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The objective of this study was to analyze the effect of the rural and urban microclimate on the presence of mosquitoes. Temperature (T) and relative humidity (RH; indoors and outdoors), as well as mosquito richness and abundance were measured in two sites (urban and rural) of the Yucatan State, Mexico. Species richness was higher in the urban site, whereas mosquito abundance was higher in the rural site. The microclimates of urban and rural housing differently affect mosquito richness and abundance. Mosquito richness and abundance were higher outdoors than indoors in the urban site, but they were higher indoors than outdoors in the rural site. For the urban site, analysis of the relation of T and RH with the registered parameters revealed that species richness increased with increasing indoor RH, and that mosquito abundance increased with increasing indoor T and RH. In the rural site, species richness was not affected, but abundance increased with increasing T and RH (indoors as well as outdoors). Results are discussed in the context of the management of mosquito transmitted diseases. No IRB approval was necessary since no ethical implications were identified to be reviewed by the ethical committee for the research of the ECOSUR Institution.

English Abstract: Our objective is to describe how a group of scientists (doctos) and people of the coast of Chiapas (legos) perceive the Sterile Insect Technique and to analyze how knowledge is socially constructed around it. During 2017 and 2018, with qualitative techniques, we analyzed the social dialogue in the discourses of interactions during workshops, meetings with different age groups, meeting with municipal and local authorities between two ejidos inhabitants, public services people, students and technicians of a biofactory. We describe a bricolage where common references help bring different ontologies, but legos and doctos face a future in which mosquitoes and nature impose challenges that only together they can solve. Here, we document the Sterile Insect Technique sociocultural complexity, and we propose cultural translation exercises for the integral management of mosquito vectors of diseases.Spanish Abstract: El presente trabajo describe la manera en la que un grupo de científicos (doctos) y pobladores (legos) de la costa de Chiapas, México perciben la Técnica del Insecto Estéril (TIE). A partir de una metodología cualitativa, analizamos la construcción social del conocimiento sobre la TIE a través del tiempo. En 2017 y 2018 realizamos en dos ejidos rurales, el análisis del registro de talleres y pláticas entre científicos, diferentes grupos de la sociedad, personal de instituciones de salud, y técnicos de una Biofábrica en Tapachula, Chiapas. A partir de un diálogo social describimos las referencias comunes que acercan las ontologías de doctos y legos. Ambos grupos se enfrentan a los mosquitos y la naturaleza, un reto que solo juntos podrán resolver. Documentamos la complejidad sociocultural de la TIE y proponemos ejercicios de traducción cultural para proyectos que busquen incidir en enfermedades zoonóticas.French Abstract: Notre objectif a été de décrire la façon dont un groupe de scientifiques (érudits) et d’habitants (laïcs) de la côte du Chiapas (Mexique) perçoivent la Technique de l’insecte stérile (TIS) et d’analyser comment ces connaissances sont socialement construites. Au cours des années 2017 et 2018, nous avons étudié, au moyen de techniques qualitatives, le dialogue social en enregistrant les interactions entre érudits et laïcs durant des ateliers et des discussions avec les autorités locales et municipales impliquant différents groupes d’âge, dans deux villages (ejidos) près de Tapachula (Etat du Chiapas). Nous décrivons un bricolage dans lequel des références communes aident à rapprocher différentes ontologies, mais les érudits et les laïcs sont confrontés à un avenir dans lequel les moustiques et la nature leur imposent des défi s qu’ils ne peuvent résoudre qu’ensemble. Nous contribuons à documenter la complexité socioculturelle de la TIS et proposons des exercices de traduction culturelle pour des projets qui cherchent à influencer les zoonoses.

The Sterile Insect Technique (SIT) is a pest control method where large numbers of sterile males are released to induce sterility in wild populations. Since a successful SIT application depends on the released sterile males being competitive with wild males, standard quality control tests are a necessary component of any SIT program. Flight ability (ability to fly out from a device) is a reliable indicator of insect quality. Based on previous studies, we developed four new tubular devices constructed with locally available materials to explore their potential as flight test devices for Aedes aegypti (L.) mass-reared males. Males were allowed to fly upwards through a vertical tube, the ones that flew out were considered successful. The effect of male age (0 to 21 d old), test time interval (30 min to 24 h), and the design of the device (40 and 80 cm height and 2 and 3.5 cm diameter) were evaluated. Our devices determined differences in the flight ability of Ae. aegypti males of different ages. During the first minutes, more old males escaped than young males in three out of four types of devices. However, young males reached higher rates of escape in all cases after 24 h. For standard quality control tests, we recommend testing 2- to 3-d-old sexually mature males in the high and narrow device (80 × 2 cm). Further observations for time intervals between 1 and 5 h might be performed to decide the shortest and more representative interval to use.

Se estudió el comportamiento depredador de dos especies de arañas del género Phonotimpus (Araneae: Phrurolithidae) frente a cuatro tipos diferentes de presas potenciales (un Collembola, dos Hemiptera y un Psocoptera). Estas arañas habitan en la hojarasca del suelo de un bosque de niebla y de un cafetal en Chiapas, México. No existen estudios previos sobre el comportamiento de caza de esta familia de arañas. Debido al reducido tamaño de las arañas, el estudio se realizó en laboratorio, mediante videograbaciones de los encuentros con cada tipo de presa. A partir de las grabaciones se elaboró un catálogo de 16 actos de comportamiento que las arañas presentaron durante los encuentros con las presas, entre los que destacan el de “abanicar” y el de “ataque”. Las grabaciones evidenciaron que ambas especies de arañas tuvieron una capacidad significativamente mayor de ataque y captura de los colémbolos que de los hemípteros y psocópteros, además de presentar un repertorio más variado de actos frente a los colémbolos y, para Phonotimpus pennimani un mayor nivel de actividad durante los encuentros con colémbolos. Así, nuestros resultados son similares a los de otros autores que estudiaron el consumo de presas en laboratorio, por dos especies distintas de Phrurolithidae, indicando que es altamente posible que en su hábitat natural los colémbolos sean parte importante de las presas de las Phrurolithidae. Las grabaciones también mostraron que ambas especies de arañas emplean dos estrategias de caza. Una es la emboscada, donde la araña permanece fija en un sitio por periodos relativamente prolongados, a la espera de la aproximación de una presa potencial, y la otra es la búsqueda activa, en la que la araña recorre activamente su entorno hasta que se topa con una presa potencial. De las dos estrategias, hubo un claro predominio de la emboscada, en cuanto su distribución de tiempos durante los encuentros.

The sterile insect technique may prove useful for the suppression of mosquito vectors of medical importance in regions where arboviruses pose a serious public health threat. In the present study, we examined the effects of sterilizing irradiation doses across different ratios of fertile:irradiated males on the mating competitiveness of Ae. aegypti and Ae. albopictus under laboratory and field-cage conditions. For both species, the percentage of females inseminated and the number of eggs laid over two gonotrophic cycles varied significantly in mating treatments involving 1:1, 1:5, and 1:10 fertile:irradiated males compared to controls of entirely fertile or entirely irradiated males but was not generally affected by the irradiation dose. Egg hatching was negatively affected in females exposed to increasing proportions of irradiated males in both laboratory and field cages. Male competitiveness (Fried’s index) values varied from 0.19 to 0.58 in the laboratory and were between 0.09 and 1.0 in field cages, depending on th species. Competitiveness values were negatively affected by th eirradiation dose in both species under field-cage conditions, whereas in the laboratory, Ae. albopictus was sensitive to the dose but Ae. aegypti was not. In general, male competitiveness was similar across all mating regimes. Most importantly, induced egg sterility was positively correlated with the proportion of irradiated males present in the mating treatments, reaching a maximum of 88% under field-cage conditions for both Ae. aegypti and Ae. albopictus males treated with 50 and 40 Gy irradiation, respectively. These results indicate that sterile males produced at our facility are suitable and competitive enough for field pilot SIT projects and provide guidance to decide the optimal sterile:fertile ratios.

Simple Summary The sterile insect technique (SIT) involves the release of massive numbers of male insects that have been sterilized by irradiation treatment during their development. Wild females that mate with sterilized males are not able to produce offspring, resulting in rapid decline in the target insect population over a large area. The success of this technique depends on the ratio of wild:sterile males achieved following male releases and the ability of sterile males to mate with wild females, i.e., their sexual competitiveness compared to fertile wild male insects. There is growing interest in applying SIT to the area-wide control of mosquitoes, such as Aedes aegypti and Aedes albopictus, that transmit important human diseases caused by dengue, chikungunya, and Zika viruses. In the present study, the sexual competitiveness of both mosquito species was affected by irradiation treatments but did not vary greatly with different ratios of fertile:sterile males in mating cages. Most importantly, the fertility of eggs was greatly reduced when more sterile males were present in mating cages, resulting in an 88% decrease in the production of fertile eggs by both species of mosquitoes in some experiments. We will use these results to perform small-scale trials in rural villages frequently affected by outbreaks of mosquito-borne diseases in southern Mexico. Abstract The sterile insect technique may prove useful for the suppression of mosquito vectors of medical importance in regions where arboviruses pose a serious public health threat. In the present study, we examined the effects of sterilizing irradiation doses across different ratios of fertile:irradiated males on the mating competitiveness of Ae. aegypti and Ae. albopictus under laboratory and field-cage conditions. For both species, the percentage of females inseminated and the number of eggs laid over two gonotrophic cycles varied significantly in mating treatments involving 1:1, 1:5, and 1:10 fertile:irradiated males compared to controls of entirely fertile or entirely irradiated males but was not generally affected by the irradiation dose. Egg hatching was negatively affected in females exposed to increasing proportions of irradiated males in both laboratory and field cages. Male competitiveness (Fried’s index) values varied from 0.19 to 0.58 in the laboratory and were between 0.09 and 1.0 in field cages, depending on th species. Competitiveness values were negatively affected by th eirradiation dose in both species under field-cage conditions, whereas in the laboratory, Ae. albopictus was sensitive to the dose but Ae. aegypti was not. In general, male competitiveness was similar across all mating regimes. Most importantly, induced egg sterility was positively correlated with the proportion of irradiated males present in the mating treatments, reaching a maximum of 88% under field-cage conditions for both Ae. aegypti and Ae. albopictus males treated with 50 and 40 Gy irradiation, respectively. These results indicate that sterile males produced at our facility are suitable and competitive enough for field pilot SIT projects and provide guidance to decide the optimal sterile:fertile ratios.

Simple Summary Aedes aegypti and Ae. albopictus are the most important mosquito vectors of dengue, chikungunya and Zika virus. There is growing interest in the control of these vectors using the sterile insect technique in which large numbers of sterilized males are released and compete with wild fertile males for mates. Females that mate with sterile males do not produce viable offspring. A study was performed on the population fluctuations of Ae. aegypti and Ae. albopictus using egg traps in two rural villages with a history of dengue in Chiapas, southern Mexico. Higher numbers of Aedes eggs were recorded in Hidalgo village compared with the village of Río Florido. In contrast, higher number of eggs were collected in areas surrounding Río Florido, compared with those around Hidalgo. Aedes aegypti was the dominant species during the dry season and at the start of the rainy season in both villages. Aedes albopictus populations were lower for most of the dry season, but increased during the rainy season and became dominant at the end of the rainy season in both villages. Aedes albopictus was also the dominant species in the zones of natural vegetation surrounding both villages. We conclude that the efficacy of a program of vector control involving the sterile insect technique could be evaluated in future studies on the isolated mosquito populations in these rural villages, in combination with habitat elimination and appropriate treatment of water sources. Abstract Indoor and outdoor ovitraps were placed in 15 randomly selected houses in two rural villages in Chiapas, southern Mexico. In addition, ovitraps were placed in five transects surrounding each village, with three traps per transect, one at the edge, one at 50 m, and another at 100 m from the edge of the village. All traps were inspected weekly. A transect with eight traps along a road between the two villages was also included. Population fluctuations of Aedes aegypti and Ae. albopictus were examined during 2016–2018 by counting egg numbers. A higher number of Aedes spp. eggs was recorded at Hidalgo village with 257,712 eggs (60.9%), of which 58.1% were present in outdoor ovitraps and 41.9% in indoor ovitraps, compared with 165,623 eggs (39.1%) collected in the village of Río Florido, 49.0% in outdoor and 51.0% in indoor ovitraps. A total of 84,047 eggs was collected from ovitraps placed along transects around Río Florido, compared to 67,542 eggs recorded from transects around Hidalgo. Fluctuations in egg counts were associated with annual variation in precipitation, with 2.3 to 3.2-fold more eggs collected from ovitraps placed in houses and 4.8 to 5.1-fold more eggs in ovitraps from the surrounding transects during the rainy season than in the dry season, respectively. Aedes aegypti was the dominant species during the dry season and at the start of the rainy season in both villages. Aedes albopictus populations were lower for most of the dry season, but increased during the rainy season and predominated at the end of the rainy season in both villages. Aedes albopictus was also the dominant species in the zones surrounding both villages. The numbers of eggs collected from intradomiciliary ovitraps were strongly correlated with the numbers of eggs in peridomiciliary ovitraps in both Río Florido (R2adj = 0.92) and Hidalgo (R2adj = 0.94), suggesting that peridomiciliary sampling could provide an accurate estimate of intradomiciliary oviposition by Aedes spp. in future studies in these villages. We conclude that the feasibility of sterile insect technique (SIT)-based program of vector control could be evaluated in the isolated Ae. aegypti populations in the rural villages of our baseline study.

The sterile insect technique (SIT) is a key element for the integrated management of pest populations of the Mexican fruit fly, Anastrepha ludens, in Mexico. Its success depends on the survival of mass-reared sterile males and their ability to mate with wild females. However, colonization and mass-rearing conditions can adversely affect their ability to avoid predators. To test if colony management strategies could contribute to improve field survival abilities of mass-reared flies, we compared the survival of males exposed to the orb-weaver spider Argiope argentata. Males compared originated from three strains with different colonization strategies: (a) a colony started from field-collected wild flies (replacement), (b) a colony started by hybridizing wild males with mass-reared adapted females (hybrid) and (c) a colony started with mass-reared males selected on the basis of their survival ability and mating competitiveness in field cages (selected). Mass-reared males and wild males were used as controls. Males were exposed to spiders under laboratory cage conditions. Overall, wild males showed better survival ability than mass-reared males. Regarding the colonization approach, wild males survived better than a hybrid, replaced and selected males. We conclude that mass-rearing conditions have a strong negative effect on the ability of males to escape spiders. The colonization systems evaluated did not counter this effect. The lower survival of males from the selected colony suggests that the selection over one generation did not contribute to improve males’ predator avoidance and escape abilities and probably needs to be modified. Possible explanations for this and implications on colonization and colony management for SIT purpose are discussed.

National audience; The history of the restoration of textiles in relation with historic monuments in the old Midi-Pyrénées region was triggered by the study of archives about work on historic monuments, observations and comments about the textiles themselves and by the exchanges of views with the restorers who had worked in the region. The people who contributed (curators, restorers, owners and supervisors) as well as the context and objectives have a lot in common with the restoration of textiles in the other regions of France or in museums.; Les oeuvres qui constituent le corpus de cette étude sont des textiles protégés au titre desmonuments historiques ou provenant de monuments historiques de l'ancienne région Midi-Pyrénées. L'exclusion des autres départements de la région Occitanie se justifie par des questionsd'accès aux archives travaux, mais également par une histoire et des stratégiesdifférentes entre les deux anciennes régions administratives dans le domaine de la restaurationdes objets mobiliers. Les tapisseries, qui font l'objet de problématiques spécifiques etqui relèvent souvent de restaurateurs spécialisés dans ce domaine, ont été exclues du corpus.Documenter l'histoire de la restauration de textiles protégés au titre des monuments historiquesrequiert un long travail de récolement de sources dispersées, et d'interprétation detraces écrites souvent très ténues. Les sources écrites doivent nécessairement être complétéespar l'observation matérielle des objets, à l'occasion de nouvelles restaurations, d'inventairesou de récolements

BackgroundThe incidence and geographical distribution of arboviruses is constantly increasing. The epidemiological patterns of the proliferation of viruses and their vectors (Aedes aegypti and Aedes albopictus) are associated with socio-environmental determinants, and are closely related to human habits, especially at the household level. The aim of this work is to analyze the influence of socio-environmental determinants on the knowledge and practices related to arboviruses and their transmission, among the residents of three communities on the southern border of Mexico.MethodologyBetween June 2017 and August 2018, our investigation covered a set of 149 households from three communities of Tapachula (Chiapas) and Villahermosa (Tabasco). We first conducted household surveys about knowledge and practices on arbovirosis. Then, we carried out direct observations of risk factors for vector proliferation at the domestic level, before and after exposing a part of the population to a cycle of community engagement prevention activities. Through semi-structured interviews, we also focused on the detection of environmental risk situations for vector breeding at the community level.Key resultsWe found that most dwellings had an adequate knowledge about the origin and transmission of arboviruses, but only a minority of them also implemented appropriate practices. Higher education levels were associated with better prevention scores. The observations made after the cycle of community activities in Chiapas revealed a decrease in the accumulation of unprotected water deposits. A higher percentage of domestic risk practices were detected in association with significant deficiencies in sanitation and water supply services. Furthermore, the perception of greater risk and difficulty in complying with preventive measures was detected among the population.DiscussionKnowledge does not necessarily lead to adequate prevention practices. A better understanding of all these dimensions and their interactions is required. In addition to the educational level, intermediate social determinants (such as water supply and environmental sanitation) influence the persistence of behaviors that are risk factors for the proliferation of arbovirosis. The achievement of an effective and sustainable vector management is required to address these related aspects.Author summaryDengue, Chikungunya and Zika are arboviral diseases, transmitted by Aedes mosquitoes. As a result of a continuous increase in the geographical spread and burden of disease, arbovirosis have become a priority issue for global health.The proliferation of viruses and their vectors are influenced by a complex interaction of environmental and social determinants. Thus, the design of effective and sustainable prevention and control measures requires an understanding of all these different aspects.The aim of our work is to explore the effects of social and environmental factors on the knowledge and practices related to Dengue, Chikungunya and Zika and their transmission, among the residents of three communities on the southern border of Mexico, currently an endemic area. Our study draws on the application of a program combining the implementation of new technologies for vector management with a participatory and holistic multidisciplinary approach.Between June 2017 and August 2018, we used different surveys and methodological approaches to explore knowledge and practices on arbovirosis, as well as to identify risk factors for vector proliferation. We found that intermediate social determinants (such as occasional water supply and infrequent waste collections) influence the persistence of behaviors that are risk factors for the proliferation of arbovirosis.Public health interventions for arbovirosis prevention must be accompanied by intersectoral work that includes the improvement of these related aspects, according to the multifactorial etiology of arboviruses.

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Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://www.nature.com/articles/s41598-018-34469-6 Vector-borne diseases are responsible for more than one million deaths per year. Alternative methods of mosquito control to insecticides such as genetic control techniques are thus urgently needed. In genetic techniques involving the release of sterile insects, it is critical to release insects of high quality. Sterile males must be able to disperse, survive and compete with wild males in order to inseminate wild females. There is currently no standardized, fast-processing method to assess mosquito male quality. Since male competitiveness is linked to their ability to fly, we developed a flight test device that aimed to measure the quality of sterile male mosquitoes via their capacity to escape a series of flight tubes within two hours and compared it to two other reference methods (survival rate and mating propensity). This comparison was achieved in three different stress treatment settings usually encountered when applying the sterile insect technique, i.e. irradiation, chilling and compaction. In all treatments, survival and insemination rates could be predicted by the results of a flight test, with over 80% of the inertia predicted. This novel tool could become a standardised quality control method to evaluate cumulative stress throughout the processes related to genetic control of mosquitoes.

Despite the importance of tarantulas in the areas of medicine and veterinary science, there is very little information on parasitoid-tarantula interactions. The present study describes the case of an endangered tarantula, Brachypelma vagans Ausserer 1875, infested by an endoparasitoid in the field. Using DNA barcoding, we identified the parasitoid as the phorid Megaselia scalaris. With more than 500 fly larvae inside the host, this particular infestation can be considered severe. The size range of the larvae indicates infestation by all three larval instars. We discuss the possible mechanism by which the parasitoid is attracted to the tarantula and make important recommendations regarding improvements in tarantula-rearing conditions. Finally, this case study exemplifies the efficiency of molecular technology for parasitoid identification.

Aedes aegypti is a major vector of arboviruses that may be controlled on an area-wide basis using the sterile insect technique (SIT). Larval diet is a major factor in mass-rearing for SIT programs. We compared dietary effects on immature development and adult fitness-related characteristics for an International Atomic Energy Agency (IAEA) diet, developed for rearing Ae. albopictus, and a standardized laboratory rodent diet (LRD), under a 14:10 h (light:dark) photoperiod ("light" treatment) or continuous darkness during larval rearing. Larval development was generally fastest in the IAEA diet, likely reflecting the high protein and lipid content of this diet. The proportion of larvae that survived to pupation or to adult emergence did not differ significantly between diets or light treatments. Insects from the LRD-dark treatment produced the highest proportion of male pupae (93% at 24 h after the beginning of pupation) whereas adult sex ratio from the IAEA diet tended to be more male-biased than that of the LRD diet. Adult longevity did not differ significantly with larval diet or light conditions, irrespective of sex. In other aspects the LRD diet generally performed best. Adult males from the LRD diet were significantly larger than those from the IAEA diet, irrespective of light treatment. Females from the LRD diet had ~25% higher fecundity and ~8% higher egg fertility compared to those from the IAEA diet. Adult flight ability did not differ between larval diets, and males had a similar number of copulations with wild females, irrespective of larval diet. The LRD diet had lower protein and fat content but a higher carbohydrate and energetic content than the IAEA diet. We conclude that the LRD diet is a low-cost standardized diet that is likely to be suitable for mass-rearing of Ae. aegypti for area-wide SIT-based vector control.

The sterile insect technique (SIT) may offer a means to control the transmission of mosquito borne diseases. SIT involves the release of male insects that have been sterilized by exposure to ionizing radiation. We determined the effects of different doses of radiation on the survival and reproductive capacity of local strains of Aedes aegypti and Ae. albopictus in southern Mexico. The survival of irradiated pupae was invariably greater than 90% and did not differ significantly in either sex for either species. Irradiation had no significant adverse effects on the flight ability (capacity to fly out of a test device) of male mosquitoes, which consistently exceeded 91% in Ae. aegypti and 96% in Ae. albopictus. The average number of eggs laid per female was significantly reduced in Ae. aegypti at doses of 15 and 30 Gy and no eggs were laid by females that had been exposed to 50 Gy. Similarly, in Ae. albopictus, egg production was reduced at doses of 15 and 25 Gy and was eliminated at 35 Gy. In Ae. aegypti, fertility in males was eliminated at 70 Gy and was eliminated at 30 Gy in females, whereas in Ae. albopictus, the fertility of males that mated with untreated females was almost zero (0.1%) in the 50 Gy treatment and female fertility was eliminated at 35 Gy. Irradiation treatments resulted in reduced ovary length and fewer follicles in both species. The adult median survival time of both species was reduced by irradiation in a dose-dependent manner. However, sterilizing doses of 35 Gy and 50 Gy resulted in little reduction in survival times of males of Ae. albopictus and Ae. aegypti, respectively, indicating that these doses should be suitable for future evaluations of SIT-based control of these species. The results of the present study will be applied to studies of male sexual competitiveness and to stepwise evaluations of the sterile insect technique for population suppression of these vectors in Mexico.

Brachypelma vagas belongs to a genus of tarantulas protected against illegal trading. Its distribution range is in Mesoamerica. The spiderlings remain together in the maternal burrow after hatching and after several weeks, they disperse forming a column of about hundred individuals leading away from the burrow. In several spider species, during the gregarious phase and dispersion, spiderlingsdo not show aggressive behavior toward siblings. Silk is an important element in dispersion. However, knowledge of the first stage of B. vagans life is scarce. In the present study, therefore, we describe the natural history of the first stage of life of this species, with particular attention to the development, silk production, interactions between sibling and dispersion. Two egg sacs were collected in the field and maintained in laboratory conditions, without the mother. After hatching, we counted 200 individuals peregg sac; they are cream colored and 2-3 mm long. The first molt occurred at emergence, and the second, five or six days after hatching. After that, a black point appeared on the dorsal part of the abdomen of each spiderling. Production of silk by the spiderlings began from hatching. Dispersion occurred in one group of siblings on the 8th day after emergence, with the production of a thread of silk stretching for at least one meter out of the box. The silk thread produced by the spiderlings during dispersal, could act as a physical guide to indicate the route, or as the support of chemical signs for the orientation of the spiderlings. The absence of silk thread reported in field observations of dispersal could be explained by thefact that it is difficult to see, by lack of production or by production that is environment-dependent. In the group where dispersion was not permitted, no aggressive behavior was observed between siblings; however, a drastic diminution of the individual number occurred in the course of the two-month observation. Mortality could be explained by diseases, unsuitable environmental conditions related to the mother’s absence or not. On the other hand, the remaining spiderlings showed an enlargement of their abdomenin spite of refusal to eat the diary food proposed. It is likely they ate spiderling cadavers or silk. This work offers new knowledge about the first life stage in tarantulas and could be used as a basis for more detailed studies on spiderlings of the tarantula group.

In this work we studied the effect of size-dependent predation and cannibalism on the spatial distribution of the wolf spider Lycosa subfusca, which shares its habitat with a bigger spider: the tarantula Brachypelma vagans, in the Yucatan Peninsula. We examined (i) in the field, the predation interaction between medium tarantulas and large, medium and small wolf spiders; (ii) in the laboratory, size-dependent cannibalism in the wolf spider; and (iii) the simultaneous occurrence of small, medium and large tarantulas, and small, medium and large wolf spiders in three sites in the field (secondary forest, backyard and grazed lawn). In predation interactions, tarantulas attacked large wolf spiders more frequently than medium ones (55% vs 25%), and never attacked small ones. Cannibalism experiments in the wolf spider showed that attack was always initiated by the larger individual. Attack frequencies increased with spider size, but capture success was similar regardless of spider size. Medium and large wolf sp...

In the Yucatan Peninsula, the tarantula Brachypelma vagans Ausserer 1875 is commonly associated with human settlements, as are the scorpions Centruroides gracilis Latreille 1804 and C. ochraceus Pocock 1898. Nonetheless, scorpions are virtually absent from villages showing a high density of tarantulas. Predatory interactions between these predators could explain the lack of local overlap. To test this hypothesis, we observed the behavioral interactions between B. vagans and C. gracilis or C. ochraceus in experimentally controlled conditions, and we compared these interactions to interactions between the tarantula and two prey species: cricket and cockroach. For observations, a pre-adult tarantula was placed in an experimental arena in which we introduced either a scorpion or an insect. In all, 115 trials were performed. We recorded time elapsed and behavioral responses: avoidance, attack, escape, capture, and attack success. Tarantulas preyed on all prey with the same attack success (63.8% ± 0.8%...

Chemically mediated communication is common in spiders but has been poorly studied in burrowing tarantulas. This study aimed to determine whether chemical cues influence the behaviour of females of Brachypelma vagans, a Mexican species of tarantula, during encounters with previously inhabited burrows or with extracts from the silk of conspecific females. In laboratory choice tests, female tarantulas entered a burrow that had previously been inhabited by a conspecific female significantly more frequently than a burrow that had never been inhabited. The identity of the previous inhabitant also affected the number of spiders that chose to enter a burrow. Spiders were quicker to choose and enter a burrow previously inhabited by themselves than a burrow previously inhabited by a conspecific or a burrow that had not been previously inhabited. Hexane, methanol and dichloromethane extracts of conspecific silk elicited different responses from female tarantulas when extracts were placed on filter paper disks at one end of an experimental arena with a control filter paper disk, on to which the corresponding solvent alone had been pipetted, placed on the other end of the arena. Spiders showed the strongest responses to hexane extracts of silk, with a significant preference to move towards the hexane extract and a significantly greater period of time spent in proximity to the hexane extract compared to the control disk. Overall and in contrast to expectations, tarantulas were most strongly attracted to the cues left by other conspecific females. As encounters between B. vagans females usually lead to aggression and mortality of one of the participants, we conclude that chemical cues are not signals that are deliberately released by burrow-inhabiting females but may inadvertently escape and cannot be easily suppressed.

Ant-gardens represent a special type of asso- ciation between ants and epiphytes. Frequently, two ant species can share the same nest in a phenomenon known asparabiosis�, but the exact nature (i.e., mutualistic or parasitic) of this interaction is the subject of debate. We thus attempted to clarify the mutual costs and benefits for each partner (ants and plants) in the Crematogaster levior/ Camponotus femoratus ant-garden parabiosis. The ants� response to experimental foliar damage to the epiphytes and to the host tree as well as their behavior and interactions during prey capture were investigated to see if the purported parasitic status of Cr. levior could be demonstrated in either the ant-ant or in the ant-plant interactions. The results show that both species take part in protecting the epiphytes, refuting the role of Cr. levior as a parasite of the ant-garden mutualism. During capture of large prey Ca. femoratus took advantage from the ability of Cr. levior to discover prey; by following Cr. levior trails Ca. femoratus workers discover the prey in turn and usurp them during agonistic interactions. Never- theless, the trade-off between the costs and benefits of this association seems then to be favorable to both species because it is known that Cr. levior benefits from Ca. femoratus building the common carton nests and furnish- ing protection from vertebrates. Consequently, parabiosis can then be defined as the only mutualistic association existing between ant species, at least in ant-gardens.

The Mexican fruit fly, Anastrepha ludens (Loew), is one of the 10 worldwide more important fruit crop pests. Orchards of southeastern Chiapas also shelter the tree-dwelling lizard Norops serranoi (Kohler), which likely prey upon these flies. In standard laboratory conditions, we determined the functional response of four male and four female lizards on mass-reared fruit flies. We used a general logistic analysis of proportion of killed prey versus available prey to determine the shape of the functional response. Male lizards showed a type II functional response, while females showed a type III functional response. For the highest fruit fly densities, female lizards caught significantly more fruit flies than males did. The predator evasion ability and the survival of mass-reared and wild fruit flies were compared. Wild fruit flies evaded more male lizard attacks than mass-reared flies. However, when female lizards attacked, there was no significant difference between strains. Fruit flies survival was higher with male than with female lizards, but it did not depend on fruit fly strains. This is the first report of a vertebrate preying on the Mexican fruit fly, demonstrating that female lizards impose a higher predation pressure and are more efficient at capturing wild fruit flies than males. We discuss the implications of our results on mass-rearing and quality control of sterile flies.

Although all species of the Brachypelma genus are protected under CITES, few studies have been performed on the genetic structure of the populations of these endangered tarantulas. Here we propose, for the first time in spiders, to use ISSR (Inter Simple Sequence Repeat) technique to study the genetic variability of Mexican populations of Brachypelma vagans (Ausserer 1875). We used a nonlethal technique to collect samples from six populations in the Yucatan peninsula and we tested seven ISSR primers. Four of these primers gave fragments (bands) that were sufficiently clear and reproducible to construct a binary matrix and determine genetic variability parameters. We revealed a very high percentage of polymorphism (P 5 98.7%) the highest yet reported for tarantula spiders. Our results show that the ISSR-PCR method is promising for intraspecific variation of tarantula spiders.

Resumen en español: "La tendencia creciente de desarrollos turísticos ha modificado, entre otros procesos ecológicos, las dinámicas poblacionales de fauna silvestre, favoreciendo aquellas especies de hábitos sinantrópicos que son beneficiadas por la oferta de recursos, como los coatíes (Nasua narica) en Quintana Roo. El incremento en la abundancia de reservorios potenciales de enfermedades transmitidas por vector, como los coatíes, el incremento en las interacciones humanos-fauna silvestre y la presencia y abundancia de mosquitos, promueven el riesgo de transmisión bidireccional de arbovirus en los coatíes y los visitantes susceptibles. Diversas enfermedades Infecciosas emergentes (EIE) son causadas por arbovirus; virus que requieren de un artrópodo hematófago para completar su ciclo de transmisión. Los arbovirus de mayor relevancia médica pertenecen a las familias: Flaviviridae, Togaviridae y Bunyaviridae. El objetivo general del trabajo fue realizar la identificación molecular de arbovirus de éstas tres familias en poblaciones de coatíes (Nasua narica) silvestres y mosquitos hematófagos para estimar la fuerza de asociación (riesgo relativo) de algunos factores de riesgo antrópicos asociados a la presencia de arbovirus. La detección molecular de arbovirus se realizó por la técnica de Transcripción Reversa y Reacción en Cadena de la Polimerasa (RT-PCR). Se analizaron 1,609 especímenes hembras de mosquito y 160 muestras de suero sanguíneo de coatíes. Ningún moquito analizado resultó positivo; seis muestras de coatíes resultaron positivas a la familia Bunyaviridae (1.87%, n=3/160) y Flaviviridae (1.87%, n=3/160). Los análisis de secuenciación de las muestras corresponden a virus del Oeste del Nilo (VON) y virus del serogrupo Bunyamwera Cache Valley (CVV) y Cholul (CHLV). No se encontró asociación epidemiológica entre los factores de riesgo y la prevalencia de infección de coatíes reportados en los sitios de estudio. Éste es el primer reporte de evidencia de ARN viral de VON, CVV y CHLV en coatíes silvestres, por ello es necesario dar continuidad a los estudios en esta especie para conocer su papel en la ecología de los arbovirus trasmitidos por mosquitos hematófagos. "