on clay. Positive correlations between dung beetle biomass and dung removal were most frequent for large, fast-burying tunnellers on sand and for ball rollers on clay. The implications of spatio-temporal differences in dung beetle functional group structure and dung dispersal are discussed with regards to the necessity of further introductions of both dung-burying and predatory dung beetles from African into Australia.

Environmental factors that affect the concentration of P and N in faecal samples collected for the determination of nutritional status

Faecal samples have been proven to be valuable in determining the nutritional status of wild herbivores. It is often, however, difficult and impractical to collect dung as it is dropped. In this study, the effect of various environmental factors that may influence P and N concentrations in faeces were investigated. Factors examined were rain, age of samples, presence of dung beetles, method of storage, length of storage, the effect of fungal growth (mould) on poorly dried samples, and drying period of samples. Results indicate that samples should only be collected from fresh dung pads that are still wet and which show no signs of dung beetle activity. Collecting of samples shortly after a rain storm should be avoided. Samples can be air-dried in a ventilated room or oven-dried at 60 @C without any effect on the nutrient concentrations, but care must be taken to avoid fungal growth during the drying period. Dried samples can be stored in paper bags for up to 1 year before analysis. The individual variation in P concentration is larger in browsers than in grazers and more samples should thus be collected from browsers to be representative of the herd when samples are pooled. During the period of this study, no difference between males and females was found and samples representing the herd can therefore be collected randomly. Faeces from juvenile impala are only representative of the herd once they have been weaned.

Dung Beetles (Coleoptera: Scarabaeidae, Geotrupidae) Attracted to Fresh Cattle Dung in Wooded and Open Pasture

The biomass of dung beetles attracted to fresh cattle dung was studied in a Mediterranean holm oak pasture ecosystem with a continental Mediterranean climate (supra-mediterranean level). Results indicated a nonuniform biomass distribution of dung beetles throughout the year. Major peaks of species activity and biomass concentration of dung beetles occurred in open areas of the pasture in the spring followed by minor peaks in the fall. Beetle biomass in the open pasture was greater than that in the wooded pasture. The species of dung beetles comprising the greatest amount of biomass and the most important species available to destroy cattle dung pats in Mediterranean ecosystems with a continental climate were Bubas bubalus Olivier, Onthophagus opacicollis d'Orbigny, Copris hispanus (L.), Copris lunaris (L.), and Onthophagus vacca (L.).

Releases of biological control agents of insect pests on Easter Island (Pacific Ocean)

For half a century, agriculture on Easter Island has been affected by an increasing number of accidentally introduced insect pests. Due to the absence of natural enemies and other factors, these have reached high density levels which claimed for intensive use of pesticides. A project supported by the National Funds for Regional Development (FNDR) was established in 1984 to develop a biological control program against these pest species. Presently, 60 beneficial species have been introduced to control agricultural pests and flies that affect cattle and humans. Some of the natural enemies have established and are reducing pest populations thereby decreasing the requirement for insecticidal treatments. Fly density has also decreased noticeably. This can be attributed to the activity of natural enemies and dung beetles which compete with larval fly for food.

The effect of dung beetle activity on the discharge ofPilobolus (Fungi, mucorales) sporangia in cattle, sheep and horse faeces

The effect ofAphodius sphacelatus andA. ater activity in cattle faeces andSphaeridium bipustulatum in sheep and horse faeces on the discharge ofPilobolus sporangia was investigated under laboratory conditions. In five trials, the median number of sporangia produced was significantly less (P<0.01) in experimental chambers (with 1 or 2 beetles/g faeces) than in control chambers (without beetles). In addition, median percentage reduction of sporangia was significantly higher (P<0.01) forA. sphacelatus (80.9%) than forA. ater (56.9%) at 1 beetle/g cattle faeces.

The effect of dung beetle activity on the discharge of Pilobolus sporangia in cattle faeces.

The effect of dung beetle activity on the discharge of Pilobolus sporangia in cattle faeces.

Howler monkeys (Alouatta palliata), dung beetles (Scarabaeidae) and seed dispersal: ecological interactions in the tropical rain forest of Los Tuxtlas, Mexico

ABSTRACTThe dispersal of seeds by howler monkeys (Alouatta palliata) and the activity of dung beetles in modulating the fate of the dispersed seed were studied at Los Tuxtlas, Mexico. Howlers consumed the fruits of 35 species of plants. The seeds of 28 of these were dispersed by the monkeys. The majority (≥90%) of the seeds dispersed by monkeys were destroyed by rodents. Rapid relocation and burial of dung by dung beetles resulted in accidental relocation and burial of large numbers of seeds shortly after deposition. Faecal clumps (20 mg) remained on the ground for an average of only 2.5 h (range 1–3 h). Ball rolling beetles transported balls up to 5.0 m from the site of deposition (range 1–5 m). Burrowing and ball-rolling dung beetles buried seeds at depths ranging from 2.5 to &gt; 12.0cm. The deeper a seed is buried, the less likely it is to be found and eaten by rodents. Eighty percent of the species used by Alouatta as sources of fruit at Los Tuxtlas benefited by the dispersal and post dispersal service provided by howlers and dung beetles respectively. Seasonality in dung beetles abundance in the forest may influence the number of seeds per species escaping post-dispersal predation during the year. Dung beetles play not only an important ecological role in the recycling of matter and energy in the ecosystem, but also in the process of rain forest regeneration.