415 research outputs found
Preliminary Observations on Zelus Obscuridorsis (Stål) (Hemiptera: Reduviidae) as Predator of the Corn Leafhopper (Hemiptera: Cicadellidae) in Argentina
The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae), is an important corn pest in most of tropical and subtropical America. This leafhopper has a rich natural enemy complex of which parasitoids and pathogens are the most studied; knowledge on its predators is limited. We noted the presence of the native assassin bug Zelus obscuridorsis (Hemiptera: Reduviidae) predating diverse motile insects, including the corn leafhopper, on corn plants cultivated in household vegetable gardens in San Miguel de Tucumán (Argentina); in order to verify its predatory actions, we exposed lab-bred individuals of D. maidis to adults of Z. obscuridorsis. The predators were starved for 24 h before trials in which the corn leafhopper in different developmental stages were exposed. Zelus obscuridorsis is highly skilled in catching specimens in motion, but it was not able to prey on eggs. The predator was capable to catch and prey on nymphs and adults.Fil: Virla, Eduardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Melo, María Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Speranza, Stefano. Universita Degli Studi Della Tuscia; Itali
Biological Control of Hazelnut Weevil (Curculio nucum L., Coleoptera, Curculionidae) Using the Entomopathogenic Fungus Beauveria bassiana (Balsamo) Vuill. (Deuteromycotina, Hyphomycetes)
The need to biologically control phytophagous insects has led researchers to
consider using microorganisms to control insect pests in the field. On this basis, we decided to conduct field tests to determine the effectiveness of a commercial product made of Beauveria bassiana (Bals.) against the key hazelnut pest Curculio nucum L. Trials were carried out in a hazelnut orchard in the province of Viterbo (Italy). Three untreated control cages and three cages treated with the fungus entomopathogens were used during the tests. The cages were located under the hazelnut canopy and buried to half their height. 200 mature C. nucum larvae were placed in each cage and allowed to burrow naturally. After the larvae had buried themselves, a commercial product was applied to the three treated cages. Mortality was monitored during the following spring. The treated cages showed 99.5% C. nucum mortality as opposed to 63.5% for the untreated cages. These data show the effectiveness of the B. bassiana biological control on key insect pests for hazelnut trees in central Italy.Research partially financed by Mi.P.A.F. Project “Studio e ottimizzazione della filiera coricola dell’area Cimino-Sabatina” D.M. 564/7303 10/11/2003
First Record of Zelus obscuridorsis (Hemiptera: Reduviidae) as a Predator of the South American Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae)
The South American tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a Neotropical key pest of tomato in South America, and in recent years, it has become established in Europe and Africa. Recently we found the native true bug, Zelus obscuridorsis (Stål, 1860) (Hemiptera: Reduviidae), predating diverse mobile insects in household vegetable gardens located in northwestern Argentina. We found that Z. obscuridorsis preys on mobile stages of T. absoluta, i.e., free larvae and adults but not on larvae in their mines, pupae or eggs. This is the first record of a Zelus species as predator of T. absoluta. We discuss the importance of this predator consuming only mobile items, in terms of using little exploited host niches, and its possible relationships with other antagonistic species of T. absoluta.Fil: Speranza, Stefano. Universita Degli Studi Della Tuscia; ItaliaFil: Melo, María Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Luna, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Virla, Eduardo Gabriel. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Systematic Creativity Tools for Product Concept Generation: Evaluation of Learning Experiences in Engineering Design Education
This study considers the use of systematic creativity tools for concept generation belonging to C-K theory and TRIZ, in addition to traditional ones used for product development. The aim of this study is twofold. On one hand, it aims to contribute to the improvement of the creative and innovation skills of engineering students and designers in general by the introduction of specific creativity enhancement tools. On the other hand, it proposes a method for evaluating the training and learning outcomes of the students involved in the courses based on Kirkpatrick\u2019s Four Levels of Evaluation and used a questionnaire to collect students' answers and opinions. This way, some practical cases are carried on and two of these are presented in detail: one concerning the ideation of a new kind of gym towel and one concerning the analysis of a knee implant for total knee replacement surgery for possible improvements. The questionnaire results show that students considered the training and learning experiences and the use of the two new methods in a positive way. In particular, TRIZ method represents the most appreciated at all, while C-K theory is revealed as the newest one and very promising for the students\u2019 future professional development
Alternative animal protein sources for aquaculture: a preliminary study on nutritional traits of Mediterranean brocade (Spodoptera littoralis, Boisduval) larvae
In formulating diets for farmed aquatic species, the main ingredi- ent used is fish meal (FM). Due to the growth that aquaculture is experiencing throughout the world, the increasing demand of feeds is resulting in a FM price increase that represents an eco- nomic limit for fish farming. The need to seek protein sources alternative to FM is a matter of great interest. Among others, the use of insect larvae as feed for fish represents an interesting alter- native. The aim of this study was to evaluate the nutritional traits of mediterranean brocade larvae (Spodoptera littoralis Bois.) in view of their possible use as feedstuffs for rainbow trout. A sample of mediterranean brocade larvae (MBL) (VI instar) and one of pupae (MBP) were assayed for fat (EE), ash (ASH) and crude pro- tein (CP) contents by conventional methods. Amino-acidic profile was obtained by HPLC on sample hydrolysates. Relative digestibil- ity of protein (RDP) was estimated by the Lazo (1988) method. Data, expressed on DM basis, were compared with those of a com- mercial feed (CF). The fat content of MBL was lower than that recorded for CF (9.4% vs 13.6%) while MBP showed a very high value (30.3% DM). Ashes in MBL (7.7%) and MBP (6.7%) were lower than in the CF (10.9%). The CP content of MBL (44.3%) was slightly higher than the CF (40.0%) but lower than in MBP (59.1%). The RDP of MBL and MBP were about a half of the value observed in CF (27.2%). Both MBL and MBP showed a lower per- centage of essential amino acids (AA) (35.8%, 36.8%) compared to CF (39.4%) even if the AA profiles were in line with the require- ments found in literature for rainbow trout. In conclusion, these preliminary results suggest that preimaginal stages of S. littoralis may be of interest in fish feeding, though more exhaustive studies have to be performed to fully assess their use as alternative for fish meal
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