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Image‐based analyses from an online repository on rhino horns asserted that declines in size over time could be the consequence of poaching and hunting.We provide reflections on whether the sample was representative enough to make generalizations, the study adequately accounted for the main sources of horn‐size variation and the statistical methods were adequate to be confident in the results.The sample had a limited representation, most coming from zoo animals. We highlight several sources of variance in horn size that such a sample could not evaluate robustly using linear regressions, both for establishing a proxy for horn size corrected for size of a rhino and assessing trends over time.Nevertheless, horn poaching continues to be the key threat to rhinos. Addressing the underlying drivers of poaching and trafficking are key priorities for responsible public debate, policy making and interventions. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Recognition is a prerequisite for non-random association amongst individuals. We explore how non-random association patterns (i.e. who spends time with whom) affect disease dynamics. We estimated the amount of time individuals spent together per month using radio-tracking data from African buffalo and incorporated these data into a dynamic social network model. The dynamic nature of the network has a strong influence on simulated disease dynamics particularly for diseases with shorter infectious periods. Cluster analyses of the association data demonstrated that buffalo herds were not as well defined as previously thought. Associations were more tightly clustered in 2002 than 2003, perhaps due to drier conditions in 2003. As a result, diseases may spread faster during drought conditions due to increased population mixing. Association data are often collected but this is the first use of empirical data in a network disease model in a wildlife population.

Postharvest disinfestation of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) in citrus fruit can be achieved through cold treatment, but chilling injury becomes increasingly problematic with lower temperature and longer exposure to the treatment. Ionising radiation is an alternative treatment, but also has a dose dependent negative effect on fruit quality. The potential of including both a reduced radiation dose and a less detrimental cold treatment in a combination treatment was assessed. The effects of 40 to 70 Gy radiation and cold treatments of 0.6 °C to 7.0 °C for periods of 10 to 22 days by themselves and in combination, were investigated on mature larvae in artificial rearing diet. It was demonstrated that various combinations of the two methods can act together to potentially provide adequate control, with the prospect of moderated fruit quality effects due to the reduced intensity of the component treatments. A combination treatment consisting of 60 Gy followed by 16 days at 2.5 °C was identified for further evaluation as a combination treatment that could potentially be validated at the probit-9 level of efficacy. [ABSTRACT FROM AUTHOR]

False codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is indigenous to sub-SaharanAfrica. It infests a large number of wild plants and can be a pest of commercial concern in cultivated fruit and nuts. A limited number of insecticides, as well as biological control and mating disruption can be applied as control measures in citrus, but they often do not reduce pre- and post-harvest crop loss adequately. The potential of the sterile insect technique (SIT) for the control of T. leucotreta was investigated between 2002 and 2006 in Citrusdal, Western Cape Province, South Africa, and entailed studies on radiation biology and F1 sterility, compatibility with the egg parasitoid Trichogrammatoidea Nagaraja (Hymenoptera: Trichogrammatidae), and field cage experiments to determine sterile:fertile moth overflooding ratios. Promising results justified a pilot experiment conducted on semi-commercial scale in citrus orchards in Citrusdal during 2005-06. One thousand mixed sex moths were treated with 150 Gy ionising radiation and released in 35 ha ofWashington navel oranges twice a week for 28 weeks during the production season. The moths were released by hand from an all-terrain vehicle, with release rows 40mapart and the numbers of released and feral moths monitored weekly with pheromone traps. Released moths dispersed well and fully overlapped between release rows. The target overflooding ratio of released to feral males (10:1) was exceeded by wide margins and ameanoverflooding ratio of 41:1 was maintained during the experiment. Fruit drop assessments were conducted once a week in the SIT-treated and control orchards. Crop loss due to T. leucotreta infestation was reduced by 95.2 % in the SIT-treated area compared to the control orchard. The project resulted in the commercialisation of the SIT for T. leucotreta on citrus. [ABSTRACT FROM AUTHOR]

To overcome constraints on ionising radiation and cold treatment as stand-alone disinfestation treatments for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) in citrus fruit, the efficacy of a combination treatment consisting of ionising radiation and cold, both at reduced doses, was tested at the probit-9 level. Earlier research indicated that combination treatments involving ionising radiation and cold suppressed larvae and their successive development stages more effectively than the individual treatments. The probit-9 level efficacy (at least 93 613 insects) of a treatment combination comprising 60Gyof ionising radiation followed by cold exposure for 16 days at 2.5 °C was evaluated. A total of 104 617 mature, fifth instars was treated. Larval mortality was 99.7%and 50.2%of the subsequent pupae died. A total of 143 moths with a sex ratio of one female to 7.9 males eclosed. Only 4.8%of the moths were able to fly. No eggs were produced by the moths in mating studies. The probit-9 level efficacy of the combination treatment was validated, indicating that it meets the efficacy requirements for utilisation as a phytosanitary disinfestation treatment for T. leucotreta in citrus fruit in international trade. [ABSTRACT FROM AUTHOR]

Translocations of Rhinocerotidae are commonly performed for conservation purposes but expose the animals to a variety of stressors (e.g. prolonged fasting, confinement, novel environment, etc.). Stress may change the composition of gut microbiota, which can impact animal health and welfare. White rhinoceroses in particular can develop anorexia, diarrhea and enterocolitis after translocation. The aim of this study was to investigate the associations of age, sex and translocation on the rhinoceros' fecal bacterial microbiota composition. fecal samples were collected from rhinoceroses at capture ( n  = 16) and after a >30-hour road transport ( n  = 7). DNA was isolated from these samples and submitted for 16S rRNA V3-V4 phylotyping. Alpha diversity indices of the rhinoceros' fecal microbiota composition of different age, sex and before and after transport were compared using non-parametric statistical tests and beta diversity indices using Permutational Multivariate Analysis Of Variance (PERMANOVA). Resulting P -values were alpha-corrected ( P adj . ). Alpha and beta diversity did not differ between rhinoceroses of different age and sex. However, there was a significant difference in beta diversity between fecal samples collected from adult animals at capture and after transport. The most abundant bacterial phyla in samples collected at capture were Firmicutes and Bacteroidetes (85.76%), represented by Lachnospiraceae , Ruminococcaceae and Prevotellaceae families. The phyla Proteobacteria ( P adj . = 0.009) and Actinobacteria ( P adj . = 0.012), amongst others, increased in relative abundance from capture to after transport encompassing potentially pathogenic bacterial families such as Enterobacteriaceae ( P adj . = 0.018) and Pseudomonadaceae ( P adj . = 0.022). Important commensals such as Spirochaetes ( P adj. = 0.009), Fibrobacteres ( P adj. = 0.018) and Lachnospiraceae ( P adj. = 0.021) decreased in relative abundance. These results indicate that the stressors associated with capture and transport cause an imbalanced fecal microbiota composition in white rhinoceroses that may lead to potentially infectious intestinal disorders. This imbalance may result from recrudescence of normally innocuous pathogens, increased shedding of pathogens or increased vulnerability to new pathogens., (© The Author(s) 2023. Published by Oxford University Press and the Society for Experimental Biology.)