Territoriality in ants revisited: iconic collective displays reflect resource, not territorial defense in meat ants Iridomyrmex purpureus.

Non-injurious, collective ritualized displays may have evolved in some species of ants as a means of resolving contests for key resources, without causing a drain in worker numbers through injury. Colonies of the Australian meat ant, Iridomyrmex purpureus, deploy numerous workers to engage in collective displays, which are widely understood to be involved in maintaining exclusive territories. A combination of field surveys and behavioral assays revealed that display grounds do not delimit borders that define exclusive territories. Rather, the proportion of workers from a focal colony found in a quadrat declines monotonically with distance from the nest. In addition, we documented collective displays around food trees, where workers congregated in greater densities and engaged in more aggressive behavior. These results refute the assumption that colonies of I. purpureus establish territorial boundaries by collective displays. Rather these collective displays may be related to the defense of specific resources, including food trees and nest sites. The difference in the level of aggression among displaying workers at different locations may reflect a balance between the benefits of defending a particular resource and an unappreciated cost of escalation.

Updated checklist with new records and molecular data for the mosquitoes (Diptera: Culicidae) of Hong Kong.

An extensive mosquito survey was carried out in Hong Kong from September to October 2022, employing a variety of collection methods. Specimens were identified using a combination of morphology and mitochondrial cytochrome C oxidase subunit 1 (COI) barcode sequences. Twenty-nine species, including three new records, i.e., Culex bicornutus (Theobald), Culex cinctellus Edwards, and Lutzia chiangmaiensis Somboon & Harbach, were collected. Phylogenetic analysis of COI sequences of Culex annulus Theobald and Culex vishnui Theobald collected in Hong Kong and elsewhere revealed that the sequences of the two nominal species are genetically very similar and are included in the same clade. Consequently, the synonymy of Cx. annulus with Cx. vishnui is reinstated. Lutzia halifaxii (Theobald) is removed from the list of species in Hong Kong and is replaced with Lutzia vorax Edwards, the identification of which is confirmed in the present study. The record of Culex spiculothorax Bram recorded in Hong Kong is replaced with the senior synonym Culex sasai Kano, Nitahara & Awaya. The occurrence of Anopheles fluviatilis James and Aedes aegypti (Linnaeus) is discussed. Finally, an updated checklist of the mosquitoes of Hong Kong, which now includes 76 species representing 14 genera, is provided, with notation of those species that vector pathogens of human diseases.

Colony-level aggression escalates with the value of food resources.

BACKGROUND: Theory predicts that the level of escalation in animal contests is associated with the value of the contested resource. This fundamental prediction has been empirically confirmed by studies of dyadic contests but has not been tested experimentally in the collective context of group-living animals. Here, we used the Australian meat ant Iridomyrmex purpureus as a model and employed a novel field experimental manipulation of the value of food that removes the potentially confounding effects of nutritional status of the competing individual workers. We draw on insights from the Geometric Framework for nutrition to investigate whether group contests between neighbouring colonies escalate according to the value to the colony of a contested food resource. RESULTS: First, we show that colonies of I. purpureus value protein according to their past nutritional intake, deploying more foragers to collect protein if their previous diet had been supplemented with carbohydrate rather than with protein. Using this insight, we show that colonies contesting more highly valued food escalated the contest, by deploying more workers and engaging in lethal 'grappling' behaviour. CONCLUSION: Our data confirm that a key prediction of contest theory, initially intended for dyadic contests, is similarly applicable to group contests. Specifically, we demonstrate, through a novel experimental procedure, that the contest behaviour of individual workers reflects the nutritional requirements of the colony, rather than that of individual workers.

A systematic review and meta-analysis of the safety and efficacy of anti-thymocyte globulin combined with eltrombopag in the treatment of severe aplastic anemia.

BACKGROUND: When it comes to the treatment of aplastic anemia fever, the Guidelines for Aplastic Anemia regards Anti-thymocyte globulin (ATG) combined with eltrombopag as the standard immunosuppressive treatment plan, and ATG is the main mode to treat severe aplastic anemia. A large number of prospective studies and clinical trials have confirmed the clinical application value of eltrombopag in aplastic anemia. Although ATG combined with eltrombopag brings satisfactory treatment results, the safety of long-term use is still unclear. Therefore, more clinical trial studies are needed to verify its safety. METHODS: Literature in the Chinese and English medical databases was searched using the following search terms: "Antithymocyte globulin", "severed aplastic anemia" and "eltrombopag". Patients in the experimental group were administered ATG combined with eltrombopag and patients in the control group received ATG treatment alone. Rev Man5.3 software was used for meta-analysis. RESULTS: A total of 16 references were included in this meta-analysis. Heterogeneity tests examining total effective rate demonstrated that Chi2 =4.48, df =15, I2=0%<50%, and P=1.00>0.01. The effective rate of the experimental group was higher than that of the control group, with odds ratio (OR) =1.90 and 95% confidence interval (CI) 1.35 to 2.68 (Z=3.70, P=0.0002). The heterogeneity test results of the survival rate within 2 years were Chi2 =3.09, df =7, I2=0%<50%, and P=0.88>0.01. The survival rate of the experimental group was higher than that of the control group, with OR =2.54, and 95% CI: 1.58 to 4.09 (Z=3.84, P=0.0001). The heterogeneity test results of the mortality rate were Chi2 =3.49, df =6, I2=0%<50%, and P=0.75>0.01. The mortality rate of the experimental group was lower than that of the control group, with OR =0.48 and 95% CI: 0.33 to 0.70 (Z=3.84, P=0.0001). The heterogeneity test results of the occurrence of side effects were Chi2 =0.12, df =3, I2=0%<50%, P=0.99>0.01. The incidence of side effects in the experimental group was lower than that in the control group, with OR =0.74, 95% CI: 0.48 to 1.17 (Z=1.29, P=0.20). DISCUSSION: This meta-analysis demonstrated that the combination of ATG with eltrombopag in the treatment of SAA is safer and more effective than ATG alone.