Enrico Barbero

Dung Beetle Conservation: Effects of Habitat and Resource Selection (Coleoptera: Scarabaeoidea)

There is increasing concern about the conservation of dung beetles which are threatened by several peculiar dangers world-wide, both at the population and community level. A noticeable threat in Europe is the dramatic reduction in the number of cattle and sheep grazing in the open, which is associated with both intensive agriculture and the progressive reforestation of previously pastured areas. We studied dung beetle habitat and resource preferences at La Mandria Park (north-west Italy) which is a mosaic of open and wooded patches where domestic (cows and horses) and wild ungulates (deer and wild boar) co-exist. Scarabaeidae were numerically dominant, accounting for 61.5% of the approximately 3000 individuals sampled (Aphodiidae accounted for 32.5% and Geotrupidae for only 6%). However, when species richness was considered, Aphodiidae were dominant, with 17 of the 27 species found (Scarabaeidae with eight and Geotrupidae with two). Assuming a null hypothesis of equal probability of colonizing any habitat or faeces, we found that most species were significantly associated with one of the four dung types or with one of the two habitats considered. On average, Scarabaeidae preferred cattle dung and open habitats whereas most Aphodiidae used deer lumps and wooded habitats. In spite of the precise ecological choices observed at La Mandria, surveys from other European areas suggest that both habitat and food selection are quite flexible. From a conservation viewpoint, the ability of coprophagous beetles to choose herbivore faeces according to their availability and to select habitats that satisfy their own microclimate requirements may certainly be useful in preserving biodiversity. Agroecology, which implies some woodland and hedgerow management practices associated with pastoralism, could be the right approach to the management of the agricultural landscape. Conversely, in reforested areas, while wild ungulate populations should be preserved, some form of human disturbance, particularly clearings used for pastoralism, should also be maintained.

Some considerations on the dispersal power of Digitonthophagus gazella (Fabricius 1787) in the New World (Coleoptera Scarabaeidae Scarabaeinae)

In recent years, imported dung beetles Scarabaeinae have been used to enhance fast manure degradation on the surface of pastures in some regions. In 1972, Digitonthophagus gazella (Fabricius 1787) was first released in Victoria County and Kleber County, Texas, and then in some other regions of the United States. Subsequently the species has extended its distribution area in the U.S.A. and Mexico. The successful dispersal of D. gazella in Mexico is presented and analysed in this paper. A table showing the dispersal speed in kilometers per year is also included. Furthermore, it is shown that the dispersal is higher towards the South, i. e., towards tropical regions.

Food relocation behaviour in Eucraniina beetles (Scarabaeidae) and the constraints of xeric environment

Food relocation in dung beetles consists in the removal of dung fragments from a source and their burial before use. Such behaviour is generally understood as an adaptive response to the degradation of food at the ground surface and to competition among coprophagous insects. We investigated the feeding behaviour of the Eucraniina in a xeric environment. New data on food preference, transportation behaviour, and the structure of the feeding burrow of these insects is presented. The food relocation behaviour of the Eucraniina strongly differs from all previously described patterns and seems to be exclusive to this subtribe. It is suggested that in the Eucraniina food relocation can be interpreted as a behavioural strategy to exploit an otherwise useless food source, by rehydrating it in hypogeal conditions. This hypothesis is supported by the properties of utilized food and the characteristics of a xeric environment.

Analysis of temporal segregation in a dung‐inhabiting beetle community at a low‐altitude area of the Italian Alps

Abstract A dung‐inhabiting beetle community has been studied at a low‐altitude area of an Italian Alpine valley (Pesio valley) by considering the pattern of beetle succession in droppings and their seasonality. As a whole, the community was characterized by a low density of individuals, with coprophagous beetles largely dominant over carnivorous beetles, both with regard to species richness and abundance. Dung beetles showed the lowest values of species richness and diversity during August a time when predatory beetles peaked. It is possible that during the dry season droppings become a refuge habitat for predatory beetles, as a consequence of moisture and prey availability. With regard to core species (abundance equal to or higher than 20), some intergeneric differences were found. On‐thophagus species mainly occurred during May and June, whereas Aphodius species were more diversified, with some mainly occurring during May and June, some during September, and others during July. Most Species arrived at t...

Systematics and phylogeny of Eodrepanus, a new Drepanocerine genus, with comments on biogeographical data (Coleoptera: Scarabaeidae: Oniticellini)

We describe here Eodrepanus gen. nov., currently comprising nine species, six previously assigned to the genus Drepanocerus and three described as new (namely, E. morgani sp. nov., E. paolae sp. nov. and E. coopei sp. nov.). Two of the new species have an Afrotropical distribution, while the last is an Eemian fossil species from England. Maximum parsimony was used to analyse reciprocal relationships among the species of Eodrepanus gen. nov., and four of the 24 species remaining in Drepanocerus. Support for these phylogenies was evaluated using the Bootstrap method and Bayesian inference as implemented in MrBayes. The biogeography of Eodrepanus gen. nov. was analysed using several different methods, namely, analysis of similarity (Ochiai Index), dispersal–vicariance analysis and parsimony analysis of endemicity.

Biology of the preimaginal stages in trogid beetles (Coleoptera): Experimental data∗

Abstract Some aspects of larval behaviour in two species of trogid beetles, Trox bispidus (Pontoppidan) from temperate Europe and Afromorgus tuberosus (Klug) from tropical Africa, have been studied experimentally. From the results obtained it emerges that the rise of the newborn larvae towards the soil surface is imputable to a simple negative geotropism. Larval food relocation also contributes to reducing aggressive interactions at the food source. The potential range of trophic and behavioural variation seems to be larger than that expressed in nature as a rule. This can contribute to explaining, in evolutive terms, the rare cases of transgression from a uniform trophic and behavioural pattern, wich are probably at the origin of the evolutive success of the group as a whole.

Tibiodrepanus tagliaferrii - a new Afrotropical Drepanocerina species (Coleoptera: Scarabaeidae: Oniticellini), with notes on phylogeny and distribution of the genus

We examined the genera Tibiodrepanus Krikken, 2009 (four Oriental and one Palaearctic species) and Sulcodrepanus Krikken, 2009 (one Afrotropical species), using type specimens and non-type specimens, in order to assess the systematic consistency of the two taxa. Within this framework, we also considered the genera Afrodrepanus Krikken, 2009 (two species) and Drepanocerus Kirby, 1828 (two species) employing sets of traits from external morphology, the genitalia of both sexes and the epipharynx. The genus Cyptochirus Lesne, 1900 was chosen as an outgroup. A new species—Tibiodrepanus tagliaferrii sp. nov.—was described based on four females from Cameroon and Namibia. The phylogenetic analyses confirmed that the Tibiodrepanus and Sulcodrepanus species were closely related, yet it did not support the hypothesis of a generic or subgeneric separation of the two taxa. Hence, we establish Sulcodrepanus as a junior synonym of Tibiodrepanus, new synonymy. The genus Tibiodrepanus shows a disjunct Afrotropical-Oriental (common to many other Drepanocerina genera) and Southeastern Palaearctic (Hindu Kush, Afghanistan) distribution pattern.

The reproductive behaviour of Kheper aeratus (Gerstaecker) and the evolution of subsociality in Scarabaeidae (Coleoptera)

An Afrotropical scarab beetle, the ball-roller Kheper aeratus (Gerstaecker), was reared in controlled conditions. Nesting behaviour and parental care are described. This behaviour is interpreted in the framework of subsociality in Scarabaeidae.

Revised classification and phylogeny of an Afrotropical species group based on molecular and morphological data, with the description of a new genus (Coleoptera: Scarabaeidae: Onthophagini)

The worldwide distributed Onthophagus genus comprises at present more than 2000 species, that often show a complicated and uncertain systematic history. In particular, the many Afrotropical species included in this genus have never been entirely reviewed after the division into 32 species groups proposed by d’Orbigny in 1913, although subsequent researches focusing on some of these species suggested that Onthophagus constituted a nonmonophyletic taxon. In order to highlight their phylogenetic relationships, the various Afrotropical species groups of d’Orbigny must thus be examined, and it would be advisable to study them separately to avoid misunderstanding. In this framework, the taxonomic position of the three species currently included in the 21st d’Orbigny group was examined. Both morphological and biomolecular analyses contributed in confirming that these species (i.e., Onthophagus caffrarius d’Orbigny, 1902; Onthophagus quadraticeps Harold, 1867; and Onthophagus signatus Fåhraeus, 1857) constituted a well-defined monophyletic group that cannot be maintained within the genus Onthophagus. Therefore, the Kurtops gen.n. is here described to accommodate these Afrotropical species, that are nevertheless always included within the Onthophagini tribe. On the basis of the phylogenetic relationships here elucidated, it was also emphasized that the new genus is strictly related to Digitonthophagus and Phalops; thus, it was proposed to include the three genera into a single clade of suprageneric rank naming it as Phalops complex.

Reproductive biology in three species of the genus Onitis Fabricius 1798 (Coleoptera Scarabaeidae Onitini)

The reproductive biology of three species of the genus Onitis Fabricius 1798 was studied in laboratory conditions. The species, O. belial (Fabricius 1789) from Morocco, O. anthracinus Felsche 1907 and O. vanderkelleni Van Lansberge 1886 from Kenya, adopted a tunneler nesting strategy, as is typical of the tribe onitini. Nevertheless, the same species can adopt different tactics, modifying the shape and depth of the nest, number of brood-masses per couple, and number of eggs laid. However, this study showed that O. vanderkelleni builds a poorly elaborated nest and lays a higher mean number of eggs, while O. belial and O. anthracinus expend a larger amount of energy in the construction of the nest, while reducing the number of eggs laid.