45 resultados para millipedes
Resumo:
Millipedes are toxic preys for many vertebrates. Two individuals of the opossum species D. albiventris were videorecorded when feeding on the millipedes G. olivaceus and L. dentellus. Data were compared with feeding behavior on Tenebrio larvae. The opossums are resistant to intoxication by millipedes. Although chemical defenses of the millipedes were not effective against the opossum predation, they make them less attractive.
Resumo:
We describe, for the first time, the predatory behaviour of Thaumatomyrmex ants on millipedes of the family Polyxenidae, based on field observations of T. atrox and a field and laboratory study of T. contumax. The capture of the prey and the removal process of its body-covering setae by the ants before they eat the millipede are described. This specialized behaviour in at least two species of the genus, belonging to two distinct groups of species, indicates a general trend in Thaumatomyrmex. We coupled this study with a comparative morphological analysis of the mouthparts and digestive tube of these and other Thaumatomyrmex species. Also, we report the first case of sympatry in the genus, which suggests that Thaumatomyrmex includes several species. and not only one highly variable taxon, as hypothesized earlier.
Resumo:
A population boom of the millipede Plusioporus setigerhas been recorded in coffee crops in the district of Patrocinio-MG, Brazil on the last five years. The millipedes spread over dwelling houses and to vegetable gardens, orchards and small plantations. It was suggested that population increase occurred as a consequence of the organic materials in high scale and also periodic irrigation in the coffee crop.
Resumo:
The effects of deltamethrin on the respiratory metabolism of Gymnostreptus olivaceus and Plusioporus setiger were investigated. Acetone solutions corresponding to half the LD50 values, i.e., 20 μg.g-1g for G. olivaceus and 4.40 μg.g-1 for P. setiger, were used. Metabolism was determined with a Warburg respirometer at 25°C. Respirometric measurements were performed 1, 3 and 6 hours after administration of the pyrethroid to the same groups of millipedes. After 24 hours, daily respirometric measurements lasting 1 hour each were made on different millipede groups for a period of 10 days. Significant differences were detected only between the groups treated with the pyrethroid and the two control groups. In G. olivaceus, respiratory rates increased by about 1.65-fold compared to normal immediately after administration of the pyrethroid, followed by a gradual decrease up to 72 hours and a return to normal levels thereafter. In P. setiger the increase was about 1.1-fold compared to normal, with a decrease up to 96 hours and a return to normal thereafter. Although increased oxygen consumption was observed, a detoxification process occurred in both species, so that the possible metabolism of the pyrethroid may justify the low toxicity of deltamethrin for G. olivaceus and P. setiger.
Resumo:
Proceedings of the 10th Conference on Dynamical Systems Theory and Applications
Resumo:
Venomous animals are those that, by means of a hunting and defense mechanism, are able to inject their prey with a toxic substance produced in their bodies, directly from specialized glands (e.g., tooth, sting, spur) through which the poison passes. Millipedes are poisonous animals; they can be harmful to humans, and their effects usually manifest as erythematous, purpuric, and cyanotic lesions; local pain; and paresthesia. Here, we report a case of skin contact with a millipede for 6h resulting in skin lesions similar to blue toe syndrome.
Resumo:
Abstract This review presents the main species of venomous and poisonous arthropods, with commentary on the clinical manifestations provoked by the toxins and therapeutic measures used to treat human envenomations. The groups of arthopods discussed include the class Arachnida (spiders and scorpions, which are responsible for many injuries reported worldwide, including Brazil); the subphylum Myriapoda, with the classes Chilopoda and Diplopoda (centipedes and millipedes); and the subphylum Hexapoda, with the class Insecta and the orders Coleoptera (beetles), Hemiptera (stink bugs, giant water bugs, and cicadas), Hymenoptera (ants, wasps, and bees), and Lepidoptera (butterflies and moths).
Resumo:
მონოგრაფია ეხება კავკასიის რეგიონის წყვილფეხიანების (Arthropoda: Diplopoda) ფაუნისტურ შემადგენლობას და მის ზოოგეოგრაფიულ ანალიზს. ნაშრომში განხილულია წყვილფეხიანების კლასის 80 სახეობა და აღწერილია ახალი სახეობები.
Resumo:
This paper deals with some Millipedes (Diplopoda), which have been verified associated with or attacking on cultivated plants. The following forms are reported: 1) Orthomorpha (Orthomorpha) coarctata (Saussure, 1860) - Enormous numbers of individuals belonging to this species, whose synanthropic habits are frequentely emphasized, were collected around coffee-plants kept in a nursery. Young plants (with 10 cm) are mentioned as damaged by the species, which gnaws the stem, just above the roots. The dusting with benzene hexachloride (BHC) was successfully employed to prevent the invasions. Other occurrences of O. coarctata are reported, ecological and biological informations being also added. 2) Orthomorpha (Kalorthomorpha) gracilis (C. L. Koch, 1847) - Observed frequentely associated with the former species, being however less numerous. Both forms are very active, seemming to be widely distributed throughout the State of S. Paulo. 3) Cylindroiulus (Aneuloboiulus) britannicus (Verhoeff, 1891) - This species represents the first european Millipede verified in Brazil, by O. SCHUBART (1942a). The Author obtained a few specimens associated with O. gracilis, from the roots of lettuce plants. The lesions shown by the stem just above the roots seem to be due to both species. 4) Alloporus setiger Broelemann, 1902; Gymnostreptus olivaceus Schubart, 1944 and Pseudonannolene tricolor Broelemann, 1902 - Total damages determined by these species (mainly G. olivaceus) were observed in cultures of sugar-beet and melon. Actually, the Millipedes destroyed entirely the roots of the former plant and the fruits of the latter, representing a serious pest, here reported by the first time. Ecological and bionomical data are also included. 5) Pseudonannolene sp. (possibly P. paulista Broelemann, 1902) - Verified gnawing sweet-potatoes, about the crackings exhibited by the tubers. The crackings in sweet-potatoes appear to result in certain instances from a root-knot nematodes infection (Meloidogyne sp). P. paulista was recentely observed attacking potatoes, destroying from 6 to 30% of the tubers, according to the variety (BOOCK & LORDELLO, 1952).
Resumo:
n.s. no.103(2004)
Resumo:
Different populations of Pseudonannolene strinatii Mauriès, 1974 collected from three caves in Iporanga, state of São Paulo, were cytogenetically compared using techniques of conventional coloration, C-banding and silver nitrate impregnation. Specimens were morphologically similar and small cytogenetic differences were observed between the populations with relation to the distribution of constitutive heterochromatin.
Resumo:
The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs) are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length) were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo) in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree), Flemingia macrophylla (a shrubby legume) or Brachiaria decumbens (a pasture grass) was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms), Porcellionides pruinosus or Circoniscus ornatus (woodlice), and Trigoniulus corallinus (millipedes) were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.
Resumo:
Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history.
Resumo:
Members of arthropod classes Chilopoda (centipedes), Diplopoda (millipedes), and Arachnida (spiders and scorpions) cause tissue injury via bites, stings, and/or a release of toxins. A few members of the Acari subclass of Arachnida (mites and ticks) can transmit a variety of infectious diseases, but this review will cover the noninfectious manifestations of these vectors. Dermatologists should be familiar with the injuries caused by these arthropods in order to initiate proper treatment and recommend effective preventative measures. (J Am Acad Dermatol 2012;67:347.e1-9.)
Resumo:
In diplopods, the presence of calcium-containing structures seems to be a common finding in some species, with its formation being similar to that observed for other intracellular mineralization systems. In the present study, using histochemistry and transmission electron microscopy, a large amount of calcium was observed in the oocytes of Rhinocricus padbergi. Calcium was detected in both less and well developed oocytes, i.e., the occurrence of calcium coincided with the beginning of vitellogenesis. Calcium was observed as fine granulation distributed within the cytoplasm or deposited in spherical structures apparently formed by overlapping calcium layers. Some authors have suggested that these structures represent a type of reserve used for the calcification of the embryo exoskeleton, whereas others believe that calcium inclusions are a mechanism of organism detoxification as a result of excess calcium ingested by animals during soil turnover. We suggest in this paper that the first hypothesis could be occurring in R. padbergi since at the juvenile stages of the individuals the uptake of calcium is low and because the oocyte is a specialized cell not associated with detoxification.