Ovipositional behavior in predator and prey blowflies

In this study we analyzed the ovipositional behavior of C. albiceps, C. megacephala and L. eximia in response to previous presence of larvae of different species, both predator and prey. The preference for substrates that previously had had no larvae was predominant for all species. However, the experiments showed that C. megacephala and L. eximia avoid laying eggs principally in patches with previous presence of C. albiceps larvae. The implications of these results for the necrophagous Diptera community dynamics are discussed.

Prey choice by Nesticodes rumpes (Araneae, Theridiidae) on Musca domestica (Diptera, Muscidae) and Dermestes ater (Coleoptera, Dermestidae)

Nesticodes rufipes is widely distributed in tropical and subtropical regions, being strongly associated with humans. However, few behavioral and ecological studies have investigated interspecific interactions between these spiders and insects of medical and veterinary importance. Here, we have investigated prey choice by N. rufipes when two different prey species, Musca domestica and Dermestes ater, were offered simultaneously. We also quantified the capture of these prey types by this predator in a poultry house and analyzed the association between prey-choice with physical characteristics of the prey. Finally, we discuss whether there is an antagonistic intraguild interaction in such a system composed of N. rufipes (top predator), D. ater (predator of larvae of M. domestica and prey of N. rufipes) and M. domestica (N. rufipes' prey). We found that Musca domestica were more abundant than D. ater in N. rufipes webs in the poultry house. Spiders given a choice of adults of M. domestica plus adults of D. ater, and also on adults plus larvae of M. domestica, preyed more on adult flies than on the other prey types. This preference was probably associated with the lesser mass and shorter lengths of adult flies. Our experiments demonstrated that the predation impact of N. rufipes on D. ater is low when compared to M. domestica. This result provides evidence that an antagonistic interaction between these predators does not occur, suggesting that they are in fact acting either synergistically or additively on M. domestica prey.

Prey choice by facultative predator larvae of Chrysomya albiceps (Diptera: Calliphoridae)

In this study we investigated predation rates on third instar larvae of Chrysomya putoria and C. megacephala by third instar larvae of C. albiceps in a two-choice situation. The highest predation rate occurred on C. putoria larvae and this result is compared to previous experiments, in which C. macellaria larvae were present. Our results suggest that, when C. macellaria is absent C. albiceps larvae attack more C. putoria than C. megacephala larvae. Prey choice decisions and its implications for introduced and native blowflies are discussed.

Ultra-structure and histochemistry of digestive cells of Podisus nigrispinus (Hemiptera: Pentatomidae) fed with prey reared on bt-cotton

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Foraging Behavior of the Swarm-Founding Wasp, Polybia (Trichothorax) sericea (Hymenoptera, Vespidae): Prey Capture and Load Capacity

The main component of the protein diet of P. sericea was larvae of Lepidoptera (75.38%), with predominance of the following Families: Noctuidae (30.99%), Hesperiidae (19.01%); Pyralidae (19.01%) and Nymphalidae (11.98%). The average weight of the prey captured was 14.2 mg, a value equivalent to 24.7% of the average wasp weight. The average glucidic food load was 28.61 mg, corresponding to approximately half the wasp weight (49.64%). The weight of the load transported in the crop varied according to the food density, which, in turn, influenced the time spent in its collection (Pearson: n=64; r=0.64;p<0.05). Polybia sericea showed predatory interactions against Lepidopteran caterpillars, who are known to be agricultural pests. P. sericea has potential to be used in Integrated Pest Management.

Geographic variation in the size of mammalian prey taken by White-tailed Kites in the Americas

I examined the size of small mammal prey taken by White-tailed Kites (Elanus leucurus) in the Americas from data obtained in the literature and unpublished material from southern Brazil. Mean weight of adult small mammal prey in the kite's diet ranged between 19.5 and 64.2 g. Mammalian prey taken weighed between 2 and 53% of the kite's body weight. Although the White-tailed Kite is a small mammal specialist, in relation to the size of prey taken, this raptor can be considered a generalist hunter.

Foot-trembling behavior in Semipalmated Plover Charadrius semipalmatus reveals prey on surface of Brazilian beaches

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of Prey Size on the Predatory Behavior of Ectatomma brunneum (Hymenoptera: Formicidae) Under Laboratory Conditions

The influence of prey size on the predatory behavior and behavioral sequence of Ectatomma brunneum under laboratory conditions was evaluated. Two behaviors were characterized: rejection and attack, the latter divided into individual and group attack. In the group attack, prey transport (Tenebrio molitor larvae) into the nest prevailed, whether immobilized as a consequence of the ant venom or not. on the other hand, in the individual attacks such behavior was not observed. There was no significant relation between the predatory behavior and the size of the larvae offered, indicating that prey dimensions do not interfere with predation. The high rejection rates registered in the experimental trials may have been a consequence of the absence of immatures in the nests used in the research and/or the decrease in the activities observed, considering that the experiments were carried out in the coldest time of the year.

Habitat associations of small mammals in southern Brazil and use of regurgitated pellets of birds of prey for inventorying a local fauna

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

The effect of gastric dilatation in rats submitted to gasified water ingestion under the hepatic metabolic function

INTRODUÇÃO: O excesso de peso na população aumentou de forma significante nas últimas décadas e as bebidas gasosas tornaram-se um fator ambiental importante no comportamento alimentar das pessoas, sendo os EUA, México e Brasil, nesta ordem, os três maiores paises produtores e consumidores de refrigerantes. OBJETIVO: Investigar os efeitos da dilatação gástrica em ratos submetidos a ingestão de água gaseificada, veículo uniforme para todos os refrigerantes, sobre parâmetros metabólicos da função hepática. MÉTODOS: Foram constituídos dois grupos de 15 ratos acompanhados por 15 semanas. Ao Grupo-I, foram oferecidos 200 g/dia de ração ad libitum e 100 ml de água não gaseificada em 3 períodos diários, ao Grupo-II, foram oferecidos 200 g/dia de ração ad libitum e 100 ml de água gaseificada em 3 períodos diários; em cada grupo,foram calculados a média (x) e o desvio padrão (s); para todos os atributos estudados foi utilizado o método estatístico de teste t pareado, comparando-se GI com GII, testando-se o efeito dos tipos de água. RESULTADOS: Os resultados identificaram que os animais que foram submetidos ao tratamento com água gaseificada (Grupo-II), apresentaram um aumento de transaminase glutâmica pirúvica (TGP) e fosfatase alcalina p<0,01), tendência de aumento da transaminase glutâmica oxalacética (TGO) (0,10>p>0,05) e aumento da área gástrica com alterações morfológicas macroscópicas como o desaparecimento do pregueamento mucoso característico. CONCLUSÃO: A água gaseificada favoreceu o aumento da área gástrica com conseqüente desaparecimento macroscópico do pregueamento mucoso do órgão, que ocasionou alterações metabólicas da função hepática.