A die-off of large ungulates following aStomoxysbiting fly out-break in lowland forest, northern Republic of Congo

Extending the conservation impact of great ape research: Flagship species sites facilitate biodiversity assessments and land preservation

To inform regional conservation planning, we assessed mammalian and avian biodiversity in the Djéké Triangle, which is an intact forest with long-term research and tourism focused on western lowland gorillas (Gorilla gorilla gorilla). This critical region serves as a conservation conduit between the Nouabalé-Ndoki National Park (NNNP) in the Republic of Congo and the Dzanga-Ndoki National Park in Central African Republic. Wildlife inventories were conducted to determine if biodiversity in the Djéké Triangle (initially part of a logging concession) was equivalent to the NNNP. Camera traps (CTs) were deployed to estimate species richness, relative abundance, naïve occupancy, and activity patterns of medium-to-large species in mixed species and monodominant Gilbertiodendron forests that comprise the majority of regional terra firma. Species inventories were collected from CTs positioned on a grid and at termite nests throughout the Djéké Triangle and compared to CTs placed in the Goualougo Triangle located within the NNNP. From 10,534 camera days at 65 locations, we identified 34 mammal and 16 bird species. Allaying concerns of wildlife depletion, metrics of species richness in the Djéké Triangle surpassed those of the Goualougo Triangle. Many species were observed to occur across habitats, while others showed habitat specificity, with termite mounds indicated as an important microhabitat feature. Our comparisons of animal activity budgets in different habitat types provide important reference information for other populations and contexts. In conclusion, this study provided empirical evidence of the high conservation value of this region that contributed to increasing the protected status of the Djéké Triangle.

Development and first evaluation of an attractant impregnated adhesive tape against blood-sucking flies

Stable flies are one of the most important arthropod pests of livestock that reduce cattle weight gain and milk production leading to annual economic losses in excess of $2 billion to the US cattle industry. The host-seeking behavior is primarily mediated by associated odors from stable fly larval development environments and host animals. The present paper reports the development and evaluation of attractant-impregnated adhesive tapes to reduce stable fly attacks on cattle. Laboratory bioassays showed that only m-cresol impregnated adhesive tapes caught significantly more stable flies (16 ± 1) than the control tape without attractant added (7 ± 1), with a 77% fly recapture rate. Attractant-impregnated adhesive tapes deployed in cattle feedlots showed significant impacts in reducing fly population, with a total of one million stable flies captured over a period of three weeks (mean catches from 57 596 to 102 088 stable flies per trap per week). It further relieved cattle stress with a significant reduction of biting fly avoidance behavior, (6 ± 0.4 cows observed with tail wagging in control vs. 3 ± 0.4 from the trap-deployed). The efficacy of the developed tapes lasted up to 1-week longevity, although 70% of m-cresol was released starting from the second day. The m-cresol impregnated adhesive tape provided an 80% reduction in cattle stress due to stable fly attack. This is the first report of a technology developed by integrating an attractant compound into an adhesive material on a plastic film with demonstrated effectiveness in trapping biting flies that attack livestock animals.

Semi-field evaluation of the predation of Macrocheles embersoni and Macrocheles muscaedomesticae (Acari: Mesostigmata: Macrochelidae) on the house fly and the stable fly (Diptera: Muscidae)

BACKGROUND

The house fly, Musca domestica L., and the stable fly, Stomoxys calcitrans (L.), are important and harmful organisms. The cosmopolitan house fly is not parasitic, but the adults are annoying and a known vector of several pathogens. The importance of the stable fly has increased in Brazil in the last 40 years, after major changes in sugarcane cultivation practices were implemented, including the widespread application of vinasse (byproduct in sugarcane mills) and the parallel reduction of sugarcane preharvest burning. These changes have favored the development of this fly, which can reach high populations, that can negatively affect cattle and other animals. The control of these flies relies heavily on the use of chemical products, which very often do not provide adequate population reduction. Predatory mites of the family Macrochelidae have been evaluated under laboratory conditions for the biological control of these organisms, especially of the house fly. The objective of this study was to examine the predation capacity of the macrochelids Macrocheles embersoni Azevedo, Castilho & Berto and Macrocheles muscaedomesticae (Scopoli) on the house fly and the stable fly, under semi-field conditions (screen-houses).

RESULTS

Reductions of 83 to 90% of the house fly and 66 to 73% of the stable fly populations were observed, with the release of 100 of these predators per square meter.

CONCLUSIONS

The number of adults of both fly species was much lower in the units where the predators had been released than in the others. However it is suggested that provisioning and or conserving alternative food sources for these macrochelids, such as free-living nematodes, could further improve biocontrol efficacy.

Insecticidal efficacy of afoxolaner against Stomoxys calcitrans (Diptera: Muscidae) in dogs

The insecticidal activity of oral afoxolaner (NexGard®) against stable flies Stomoxys calcitrans (Diptera: Muscidae) that had fed on dogs was evaluated in a blinded, randomised, and negative controlled efficacy study. The efficacy assessments were based on survival rates of fed flies after challenges to treated dogs. For a challenge, each dog was exposed to 50 unfed S. calcitrans for 30 minutes, after which time live fed flies were collected and incubated in an insectarium for viability assessment after 48, 72 and 96 hours. Fourteen dogs were randomly allocated to an untreated control group and an afoxolaner-treated group of seven dogs each. NexGard® was administered on Day 0 per label instructions to the treated group. All dogs were challenged on Days 1, 7, 14, 21 and 28. Efficacy was calculated by comparison of the proportion of incubated live fed flies for each individual after their related 30-min challenges in the control and treated groups after 48, 72 and 96 hours of incubation. A significant afoxolaner activity against S. calcitrans was demonstrated, with efficacy at 96 hours after blood-feeding ranging from 76.4 to 98.5% through Day 28.

Retrospective analysis of the lifetime endocrine response of southern right whale calves to gull wounding and harassment: A baleen hormone approach

Physiological measurements are informative in assessing the relative importance of stressors that potentially impact the health of wildlife. Kelp Gulls, Larus dominicanus (KG), resident to the region of Península Valdés, Argentina, have developed a unique behavior of landing on the backs of southern right whale adults and calves, Eubalaena australis (SRW), where they feed on their skin and blubber. This parasitic behavior results in large open wounds on the dorsal surface of the whale. Coincidently, the SRW population off the coast of Península Valdés has experienced elevated calf mortality. We quantified levels of glucocorticoids and thyroid hormone extracted from baleen of dead calves to evaluate, retrospectively, the endocrine response of whale calves to gull wounding and harassment. Baleen accumulates hormones as it grows, allowing evaluation of long-term trends in physiological condition. While glucocorticoids (GCs) are known to increase in response to stressors such as disturbance, the metabolic hormone triiodothyronine (T₃) has been shown to decrease under sustained food deprivation but is largely unaffected by disturbance stress. We quantified lifetime patterns of GCs and T₃ in baleen recovered at necropsy from 36 southern right whale calves with varying severity of wounding from KGs. GC levels in baleen correlated positively with the degree of wounding, while T₃ levels remained stable irrespective of the severity of the wounding. Our results suggest no evidence of malnutrition in low vs. severely wounded whales. However, the positive correlation of GCs with wound severity indicates that heavily wounded calves are suffering high levels of physiological stress before they die. This suggests that KG wounding may have contributed to the high southern right whale calf mortality observed in the Península Valdés region of Argentina.

Stomoxys calcitrans (Diptera: Muscidae) outbreaks: current situation and future outlook with emphasis on Brazil

The stable fly (Stomoxys calcitrans) has historically been a pest of dairy cattle and feedlots due to the availability of decaying plant matter mixed with animal excrements in such production systems. In the last few decades, stable fly outbreaks have also been reported in pasture-raised beef cattle, usually associated with wastes accumulated from animal feeding during winter, the introduction of large-scale crop operations near cattle ranches, and/or the inadvertent use of organic fertilizers. Population explosions of Stomoxys flies may also have natural causes, affecting not only domestic and/or wild animals but also humans. This article compiles information on stable fly outbreaks in Brazil and abroad and discusses their causes and consequences.

Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés, Argentina

At least 626 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus) began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequency of gull attacks has increased dramatically over the last three decades and mother-calf pairs are the primary targets. Pairs attacked by gulls spend less time nursing, resting and playing than pairs not under attack. In successive attacks, gulls open new lesions on the whales' backs or enlarge preexisting ones. Increased wounding could potentially lead to dehydration, impaired thermoregulation, and energy loss to wound healing. The presence, number and total area of gull-inflicted lesions were assessed using aerial survey photographs of living mother-calf pairs in 1974-2011 (n = 2680) and stranding photographs of dead calves (n = 192) in 2003-2011. The percentage of living mothers and calves with gull lesions increased from an average of 2% in the 1970s to 99% in the 2000s. In the 1980s and 1990s, mothers and calves had roughly equal numbers of lesions (one to five), but by the 2000s, calves had more lesions (nine or more) covering a greater area of their backs compared to their mothers. Living mother-calf pairs and dead calves in Golfo Nuevo had more lesions than those in Golfo San José in the 2000s. The number and area of lesions increased with calf age during the calving season. Intensified Kelp Gull harassment at Península Valdés could be compromising calf health and thereby contributing to the high average rate of calf mortality observed in recent years, but it cannot explain the large year-to-year variance in calf deaths since 2000.

Transmission of pathogens by Stomoxys flies (Diptera, Muscidae): a review

Stomoxys flies are mechanical vectors of pathogens present in the blood and skin of their animal hosts, especially livestock, but occasionally humans. In livestock, their direct effects are disturbance, skin lesions, reduction of food intake, stress, blood loss, and a global immunosuppressive effect. They also induce the gathering of animals for mutual protection; meanwhile they favor development of pathogens in the hosts and their transmission. Their indirect effect is the mechanical transmission of pathogens. In case of interrupted feeding, Stomoxys can re-start their blood meal on another host. When injecting saliva prior to blood-sucking, they can inoculate some infected blood remaining on their mouthparts. Beside this immediate transmission, it was observed that Stomoxys may keep some blood in their crop, which offers a friendly environment for pathogens that could be regurgitated during the next blood meal; thus a delayed transmission by Stomoxys seems possible. Such a mechanism has a considerable epidemiological impact since it allows inter-herd transmission of pathogens. Equine infectious anemia, African swine fever, West Nile, and Rift Valley viruses are known to be transmitted by Stomoxys, while others are suspected. Rickettsia (Anaplasma, Coxiella), other bacteria and parasites (Trypanosoma spp., Besnoitia spp.) are also transmitted by Stomoxys. Finally, Stomoxys was also found to act as an intermediate host of the helminth Habronema microstoma and may be involved in the transmission of some Onchocerca and Dirofilaria species. Being cosmopolite, Stomoxys calcitrans might have a worldwide and greater impact than previously thought on animal and human pathogen transmission.

Zoonoses Animal and Human Diseases Endo and Ectoparasites Mainly Mammal I

The definition of a zoonosis is that it must affect man but the term is used often outside of medical terminology of animal diseases where man is not involved. Zoonoses are diseases naturally transmitted between animals and man and comprise in total about 80% of all described human infections. Attempts have been made to define different classes of zoonoses according to the man-animal relationship but generally this does not seem to have been accepted. Elton in 1927 stressed the field of wild animal pathology was still virtually untouched, and in 1968 McDiarmid reiterated the view that it remained one of the most neglected aspects of animal ecology. There is now an extensive literature but it is rarely incorporated into ecological texts although disease is often the driving force in population dynamics. The primary driver of infectious disease dynamics is transmission between individuals, yet in most important respects remarkably little is known about the subject (Craft et al. 2008, Haydon 2008). Occasionally, under high population densities, an organism may infect a host outside of its normal range with highly pathogenic effect in its adventitious host.

Surtos por Stomoxys calcitrans em gado de corte no Mato Grosso do Sul

A expansão da indústria sucroalcooleira tem levado à instalação de usinas de álcool em áreas tradicionalmente ocupadas pela pecuária de corte na região Centro-Oeste do País. Surtos pela mosca-dos-estábulos (Stomoxys calcitrans) em bovinos Nelore têm sido relatados nos últimos dois anos em Mato Grosso do Sul, associados a estas usinas. Visitas em propriedades pecuárias e usinas foram realizadas em meados de novembro 2009, ao final de surtos por S. calcitrans ocorridos nos municípios de Angélica e Ponta Porã, MS. Entrevistas, observações e coletas de imaturos de dípteros foram realizadas nos locais e o material entomológico coletado foi levado ao laboratório para posterior emergência. Elevadas infestações pela mosca-dos-estábulos e comportamento de agrupamento dos bovinos foram observados. Sítios de reprodução foram encontrados nos locais e a emergência de S. calcitrans foi constatada nas amostras coletadas tanto nas fazendas como nas usinas. O conjunto de informações, observações in loco e resultados das amostragens possibilitaram realizar uma abordagem epidemiológica preliminar sobre a dinâmica dos referidos surtos por S. calcitrans e discutir potenciais fatores de risco.