Immune response to sympatric and allopatric parasites in a snail-trematode interaction

BACKGROUND: The outcome of parasite exposure depends on the (1) genetic specificity of the interaction, (2) induction of host defenses, and (3) parasite counter defenses. We studied both the genetic specificity for infection and the specificity for the host-defense response in a snail-trematode interaction (Potamopyrgus antipodarum-Microphallus sp.) by conducting a reciprocal cross-infection experiment between two populations of host and parasite. RESULTS: We found that infection was greater in sympatric host-parasite combinations. We also found that the host-defense response (hemocyte concentration) was induced by parasite exposure, but the response did not increase with increased parasite dose nor did it depend on parasite source, host source, or host-parasite combination. CONCLUSION: The results are consistent with a genetically specific host-parasite interaction, but inconsistent with a general arms-race type interaction where allocation to defense is the main determinant of host resistance

Leptofoenus stephanoides (roman 1920) (pteromalidae: leptofoeninae): nueva localidad y rango de distribución para Colombia

 Leptofoenus (Leptofoeninae) is an unusual group within Pteromalidae due to its morphological peculiarities. Although, widely distributed in America few, are documented reports. In this note, the department of Valle del Cauca (Buenaventura) is registered as a new locality of Leptofoenus stephanoides for Colombia; After 38 years the species is reported again in the country. The only female collected is deposited in the Museo de Entomología de la Universidad del Valle (MUSENUV) Cali, Valle del Cauca.RESUMEN. Leptofoenus (Leptofoeninae) es un grupo inusual dentro de Pteromalidae debido a sus particularidades morfológicas. Aunque, distribuido ampliamente en América pocos son los reportes documentados. En esta nota se registra el departamento del Valle del Cauca (Buenaventura) como nueva localidad de Leptofoenus stephanoides para Colombia; después de 38 años se reporta la especie nuevamente en el país. La única hembra colectada se encuentra depositada en el Museo de Entomología de la Universidad del Valle (MUSENUV) Cali, Valle del Cauca

Divergent drivers of leaf trait variation within species, among species, and among functional groups.

Understanding variation in leaf functional traits-including rates of photosynthesis and respiration and concentrations of nitrogen and phosphorus-is a fundamental challenge in plant ecophysiology. When expressed per unit leaf area, these traits typically increase with leaf mass per area (LMA) within species but are roughly independent of LMA across the global flora. LMA is determined by mass components with different biological functions, including photosynthetic mass that largely determines metabolic rates and contains most nitrogen and phosphorus, and structural mass that affects toughness and leaf lifespan (LL). A possible explanation for the contrasting trait relationships is that most LMA variation within species is associated with variation in photosynthetic mass, whereas most LMA variation across the global flora is associated with variation in structural mass. This hypothesis leads to the predictions that (i) gas exchange rates and nutrient concentrations per unit leaf area should increase strongly with LMA across species assemblages with low LL variance but should increase weakly with LMA across species assemblages with high LL variance and that (ii) controlling for LL variation should increase the strength of the above LMA relationships. We present analyses of intra- and interspecific trait variation from three tropical forest sites and interspecific analyses within functional groups in a global dataset that are consistent with the above predictions. Our analysis suggests that the qualitatively different trait relationships exhibited by different leaf assemblages can be understood by considering the degree to which photosynthetic and structural mass components contribute to LMA variation in a given assemblage

Registros de Streblidae (Diptera: Hippoboscoidea) en un fragmento de bosque seco tropical en Colombia

Streblidae is a highly specialized fly family, which feeds exclusively on bats. Here we present information about the species of streblids occurring in two fragments of tropical dry forest in Cauca, Colombia. Between April and November 2012, we conducted 16 capture events of bats using mist nets, which were open from 18:00 until 06:00. Each captured bat was identified and the ectoparasites found were preserved in 90% alcohol solution. A total of 85 ectoparasites were collected and 10 species of streblids were identified in seven bat species. Our analysis showed that these parasites are locally specialized, which strongly contrasts with the high number of host species that have been reported for them. We hypothesize that this discrepancy is due to local constraints that filter the fundamental niche of these flies. This work enriches the inventories of the entomofauna in remnants of tropical dry forest, an ecosystem in a critical state of conservation.Streblidae es una familia de moscas altamente especializada, la cual se alimenta exclusivamente de murciélagos. Aquí se presenta información sobre las especies de Streblidae presentes en dos fragmentos de bosque seco tropical en Cauca, Colombia. Entre abril y noviembre de 2012 se realizaron 16 jornadas de captura de murciélagos, utilizando redes de niebla, las cuales estuvieron abiertas desde las 18:00 hasta las 06:00. Cada murciélago capturado se revisó y los ectoparásitos encontrados se conservaron en alcohol al 90%. Se recolectaron 85 ectoparásitos y se identificaron 10 especies de estréblidos en siete especies de murciélagos. El análisis mostró que estos parásitos son localmente especializados, lo cual contrasta fuertemente con el alto número de especies hospederas que han sido reportadas para ellos. Se hipotetiza que esta diferencia se debe a restricciones locales que filtran el nicho fundamental de estas moscas. Este trabajo enriquece los inventarios de la entomofauna en remanentes de bosque seco tropical, un ecosistema en estado crítico de conservación

To exclose nests or not: structured decision making for the conservation of a threatened species

Decisions regarding endangered species recovery often face sparse data and multiple sources of uncertainty about the effects of management. Structured decision making (SDM) provides a framework for assembling knowledge and expert opinion and evaluating the tradeoffs between different objectives while formally incorporating uncertainty. The Atlantic Coast piping plover provides an illustrative case for the utility of SDM in endangered species management because its population growth is simple to model, most populations are monitored, decision alternatives are well defined, and many managers are open to recovery recommendations. We built a model to evaluate the decision to use nest exclosures to protect piping plover eggs from predators, where the objective was to maximize λ and the tradeoff was between nest survival and adult survival. The latter can be reduced by exclosures. We used a novel mixed multinomial logistic exposure model to predict daily nest fates and incorporated the results into a stochastic projection matrix that included renesting after nest failure, and adult mortality associated with abandonment. In our test data set (n = 329 nests from 28 sites over four years), the mean nest survival over 34 days was markedly higher for exclosed nests (0.76 ± 0.03 SE) than for unexclosed nests (0.37 ± 0.07). Abandonment rates were also higher for exclosed nests (0.092 ± 0.017) than for unexclosed nests (0.045 ± 0.017), but the difference was not statistically signifi- cant and the loss rate to “other sources” (mostly predators) was much lower for exclosed nests (0.15 ± 0.03) than for unexclosed nests (0.58 ± 0.07). Population growth rate (λ) was clearly improved by exclosure use at the sites with high background nest loss rates, but λ was still \u3c1 with exclosure use. Where the background nest loss rates were low, the decision to use exclosures was ambiguous, and λ could benefit from reducing uncertainty in vital rates. Our process demonstrated that geographic and temporal variation in nest mortality determines whether exclosures will be useful in attaining positive population growth rates and that other management options must be considered where the background nest mortality rates are high