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  • Author or Editor: L. Arellano x
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Obtaining knowledge about a species’ life history and reproductive behaviour is fundamental for understanding its biology, ecology, and potential role in ecosystem services. Here, we focused on the dung beetle species Onthophagus lecontei. Adults were collected in the field and then confined to terrariums, where they were supplied with semi-fresh domestic goat dung (Capra aegagrus Erxleben, 1777). After being paired (26 pairs), the nesting behavior of beetles was observed under laboratory conditions and the preimaginal development of individuals obtained from mating (from the deposition of the egg until the emergence of the adult) was described. Their nesting behavior was found to be characteristic of what is known as pattern I, which comprises building of brood masses, oviposition of a single egg in each brood mass, development of three larval instars, construction of a pupation chamber, pupal stage and adult emergence. Both sexes were involved in the handling of dung, tunnel construction, and mass nest elaboration. Pairs built from one to seven brood masses. The pre-nesting period (feeding) lasted 16 days; the egg stage two days, the larval period 22 days; the pupal period 11 days and the imagoes four days, after which the adults emerged. Our results are discussed and compared with other species in the genus. However, our knowledge of this dung beetle is still limited, and further studies are required in all areas of its biology.

In: Animal Biology
In: XX International Grassland Conference: Offered papers

Horses under grazing regime are at a high risk for infection by several parasites affecting the digestive tube, especially the strongyles. Infection occurs by the ingestion of free-living third stage larvae (also called L3) when grazing in pastures. While deworming reduces the presence of adult parasites in the horses, some action against the L3 in the pasture is needed for reducing the risk of infection. Eight adult horses exceeding a cut-off value of 300 eggs per gram of feces (EPG) were utilized in the current study. Control of parasitic strongyles consisted of the combination of two measures. Firstly, the horses were given moxidectin (Equest® oral gel, Pfizer, Madrid, Spain; 0.4 mg/kg bw dosage), and in addition, a dose of 2×106 Duddingtonia flagrans chlamydospores kg/bw was bi-weekly given to each horse. The effect of this combined procedure was assessed by estimating the reduction in the faecal egg counts. After the horses received the chemotherapy and the D. flagrans chlamydospores a significant reduction in the EPG was observed (Z=-11.391, P= 0.001). No strongyle egg-output was observed for 2 months, whereas the need for applying a new dosage of chemotherapy was established at the 6th month after the initial deworming of the equines. Our results point the efficacy of a combined strategy by giving chemotherapy and chlamydospores for reducing the frequency of antiparasitic drug administration to grazing horses. Besides the presence of free-infective larval stages can be significantly lowered and thus the risk of infection in the horses, this procedure seems a very valuable and helpful contribution to the sustainability of the environment by minimizing the effect of chemical residues dangerous for some organisms as dung beetles, essential for the natural fertilization of the soil.

In: Forages and grazing in horse nutrition