163 resultados para Caterpillars
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Many small firms increasingly operate in markets under siege from new entrants who exploit the technologies associated with the Internet's World Wide Web (the web). In these circumstances, interpreting the operating environment is like a vu jade, the opposite of deja vu, a time in space where they have never been, have no idea what they are doing and who it is that could help them. Through the use of the story of the Caterpillar and the Butterfly, this paper considers the inherent difficulties faced by small firms considering the prospect of becoming an e-firm. When considered from an evolutionary perspective, the journey from small firm to small e-firm is not seen as one of choice, but rather one of necessity. In such markets, a race currently appears to exist between entrepreneurs exploiting the web's technologies, and the process of natural selection acting upon firms whose routines have lost favour.
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Is childhood valuable? And is childhood as, less, or more, valuable than adulthood? In this essay I first delineate several different questions that we might be asking when we think about the ‘value of childhood’, and I explore some difficulties of doing so. I then focus on the question of whether childhood is good for the person who experiences it. I argue for two key claims. First, if childhood wellbeing is measured by the same standards as adulthood, then children are worse off than adults. Second, if childhood and adulthood wellbeing are measured by different standards, then we cannot compare them, and children are neither better off nor worse off than adults. This has some counter-intuitive implications, such as we do not harm persons by depriving them of a childhood, nor by keeping them as children for elongated periods.
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Ecosystem engineers are organisms that change the physical structure of environments and provide habitats for other organisms. Lepidopteran caterpillars may act as ecosystem engineers by rolling leaves as shelters to complete metamorphosis. After being abandoned, these structures may provide shelter for other organisms. In this study, the influence of leaf-rolling caterpillars on tropical mite communities was reported. Expanded leaves and leaves rolled by larvae and also developed field experiments using leaves rolled manually with different shapes and sizes (i.e. different architectures) in different seasons were surveyed (dry and rainy). While the abundance and diversity of predatory mites were higher in rolled leaves, the abundance of phytophages decreased in these leaves. Species composition differed between rolled and expanded leaves. The structure of shelters affected the distribution of predatory mites, with higher abundances found on funnel-shaped leaves. Predatory mites only benefited from the rolled leaves in the dry season. This is the first study showing (i) the contrasting effects of ecosystem engineers on microarthropod communities, favouring some feeding guilds and inhibiting others; (ii) that the shape of rolled leaves has variable effects on mite communities; and (iii) that facilitation was temporally dependent, i.e. occurred only in the dry season. © 2013 The Royal Entomological Society.
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Ficus benjamina L. (Moraceae) is an exotic ornamental plant in Brazil. The aim of this study was to identify a defoliator and its parasitoid on F. benjamina plants in Vicosa, Minas Gerais, Brazil and to determine the number of pupae and the emergence of lepidopteran and a dipteran. Four Halysidota sp. (Lepidoptera: Arctiidae) groups, with 158, 144, 137 and 129 last-instar caterpillars aggregated on the trunks of 4 F. benjamina trees. These caterpillars were collected, held in plastic containers with ficus leaves until development and emergence were completed. Adults of 1 undescribed lepidopteran species (Halysidota) and 1 dipteran species [Belvosia (Tachinidae)] emerged from the Halysidota pupae. An average of 118 viable Halysidota pupae per group were formed, and an average of 62.5 Belvosia individuals emerged from these host pupae per Halysidota group. From a grand total of 472 Halysidota pupae only one adult emerged. Halysidota sp. damaged F. benjamina plants in Vicosa, Minas Gerais, Brazil, but this defoliator was parasitized by Belvosia sp. The findings reported here indicate that Belvosia sp. appears to have the potential to reduce populations of Halysidota sp. and possibly protect F. benjamina in ornamental plantings.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In order to succeed in biological control programs, not only is it crucial to understand the number of natural enemies to be released but also on how many sites per area this releasing must be performed. These variables might differ deeply among egg parasitoid species and crops worked. Therefore, these trials were carried out to evaluate the parasitism (%) in eggs of Anticarsia gemmatalis and Pseudoplusia includens after the release of different densities of the egg parasitoid Trichogramma pretiosum. Field dispersal was also studied, in order to determine appropriate recommendations for the release of this parasitoid in soybean fields. The regression analysis between parasitism (%) and densities of the parasitoid indicated a quadratic effect for both A. gemmatalis and P. includens. The maximum parasitism within 24 h after the release was reached with densities of 25.6 and 51.2 parasitoids per host egg, respectively, for the two pests. Parasitism of T. pretiosum in eggs of P. includens decreased linearly as the distance of the pest eggs from the parasitoid release sites increased. For P. includens, the mean radius of T. pretiosum action and the area of parasitoid dispersal in the soybean crop were 8.01 m and 85.18 m(2), respectively. We conclude that for a successful biological control program of lepidopteran pests using T. pretiosum in soybean fields, a density of 25.6 parasitoids per host egg, divided into 117 sites per hectare, should be used.
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Mode of access: Internet.
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"November 1997."
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When I was seven I worked on a science project about caterpillars and moths. I was completely immersed in this project, fascinated by caterpillar body markings, the rhythmical, semi-circular pattern caterpillars adopt to eat leaves, their spiral construction of the chrysalis, and their transformation into moths or butterflies. I demonstrated my fascination, my research and study through carefully executed and detailed drawings. I could read and write well, but I wasn’t as interested in writing and produced a half-page summary to support my visual work.
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The host location behaviour of foraging caterpillars has received little attention, despite the wealth of theoretical and empirical studies that have been directed at this behavioural trait in adult Lepidoptera. Here, we study caterpillars of the moth Heliothis punctifera Walker (Lepidoptera: Noctuidae), which inhabits the arid inland desert areas of Australia. Caterpillars of this species consume many flowerheads before completing development and can be observed moving across the sand in search of new hosts. Consequently, if host location behaviour favours attraction to certain plant species, it might be expected to influence the distribution and abundance of caterpillars in the field. We present field data showing that H. punctifera caterpillars are unevenly distributed throughout mixed patches of two of its host species, with a higher abundance on Senecio gregorii F. Muell., the annual yellow top, compared to Myriocephalus stuartii (F. Muell. & Sond.) Benth., the poached egg daisy (both Asteraceae). Using laboratory studies, we test whether this distribution may, in part, be due to host location behaviour of caterpillars. Our results show that caterpillars exhibit a preference for locating S. gregorii in their pre- and post-contact foraging behaviour. In addition, our results provide evidence that feeding history plays a role in host location behaviour in this insect. We propose that key features of the desert environment and the ecology of H. punctifera would favour adaptations to host location behaviour by immatures.
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The early years are significant in optimising children’s educational, emotional and social outcomes and have become a major international policy priority. Within Australia, policy levers have prioritised early childhood education, with a focus on program quality, as it is associated with lifelong success. Longitudinal studies have found that high quality teacher-child interactions are an essential element of high quality programs, and teacher questioning is one aspect of teacher-child interactions that has been attributed to affecting the quality of education, linking open ended questioning to higher cognitive achievement. Teachers, however, overwhelmingly ask more closed than open questions. In the classroom, like everyday interaction, questions in interaction require answers. They are used to request, offer, repair, challenge, seek agreement (Curl & Drew, 2008; Enfield, Stivers, & Levinson, 2010; Hayano, 2013; Schegloff, 2007). Teachers use questions to set agendas and manage lessons (McHoul, 1978; Mehan, 1979; Sacks, 1995), and to gauge students’ knowledge and understanding (Lerner, 1995; McHoul, 1978; Mehan, 1979). Drawing on data from the Australian Research Council project Interacting with Knowledge: Interacting with people: Web searching in early childhood, this paper focuses on an extended sequence of talk between a teacher with two students aged between 3.5 and 5 years in a preschool classroom. The episode, drawn from a corpus of over 200 hours of video recorded data, captures how the teacher and children undertake an online search for images of lady beetles and hairy caterpillars on the Web. Ethnomethodological and conversation analysis approaches examine how the teacher asks questions, which call on the children to display their factual knowledge about the search topic. The fine grained analysis shows how teachers design their interactions to prompt children’s displays of factual knowledge, and how the design of factual questions affect a student’s response in terms of what and how they respond. In focussing on how the teacher designs factual questions and how children respond to these questions it shows that question design can close down a student’s reply; or elicit a range of answers, from one word to extended more detailed responses. Understanding how the design of teachers’ questions can influence students’ responses has pedagogic implications and may support educators to make intentional decisions regarding their own questioning techniques.
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[Excerpt] Martha Smith said goodbye to her long withstanding career as Associate Director of ILR’s Office of Career Services. Smith earned a B.S. in Business Administration from California State University, Hayward in 1969. In 1976, she came to Ithaca when her husband was a Ph.D. student at Cornell, and in 1978 Smith became a temporary assistant to Professor Larry Williams. Shortly after, Smith was offered a permanent position in the Office of Career Services where she advised and befriended students for over 26 years. After retiring, Smith plans to devote more time to her community and her church. When reflecting upon her career of assisting and nurturing in the development of ILR students, Smith said, "They come in as caterpillars; they evolve, and then they leave as butterflies. They have to learn to be students, it isn’t always easy Martha Smith but they always manage. As they open up we all learn that we are more alike than we are different and together we learn to appreciate the likenesses and the differences."