A new species of Ribautiella (Myriapoda, Symphyla, Scolopendrellidae) from an Amazonian black-water inundation forest and notes on its natural history and ecology

Ribautiella amazonica is described from a black-water inundation forest near Manaus, Brazil. The genus is recorded for the first time for the Americas. R. amazonica was predominantly collected from the forest soil, mainly between 7 and 14 cm depth and is considered euedaphic. Data indicate, that advanced immature stages and adults withstand forest-inundation of 5 - 6 months duration in the soil and reproduce in the early part of the emersion period

Illustrated key for Neotropical Myriapoda (Arthropoda)

An illustrated key is given in Portuguese and German for the orders of neotropical Myriapoda (Arthropoda)

Comparative ecological studies of the terrestrial arthropod fauna in Central Amazonian inundation-forests

"Reactions" of animal populations in Central Amazonian inundation-forests to annual flooding have been poorly investigated. The terrestrial arthropod-fauna was studied in 1976 in a Várzea-forest (white-water region) and in 1976/77 in an Igapó-forest (black-water region) near Manaus. As capture devices ground photo-eclectors, pitfall traps and arboreal photo-eclectors were used. All captured animals have been registered and separated to order, family and in some cases to species, except Collembola, Acari, Thysanoptera and part of the Diptera. Igapó 1. In the trunk region about 127.000 arthropods were caught (46 % lnsecta - mainly Holometabola -, 32 % Arachnida, 22 % lsopda and Myriapoda). Formicoidea dominated (71 species), as well as Pseudoscorpiones, Araneae and Diplopoda. On the forest floor about 80,000 arthropods were captured (90 % lnsecta - mostly Holometabola -, 9 % Arachnida, 1 % lsopoda and Myriapoda). 2. Activity density and emergence abundance of arthropods change throughout the year. In the dry season holometabole insects dominate, in the rainy season Arachnida, Myriapoda and Isopoda dominate on forest-floor and trunk. 3. Numerous arthropods, particularly non-flying ones obviously survive the submersion phase (March/April - Aug./Sept.) in the trunk and canopy region. However, a great part of them perish during the actual inundation, many become prey to predaceous arthropods, paticularly of Formicoidea. With the beginning of the rainy season (in Dec.) upward migration on the trunk increases as well as downward migration near the end of the submersion phase, particularly of Arachnida and Myriapoda. Trunk migration (upwards/downwards) and flight activity to trunks (=trunk approach) are regulated in a high degree by abiotical factors (soil wetness, rel. humidity) changing with the climate (dry season/rainy season) 4. Development of many arthropods is well synchronized with the annual water-fluctuations.This is exemplarily shown for Pseudoscorpiones (18 species in 8 families, litter and bark inhabitants and Meinertellidae (2 species). 5. The non-flying and limited-flying arthropod fauna of the Igapó is classified into terricole and arboricole groups ("nonmigrants", "migrants"). Várzea 1. About 45.000 arthropods were captured in the trunk region (94 % lnsecta - mainly Formicoidea as well as Coleoptera -, 5,7 % Arachnida, 0,3 % lsopoda and Myriapoda). About 2.000 animals were caught on the forest floor (91,1 % lnsecta - mostly Holometabola -, 9,3 % Araneae, 0,6 % Myriapoda). 2. Arthropods of the Várzea presumably are mostly trunk and canopy inhabitants. Many of them also come on to the forest floor during the emersion phase for oviposition (esp. Diptera) or nutrition (esp. Formicoidea). 3. Non-flying arthropods which emigrate to the trunk and canopy region do not occur. Conditions for a rich soil life are unfavorable, Pseudoscorpiones e.g. (11 species in 8 families) are almost exclusively represented by bark inhabitants

Sedimentological studies of the "Ilha de Marchantaria" in the Solimões/Amazon River near Manaus

Sedimentological studies on the Ilha de Marchantaria an island in the Amazon river near Manaus reveal the existence of four different structural main units. A: Sandy channel bars consisting of giant ripples constitute deposits for the formation of islands or newly formed areas of the Varzea. B: Gradual accumulation on the channel bars leads to the formation of point bar ridges which consist chiefly of small-scale ripples. C: Between point bar ridges of different ages there exist swales. During rising water level the river water flows from the downward side into the swales where finegrained sediments are deposited. D: Permanent lakes are formed mainly in the centre of the islands. During low water periods the lakes may be cut of from the river. During high water periods when the whole island is flooded by the river, additional sedimentation takes place especially in the upstream area of the island. There is however, extensive erosion of the banks on the upstream side of the island. By erosion of the upstream end and sedimentation processes on the downstream end the island moves slowly downstream

Description of Taulidesmella tabatinga n.sp. (Diplopoda, Polydesmida, Pyrgodesmidae) from Amazon River floodplains, with notes on its distribution and ecology

A new pyrgodesmid, Taulidesmella tabatinga n.sp., is described from near lquitos, Peru, from near Tabatinga (an area at the border between Brazil, Peru and Colombia), from the environs of Manaus and from Rio Madeira, Brazil, all these localities lying along the Solimões/Amazon River. T. tabatinga is only a second congener distinct from the type-species T. chanchamayo KRAUS, 1959, from Peru, chiefly by the much larger body size, 12-lobed collum, somewhat differently lobulated paraterga and simpler gonopods. This species, apparently widespread in Amazonian floodplains, represents a "terricolous migrant" which passes the aquatic phase on tree trunks above the water-level and has a low flood tolerance (1 < 16 hs)

On the natural history and ecology of Pseudoscorpiones (Arachnida) from an Amazonian blackwater inundation forest

The habitats and changes in habitat of 20 pseudoscorpion species in response to up to six months forest inundation are presented. The fauna is divided into 16 nonmigrating and 4 migrating species (2 terricolous and 2 arboricolous species). Adaptations of life-cycle to forest flooding and seasonal tree trunk migration are discussed for Tyrannochthonius amazonicus, T. migrans (Chthoniidae), Brazilatemnus browni (Miratemnidae) and Pachyolpium irmgardae (Olpiidae) based on data from trunk traps (arboreal photo-eclectors), emergence traps on the forest floor (ground photo-eclectors), soil extraction (KEMPSON method), canopy fogging (pyrethrum method) and the collection of epiphytes

Key to the families of Amazonian Pseudoscorpiones (Arachnida) (in English, German and Portuguese)

A detailed and well illustrated key is given for 12 families of Pseudoscorpiones recorded from Amazonia

Arthropod community associated with the canopy of Attalea phalerata Mart. (Arecaceae) during the flood period of the Pantanal of Poconé, Mato Grosso, Brazil

Six trees of the palm species Attalea phalerata Mart. were sampled during high water (aquatic phase) of the Pantanal of Mato Grosso (February 2001), by canopy fogging. The composition, structure, and biomass of the arthropod community associated with their canopies were analysed, as well as the influence the flood pulse renders on it. Each tree was fogged once, followed by three consecutive collections. A total of 63,657 arthropods (643.0 ± 259.87 ind/m2) were collected, representing 25 orders in the classes Insecta, Arachnida, Diplopoda and Crustacea. The dominant groups were Acari (40.0%; 257.2 ± 116.50 ind./m2), Coleoptera (12.0%; 77.5 ± 64.93 ind./m2), Psocoptera (9.2%; 59.0 ± 38.00 ind./m2), Diptera (8.4%; 54.1 ± 18.72 ind./m2), Collembola (8.3%; 53.4 ± 26.24 ind./m2) and Hymenoptera (7.9%; 50.6 ± 21.40 ind./m2), the latter mostly represented by Formicidae (49.2%). Arthropod biomass amounted to 8.86 g dry weight and 0.18 mg/m2. Coleoptera, Blattodea, Orthoptera, Araneae and Hymenoptera were the most representative taxa. The hydrological regime (flood pulse), as well as seasonality, appear to strongly affect the composition and structure of this canopy community

Development and mating behaviour of Meinertellidae (Machiloidea, Archaeognatha, Insecta) from the Central Amazon

Collected in different types of rain forest near Manaus, Amazonas, scaleless instars of three species of the Meinertellidae are described for the first time. The first and second instars are described for Meinertellus adisi, and the second instars for Neomachilellus amazonicus and N. scandens. Differential characteristics are given for these instars as well as for advanced juvenile and subadult instars. Based on samples collected with various methods, the development time (hatched - adult time span) of N. scandens in the natural environment is estimated to be 3 - 4 months. The matting behaviour of this species is described and represents the first observation of this nature for the family Meinertellidae. Different from the sperm-transfer modus observed in Machilidae, the male deposits a stalked spermatophore on the ground and the sperm sac, covered by secretory products, is picked up by the female with the ovipositor

Nesting behaviour of Trypoxylon (Trypargilum) rogenhoferi KOHL (Hymenoptera, Sphecidae) in a várzea inundation forest of Central Amazonia

The nesting behaviour of Trypoxylon rogenhoferi was studied in a whitewater inundation forest (várzea) of Central Amazonia. Nests were constructed in artificial nesting sites ("trap-nests") made of wood drilled longitudinally to a depth of 80 mm with apertures of 9.5 mm and 12.7 mm diameter respectively. The nest architecture and most of the behavioral characteristics of T. rogenhoferi generally were similar to those observed in other species of the genus. The nests consisted of a linear sequence of prey stocks separated by mud partitions. Nesting activity was greater in the 9.5 mm diameter traps than in the 12.7 mm diameter traps. Observations of the behaviour of immature T. rogenhoferi provide answers to questions posed by some authors, such as the use of mud in the construction of the cocoon wall. The larvae of T. rogenhoferi take bits of mud from the internal wall and mix them with the silk mesh to form a girdle around the body. The mud from the girdle is subsequently spread throughout the cocoon wall. Another question relates to the function of the mud deposited by the female at the innermost cavity, the preliminary plug. It was observed that the larvae produce a fragile-walled cocoon if a source of mud is not available. The preliminary plug in a nest serves as a source of mud for the larva of the first cell. The cells were provisioned with Alpaida veniliae (KEYSERLING) (Araneidae) only. Males, in contrast to females, developed in the innermost cells and were more abundant in the 9.5 mm diameter nests. The hatching rate from the cells provisioned by T. rogenhoferi was 41 %, mortality from unknown causes was 38 %, and mortality due to parasitoids was 21 %. The parasitoids most frequently involved in the destruction of cells were Pleurochrysis postica, P. morosa, Neochrysis lecointei and two unidentified species of Caenochrysis (Hymenoptera, Chrysididae; 60.7 %), followed by Lepidophora and Anthrax (Diptera, Bombyliidae; 23.3 %). Nesting activity was greater during the receding water phase, which coincides with the period of less precipitation. It is suggested that the seasonality of T. rogenhoferi is dependent on prey availability, which in turn is influenced by the flood cycle