A new species of Scymnobius Casey (Coleoptera, Coccinellidae, Scymnini) from Pernambuco, Brazil

A new species of Scymnobius Casey (Coleoptera, Coccinellidae, Scymnini) from Pernambuco, Brazil. Scymnobius pernambucensis sp. nov. from Pernambuco, Brazil, is described and illustrated. This is the third species of this genus recorded from Brazil.

Necrophagous diptera associated with wild animal carcasses in southern Brazil

Necrophagous Diptera associated with wild animal carcasses in southern Brazil. The aim of this study was to acquire a better knowledge concerning the diversity of necrophagous Diptera that develop on wild animal carcasses. For this purpose, the decomposition of six wild animal carcasses was observed in order to collect and identify the main species of necrophagous flies associated with the decomposition process. The carcasses were found on highways near the cities of Pelotas and Capão do Leão in the initial stage of decomposition, with no significant injuries or prior larval activity. Four wild animal models were represented in this study: two specimens of Didelphis albiventris Lund, 1840; two Tupinambis merianae Linnaeus, 1758; one Nothura maculosa Temminck, 1815; and one Cerdocyon thous Linnaeus, 1766. A total of 16,242 flies from 14 species were reared in the laboratory, where Muscidae presented the greatest diversity of necrophagous species. Overall, (i) carcasses with larger biomass developed a higher abundance of flies and (ii) the necrophagous community was dominated by Calliphoridae, two patterns that were predicted from published literature; and (iii) the highest diversity was observed on the smaller carcasses exposed to the lowest temperatures, a pattern that may have been caused by the absence of the generalist predator Chrysomya albiceps (Wiedemann, 1819). (iv) An UPGMA analysis revealed a similar pattern of clusters of fly communities, where the same species were structuring the groupings.

L'Arpella vulgar

L'arpella vulgar, un rapinyaire de zones humides, més abundant al nord que al sud d'Europa, es pot veure durant tot l'any al Baix Ter

Lipid reserves of red mullet (Mullus barbatus) during pre-spawning in the northwestern Mediterranean

Lipid reserves are a particularly important attribute of fishes because they have a large influence on growth, reproduction and survival. This study analyses the lipid content of red mullet (Mullus barbatus) pre-spawners in three different areas of the northwestern Mediterranean in relation to trawling activities and river runoff. The muscle lipid was considered as an indicator of the somatic condition of individuals whilst the gonad lipid was used as a proxy of the energy invested in reproduction. The results show that fish with the highest muscle lipid levels inhabited the area where fishing impact was lowest. Since the abundance and biomass of polychaetes, which represent the main food source for red mullet, were found to be lower in trawled zones than in unfished ones, we suggest that differences in the muscle lipid levels between areas might be attributed to variation in prey abundance in relation to fishing impact. However, no impact of river runoff on lipid reserves of red mullet was observed. The results also show that muscle and gonad lipid reserves are not related to each other during pre-spawning

Dinámica espacio temporal en la ecología trófica de la anchoveta (Engraulis ringens Jenyns, 1842; pisces: engraulide) en el mar peruano

El objetivo de este trabajo es estudiar las variaciones ontogénicas, espaciales y nictemerales en la dieta de la anchoveta peruana (Engraulis ringens). El trabajo se basa en el análisis de contenido estomacal de 13 430 anchovetas (peces de 4 a 19,5 cm) muestreados durante 22 cruceros de investigación realizados a bordo de las embarcaciones científicas del Instituto del Mar del Perú durante el período 1996-2003. Previo a los análisis estadísticos la contribución de cada grupo de presa fue convertido a carbonó. Los datos fueron procesados por medio de estadística uni y multivariada en función de la talla de la anchoveta, la latitud, la distancia de la costa, la distancia del borde de la plataforma continental y el período nictemeral. Los resultados enseñan que la anchoveta se alimenta mayormente de zooplancton cualquier sea su tamaño o su distribución espaciotemporal. La anchoveta cambio gradualmente su dieta a lo largo de su ciclo de vida. Así, los individuos mas pequeños han ingerido mayormente copépodos calanoideos (68.0%) y eufausidos (23.3%), mientras que los individuos mas grandes ingirieron mayormente eufausidos (84.9%) y copépodos calanoideos (11.5%). Latitudinalmente, la mayor contribución de los copépodos calanoideos se observó en las zonas de afloramiento de Chicama y San Juan, con el 52.3% y 47.5%, respectivamente. Hasta los 160 km de distancia de la costa, no se ha observado un patrón regular en la contribución de las principales presas, mientras que por fuera, se insinúa un patrón caracterizado por el predominio de los eufausidos (>84%) y la menor contribución de copépodos calanoideos (<14,1%). En la plataforma continental los eufausidos contribuyeron con el 55.6% y los copépodos calanoideos con el 36.9%; mientras que por fuera de esa zona, los eufausidos se incrementaron al 75.3% y los copépodos calanoideos disminuyeron al 20.1%. Al considerar el período nictemeral, el ítem presa predominante durante el día fueron los eufausidos (52.7%) seguido de los copépodos calanoideos (40.9%); mientras que durante la noche, los eufausidos se incrementaron al 80.2% y los copépodos calanoideos disminuyeron al 15.7%. Estos resultados contradicen lo que se conocía acerca de la variabilidad de la dieta de la anchoveta, desestimándose: (i) que en el norte es fitoplanctívora y en el sur es zooplanctívora; (ii) que la fracción zooplanctónica es mayor en la zona oceánica. Asimismo, se ha demostrado que: (i) la anchoveta es principalmente zooplanctófaga durante su ciclo de vida, con modificaciones que corresponden a la mayor ingesta de presas pequeñas cuando son juveniles y de presas grandes cuando son adultas, (ii) en la zona de influencia de la plataforma continental consume aproximadamente el doble de copépodos calanoideos que en la zona oceánica, y aproximadamente una tercera parte menos de eufausidos en la zona interna que en la zona oceánica, y (iii) durante la noche y el día ingiere principalmente eufausidos pero la contribución de los copépodos calanoideos sube al 40%.

Trophic dynamics in the northern Humboldt Current system: insights from stable isotopes and stomach content analyses

The northern Humboldt Current system (NHCS) off Peru is one of the most productive world marine regions. It represents less than 0.1% of the world ocean surface but presently sustains about 10% of the world fish catch, with the Peruvian anchovy or anchoveta Engraulis ringens as emblematic fish resource. Compared with other eastern boundary upwelling systems, the higher fish productivity of the NHCS cannot be explained by a corresponding higher primary productivity. On another hand, the NHCS is the region where El Niño, and climate variability in general, is most notable. Also, surface oxygenated waters overlie an intense and extremely shallow Oxygen Minimum Zone (OMZ). In this context, the main objective of this study is to better understand the trophic flows in the NHCS using both stomach content and stable isotope analyses. The study focuses on a variety of organisms from low trophic levels such as zooplankton to top predators (seabirds and fur seals). The approach combines both long-term and specific studies on emblematic species such as anchoveta, and sardine Sardinops sagax and a more inclusive analysis considering the 'global' food web in the recent years (2008 – 2012) using stable isotope analysis. Revisiting anchovy and sardine we show that whereas phytoplankton largely dominated anchoveta and sardine diets in terms of numerical abundance, the carbon content of prey items indicated that zooplankton was by far the most important dietary component. Indeed for anchovy euphausiids contributed 67.5% of dietary carbon, followed by copepods (26.3%). Selecting the largest prey, the euphausiids, provide an energetic advantage for anchoveta in its ecosystem where oxygen depletion imposes strong metabolic constrain to pelagic fish. Sardine feed on smaller zooplankton than do anchoveta, with sardine diet consisting of smaller copepods and fewer euphausiids than anchoveta diet. Hence, trophic competition between sardine and anchovy in the northern Humboldt Current system is minimized by their partitioning of the zooplankton food resource based on prey size, as has been reported in other systems. These results suggest an ecological role for pelagic fish that challenges previous understanding of their position in the foodweb (zooplanktophagous instead of phytophagous), the functioning and the trophic models of the NHCS. Finally to obtain a more comprehensive vision of the relative trophic position of NHCS main components we used stable isotope analyses. For that purpose we analyzed the δ13C and δ15N stable isotope values of thirteen taxonomic categories collected off Peru from 2008 - 2011, i.e., zooplankton, fish, squids and air-breathing top predators. The δ15N isotope signature was strongly impacted by the species, the body length and the latitude. Along the Peruvian coast, the OMZ get more intense and shallow south of ~7.5ºS impacting the baseline nitrogen stable isotopes. Employing a linear mixed-effects modelling approach taking into account the latitudinal and body length effects, we provide a new vision of the relative trophic position of key ecosystem components. Also we confirm stomach content-based results on anchoveta Engraulis ringens and highlight the potential remarkable importance of an often neglected ecosystem component, the squat lobster Pleuroncodes monodon. Indeed, our results support the hypothesis according to which this species forage to some extent on fish eggs and larvae and can thus predate on the first life stages of exploited species. However, the δ13C values of these two species suggest that anchoveta and squat lobster do not exactly share the same habitat. This would potentially reduce some direct competition and/or predation.

Trophic ecology of jumbo squid and predatory fishes in the Northern Humboldt Current System

This work provides a contribution to a better understanding of the trophic ecology of important predators in the Northern Humboldt Current System, the jack mackerel (Trachurus murphyi), the chub mackerel (Scomber japonicus) and the jumbo squid (Dosidicus gigas) by the characterization of the highly variable feeding patterns of these species at different spatiotemporal scales. We provided new knowledge on the comparative trophic behaviour of these species, defined as opportunistic in previous investigations. For that purpose we applied a variety of statistical methods to an extensive dataset of 27,188 non-empty stomachs. We defined the spatial organization of the forage fauna of these predators and documented changes in prey composition according to predators’ size and spatiotemporal features of environment. Our results highligh the key role played by the dissolved oxygen. We also deciphered an important paradox on the jumbo squid diet: why do they hardly forage on the huge anchovy (Engraulis ringens) biomass distributed of coastal Peru? We showed that the shallow oxygen minimum zone present off coastal Peru could hamper the co-occurrence of jumbo squids and anchovies. In addition, we proposed a conceptual model on jumbo squid trophic ecology including the ontogenetic cycle, oxygen and prey availability. Moreover we showed that the trophic behaviour of jack mackerel and chub mackerel is adapted to forage on more accessible species such as for example the squat lobster Pleurocondes monodon and Zoea larvae. Besides, both predators present a trophic overlap. But jack mackerel was not as oracious as chub mackerel, contradictorily to what was observed by others authors. Fish diet presented a high spatiotemporal variability, and the shelf break appeared as a strong biogeographical frontier. Diet composition of our fish predators was not necessarily a consistent indicator of changes in prey biomass. El Niño events had a weak effect on the stomach fullness and diet composition of chub mackerel and jack mackerel. Moreover, decadal changes in diet diversity challenged the classic paradigm of positive correlation between species richness and temperature. Finally, the global patterns that we described in this work, illustrated the opportunistic foraging behaviour, life strategies and the high degree of plasticity of these species. Such behaviour allows adaptation to changes in the environment.

New trapping method to survey for presence of the Etruscan shrew Suncus etruscus, the smallest mammal

The presence of the Etruscan shrew Suncus etruscus is hard to prove where its predator, the barn owl Tyto alba, is absent, because most live traps are not triggered by it. I therefore developed a new trapping method involving a feeding period of 1 week followed by one night of trapping using modified Trip Trap traps. I show here in detail how I caught four Etruscan shrews in 2010 with 24 traps in the Valley of Dora Baltea (Piemonte, Italy). In 2011, another 11 Etruscan shrews were caught in Piemonte and Lombardia, Italy, and Ticino, Switzerland. The proposed new method is useful for establishing the presence of the species.

Consequences of genetic erosion on fitness and phenotypic plasticity in European tree frog populations (Hyla arborea).

The detrimental effects of genetic erosion on small isolated populations are widely recognized contrary to their interactions with environmental changes. The ability of genotypes to plastically respond to variability is probably essential for the persistence of these populations. Genetic erosion impact may be exacerbated if inbreeding affects plastic responses or if their maintenance were at higher phenotypic costs. To understand the interplay 'genetic erosion-fitness-phenotypic plasticity', we experimentally compared, in different environments, the larval performances and plastic responses to predation of European tree frogs (Hyla arborea) from isolated and connected populations. Tadpoles from isolated populations were less performant, but the traits affected were environmental dependant. Heterosis observed in crosses between isolated populations allowed attributing their low fitness to inbreeding. Phenotypic plasticity can be maintained in the face of genetic erosion as inducible defences in response to predator were identical in all populations. However, the higher survival and developmental costs for isolated populations in harsh conditions may lead to an additional fitness loss for isolated populations.

Geographic and temporal variation in the consumption of bats by European barn owls

Capsule We report a review of the occurrence of bats in the Barn Owl diet Tyto alba in Europe. Based on 802 studies reporting 4.02 million prey items identified in pellets, 4949 were bats (0.12%). We found that bat predation decreased during the last 150 years, is more frequent on islands than mainland, and is higher in eastern than western Europe and in southern than northern Europe. Although Barn Owls usually capture bats opportunistically, they can sometimes specialize on them.

Predatory cannibalism in Drosophila melanogaster larvae.

Hunting live prey is risky and thought to require specialized adaptations. Therefore, observations of predatory cannibalism in otherwise non-carnivorous animals raise questions about its function, adaptive significance and evolutionary potential. Here we document predatory cannibalism on larger conspecifics in Drosophila melanogaster larvae and address its evolutionary significance. We found that under crowded laboratory conditions younger larvae regularly attack and consume 'wandering-stage' conspecifics, forming aggregations mediated by chemical cues from the attacked victim. Nutrition gained this way can be significant: an exclusively cannibalistic diet was sufficient for normal development from eggs to fertile adults. Cannibalistic diet also induced plasticity of larval mouth parts. Finally, during 118 generations of experimental evolution, replicated populations maintained under larval malnutrition evolved enhanced propensity towards cannibalism. These results suggest that, at least under laboratory conditions, predation on conspecifics in Drosophila is a functional, adaptive behaviour, which can rapidly evolve in response to nutritional conditions.

Differences in diet between the two largest breeding colonies of Audouin's gulls: the effects of fishery activities

We analysed and compared the diet of Audouin´s gulls Larus audouinii between their two largest breeding sites in the world: the Ebro Delta and the Chafarinas Islands (western Mediterranean). These two localities showed marked differences in the features of the commercial fishing fleet: in the Ebro Delta area a large fishing fleet produced large amounts of discards, while in the Chafarinas the fleet discarded smaller amounts of fish and marine invertebrates, due to the smaller number of vessels. It is also likely that the percentage of discards from total catches is also lower around the Chafarinas than at the Ebro Delta. We distinguished two types of fishing to compare diet compositions: diurnal (only trawling activity) and diurnal and nocturnal (trawling and purse-seine activity, respectively). We also differentiated regurgitates from young nestlings (up to 20 days old) and from older nestlings or adult birds. At the two localities, fish was the main food of Audouin´s gulls, with epipelagic prey (mainly clupeoids) being more important when both diurnal and nocturnal fisheries were operating. This confirms that epipelagic prey either caught actively by the gulls or linked to fisheries was particularly important in the feeding habits of Audouin´s gulls. Nevertheless, differences between the two colonies appear mainly when only trawlers operated: while at the Ebro Delta gulls showed higher consumption of benthic-mesopelagic prey (probably linked to a higher trawler discard availability), gulls from the Chafarinas Islands consumed higher biomass of epipelagic prey probably caught actively at night. When both fleets operated around the two colonies, the average biomass of prey in a regurgitate of younger chicks was significantly higher at the Ebro Delta than at Chafarinas, and the opposite trend was recorded for older nestlings and adults. Niche width was broader in Chafarinas than in the Ebro Delta for both age classes and for any fishing fleet schedule, suggesting again that the exploitation of discards was higher at the Ebro Delta than at the Chafarinas, where gulls showed a more varied diet. Despite the fact that availability of discards was probably higher at the Ebro Delta than at Chafarinas, the per capita availability was not so different at both localities due to the increasing seabird community population at the Ebro Delta, which ca. doubled that at Chafarinas in the last decade.

Nestling barn owls assess short-term variation in the amount of vocally competing siblings.

Assessing the amount of rivals is crucial to optimally adjust investment into a contest. If laboratory animals show numerical abilities, little is known about the ecological implications particularly in young animals. The two to nine barn owl (Tyto alba) siblings vocally compete for priority of access to food resources before parents actually deliver them. In dyads, the individual that vocalizes at the highest rate in the absence of parents deters its siblings from competing for next delivered prey. We tested the novel hypothesis that to optimally adjust vocal investment, barn owl nestlings assess how many of their siblings are currently competing. To singleton owlets, we broadcasted a fixed global number of calls emitted by one, two or four pre-recorded unfamiliar nestlings. We could thus distinguish the independent effect on singletons' vocal behavior of the global number of calls produced by a brood from the number of competitors that produced these calls. Overall, nestlings retreated more from vocal contest when facing more competitors. However, in front of one highly motivated competitor, nestlings refrained from vocalizing to a larger extent than when competing against more but less motivated individuals. Therefore, young animals assess variation in the number of currently competing siblings based on individual-specific vocal cues.

Population differentiation and its consequences in the white campion "Silene latifolia" (Caryophyllaceae): a functional analysis

Summary In his theory On the Origin of Species by Means of Natural Selection (1859), Darwin describes evolution as a gradual change in population over time and that natural selection is a process that caused evolution. Because quantitative variation in species is partly influenced by several genes and thus heritable, association between levels of genetic variation at neutral markers and at quantitative traits and their partitioning within and among populations are important to study mechanisms that drive evolution in populations. Most studies addressing quantitative variation in plants focused on morphological and life history traits but not in traits affecting reproductive success. The aim of this thesis is to better understand how patterns of variation for neutral molecular markers and phenotypic traits drive the evolution of reproduction and defensive mechanisms in six European populations of Silene latifolia, a dioecious plant species. We found evidence for extremely high within and between population variation at six microsatellite loci and at most quantitative traits studied in plants grown under standardized conditions (morphology, life history and reproductive traits). Interestingly, there was clinal variation between age at first flowering and latitude. This pattern is likely due to natural selection since differentiation of this trait was high, heritable and probably higher than differentiation at neutral markers. Our study focused on sex specific selective pressures: mechanisms of intersexual coadaptation and defence mechanism against the seed predator Hadena bicruris. To address divergence at reproductive traits, we studied male and female population of origin effects and in particular pollen competitive ability on male post-pollination success in the study populations with within and between populations crosses. We crossed the same female plant with pollen from a male within the same population of origin and pollen from two males from two distinct populations, using a fixed tester male as a competitor. Additionally, we conducted control crosses with pollen from each male as a single donor. We analysed paternity success of each competitor with two microsatellite loci, seed set and offspring fitness. Male population of origin showed significant among-population variation for siring success at pollen competition. In vitro pollen germination rate showed heritable variation among populations and was positively correlated to siring success. Local or foreign pollen did not have a consistent advantage. Furthermore, female population of origin affected the outcome of pollen competition in some populations. There was no difference of seed set or offspring fitness in within/ between population crosses. This suggests that reproductive divergence may occur via pollen competition in Silene latifolia. The specialist seed predator Hadena bicruris may also induce divergence between populations. We tested potential constitutive and induced defence mechanisms against the specialist predator Hadena bicruris. Because fruit wall thickness is smaller in the invasive range (Northern America) were the moth is absent, this suggests that a thicker fruit wall is a potentially defensive trait against larval attack, and that relaxed selection in the absence of the seed predator has resulted in an evolutionary loss of this defence in the invasive range. Fruit wall thickness was different among three populations. Experimental exposure to moth eggs increased fruit abortion. Fruits built after attack on exposed plants did not have thicker fruit walls compared to fruits on non-exposed plants. Furthermore, fruits with thicker fruit walls were not less profitable, nor did they require longer handling time when exposed to larvae, suggesting no defensive role of fruit wall thickness. Our results show that there is high molecular and phenotypic variation in Silene latifolia and that traits potentially involved in reproductive success both for intra-specific (between sexes) and inter-specific interactions are heritable. Different selective forces may thus interact and cause differential evolution of geographically separated Silene latifolia populations in Europe, leading to the observed differentiation. Résumé Dans sa théorie de l'évolution, L'origine des espèces, ch. 4 (1859), Darwin décrit l'évolution comme un processus continu au cours du temps à l'intérieur de populations et que la sélection naturelle en est le moteur. La variation quantitative est en partie déterminée par plusieurs gènes, donc transmissible à la descendance. Associer le niveau de variation génétique à des marqueurs neutres au niveau de la variation à des traits quantitatifs, ainsi que la répartition à l'intérieur et entre les populations d'une espèce donnée de cette variation, sont importants dans la compréhension des forces évolutives. La plupart des études scientifiques sur la variation quantitative chez les plantes se sont intéressées à la morphologie et à la phénologie mais pas aux caractères impliqués dans le succès reproducteur. L'objectif de cette thèse est de mieux comprendre comment la répartition de la variation à des marqueurs neutres et des caractères quantitatifs influence l'évolution de la reproduction et des mécanismes de défense dans six populations Européennes de l'espèce dioïque Silene latifolia. Nous avons mis en évidence une grande diversité intra et inter-population à six loci microsatellites ainsi qu'à la plupart des caractères quantitatifs mesurés (morphologie, phénologie et traits reproducteurs) sur des plantes cultivées dans des conditions standardisées. Un résultat intéressant est la présence d'un cline latitudinal pour l'âge à la floraison. Ceci est probablement une conséquence de la sélection naturelle, puisque ce caractère est différencié entre les populations étudiées, héritable et que la différenciation de ce trait est supérieure à la différenciation des marqueurs neutres étudiés. Notre étude a ensuite porté plus précisément sur les pressions de sélection spécifiques aux sexes : la coadaptation entre les sexes et les mécanismes de défense contre l'insecte granivore Hadena bicruris. Afin d'évaluer la divergence sur les traits reproducteurs, nous avons étudié les effets des populations d'origine des mâles et des femelles et en particulier le succès reproducteur des mâles après pollinisation à l'aide de croisements inter et intra-population. Nous avons pollinisé la même femelle avec du pollen provenant d'un mâle de la même population ainsi qu'avec le pollen de deux mâles provenant de deux autres populations en situation de compétition avec un pollen provenant d'une population test. Des croisements contrôle ont été réalisés avec les mêmes mâles en pollinisation pure. Nous avons évalué le succès reproducteur de chaque mâle à l'aide d'analyses de paternité ainsi que la production de graines et la fitness de la descendance. L'origine du mâle avait un effet sur la paternité. Le taux de croissance in vitro du pollen est un caractère héritable et a eu un effet positif sur le succès reproducteur. De plus, l'origine de la femelle avait un effet sur le succès des mâles en compétition dans certaines populations. Nos résultats suggèrent qu'une divergence reproductive chez Silene latifolia pourrait apparaître suite à la compétition pollinique. Nous avons ensuite testé des mécanismes potentiels de défense constitutive et induite contre l'herbivore spécialiste Hadena bicruris, un papillon nocturne qui pourrait aussi jouer un rôle dans la différenciation des populations. L'épaisseur des fruits étant plus faible dans les régions où la plante est invasive (Amérique du Nord) et où l'insecte est absent, ce trait pourrait jouer un rôle défensif. Une pression de sélection plus faible causée par l'absence de l'herbivore aurait abouti à une perte de cette défense dans ces régions. Nous avons montré que l'épaisseur du fruit est variable selon les populations. L'infestation artificielle de fruit par l'insecte induit l'abscission sélective des fruits. Les fruits produits après une infestation n'étaient pas plus épais que les fruits issus de plantes non infestées. De plus, les fruits épais n'étaient pas moins nutritifs et ne causaient pas de perte de temps pour la prédation pour les larves, ce qui suggère que l'épaisseur des fruits ne joue pas un rôle défensif. Nos résultats montrent que plusieurs pressions de sélection interviennent et interagissent dans l'évolution de populations distantes, provoquant la divergence des populations Européennes de l'espèce Silene latifolia.

Influence of mineral fertilization on edaphic fauna in Acacia auriculiformis (A. Cunn) plantations

Fertilization and/or the accumulation of organic matter from plant residues can influence the composition of soil and litter community. The goal of this study was to evaluate the effects of P and K fertilization on total faunal and nematode faunal composition and richness in plant litter and soil for 360 days in an area reforested with Acacia auriculiformis (A. Cunn), located in the municipality of Conceição de Macabu in the State of Rio de Janeiro. For each treatment (fertilized and unfertilized plots), samples of litter and soil (to a depth of 5 cm) were collected and transferred into a Berlese-Tüllgren funnels for the extraction of fauna. Mesofauna and macrofauna were quantified, and the major taxa identified. Nematodes were extracted by centrifugal flotation in sucrose solution and identified according to feeding habits. Density (number of individuals m-2) of total fauna, microphages, social insects and saprophages varied significantly per treatment and sampling time in both litter and soil. The total number of individuals collected was 5,127, and the total number of nematodes 894. Phosphorus and potassium fertilization resulted in an increase in total fauna density and richness in the litter due to an increased abundance of social insects, saprophages and herbivores. In the soil, fertilization increased the saprophage and predator densities. Saprophages were the predominant taxa in the litter, while social insects (Formicidae) prevailed in the soil. Litter nematode populations were favored by mineral fertilization. Bacteriophages were the predominant nematode group in both litter and soil.