Genetic differentiation among distinct karyomorphs of the wolf fish Hoplias malabaricus species complex (Characiformes, Erythrinidae) and report of unusual hybridization with natural triploidy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A transitoriedade entre o mundo primitivo e o moderno nas obras The Sea-Wolf e White Fang de Jack London

The American author Jack London wrote the books The Sea-Wolf and White Fang in 1904 and 1906, respectively. The former portrays the life of a literary critic, Humphrey Van Weyden, who after the wreckage of the ship in which he was is rescued by a seal-hunting schooner, where he is obliged to work and to live with the brutal captain Wolf Larsen, and in doing so he develops a more primitive profile. The latter work portrays the life of the eponymous character, a wolf that leaves the wild world in which it was born to follow its last master in the city, thus developing features of the modern world. This paper aims to conduct an analysis of the aspects that allow the transition between the primitive and the modern world in those works

Two-spotted spider mite and its natural enemies on strawberry grown as protected and unprotected crops in Norway and Brazil

Cultivation of strawberry in plastic tunnels has increased considerably in Norway and in southeastern Brazil, mainly in an attempt to protect the crop from unsuitable climatic factors and some diseases as well as to allow growers to expand the traditional production season. It has been hypothesized that cultivation under tunnels could increase the incidence of one of its major pests in many countries where strawberry is cultivated, including Norway and Brazil, the two spotted spider mite, Tetranychus urticae. The objective of this study was to evaluate the effect of the use of tunnels on the incidence of T. urticae and on its natural enemies on strawberry in two ecologically contrasting regions, Norway (temperate) and southeastern Brazil (subtropical). In both countries, peak densities of T. urticae in tunnels and in the open fields were lower than economic thresholds reported in the literature. Factors determining that systematically seem to be the prevailing relatively low temperature in Norway and high relative humidity in both countries. The levels of occurrence in Norway and Brazil in 2010 were so low that regardless of any potential effect of the use of tunnel, no major differences were observed between the two cropping systems in relation to T. urticae densities. In 2009 in Norway and in 2011 in Brazil, increase in T. urticae population seemed to have been restrained mainly by rainfall in the open field and by predatory mites in the tunnels. Phytoseiids were the most numerous predatory mite group of natural occurrence on strawberry, and the prevalence was higher in Brazil, where the most abundant species on strawberry leaves were Neoseiulus anonymus and Phytoseiulus macropilis. In Norway, the most abundant naturally occurring phytoseiids on strawberry leaves were Typhlodromus (Anthoseius) rhenanus and Typhlodromus (Typhlodromus) pyri. Predatory mites were very rare in the litter samples collected in Norway. Infection rate of the pest by the fungus Neozygites floridana (Neozygitaceae) was low. The results of this work suggest that in Norway the use of tunnels might not affect the population densities of T. urticae on strawberry in years of lower temperatures. When temperature is not a limiting factor for the development of T. urticae in that country (apparently always the case in southern Brazil), strawberry cultivation in the tunnels may allow T. urticae to reach higher population levels than in open fields (because of the provided protection from the direct impact of rainfall), but natural enemies may prevent higher levels from being reached.

Structural insights into substrate binding of brown spider venom class II phospholipases D

Phospholipases D (PLDs), the major dermonecrotic factors from brown spider venoms, trigger a range of biological reactions both in vitro and in vivo. Despite their clinical relevance in loxoscelism, structural data is restricted to the apo-form of these enzymes, which has been instrumental in understanding the functional differences between the class I and II spider PLDs. The crystal structures of the native class II PLD from Loxosceles intermedia complexed with myo-inositol 1-phosphate and the inactive mutant H12A complexed with fatty acids indicate the existence of a strong ligand-dependent conformation change of the highly conserved aromatic residues, Tyr 223 and Trp225 indicating their roles in substrate binding. These results provided insights into the structural determinants for substrate recognition and binding by class II PLDs.

Bromeliads as biodiversity amplifiers and habitat segregation of spider communities in a Neotropical rainforest

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Management of Wolf-Livestock Conflicts in Minnesota

In 1975, the gray wolf (Canis lupus) population in Minnesota was protected by the federal Endangered Species Act (USA). At that time, there were 500-750 wolves. By 2004, the population had grown to an estimated 3,020 wolves. Over time, conflicts between wolves and livestock increased. Wolf depredation control programs have been conducted by the U.S. Fish and Wildlife Service (1975-1986) and by the U.S. Department of Agriculture’s Wildlife Services program (1986 to present). In 1978, Minnesota’s wolves were reclassified from endangered to threatened which allowed authorized federal agents to lethally remove wolves that had depredated on livestock or pets. A State funded wolf compensation program was also established in 1978. Wildlife Services’ wolf damage management approach utilizes both nonlethal and lethal methods of control. Currently, wolf depredations are verified at 60-85 farms annually and 125-175 wolves are taken each year. Wolf compensation payments to livestock producers have averaged $67,111 per year during the past five years. Most livestock losses occur during spring and summer. Selective removal of depredating wolves, coupled with improvements in animal husbandry practices, has potential for reducing wolf-livestock conflicts. Minnesota’s wolf population is currently considered to be fully recovered and federal delisting is expected to occur in the near future.

G93-1167 Spider Mite Management in Corn and Soybeans

This NebGuide describes the two common spider mites found in Nebraska corn and soybeans, their natural enemies and management. Two species of spider mites, the Banks grass mite and twospotted spider mite, commonly feed on Nebraska corn. Banks grass mites (BGM) feed almost exclusively on grasses, including corn and sorghum. Twospotted spider mites (TSM) not only feed on many species of grasses, but also on soybeans, fruit trees and a variety of vegetables and ornamental plants. Although these two species are somewhat similar in appearance, they differ in several biological characteristics and in their susceptibility to pesticides. Banks grass mites usually appear earlier in the season, feed mostly on the lower leaves of the corn plant, and in Nebraska are moderately susceptible to many of the commonly used miticides. On the other hand, TSM tend to appear in mid to late season, increase rapidly, feed over the entire plant, and often are not consistently controlled by available pesticides.

WOLF CONTROL IN BRITISH COLUMBIA, CANADA

Up to 1949, the Fish and Game Branch employed personnel, some of whom were temporary, to attempt control of the extremely high wolf pop¬ulations of the central and northern portions of British Columbia. Coyotes were also very numerous in the central and southern regions and had to be considered because of their depredations. The field men were keen and conscientious but their efforts were not co-ordinated. Control areas were severely restricted in size as techniques were not adaptable enough and because of a lack of manpower. Eventually, sheepmen went out of business entirely over wide areas, cattlemen were subjected to huge annual losses, and sportsmen were very concerned. However, stock losses constituted the major complaint and resulted in ranchers demanding action* Two major changes came out of this. First, the bounty on wolves was raised and second, the present Predator Control Division was formed. The administration was convinced that a force of experienced, fully-trained field staff under a single supervision would be far more effective than bounty payments. Unfortunately, bounties were in vogue during that time and forced the necessity of proving the worth of organized controls before any consideration could be given to the elimination of the bounty system.

Influence of Prey Size on the Capture of Social Wasps (Hymenoptera: Vespidae) by the Orb-Web Spider Nephilengys cruentata

The objective of the present study was to evaluate the plasticity of the hunting behavior of the spider Nephilengys cruentata (Araneae: Nephilidae) facing different species of social wasps. Considering that wasps can consume various species of spiders and that their poison can be used as defense against many predators, the effect of the corporal size of the prey was evaluated in the behavior of N. cruentata. Predation experiments were conducted using three species of social wasps of different sizes and the data registered in this research were compiled through annotations and filming of the hunting behavior of each spider, in relation to the offered prey. The results revealed that the size of the wasp and the sequential offer of prey change the hunting behavior of the spider, and prey of large size have high influence on this behavior.

Costs and benefits of freezing behaviour in the harvestman Eumesosoma roeweri (Arachnida, Opiliones)

Animals present an enormous variety of behavioural defensive mechanisms, which increase their survival, but often at a cost. Several animal taxa reduce their chances of being detected and/or recognized as prey items by freezing (remaining completely motionless) in the presence of a predator. We studied costs and benefits of freezing in immature Eumesosoma roeweri (Opiliones, Sclerosomatidae). Preliminary observations showed that these individuals often freeze in the presence of the syntopic predatory spider Schizocosa ocreata (Araneae, Lycosidae). We verified that harvestmen paired with predators spent more time freezing than when alone or when paired with a conspecific. Then. we determined that predator chemical cues alone did not elicit freezing behaviour. Next, we examined predator behaviour towards moving/non-moving prey and found that spiders attacked moving prey significantly more, suggesting an advantage of freezing in the presence of a predator. Finally, as measure of the foraging costs of freezing, we found that individuals paired with a predator for 2 h gained significantly less weight than individuals paired with a conspecific or left alone. Taken together, our results suggest that freezing may protect E. roeweri harvestmen from predatory attacks by wolf spiders, but at the cost of reduced food and/or water intake. (C) 2009 Elsevier B.V. All rights reserved.

Podochela meloi Sankarankutty, Ferreira & Cunha, 2001, a junior synonym of the spider crab Inachoides forceps A. Milne-Edwards, 1879 (Crustacea: Brachyura: Inachoididae)

Podochela meloi Sankarankutty, Ferreira & Cunha, 2001, originally described in the Inachidae MacLeay, 1838, was recently transferred to the Inachoididae genus Inachoides H. Milne Edwards & Lucas, 1842, based upon overall similarities. Placement of P. meloi in both Inachoididae and Inachoides is found to be supported by a number of synapomorphies as shown herein. Podochela meloi is shown to be a junior synonym of Inachoides forceps A. Milne-Edwards, 1879.

Solanum americanum as a reservoir of natural enemies of the tomato red spider mite, Tetranychus evansi (Acari: Tetranychidae)

Brazilian populations of the pathogenic fungus Neozygites floridana (Weiser & Muma) Remaudiere & S. Keller (Entomophthoromycotina: Entomophthorales) and the predatory mite Phytoseiulus longipes Evans (Acari: Phytoseiidae) are potential candidates for introduction into Africa for classical biological control of the tomato red spider mite, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae). The efficiency of these natural enemies against T. evansi has been demonstrated under laboratory conditions, but little is known about their performance on native Solanaceae in the field. The American nightshade, Solanum americanum Mill., is native to the Americas and may serve as an alternative host plant for T. evansi and its natural enemies in the absence of tomato plants. In this work, we studied the population dynamics of T. evansi and its natural enemies on S. americanum in a screen house, semi-field and field plots in Recife, Pernambuco, Brazil, to evaluate the potential of natural enemies for controlling T. evansi. Of the four natural enemies found in association with T. evansi, only N. floridana and P. longipes were clearly associated with the reduction of the populations of T. evansi. Neozygites floridana was observed in a screen house, semi-field and field plots, but P. longipes was only detected in the semi-field plots. Increases in the population of T. evansi were always followed by increases in the density of one of these natural enemies, suggesting that they were important factors regulating T. evansi populations on S. americanum. The presence of this host plant near the release sites in Africa thus might increase the chances for the permanent establishment of these natural enemies.

Sexual Differences in the Behavior of the Harvestman Leiobunum vittatum (Opiliones, Sclerosomatidae) Towards Conspecific Cues

Preliminary observations of the harvestman Leiobunum vittatum found that individuals rub their bodies against the substrate, presenting the possibility of chemical marking. To determine whether or not L. vittatum individuals can detect substrate-borne chemical cues, we compared responses of L. vittatum males and females to substrate-borne male and female cues. We found that individuals of L. vittatum do respond to conspecific cues and that their responses are sex-specific. In response to substrate-borne conspecific cues, male L. vittatum spent more time, engaged in more scraping with their sensory legs I, and engaged in pedipalpal tapping more often in the presence versus absence of conspecific cues (male and female equally). Furthermore, in the presence of conspecific cues, males engaged in two behaviors never observed in females-(a) "fast approach" and (b) "jerking", the latter of which was never observed in the presence of cricket cues. In contrast to males, females did not spend more time on conspecific cues, but did spend more time tapping their pedipalps in the presence of male vs female cues, suggesting an ability to distinguish between them. A final experiment explored the possibility that females could discriminate among males of varying histories of agonistic interactions based upon their chemical cues. We found no support for this hypothesis. Our results demonstrate that L. vitattum do respond to conspecific cues, and introduce the possibility that intraspecific communication may be mediated in part by chemical cues.

A new species of spider fly in the genus Sabroskya Schlinger from Malawi, with a key to Acrocerinae world genera (Diptera, Acroceridae)

In this paper we diagnose the genus Sabroskya Schlinger, 1960 and describe Sabroskya schlingeri sp. n. from Malawi. We also provide dichotomous keys to species of Sabroskya and to world genera of the subfamily Acrocerinae, both extant and extinct.

Phoneutria nigriventer spider toxin Tx2-6 causes priapism and death: A histopathological investigation in mice

Phoneutria nigriventer spider bite causes priapism, an effect attributed to the peptide toxins Tx2-5 and Tx2-6 and involving nitric oxide. Tx2-6 (MW = 5287) is known to delay the inactivation of Sodium channels in the same fashion as many other venom toxins. In the present study we evaluated the i.p. dose that induces priapism and the other symptoms in mice. Animals killed by the toxin or crude venom (0.85 mg/kg) were autopsied and a pathological study of brain, lung, kidney, liver and heart was undertaken using standard techniques. The same protocol was employed with animals injected with crude venom. Results showed that priapism is the first sign of intoxication, followed by piloerection, abundant salivation and tremors. An i.p. injection of about 0.3 mu g/kg induced only priapism with minimal side-effects. The most remarkable histological finding was a general vascular congestion in all organs studied. Penis showed no necrosis or damage. Lungs showed vascular congestion and alveolar hemorrhage. Heart showed also sub-endothelial hemorrhage. Brain showed only a mild edema and vascular congestion. Results obtained with crude venom closely resemble those of purified toxin. We conclude that Tx2-6 have profound effects on the vascular bed especially in lungs and heart, which may be the cause of death. Interestingly brain tissue was less affected and the observed edema may be attributed to respiratory impairment. To the best of our knowledge this is the first histopathological investigation on this toxin and venom suggesting a possible cause of death. (C) 2012 Elsevier Ltd. All rights reserved.