Search

Parasitoid A. lopezi was introduced into Indonesia in 2014 to control P. manihoti. A. lopezi interacts with the predators P. ramburi and C. montrouzieri commonly found in cassava fields infested by mealybugs. Study was conducted with the objective to elucidate an interference of both predators on the effectiveness of A. lopezi. Experiments were carried out into petridish and insect cage in laboratory. The 3rd instar mealybug nymphs were exposed to both predators for 24 hours. Observations were done on parasitoid behavior and predation levels of predators. The presence of predators significantly affected the decrease in visiting period, host finding time, and the number of eggs successfully laid by A. lopezi on the mealybug nymphs. The two predatory insects were able to prey on unparasitized and parasitized mealybugs aged 1-8 days. Predators were able to discriminate against parasitized mealybugs aged 14 days (mummy). Predation of predators occurred on parasitized mealybugs aged 1-, 3-, and 8-days. The combination of parasitoids with both predators shows an antagonistic interaction. The presence of predators P. ramburi and C. mountrouzieri reduced the parasitism rate of A. lopezi on P. manihoti. [ABSTRACT FROM AUTHOR]

Primer registre de Pharyngodon travassosi (Nematoda, Pharyngodonidae) en Teius teyou (Squamata, Teiidae) al desert del Monte, Argentina Per tal de contribuir al coneixement dels paràsits de les sargantanes Teiidae a l'Argentina es va analitzar el contingut gastrointestinal de cinc exemplars mascles de Teius teyou de la localitat d'El Encón, San Juan, Argentina. Es van trobar un total de 78 nematodes que van ser assignats a Pharyngodon travassosi, amb una prevalença del 100 % i una intensitat mitjana de 15,6. Les característiques diagnòstiques dels nematodes són: mascles amb ales caudals que formen una bossa que embolica totes les papil·les pedunculades anals i cua de la mateixa grandària aproximadament que la bossa; femelles amb cua llisa i ous truncats. Aquest és el primer registre d'aquesta espècie de nematodes a l'Argentina, com també de la interacció paràsit-hoste.

Copyright of Revue d'élevage et de Médecine Vétérinaire des pays Tropicaux is the property of CIRAD and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

L’écotoxicité des traitements antiparasitaires vétérinaires et l’apparition de résistances vis-à-vis de plusieurs familles de molécules antiparasitaires amènent à réfléchir à la bonne utilisation de ces produits afin de réduire leur impact écologique tout en maitrisant les enjeux sanitaires et économiques au sein des troupeaux. La présente étude explore ces notions dans le cadre de l’accompagnement de dix-neuf éleveurs de deux départements français (Gard et Hérault) engagés dans un processus de gestion raisonnée du risque parasitaire à travers le respect d’un cahier de charge de protection de l’environnement, relatif notamment à la conservation d’espèces menacées telles que le lézard ocellé (Timon lepidus). Ces éleveurs pratiquent diverses activités ainsi que différents types d’élevage (ovins ou bovins à viande, bovins camarguais, caprins laitiers, chevaux de course). Des entretiens semi-directifs ont permis de décrire leurs pratiques et de comprendre comment ils intégraient la gestion raisonnée du risque parasitaire dans leur stratégie. Des coprologies ont été réalisées afin de déterminer le taux d’infestation des troupeaux par les endoparasites gastro-intestinaux, et de préconiser des traitements ciblés utilisant des molécules non écotoxiques pour l’environnement ou/et des alternatives efficaces, dont la stratégie doit être adaptée selon le type d’élevage et l’espèce. Quatre-vingt pour cent des éleveurs se sont orientés vers une stratégie raisonnée sans forcément en avoir conscience puisqu’ils traitaient rarement leurs animaux et étaient dans l’ensemble soucieux d’appliquer les bonnes modalités de traitement. Néanmoins, ils semblaient avoir besoin d’un accompagnement rapproché pour le diagnostic, le choix du moment du traitement et les molécules à utiliser, ainsi que pour la gestion des mouvements des animaux entre les parcelles. L’étude a montré le rôle essentiel des vétérinaires praticiens dans ce type d’approche. Cependant, un travail de sensibilisation et de formation doit être organisé afin de favoriser leur implication.

Copyright of Romanian Journal of Intellectual Property Law / Revista Română de Dreptul Proprietăţii Intelectuale is the property of Universul Juridic Publishing House and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Une étude a été menée sur le parasitisme digestif des poules villageoises collectées dans deux marchés de la ville de Ngaoundéré (Cameroun) entre mai et août 2018. Neuf genres (Eimeria sp., Raillietina sp., Capillaria sp., Choanotaenia sp., Gongylonema sp., Amoebotaenia sp., Hymenolepis sp., Tetrameres sp. et Echinostoma sp.) et trois espèces (Ascaridia galli, Heterakis gallinarum et Trichostrongylus tenuis) ont été identifiés. Sur les 429 échantillons examinés, 362 étaient porteurs d’un ou de plusieurs parasites, soit un taux d’infestation de 84,4 %. Ce taux était de 86,3 % chez les 240 oiseaux examinés par coproscopie, et de 82,0 % chez les 189 examinés par autopsie. A la coproscopie, les oiseaux adultes étaient plus infestés que les jeunes par Ascaridia galli, Raillietina sp. et Eimeria sp. De même, à l’autopsie une plus forte prévalence de Capillaria sp. et Raillietina sp. a été observée chez les adultes. La plupart des helminthes parasitaient l’intestin grêle. Aucune lésion coccidienne n’a été observée le long du tractus intestinal. Diverses associations de parasites ont été observées avec celle prédominante de Eimeria sp. L’intensité moyenne d’infestation par Eimeria sp., estimée par la méthode de détermination du nombre d’oeufs par gramme de fèces de McMaster, a été la plus élevée chez les volailles adultes.

Pollenia rudis (Diptera, Calliphoridae) is a major nuisance insect pest in buildings and other structures during the fall and winter months. Adult flies invade to overwinter and cluster around windows and attics. These flies are parasites of earthworms, but the host worms are very poorly documented across North America. We report the first identification of Aporrectodea trapezoides as the host of Pollenia rudis in Colorado. We report the first two earthworm records for Washington County, Colorado (Aporrectodea trapezoides and Ap. turgida). [ABSTRACT FROM AUTHOR]

Une étude parasitologique a été menée en 2015 sur des chiens de sexe, âge et race différents, vivant en liberté dans la ville de Lubumbashi, République démocratique du Congo. Des échantillons de fèces ont été prélevés et analysés par coproscopie selon une méthode de flottation. Sur les 120 chiens examinés, 78 (65 %) étaient infestés, parmi lesquels 74 (61,7 %) avaient des helminthes gastro-intestinaux et 4 (3,3 %) avaient des coccidies. Les coproscopies ont révélé la présence de cinq espèces de parasites : Ankylostoma spp. (41 chiens), Toxocara canis (22), Toxascaris leonina (8), Isospora canis (4) et Dipylidium caninum (3). I. canis n’a été retrouvé que chez les chiots. Le dépistage fréquent d’ankylostomes et de T. canis suggère qu’il existe à Lubumbashi un risque de contamination de l’homme par ces parasites zoonotiques.

Lobster mushroom is a wild edible mushroom with potential commercial value. It is the product resulting of the infection, most commonly of Russula brevipes, by Hypomyces lactifluorum. This study undertook quantitative polymerase chain reaction analysis of tissues sampled at different infection stages to investigate R. brevipes - H. lactifluorum interaction. We followed the colonization of R. brevipes sporocarps by H. lactifluorum that leads to the edible lobster mushrooms. In parallel, metabolomics analysis was performed to detect differences in metabolite profile among non-infected R. brevipes sporocarp and lobster mushroom. The results show that H. lactifluorum DNA is not restricted to the margin but is distributed relatively evenly across the sporocarp of the lobster mushroom. Russula brevipes DNA was also present throughout the sporocarp but was less abundant at the margins and increased inwards. Russula brevipes DNA also declined as the infection progressed. Metabolomics analysis revealed that the flesh of lobster mushroom, which remains identical in appearance to the flesh of the host, undergoes transformation that alters its metabolite profile, most notably of lipids and terpene compounds. These results define a parasitic relationship between the two species that entails a decline of R. brevipes DNA and a modification of its metabolite profile. [ABSTRACT FROM AUTHOR]

Eastern dwarf mistletoe ( Arceuthobium pusillum Peck) parasitizes the branches of white spruce ( Picea glauca [Moench] Voss) and ultimately kills this host species. Previous studies of host needle physiology generally focused on trees experiencing infections of moderate severity; here, we expanded upon previous research to investigate the morphological, physiological, and biochemical properties of needles from white spruce trees experiencing the full range of infection severities. We found that the impact of parasitism on host needle parameters did not scale uniformly with infection severity. Rather, parasitism reduced host needle size distal to infection and resulted in more negative carbon isotope ratios across all infection severities. Reduced foliar nitrogen and chlorophyll content were only evident in trees with moderate or severe infection, while photosynthetic capacity was depressed in only severely infected trees. Furthermore, while some impacts were confined to infected host branches, others, such as smaller needles and reduced photosynthetic capacity, were also evident in branches showing no visible signs of infection. We conclude that symptoms of infection appearing only after infection worsened in severity or appearing in uninfected branches may in whole or in part also be manifestations of a decline in resource availability and vigor of the whole tree. [ABSTRACT FROM AUTHOR]

Copyright of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Here we identify, for the first time, a generalist orange parasitic mite found on multiple small-mammal species in Algonquin Provincial Park, Ontario, Canada. Results from 18S rRNA sequencing suggest that these mites may belong to the family Trombiculidae (Acari: Trombidiformes), although morphological and additional genetic analyses are needed to confirm this identification. The presence of these mites was associated with lower body condition in North American red squirrels ( Tamiasciurus hudsonicus (Erxleben, 1777)), suggesting that these mites may be a detriment to fitness in small mammals or are more successful when targeting individuals in poorer condition. A lack of sex-biased host infection, emergence dates outside of the host reproductive season, and stability of mite prevalence across study years indicate mite population dynamics may be driven predominantly by factors external from host status, such as climatic conditions or habitat preference. Future research should focus on providing additional reliable identification of these mites, as well as broadening our knowledge on their range, pathogenicity, and impact on small-mammal community dynamics. [ABSTRACT FROM AUTHOR]

Increasing evidence indicates that parasites play an important role within many systems as prey for higher trophic levels. Predation on parasites can decrease their numbers and may affect host infection rates. Cercariae, a free-living infectious stage of trematode parasites, are abundant in freshwater systems and are directly consumed by a number of freshwater predators. However, few studies have tested whether predators exhibit a preference for cercariae when alternative prey are available or how these preferences vary across predator body sizes. We assessed whether dragonfly larvae (dot-tailed whiteface, Leucorrhinia intacta (Hagen, 1861)), top predators in freshwater systems without fish, foraged preferentially when presented with two prey types, cercariae and zooplankton, and whether foraging preferences changed across predator body size. Body size of larval dragonfly predators was found to be significantly, and negatively, related to the fraction of cercariae in the diet. Larger bodied dragonfly larvae shifted their diet choice from cercariae to zooplankton. Changes in foraging selectivity as body size increases across a predator's ontogeny can alter the strength of predator-prey interactions. Further investigation into size-selective foraging on parasites may provide new insights into the effects of predation on parasite abundance and transmission in natural systems. [ABSTRACT FROM AUTHOR]

Transposable elements (TEs) are the major components of eukaryotic genomes. Their propensity to densely populate and in some cases invade the genomes of plants and animals is in contradiction with the fact that transposition is strictly controlled by several molecular pathways acting at either transcriptional or post-transcriptional levels. Horizontal transfers, defined as the transmission of genetic material between sexually isolated species, have long been considered as rare phenomena. Here, we show that the horizontal transfers of transposable elements (HTTs) are very frequent in ecosystems. The exact mechanisms of such transfers are not well understood, but species involved in close biotic interactions, like parasitism, show a propensity to exchange genetic material horizontally. We propose that HTTs allow TEs to escape the silencing machinery of their host genome and may therefore be an important mechanism for their survival and their dissemination in eukaryotes. [ABSTRACT FROM AUTHOR]

Antiparasitic macrolides (or endectocides) represent the most recent class of antiparasitic drugs. This class is homogeneous because of its unique and specific, glutaminergic, mode of action, and its pharmacological properties. These drugs have a spectrum of action directed against many nematodes, as well as many insects and mites. Their structures and associated galenic formulations also enable them to have a high remanent potential. Unfortunately, endectocides are generally used in African countries without any recording procedure. Moreover, the introduction of generic formulations facilitated massive and repetitive uses that have led to therapeutic failures. These drugs should be given a good set-up to be effective in an African tropical environment, in particular by taking into account the characteristics of local breeds and environmental constraints. The first element to consider is the choice of the most potent route of administration. At the same time, the differences observed between animal species targets as well as physiological peculiarities must lead to a better adapted use.

The central Guinea savannah of Côte d’Ivoire is a very suitable area for cattle breeding due to the abundance of forage throughout the year; the presence of tsetse flies favors farming of trypanotolerant livestock. Little is known on the productivity and overall health status of N’Dama cattle under traditional farming conditions in the humid savannah of Côte d’Ivoire. This study aimed at investigating productivity parameters (demography, live weight, overall health status) of local N’Dama cattle to generate baseline knowledge on production and health parameters including aspects of ecto- and endoparasitism under traditional farming conditions in this area. In a longitudinal study, three randomly selected village cattle herds were monitored during a period of 20 months. The annual calving rate was 52 ± 1% (mean and standard error) and the annual cumulative mortality rate of calves under one year of age was 19 ± 6%. Birth weights were 16.5 ± 0.9 kg for males and 15.7 ± 1.1 kg for females. Adult females achieved a mean weight of 198 ± 5 kg. The live weight of young N’Dama cattle showed no significant relationship with tick and gastrointestinal strongyle burdens. N’Dama cattle could be productive in this harsh environment, but the local production of milk and beef was still insufficient to meet consumers’ demand. Based on the assessed parameters the authors simulated the potential development of N’Dama cattle breeding in this area over a ten-year period, with the option of increased milk or meat production.

Une étude sur un cycle annuel du parasitisme de Glossina palpalis palpalis par Hexamermis glossinae a été effectuée dans les secteurs d'Abengourou, d'Aboisso et de Daloa (zones forestières de Côte d'Ivoire). Les dissections de 2 168 glossines à Abengourou et 9732 à Aboisso n'ont pas permis de mettre le parasite en évidence. À Daloa, en revanche, le pourcentage d'infection est de 1,75 % sur un total de 7341 mouches disséquées. Tous les parasites sont localisés dans la cavité abdominale sans léser les organes. Les mâles sont plus infectés que les femelles (2,68 % contre 1,26 %), et parmi celles-ci les nullipares sont plus infectées que les jeunes pares et vieilles pares (2,30 % contre 1,19 % et 0,52 % respectivement). Le parasite est le plus abondant chez les glossines en début de saison des pluies (5, 17 %) et plus rare en saison sèche (0,23 %). Le faible niveau de parasitisme observé ici semble indiquer que celui-ci a naturellement peu d'impact sur la dynamique du principal vecteur de la maladie du sommeil en Côte d'Ivoire.

Copyright of Bulletin de la Societe Zoologique de France is the property of Societe Zoologique de France and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite many studies on avian blood parasites, we still have a limited understanding of the mechanisms that drive patterns of haemosporidian infection among tropical birds, including effects associated with sex, age, and seasonality. Using molecular and morphological methods for blood-parasite detection, we found that juvenile White-banded Tanagers ( Neothraupis fasciata (Lichtenstein, 1823)) had lower haemosporidian prevalence than adults in a population within central Brazil. However, no sex or seasonal differences were detected. Of the 92 White-banded Tanagers analyzed, 67 individuals (72.8% prevalence) were infected with either Haemoproteus or Plasmodium (phylum Sporozoa, class Coccidea, order Haemosporida). Sequencing of a portion of the mitochondrial cytochrome b gene revealed six haemosporidian lineages: two lineages within the genus Haemoproteus and four within the genus Plasmodium. The prevalences of Plasmodium and Haemoproteus parasites were 43.5% and 17.4%, respectively. Our results suggest that this species maintains chronic infections all year round and individuals are able to sustain high parasite pressure. [ABSTRACT FROM AUTHOR]

Sex biases in parasitism rates are widely reported in the literature. Among vertebrates in particular, males are more frequently parasitized than females. These sex-linked differences are often attributed to different investment strategies in current versus future reproduction at the ultimate level and to different levels of circulating androgens at the proximate level. But there are other factors that can influence parasitism rates that are often neglected. In this study, we examined multiple measures of parasitism in male and female Red-winged Blackbirds ( Agelaius phoeniceus (L., 1766)) to determine whether sex biases occur and sought to identify physiological and ecological factors that may be shaping such differences. We assessed three groups of parasites (ectoparasites, intestinal parasites, blood parasites), one measure of immune function (bacteria-killing ability), and diet. We found that male-biased infections were common only for intestinal parasites, but could not be attributed to dietary or immunological differences. We also found that immune function was associated with an individual's infection status, appearing elevated in males infected with helminths. Our results suggest that, for this species, sex biases in parasitism do occur but are not the norm. Furthermore, their existence may depend on the nature of the host-parasite relationship. [ABSTRACT FROM AUTHOR]

A review of recent studies published over a 23-year timespan (1990-2012) showed rapidly increasing interest in exploring how environmental contaminants and parasitism might influence each other and (or) interact to affect host health. Those experimental and observational studies fall into three broad categories (comparative studies of the possible influence of each factor on the other, correlative studies between contaminants and parasitism, and studies on relative bioaccumulation of contaminants by parasites versus their hosts). Despite the exponential increase in relevant studies, little attention has been paid to how contaminants and parasitism should co-occur among individuals within host populations and (or) how the nature of co-distributions should be incorporated into study designs and analyses. Null expectations of co-distributions between contaminants and parasitism can be derived from underlying distributions of each factor. Using a subset of studies, we found contaminant distributions showed positive skew in about one third of cases testing for correlations between contaminant concentrations and parasitism among hosts. We show such skew is expected for theoretical reasons. We used this information to guide simulations wherein the oft-cited negative binomial distribution of parasitism (also supported by theory) was combined with both log-normal (skewed) and normal distributions of contaminants to generate expected null co-distributions. Simulations demonstrated an increasingly concave (or L-shaped) co-distribution with increasing contaminant positive skew: proportionately more individuals experience low levels of each factor while few to none experienced high contaminant and high parasite burdens simultaneously. Our results have the following implications: they call into question experimental studies exposing specimens to parasites and pollutants at levels higher than, or even equal to, observed averages, and they provide a framework for exploring how individual-based effects might scale up into effects at the population level. Potential improvements to study designs and (or) statistical tests are offered that recognize the need to understand the underlying distributions of both contaminants and parasitism and the degree to which one can infer host population effects. [ABSTRACT FROM AUTHOR]

Our knowledge of arbuscular mycorrhizal (AM) function is largely based on results from short-term studies in controlled environments. While these have provided many important insights into the potential effects of the symbiosis on the two symbionts and their communities, they may have also inadvertently led to faulty assumptions about the function of the symbiosis in natural settings. Here we highlight the consequences of failing to consider the AM symbiosis from the perspectives of community ecology and evolutionary biology. Also, we argue that by distinguishing between physiological and evolutionary viewpoints, we may be able to resolve controversies regarding the mutualistic vs. parasitic nature of the symbiosis. Further, while most AM research has emphasized resource transfers, primarily phosphate and carbohydrate, our perceptions of parasitism, cheating, bet-hedging, and partner choice would most likely change if we considered other services. Finally, to gain a fuller understanding of the role of the AM symbiosis in nature, we need to better integrate physiological processes of plants and their AM fungi with their naturally occurring temporal and spatial patterns. It is our hope that this article will generate some fruitful discussions and make a contribution toward this end. [ABSTRACT FROM AUTHOR]

Copyright of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)