Evaluation of functional muscle anatomy scalability in the canine hind limb

In contrast to other mammals, the large variation in dog sizes is not accompanied by any significant genetic re-organization. In order to study the relationship between body mass, limb length and the functional anatomical muscle parameters of the canine hind limb, a large dataset comprising of muscle masses, optimal muscle fibre lengths and physiological cross-sectional area's (PCSA) were acquired for twenty-five muscles in ten dogs of sizes varying between 20 kg and 52 kg. The potential of body mass and limb length for reliably scaling individual muscle masses, optimal muscle fibre lengths and PCSA's were examined. For the majority of the muscles of the canine hind limb, neither body mass nor limb length were reliable scaling parameter for either muscle masses, PCSA's and optimal fibre length. These results indicate the need of a breed-specific approach to musculoskeletal modelling in future canine musculoskeletal research.     

First report of Thrips setosus in Belgium

The Japanese flower thrips, Thrips setosus, is a polyphagous insect which in Europe has mainly been observed on hydrangeas (Hydrangea spp.). The first report of T. setosus in the EPPO region was in the Netherlands (2014). Since then it has been observed in four other countries inside the EPPO region: Germany (2015), the United Kingdom (2016), France (2016) and Croatia (2016). Its dispersal is most likely to be related to trade. Because of its polyphagous nature, there is a risk of spread to other economically important crops. Therefore, T. setosus was included in the national survey project ‘STATREGO’, during which the status of several invasive plant pests and diseases in Belgium was determined.     

Oak (Quercus robur L.) regeneration in early successional woodlands grazed by wild ungulates in the absence of livestock

Wooded pastures grazed by livestock are believed to be landscapes that provide favourable conditions for spontaneous regeneration of oaks, including Quercus robur. A key mechanism for oak regeneration in these systems is ‘associational resistance’, spatial association with unpalatable plants which offer protection against herbivory. There is little knowledge on how oak regenerates without livestock grazing and in the presence of only wild large herbivores. We studied this in an area (114 ha) abandoned from agricultural use and in the early 1980s incorporated into the Bia?owie?a National Park, Poland. Its ungulate community consists of native red deer, European bison, roe deer, moose and wild boar. Secondary succession has led to the development of a mosaic habitat including tree and tall shrub groves (29% of the area), open meadow communities (60%), and edge, transitory zone between groves and meadows (11%). Our systematic inventory assigned oaks to height classes (0-0.2, 0.2-0.5, 0.5-1.3, 1.3-2.5, 2.5-5.0, >5.0 m), dichotomous shape characteristic (regular vs. “bonsai” sapling), as well as a habitat definition, in particular the characteristics of woody vegetation in the immediate surroundings of oaks. A selection of 17 oaks was subject to coring for the comparison of growth dynamics. Oak density was highest inside groves, with 504 oaks ha⁻¹, and in the edge zone (493 oaks ha⁻¹) and lowest in meadows (47 oaks ha⁻¹). Most of the 0-5-m oaks (62%) grew without another woody plant species within 1 m radius. The remaining oaks (38%) were associated mainly with Rubus idaeus and saplings of Carpinus betulus and Populus tremula - all highly ungulate-preferred species. The age (0.5 m above ground) of cored oaks in grove and edge habitats varied from 11 to 37 years, indicating continuous recruitment since agricultural abandonment. The initial growth dynamics of the more mature oaks did not differ from that of present “bonsais,” supporting the idea that browsing is not an unconditional impediment and that “bonsai” can be a temporary stage of successful oak development. In contrast to other studies, we found that associational resistance from unpalatable plants is not necessary to secure successful oak regeneration in woodlands subject to browsing by wild ungulates. This might have been possible because of the abundance of highly attractive vegetation making oak relatively unpreferred by ungulates. We suggest that the observed secondary succession provides a contemporary analogy of historic processes that resulted in the establishment of broadleaf forests with a substantial proportion of oak.     

Development and reproduction of Adalia bipunctata (Coleoptera: Coccinellidae) on eggs of Ephestia kuehniella (Lepidoptera: Phycitidae) and pollen

Due to growing criticism over the use of non-indigenous coccinellids, the two-spot ladybird, Adalia bipunctata (L.), has enjoyed increasing attention for aphid biocontrol in Europe. In the current study, eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller, whether or not supplemented with bee pollen, were evaluated as a factitious food for larvae and adults of A. bipunctata. The predator showed slower larval development and lower survival when reared on live pea aphids, Acyrthosiphon pisum (Harris), than on E. kuehniella eggs. Survival on gamma-irradiated eggs of E. kuehniella was superior to that on frozen flour moth eggs, but other developmental characteristics were similar. Adults of A. bipunctata reared on Ac. pisum were only half as fecund as those offered irradiated or frozen E. kuehniella eggs, but egg hatch was markedly better on live aphids than on flour moth eggs (61 versus 20-27%, respectively). However, when a diet of flour moth eggs was supplemented with frozen moist bee pollen, egg hatch of A. bipunctata was equally as good as on live aphids. Supplementing flour moth eggs with dry pollen did not yield satisfactory results. Only 10% of larvae reached adulthood on moist bee pollen alone and resulting adults weighed less than half as much as those obtained on flour moth eggs. Our findings indicate that A. bipunctata is able to compensate for a suboptimal diet of animal prey by supplementary feeding on flower pollen. It is concluded that pollinivory may be a crucial trait for both the rearing of this natural enemy and its use in biological control programmes.     

Property Rights Effects on Farmers’ Management Investment in Forestry Projects: The Case of Camellia in Jiangxi,China

China’s central government has carried out a series of collectivization and de-collectivization attempts of forest tenure over time, which have led to multiple forest tenure arrangements within provinces. This paper investigates the motivation of farmers to maintain forestry under various forest tenure regimes. First, the paper provides a qualitative analysis of the different forest tenure regimes using the New Property Rights Theory. Second, an econometric analysis based on data from camellia projects in Jiangxi province is carried out. Camellia projects are long-term projects for the production of non-timber forest products which are important for rural income generation. Qualitative results of the research show that a multitude of different tenure regimes exist across forestry projects. Community-based or collective forest management regimes are the most important tenure regimes in forest management in Jiangxi province. Village communities and farmers are the main actors in forest resource management and investment in camellia projects in Jiangxi province. The results of the econometric analysis show that higher degrees of tenure security and residual claimancy for farm households lead to a higher use of household labor and capital within camellia forestry projects. Uncertainty about the future forestland distribution is an obstacle for household investments in forestry.     

Effect of intratesticular inoculation with Aujeszky's disease virus on genital organs of boars

Ten 8-10-month-old Belgian Landrace boars were intratesticularly inoculated with 500 TCID50 of a virulent Belgian Aujeszky's disease virus (ADV) isolate (75V19) in 0.1 ml volume. One control boar was similarly inoculated with phosphate-buffered saline solution. The genital organs of six inoculated boars were examined by virus isolation and immunofluorescence. In spite of high virus titers, the fluorescence in the testicles remained limited to a few small foci in the interstitial connective tissue and tunica albuginea at or close to the inoculation site. Neither virus replication, necrosis nor inflammatory lesions could be demonstrated in the epithelium of the seminiferous tubules. However, virus replication was regularly demonstrated in the serosa covering testicles, plexus pampiniformis, ductus deferens and tunica vaginalis. Virus was also isolated from the scrotal fluid. It is suggested that the serosa is the primary target tissue for ADV. The other four boars were inoculated to study the effect of ADV on semen. Severe morphologic alteration and lowered sperm cell concentrations were observed during several weeks after inoculation or until slaughter at 47, 53 and 58 days post inoculation. Virus was isolated from semen of only two out of four boars examined at 9 and 10 days post inoculation.     

End-use related physical and mechanical properties of selected fast-growing poplar hybrids (Populus trichocarpa × P. deltoides)

This study focused on physical and mechanical properties of fast-growing poplar clones in relation to potential end uses with high added value. A total of 14 trees from three different clones, all P. trichocarpa × deltoides (T×D) hybrids, were felled in a poplar plantation in Lille (Belgium): six ‘Beaupré’, four ‘Hazendans’ and four ‘Hoogvorst’. Growth rate was found to have no significant influence on the physical mechanical properties. Although the investigated clones are genetically closely related, important variations in physical and mechanical properties were observed. Specific features such as spatial distribution of tension wood and dimensional stability are the main quality factors. It was concluded that ‘Beaupré’ is suitable for a wide range of high value added applications, such as plywood or construction wood. ‘Hazendans’ and ‘Hoogvorst’ will need adapted technology in processing. Further research is needed to characterize clonally induced variation in properties and to assess adequate processing strategies for multiclonal poplar stands.     

Breed differences in the pharmacokinetics of ivermectin administered subcutaneously to Holstein and Belgian Blue calves

Belgian Blue (BB) cattle are very sensitive to mange caused by Psoroptes ovis and, in contrast to the case in Holstein cattle, single treatments with ivermectin do not result in complete elimination of the parasite. The objective of the present study was to determine the concentration of ivermectin in plasma, skin and hair following subcutaneous administration to Holstein and BB calves and to assess the influence of breed on drug pharmacokinetics and availability. Two groups of six healthy female Holstein and BB calves were treated with ivermectin (SC formulation) at a dose of 0.2 mg/kg. Blood, skin and hair were collected before treatment and up to 21 days after treatment. Ivermectin was analyzed in plasma and tissue by high-performance liquid chromatography (HPLC). The peak concentrations (Cmax), time-peak concentrations (Tmax), the area under the plasma concentration-time curves (AUC) and the mean residence time (MRT) were determined. The patterns of plasma and tissue ivermectin concentrations were similar in the two breeds of animals, however, the AUC and Cmax levels for plasma and skin were significantly higher in the BB calves. In hair, ivermectin was detected later than in plasma and skin, with the Tmax ranging between 4 days (Holstein group) and 6 days (BB group). The possible reasons for the significantly higher levels in plasma and skin in BB calves compared to Holstein calves are discussed.     

Integrating environmental conditions and functional life-history traits for riparian arthropod conservation planning

River banks are naturally disturbed habitats, in which local flood events and the landscape structure are expected to govern riparian species assemblages. Not solely effects of flooding per se, but also related changes in vegetation structure will affect species distribution. By elucidating the relationships between species occurrences and multivariate habitat conditions on a restricted spatial scale, insight into conservation strategies to preserve riparian species is gained. Ordination and grouping methods revealed important environmental and functional trait constraints on the composition of predatory riparian arthropods. Mainly flooding disturbance appeared to affect spider and carabid beetle assemblages. Habitat affinity and dispersal ability were retained as important traits explaining similarity between arthropod assemblages. River banks similar in species composition differed in absolute and functional group species richness. Furthermore, Poisson regressions demonstrated the importance of variation in discharge regime, sediment composition and vegetation structure for the preservation of rare riparian arthropods. Xerothermophilic specialists were disfavoured by increased flooding disturbance, whereas hygrophilic species benefited from increased vegetation cover. In contrast to flight-active riparian carabids, occurring throughout the river system, especially cursorial spiders are expected to go extinct under increased anthropogenic alterations of discharge regimes. In general, river restoration should generate the required heterogeneity in environmental conditions (e.g. dynamic processes) at the river bank level, thereby increasing the sustainability of dynamic riverine landscapes and the conservation of vulnerable riparian arthropods. Moreover, we argue that the understanding of functional responses towards environmental factors on a local scale results in general and widely applicable guiding concepts for species conservation and ecosystem management.