Beyond Coprinisphaera: fossil nests of dung beetles

Forty‐two remains of fossil nests of dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae), which were recorded in four formations of the Cenozoic of South America, are described herein for the first time. Most of them are represented by nesting chambers containing a fossil brood ball (Coprinisphaera). However, in the most remarkable cases, parts of the burrows constructed by the parents and/or the vertical emergence burrows constructed by the offspring are preserved too. The preservation of the dung beetle nests is very unusual but more recurrent in younger formations probably because of the short‐term action of the diagenetic processes. Considering that the construction of brood balls always involves the construction of nests, the ichnotaxonomical proposal is that the remains of fossil nests should be considered as ‘structures associated with Coprinisphaera’ and added to the diagnosis to avoid the proliferation of names. The study of the fossil nests provides new palaeoetological inferences for dung beetles, such as the Nesting Pattern of the trace makers of Coprinisphaera tonnii and Coprinisphaera akatanka, and how phylogenetically related were they with the extant necrophagous species of the genera Coprophanaeus and Canthon, respectively. Additionally, the fossil evidence suggests that simple nests of dung beetles predate compound nests.     

The earliest burst of necrophagous dung beetles in South America revealed by the Cenozoic record of Coprinisphaera

New ichnological, sedimentological and palaeobotanical information from a Miocene palaeosol succession from Patagonia bearing abundant fossil brood balls of dung beetles (Coprinisphaera) allow inferring novel aspects of the evolutionary history, biology and feeding habits of Scarabaeinae, along with the palaeoenvironmental and palaeoclimatic conditions in which they nested. Coprinisphaera tonnii and Coprinisphaera akatanka, both attributed to necrophagous dung beetles, represent 40.2% of the specimens. Considering their scarce or null record in older Cenozoic units from South America, these high values reveal that the first burst of necrophagous Scarabaeinae took place during the Miocene. Some Coprinisphaera preserve characters that indicate the developmental stage of the ball occupant and the adult emergence success. Both ichnospecies show the egg chamber isolated from the provision chamber, which was associated with a higher preference of cleptoparasites for necrophagous balls. The comparison among the abundance of traces of nest intruders in Coprinisphaera attributed both to necrophagous and to coprophagous beetles from different units of South America indicates that the presence of such intruders would be independent of the nature of the organic matter contained within the balls. Phytolith analyses performed in Coprinisphaera and extant necrophagous and coprophagous balls indicate that the comparison between the relative abundance of phytoliths in the wall of the brood ball, their infilling and the bearing palaeosol is a useful tool for inferring the feeding behaviour of the trace makers and support the attribution of Coprinisphaera tonnii and Coprinisphaera akatanka to necrophagous Scarabaeinae. Sedimentary and palaeosol analyses indicate that the beetles would have nested in well-drained soils showing mollic-like features, in grass-dominated habitats, under a seasonal sub-humid, temperate–warm climate.     

Phytolith analysis of Coprinisphaera,unlocking dung beetle behaviour,herbivore diets and palaeoenvironments along the Middle Eocene–Early Miocene of Patagonia

The analysis of the total number of phytoliths, and the absolute frequencies of the different morphotypes, extracted from fossil dung beetle brood balls (Coprinisphaera) from the Middle Eocene–Early Miocene Sarmiento Formation (Patagonia, Argentina), revealed that this trace fossil represents a concentrated locus for phytolith sampling. Particularly, differences found in the total number of phytoliths among parts of that trace fossil and the bearing paleosol, allowed to infer that the infilling represents mostly a sample of the original surrounding soil, whereas in most cases the wall shows a significantly higher number of phytoliths than in the paleosol or infilling. Modern brood balls also revealed that in an environment with high density of grasses, the walls, composed of soil and dung fibres, showed a lower concentration of phytoliths than the soil. In contrast, in other environment with scarce grass coverage, the dung, which had a higher concentration of phytoliths than the soil, added to the wall produced an increase in the number of phytoliths in it. Accordingly, the larger number of phytoliths of the Coprinisphaera wall in comparison with that of the paleosol, would be reflecting the addition of dung fibres to the wall in palaeoenvironments with moderate to poor presence of phytolith-bearing plants. The absence of differences in the total number of phytoliths between the internal and the external layer of the brood ball wall, suggests that the dung fibres would have been uniformly distributed in most of the wall, due to the addition of dung fibres during the brood ball construction by the dung beetle. In contrast, the absence of differences among wall and paleosol or infilling, could be suggesting that no dung fibres were added to construct the wall, that those added had no phytoliths, that the Coprinisphaera involved could had been a brood ball of a necrophagous scarab, or that the soils were richer in phytoltihs than the dung. Those balls that showed evidence of increased numbers of phytoliths in the wall, likely caused by dung fibres added to it, enable the study of diet preferences of the herbivores that produced the dung. Differences found in the phytolith morphotype frequencies among the wall, and the other two samples (infilling and paleosol), allow to infer that some herbivores were more generalists among phytolith-bearing plants feeding on the most abundant grasses and palms, whereas others preferred more rare grasses and dicots.     

New Miocene scarabeid and hymenopterous nests and early miocene (santacrucian) paleoenvironments,patagonian Argentina

Three new trace fossils are described from Miocene paleosols of southern Argentina. Celliforma pinturensis, n. ichnosp. and Celliforma rosellii, n. ichnosp. are interpreted as cells of digging bees, possibly Anthophoridae, and Coprinisphaerafrenguellii, n. ichnosp. are brood balls of dung‐beetles. Both burrowing bees and dung‐beetles are common nesters in relatively open areas, confirming previous reconstructions of the paleoenvironment of the Pinturas Formation. A brief review of scarabeid and bee fossil nests from South America is presented, and we propose that constructed nests have a higher preservation potential than excavated nests. This fact explains their more common occurrences as trace fossils in paleosols. A new ethological category, calichnia, is proposed for hymenopterous and coleopterous traces, in which adult individuals make nests exclusively for larvae.     

Nest construction and larval behaviour of Bubas bison (L.) and Bubas bubalus (01.) (Coleoptera, Scarabaeidae)

Abstract.

• 1 Female beetles working alone or in cooperation with a male excavated vertical, tunnel-shaped brood chambers. Each chamber was filled with dung to form a cylindrical brood mass which contained two eggs, one near each pole.
• 2 To examine the possible relationship with other Onitini (which lay either one or several eggs per brood mass) factors that influence the two-egg programme were studied. Brood masses with only a single egg were formed if excavation was resumed prematurely. Conversely, when excavation was suppressed several oviposition programmes fused to produce a multi-egg brood mass.
• 3 The larvae repaired their chambers in the typical Scarabaeine manner by building a self-supporting wall formed from their own excrement. This behaviour also prevented direct contact and fighting between adjacent larvae in the same brood mass, and it allowed the larvae to survive inside artificial brood balls. Similar behaviour was observed in larvae of Onthophagus taunts and Ontho-phagus vacca (which develop in one-egg brood masses). The evolution of nesting habits that involve multi-egg brood masses or free-standing brood balls may depend on the pre-existence of this larval repair behaviour.

     

First discovery of fossil dung beetle brood balls and nests in the Chadian Pliocene Australopithecine levels

The Pliocene continental formations of the paleo-lake Chad system are known because of the recent discovery of the first australopithecine known west of the Rift Valley. The structures under study are found in sandstone levels associated with a rich fauna, including mammals, birds, reptiles and fishes. Analysis of the depositional environment and fauna indicates a mosaic landscape of gallery forest, savannah, grassland and ephemeral rivers interrupted by lacustrine episodes. This sandstone facies contains bioturbation in the form of sandstone balls 4-12 cm in diameter, slightly flattened at the poles. These structures are characterized by an external husk or crust and by a decimetric cavity in the upper part of the ball. Between the husk and the cavity are a number of concave laminae similar to those of a bulb, whose concavity is directed toward the upper cavity. The comparison between these structures and the brood balls of modern Scarabaeidae shows great similarity, especially in the external husk, the concave internal laminae and the chamber of the grub in the upper part of the structures. This bioturbation is interpreted as fossil brood balls of dung beetles (Coleoptera, Scarabaeidae). Fossil dung beetle brood balls are generally rare, but have been known since the 1940s. They can be very abundant in any series, as described by several authors in South America. The first fossil dung balls were described in this area in 1938 by Frenguelli and by Roselli. These authors describe elementary spherical forms of 35 mm in diameter on average, flattened at the poles and with an upper cavity. The fossil dung beetle brood balls discovered in Chad are the first in which all the internal characteristic structures are preserved. Many of them are connected by a remarkably large net of tunnels which has no parallel in the past or the present.     

The evolution of parental behaviour in Scarabaeinae (Coleoptera, Scarabaeidae): an experimental approach

ABSTRACT.

• 1 Dung beetle lifestyles are reviewed. Most Scarabaeinae lay their eggs in dung masses that are packed into underground chambers, but Coprini and Scarabaeini typically lay their eggs in free-standing brood balls and it is in these tribes that parental care of the brood has evolved.
• 2 Brood balls are constructed by aggregating fragments of dung. This technique is derived from the method of gathering dung at the surface. Larvae developing in brood balls are better protected against dehydration and parasite attack. The repair technique of Scarabaeine larvae preadapts them to life in brood balls.
• 3 Parental care by Copris lunaris depends on appropriate responses by the female to the brood, and it has the selective advantage of protecting the brood against parasites. Preadaptations for parental care in‘non-brooding’Coprini are discussed.
• 4 Variations in the basic Copris nesting behaviour are summarized. Similar variations can occur spontaneously in C.lunaris and can also be released by unusual circumstances.
• 5 C.lunaris females could in principle cooperate but certain factors have prevented this social evolution. The significance of the transient cooperation with the male beetle is discussed.

     

Nest construction and larval behaviour of Onitis belial and Onitis ion (Coleoptera, Scarabaeidae)

Abstract. 1. Female beetles working alone or in cooperation with a male buried dung to make brood masses. O.belial brood masses were packed close together in clusters; each mass was constructed as a horizontal thick-walled tube of dung which was filled with a dung sausage containing two to six eggs. O.ion made vertical sausage-shaped brood masses with one to four eggs.
2. The larvae of both species were able to survive in artificial brood balls as well as in multi-egg brood masses because of their ability to repair larval chambers with their own excrement.
3. The multi-egg brood mass of Onitis has probably evolved from a simple one-egg brood mass. It does not resemble the underground dung mass from which brood balls are made by certain Coprini.     

Gut microbiota of dung beetles correspond to dietary specializations of adults and larvae

Vertebrate dung is central to the dung beetle life cycle, constituting food for adults and a protective and nutritive refuge for their offspring. Adult dung beetles have soft mandibles and feed primarily on nutritionally rich dung particles, while larvae have sclerotized mandibles and consume coarser dung particles with a higher C/N ratio. Here, using the dung beetles Euoniticellus intermedius and E. triangulatus, we show that these morphological adaptations in mandibular structure are also correlated with differences in basic gut structure and gut bacterial communities between dung beetle life stages. Metagenome functional predictions based on 16S rDNA characterization further indicated that larval gut communities are enriched in genes involved in cellulose degradation and nitrogen fixation compared to adult guts. Larval gut communities are more similar to female gut communities than they are to those of males, and bacteria present in maternally provisioned brood balls and maternal ‘gifts’ (secretions deposited in the brood ball along with the egg) are also more similar to larval gut communities than to those of males. Maternal secretions and maternally provisioned brood balls, as well as dung, were important factors shaping the larval gut community. Differences between gut microbiota in the adults and larvae are likely to contribute to differences in nutrient assimilation from ingested dung at different life history stages.     

INSECTARY STUDIES ON THE CONTROL OF DUNG BREEDING FLIES BY THE ACTIVITY OF THE DUNG BEETLE, ONTHOPHAGUS GAZELLA F. (COLEOPTERA: SCARABAEINAE)

i
The Afro-Asian dung beetle, Onthophagus gazella F., buries bovine dung as food for its larvae so rapidly that when beetle populations are of the order of 4 insects per 100 c.c. dung, entire cow pads are completely broken up and buried within 30 to 40 hours.
Insectary studies show that this rate of dung disposal caused 80 to 100 per cent. reduction in the numbers of the bushfly Musca vetustissima Walker emerging from the pads. Surviving maggots gave rise to small, stunted flies of low or nil reproductive capacity. Viable fly eggs or maggots were never found in brood balls, and it is presumed that they were destroyed in the course of the elaborate process by which the beetles convert lumps of dung into brood balls.
Speed of dung burial is the critical factor in fly control. If half of a cow pad is buried within the first 24 hours, few or no adult flies emerge. More rapid burial within this period resulting in the complete removal of the cow pad, produces complete fly control.     

中国四种蜣螂幼虫形态记述(鞘翅目:金龟科:金龟亚科)

基于3龄幼虫首次描述了中国4种蜣螂幼虫的形态特征,分别是：捷氏凯蜣螂Caccobius jessoensis Harold、短亮凯蜣螂C．brevis Waterhouse、双顶嗡蜣螂Onthophagus bivertex Heyden和小驼嗡蜣螂0．gibbulus（Pallas）。文中列出了中国凯蜣螂和嗡蜣螂属幼虫分种检索表。标本保存在沈阳农业大学昆虫博物馆。     

An analysis of the nesting behaviour of Geotrupes spiniger Marsham (Coleoptera, Scarabaeidae)

Abstract. 1. Female G.spiniger adults working alone made nests each consisting of a vertical shaft leading to a series of horizontal brood chambers filled with dung brood masses. Oviposition near the tip of the brood mass occurred while the egg cell was being completed over the expanded ovipositor. The shaft above each brood mass was filled with soil excavated from the next brood chamber. A similar response also filled artificial diverticula. An avoidance reaction towards buried dung prevented damage to pre-existing brood masses. 2. Virgin females did not make nests and did not avoid buried dung, but after mating (at about 4 weeks after eclosion) both types of behaviour were released within a few hours. 3. The presence of dung was required to initiate but not to maintain nesting behaviour. If dung was removed after oviposition the chamber was filled with soil produced by renewed excavation. Cellulose pulp could substitute for dung in brood mass formation. 4. Beetles interchanged between burrows at different stages before oviposition readily repeated all pre-oviposition behaviour. They appeared to respond to the length of the shaft and of the brood chamber since they extended short shafts and short brood chambers considerably more than those of normal length. After oviposition the beetles continued to make brood masses even under abnormal conditions. 5. Tilting the cage through 90° caused beetles before oviposition to re-orientate their burrowing direction, but tilting just after oviposition caused them to make vertical brood masses. Placing the shaft in a horizontal position towards the end of brood mass formation postponed the termination of this phase. 6. Beetles repeatedly excavated shafts and chambers when transferred to new cages. Conversely they repeatedly made brood masses when maintained in preformed plaster-of-Paris burrows. 7. This nesting behaviour can be described as a reaction chain in which each action generates its own terminating stimulus and initiates the subsequent response. The behaviour before oviposition could be omitted or repeated as required by the environment, but after oviposition there was little response to external interference. These characteristics have direct relevance to the survival of the larvae.     

Experimental warming disrupts reproduction and dung burial by a ball‐rolling dung beetle

1. Insects are sensitive to climate change. Consequently, insect‐mediated ecosystem functions and services may be altered by changing climates. 2. Dung beetles provide multiple services by burying manure. Using climate‐controlled chambers, the effects of warming on dung burial and reproduction by the dung beetle Sisyphus rubrus Paschalidis, 1974 were investigated. Sisyphus rubrus break up dung by forming and rolling away balls of manure for burial and egg deposition. 3. To simulate warming in the chambers, 0, 2 or 4 °C offsets were added to field‐recorded, diurnally fluctuating temperatures. We measured dung ball production and burial, egg laying, survival and residence times of beetles. 4. Temperature did not affect the size or number of dung balls produced; however warming reduced dung ball burial by S. rubrus. Because buried balls were more likely to contain eggs, warming could reduce egg laying via a reduction in ball burial. Warming reduced the humidity inside the chambers, and a positive relationship was found between the number of dung balls produced and humidity in two temperature treatments. Temperature did not affect survival, or whether or not a beetle left a chamber. Beetles that did leave the chambers took longer to do so in the warmest treatment. 5. This study demonstrates that climate warming could reduce reproduction and dung burial by S. rubrus, and is an important first step to understanding warming effects on burial services. Future studies should assess warming effects in field situations, both on individual dung beetle species and on aggregate dung burial services.     

Nesting of Afrotropical Oniticellus (Coleoptera, Scarabaeidae) and its evolutionary trend from soil to dung

Abstract. 1. Oniticellus egregius Klug constructs brood ovoids of dung in the soil immediately under the edge of animal droppings. Each successive brood ovoid is enveloped within a soil shell. After completion of brood construction, loose earth is cleared from around the broods to produce a brood chamber. The immatures are then abandoned as eggs or first instar larvae.
2. O.planatus Castelnau and O.formosus Chevrolat usually construct brood balls of dung within animal droppings. Each brood is progressively enlarged by the addition of further dung after egg-laying. This enlargement is slight in O.planatus and marked in O.formosus. Parental females of both species remain in the brood chambers during development of the immatures which are abandoned principally as pupae.
3. Under very moist experimental conditions, O.planatus buries dung and constructs broods shallowly in the soil. Such nests are frequently connected to the pad by a short tunnel.
4. From a consideration of behavioural patterns it is suggested that the specialized nesting habits of these species have been derived from those of dung-burying ancestors similar to the modern genus, Euoniticellus, through reduction and loss of tunnelling in the soil.     

Brood care in the dung beetle Onthophagus vacca (Coleoptera: Scarabaeidae): the effect of soil moisture on time budget, nest structure, and reproductive success

Under laboratory conditions brood care behaviour, nest structure and weight of dung supply in brood chambers of the dung beetle Onthophagus vcca proved to depend on water content of the soil beneath the dung. The substrate in a bucket beneath the dung pat was dry sand (4% water content) or moist sand (8% water content). Emigrating beetles were trapped and counted at 12 h intervals. In a total of 109 replicates one pair was released on an artificial 1000 g dung pat. From 95 replicates in which brood chambers were built the following results were derived: 1) Breeding females and resident males which helped the female stayed longer in dung pats on dry sand than in those on moist sand. 2) Nest architecture was influenced by substrate moisture: length of main tunnels did not differ between nests in dry and moist sand, but total length of side tunnels was shorter in dry sand. 3) Numbers of brood chambers were equal in both substrate types, weight of the dung supplies was larger in dry sand. 4) Offspring size was not only influenced by dung provision in the brood chambers. Beetles emerging from chambers in dry sand were smaller than those emerging from moist sand even if the amount of dung supply was equal.     

Brood burrow construction and brood care by Heliocopris japetus (Klug) and Heliocopris hamadryas (Fabricius) (Coleoptera, Scarabaeidae)

• 1 Brood burrow construction and brood care were studied by excavating burrows of different ages and by re-excavating certain burrows after a defined interval.
• 2 Brood burrows consisted of tunnels running via an upper chamber to a lower chamber 0.55–1.3 m below ground.
• 3 The female excavated the upper chamber, filled it with dung, then excavated the lower chamber and packed it with dung from the upper chamber.
• 4 Soil was removed from around the dung to give adungmasslying free in the lower chamber. The male was present during and just before this stage, and may cooperate in pushing soil out through the tunnel. Later the tunnel was filled with soil, excluding the male from the lower chamber.
• 5 The female formed the dung mass into balls each of which contained an egg. Development of the larvae led to an expansion at the upper pole, producing a pear shape. Third instar larvae were found in pears with a soil covering.
• 6 In the case of H.japetus the pears later became soil-covered balls containing the new adults, and the female remained in the chamber and died after the young had emerged.
• 7 The push-ups of H.japetus and of H.hamadryas were distinguishable, reflecting slight differences in the technique of burrow construction. H.hamadryas burrows were deeper and contained smaller brood balls.

     

Parental behaviour in Copris lunaris (Coleoptera, Scarabaeidae): care and defence of brood balls and nest

Abstract. 1. Nesting female beetles righted brood balls (so as to replace the egg or larva in the uppermost position) and repaired damaged balls. This behaviour required the presence of an egg or larva in the ball, or of a short-lasting material found just after oviposition. The shape of the ball was also a righting stimulus since artificial ellipsoids were stood on end.
2. Balls containing dichloromethane extracts of C.lunaris brood were righted and repaired. Eggs and larvae of several other Scarabaeidae did not release these responses but were destroyed.
3. Righting behaviour was released when brood was absent from the top of the ball. The beetle then crawled vertically downwards and, if it encountered the displaced apex, a novel rolling action followed which automatically turned the ball towards the correct position.
4. An opening made in the nest was repaired with soil excavated from the chamber floor. Clunaris adults and Aphodius fossor larvae were attacked if they were encountered in the nest.     

Intraspecific female brood parasitism in the dung beetle Onthophagus taurus

Abstract.  1. Brood parasitism occurs when individuals parasitise each others' investment into parental care, and has been documented primarily as an interspecific interaction. Intraspecific brood parasitism, in contrast, is often difficult to detect and quantify, and evidence for it is comparatively scarce. The present study documents the occurrence of intraspecific brood parasitism by females of the tunnelling dung beetle Onthophagus taurus , and investigates the contributions of two variables to the propensity of female brood parasitism: female body size and dung desiccation rate.
2. Female O. taurus were found to routinely utilise brood balls made by conspecific females as food provisions for their own offspring.
3. Contrary to expectations, large and small females did not differ in the likelihood of engaging in brood-parasitic behaviour.
4. Dung desiccation rate appeared to influence likelihood of brood parasitism. Females that were given access to rapidly drying dung were significantly more likely to detect and utilise brood balls produced by conspecific females.
5. While interspecific brood parasitism has been documented in dung beetles before, the present study is among the first to present evidence for intraspecific brood parasitism as an alternative reproductive tactic of female dung beetles. Results are discussed in the context of the evolutionary ecology of onthophagine beetles.     

Effects of brood parasitism on host reproductive success: evidence from larval interactions among dung beetles

This paper investigates the effect of brood parasitism in a dung beetle assemblage in an arid region of Spain. The study was conducted during the spring season (March-May 1994-1998) using mesh cylinders buried into the ground, filled with sand and with sheep dung on top. We quantified the proportion of nests containing larvae of parasitic beetles and their effect on host larvae survival. Experiments on the effect of parasitic larvae on host-larvae survival were conducted by placing scarab brood masses (raised from captive scarabs in the laboratory) in containers with and without aphodiid larvae. During the spring, dung desiccation is rapid, preventing aphodiids nesting in the dung, and forcing these species to adopt brood parasitism as a nesting strategy. Parasitic aphodiids were found in 12-47% of scarab nests of three species. The incidence of brood parasitization was positively related with the number of brood masses contained in the nests, being also higher in the most abundant species. Field data and experiments showed that brood parasites significantly reduced host larvae survival from 74.8% in non-parasitized nests to 8.8% in parasitized nests. Because different rates of nest parasitization and mortality were caused by parasites, brood parasitism had a differential effect on different host species. Thus, brood parasitism constitutes an important mortality factor reducing the reproductive success of the host species and potentially affecting the beetle abundance in the area.     

Brood Ball-Mediated Transmission of Microbiome Members in the Dung Beetle,Onthophagus taurus (Coleoptera: Scarabaeidae)

Insects feeding on plant sap, blood, and other nutritionally incomplete diets are typically associated with mutualistic bacteria that supplement missing nutrients. Herbivorous mammal dung contains more than 86% cellulose and lacks amino acids essential for insect development and reproduction. Yet one of the most ecologically necessary and evolutionarily successful groups of beetles, the dung beetles (Scarabaeinae) feeds primarily, or exclusively, on dung. These associations suggest that dung beetles may benefit from mutualistic bacteria that provide nutrients missing from dung. The nesting behaviors of the female parent and the feeding behaviors of the larvae suggest that a microbiome could be vertically transmitted from the parental female to her offspring through the brood ball. Using sterile rearing and a combination of molecular and culture-based techniques, we examine transmission of the microbiome in the bull-headed dung beetle, Onthophagus taurus. Beetles were reared on autoclaved dung and the microbiome was characterized across development. A ~1425 bp region of the 16S rRNA identified Pseudomonadaceae, Enterobacteriaceae, and Comamonadaceae as the most common bacterial families across all life stages and populations, including cultured isolates from the 3^rd instar digestive system. Finer level phylotyping analyses based on lepA and gyrB amplicons of cultured isolates placed the isolates closest to Enterobacter cloacae, Providencia stuartii, Pusillimonas sp., Pedobacter heparinus, and Lysinibacillus sphaericus. Scanning electron micrographs of brood balls constructed from sterile dung reveals secretions and microbes only in the chamber the female prepares for the egg. The use of autoclaved dung for rearing, the presence of microbes in the brood ball and offspring, and identical 16S rRNA sequences in both parent and offspring suggests that the O. taurus female parent transmits specific microbiome members to her offspring through the brood chamber. The transmission of the dung beetle microbiome highlights the maintenance and likely importance of this newly-characterized bacterial community.