Biology of the immature stages of Strymon crambusa (Lycaenidae, Theclinae) on Oxalidaceae

ABSTRACT We document the biology and morphology of the egg, caterpillar, and pupa of Strymon crambusa (Hewitson, 1874), a Neotropical Eumaeini. In the Cerrado, the caterpillar feeds on the inflorescences and leaves of Oxalis L. S. crambusa has four larval instars, all of which are illustrated. The density of caterpillars on plants is higher than that recorded for leaf-feeding caterpillars and other flower-feeding Eumaeini, which suggests that the species is a specialist on Oxalidaceae in the Cerrado.

Timeline and geographical distribution of Helicoverpa armigera (Hübner) (Lepidoptera, Noctuidae: Heliothinae) in Brazil

ABSTRACT This study presents registers of Helicoverpa armigera (Hübner) occurrence to assess its spatial and temporal distribution in Brazil. We used data from collections, especially from the Southern Region, systematic collections in Rio Grande do Sul, occasional collections of caterpillars and adults in different regions of Brazil, as well as literature registers. We conclude that the introduction of H. armigera in Brazil probably occurred before October 2008. We also register that in August 2012 H. armigera was already present from the extreme southern part (Rio Grande do Sul) to the extreme northern part (Amapá) of Brazil.

Microbial alterations of the soil influenced by induced compaction

Compaction is one of the most destructive factors of soil quality, however the effects on the microbial community and enzyme activity have not been investigated in detail so far. The objective of this study was to evaluate the effects of soil compaction caused by the traffic of agricultural machines on the soil microbial community and its enzyme activity. Six compaction levels were induced by tractors with different weights driving over a Eutrustox soil and the final density was measured. Soil samples were collected after corn from the layers 0-0.10 and 0.10-0.20 m. The compaction effect on all studied properties was evident. Total bacteria counts were reduced significantly (by 22-30 %) and by 38-41 % of nitrifying bacteria in the soil with highest bulk density compared to the control. On the other hand, fungi populations increased 55-86 % and denitrifying bacteria 49-53 %. Dehydrogenase activity decreased 20-34 %, urease 44-46 % and phosphatase 26-28 %. The organic matter content and soil pH decreased more in the 0-0.10 than in the 0.10-0.20 m layer and possibly influenced the reduction of the microbial counts, except denitrifying bacteria, and all enzyme activities, except urease. Results indicated that soil compaction influences the community of aerobic microorganisms and their activity. This effect can alter nutrient cycling and reduce crop yields.

Field Evaluation of Compaction Monitoring Technology: Phase II Volumes 1 and 2, TR-495, 2006

This report documents an extensive field program carried out to identify the relationships between soil engineering properties, as measured by various in situ devices, and the results of machine compaction monitoring using prototype compaction monitoring technology developed by Caterpillar Inc. Primary research tasks for this study include the following: (1) experimental testing and statistical analyses to evaluate machine power in terms of the engineering properties of the compacted soil (e.g., density, strength, stiffness) and (2) recommendations for using the compaction monitoring technology in practice. The compaction monitoring technology includes sensors that monitor the power consumption used to move the compaction machine, an on-board computer and display screen, and a GPS system to map the spatial location of the machine. In situ soil density, strength, and stiffness data characterized the soil at various stages of compaction. For each test strip or test area, in situ soil properties were compared directly to machine power values to establish statistical relationships. Statistical models were developed to predict soil density, strength, and stiffness from the machine power values. Field data for multiple test strips were evaluated. The R2 correlation coefficient was generally used to assess the quality of the regressions. Strong correlations were observed between averaged machine power and field measurement data. The relationships are based on the compaction model derived from laboratory data. Correlation coefficients (R2) were consistently higher for thicker lifts than for thin lifts, indicating that the depth influencing machine power response exceeds the representative lift thickness encountered under field conditions. Caterpillar Inc. compaction monitoring technology also identified localized areas of an earthwork project with weak or poorly compacted soil. The soil properties at these locations were verified using in situ test devices. This report also documents the steps required to implement the compaction monitoring technology evaluated.

Herbivory in the previous generation primes plants for enhanced insect resistance.

Inducible defenses, which provide enhanced resistance after initial attack, are nearly universal in plants. This defense signaling cascade is mediated by the synthesis, movement, and perception of jasmonic acid and related plant metabolites. To characterize the long-term persistence of plant immunity, we challenged Arabidopsis (Arabidopsis thaliana) and tomato (Solanum lycopersicum) with caterpillar herbivory, application of methyl jasmonate, or mechanical damage during vegetative growth and assessed plant resistance in subsequent generations. Here, we show that induced resistance was associated with transgenerational priming of jasmonic acid-dependent defense responses in both species, caused caterpillars to grow up to 50% smaller than on control plants, and persisted for two generations in Arabidopsis. Arabidopsis mutants that are deficient in jasmonate perception (coronatine insensitive1) or in the biogenesis of small interfering RNA (dicer-like2 dicer-like3 dicer-like4 and nuclear RNA polymerase d2a nuclear RNA polymerase d2b) do not exhibit inherited resistance. The observation of inherited resistance in both the Brassicaceae and Solanaceae suggests that this trait may be more widely distributed in plants. Epigenetic resistance to herbivory thus represents a phenotypically plastic mechanism for enhanced defense across generations.

the Gypsy Moth, September 2000

The Gypsy moth is a serious pest of trees ans shrubs. It damages the plants when the caterpillar stage eats the leaves. When there are many caterpillars, They defoliate entire trees, which can weaken and sometimes kill the trees. The gypsy moth is a notorious hitchhiker; it has been brought into Iowa on recreations vehicles and nursery stock. Learning the recognize the gypsy moth is an important part of preventing infestations and severe damage to Iowa's forests, woodlands, and urban landscapes.

Identity and combinations of arbuscular mycorrhizal fungal isolates influence plant resistance and insect preference

1. Accumulating evidence indicates that plant resistance against above-ground herbivores can be affected by the presence of arbuscular mycorrhizal fungi (AMF) in association with the host plant. Little is known, however, about how AMF composition can influence herbivore choice to feed on a particular plant. 2. Unravelling the preference-performance hypothesis in a multitrophic context is needed to expand our knowledge of complex multitrophic interactions in natural systems. If given mycorrhizal fungal genotypes increase attractiveness for a herbivore (reduced plant resistance), then the benefits of increased unpalatability provided by the mycorrhizal fungi (increased plant resistance) might be outweighed by the increased herbivore recruitment. 3. This was addressed by designing three experiments to test the effects of different AMF genotypes, inoculated either alone or in combination, to measure intraspecific AMF effects on plant resistance and insect herbivore preference. Using strawberry (Fragaria vesca L.) plants that were colonised by eight different combinations of Rhizophagus irregularis isolates, we measured effects on plant growth, insect growth and survival, as well as feeding preferences of a generalist herbivore caterpillar (Spodoptera littoralis Boisduval). 4. Overall, it was found that: (i) AMF influenced plant resistance in an AMF genotype-specific manner; (ii) some AMF inoculations decreased insect performance; (iii) insects preferentially chose to feed more on leaves originating from non-mycorrhizal plants; but also that (iv) in a whole plant bioassay, insects preferentially chose the biggest plant, regardless of their mycorrhizal status. 5. Therefore, AMF-mediated trade-offs between growth and resistance against herbivores have been shown. Such trade-offs, particularly driven by plant attractiveness to herbivores, buffer the positive effects of the mycorrhizal symbiosis on enhanced plant growth.

Field Evaluation of Compaction Monitoring Technology: Phase I, 2004

This Phase I report describes a preliminary evaluation of a new compaction monitoring system developed by Caterpillar, Inc. (CAT), for use as a quality control and quality assurance (QC/QA) tool during earthwork construction operations. The CAT compaction monitoring system consists of an instrumented roller with sensors to monitor machine power output in response to changes in soil machine interaction and is fitted with a global positioning system (GPS) to monitor roller location in real time. Three pilot tests were conducted using CAT’s compaction monitoring technology. Two of the sites were located in Peoria, Illinois, at the Caterpillar facilities. The third project was an actual earthwork grading project in West Des Moines, Iowa. Typical construction operations for all tests included the following steps: (1) aerate/till existing soil; (2) moisture condition soil with water truck (if too dry); (3) remix; (4) blade to level surface; and (5) compact soil using the CAT CP-533E roller instrumented with the compaction monitoring sensors and display screen. Test strips varied in loose lift thickness, water content, and length. The results of the study show that it is possible to evaluate soil compaction with relatively good accuracy using machine energy as an indicator, with the advantage of 100% coverage with results in real time. Additional field trials are necessary, however, to expand the range of correlations to other soil types, different roller configurations, roller speeds, lift thicknesses, and water contents. Further, with increased use of this technology, new QC/QA guidelines will need to be developed with a framework in statistical analysis. Results from Phase I revealed that the CAT compaction monitoring method has a high level of promise for use as a QC/QA tool but that additional testing is necessary in order to prove its validity under a wide range of field conditions. The Phase II work plan involves establishing a Technical Advisor Committee, developing a better understanding of the algorithms used, performing further testing in a controlled environment, testing on project sites in the Midwest, and developing QC/QA procedures.

Recognition of insect eggs in Arabidopsis modulates defense responses

Plants activate direct and indirect defenses in response to insect egg deposition. In Arabidopsis thaliana, oviposition by the butterfly Pieris brassicae triggers cellular and molecular changes that are similar to the changes caused by biotrophic pathogens. Even though this innate immune response did not affect egg survival in Arabidopsis, we could show that different insect eggs elicit specific gene expression changes. Additionally, egg- induced necrosis could be observed in a variety of plants from different families ranging from dicotyledonous plants to monocots, suggesting that insect-egg detection by plants is a widespread mechanism and that different insect species contain elicitors of immune responses. Extracts from caterpillars and eggs contain elicitors that co-purified over several extraction steps. Chemical fractionation of caterpillar extracts lead to the characterisation of an active compound that was determined to be a triglyceride by NMR analysis. The exact structure of the side chains as well as the elicitor's presence in insect eggs have yet to be confirmed.We also found that the plant defense signal salicylic acid (SA) accumulates at the site of oviposition. This is unexpected, as the SA pathway controls the defense against fungal and bacterial pathogens whereas it negatively interacts with the jasmonic acid (JA) pathway, which is crucial for the defense against herbivores. Application of P. brassicae or Spodoptera littoralis egg extract onto leaves reduced the induction of insect-responsive genes after challenge with caterpillars, suggesting that egg-derived elicitors suppress plant defense. Consequently, larval growth of the generalist herbivore S. littoralis, but not of the specialist P. brassicae, was significantly higher on plants treated with egg extract than on control plants. In contrast, suppression of gene induction and enhanced S. littoralis performance were not found in the SA-deficient mutant sid2-l, indicating that SA mediates this phenomenon. These data reveal an intriguing facet of the crosstalk between SA- and JA-signalling pathways and suggest that insects have evolved a way to suppress the induction of defense genes by laying eggs that release elicitors. Additionally, we demonstrated that mutants of known crosstalk regulators, including nprl-1, tga2356, ein2-l and wrky70-l, are not affected in egg-induced suppression of herbivore defenses. JA treatment was not able to alleviate this SA/JA negative crosstalk, suggesting that this suppression operates through a novel mechanism downstream of JA biosynthesis.

Hitsaavan tuotannon kehittäminen pyöräkuormainkaivureita valmistavassa yrityksessä

Diplomityössä käsitellään pyöräkuormainkaivureita valmistavan yrityksen konepajatuotannon kehittämistä aihiovalmistuksen, hitsauksen ja koneistuksen osalta. Pääpaino kehittämistoimissa on hitsauksessa. Lähtökohtana tuotannonkehittämisen tarpeelle ovat tuotannon kasvu, kustannustehokkuuden lisääminen sekä pula ammattitaitoisesta työvoimasta. Diplomityössä selvitetään yrityksen vanhan konekannan päivittämismahdollisuuksia ja säästöjen hakemista tehokkaampia valmistusmenetelmiä käyttöönottamalla. Pohjatyönä tulevaisuuden tuotannon tehostamiselle selvitettiin nykyiset valmistuskustannukset. Työajankäytön historiatiedot löytyivät yrityksen tietojärjestelmästä, joita tarkennettiinkentältä kerätyin tiedoin. Myös koneiden käyttökustannukset tuntihinnat eri työvaiheille. selvitettiin ja näin saatiin määritettyä Lännen Tractors Oy:lle löytyi hitsaavassa tuotannossa kehitystoimenpiteitä, mitkä tekemällä voidaan tuotantoa tehostaa ilman investointeja. Tuotannon kehittäminen jaettiin kahteen vaiheeseen: 1. vaihe, missä ei investoida vaan keskitytään nykyisten menetelmien kehittämiseen ja vanhojen koneiden tehokkaampaan hyödyntämiseen ja 2.vaihe, missä tarkastellaan mahdollisten investointien kannattavuutta sekä selvitetään alihankinnan mandollisuutta. Tuotannon tehostamisen 1. vaiheen toimenpiteillä saadaan hitsauskustannuksia pienennettyä jopa 20 %. 2. vaiheen oman tuotannon tehostamiseksi koneistuksen eri tehtiin investointilaskelmat robottihitsaussolun ja vaihtoehtojen takaisinmaksuajasta sekä sisäisestä korkokannasta. Uuden robottihitsaussolun takaisinmaksuaika on n. 3 vuotta. Näiden laskelmien perusteella mahdollisuudet valmistaa komponentteja taloudellisesti. investoinneilla voidaan pyöräkuormainkaivureiden saavuttaa hitsattuja

Creació d’un programa informàtic per al monitoratge dels paràmetres de treball i a l’ajut al guiatge d’un tractor agrícola

L’objectiu projecte és desenvolupar un sistema d’ajut al guiatge universal adaptable a qualsevol vehicle que permeti incrementar significativament l’eficiència de les feines a realitzar per la maquinària al camp. El sistema proposat es pot configurar d’acord amb les característiques de la maquinària o de la tasca a realitzar i és capaç de guiar en línia recta i crear paral·leles a la passada recta de referència. Un altre objectiu és millorar el rendiment, la fiabilitat i la usabilitat del programari de monitoratge inicial instal·lat al tractor, com també caracteritzar el receptor GPS AgGPS 332 de Trimble® per a comprovar la precisió de l’aparell. Els resultats obtinguts en la millora del programa de monitoratge són molt satisfactoris a l’haver corregit imprecisions de funcionament que en limitaven l’usabilitat. Els resultats obtinguts en la caracterització del receptor AgGPS 332 permeten valorar millor quin tipus de correcció diferencial és més convenient per a la precisió de treball requerida segons el seu cost de posada en marxa i de funcionament.Els resultats obtinguts en la validació de l’ajut al guiatge, han validat el guiatge a 10 metres vista com un ajut al guiatge equivalent al guiatge manual quan la velocitat de treball és de 5 km/h, el tractorista té referències visuals i no està fatigat. Els resultats obtinguts pels guiatges a 3 i 50 metres no són satisfactoris a 5 km/h. Tanmateix, durant el procés de disseny, la realització dels assajos i durant l’anàlisi de resultats s’han identificat algunes mancances i limitacions i es proposen una sèrie de millores per tal de solucionar-les.

Criterios para la selección del tractor frutero

La selección del tractor más adecuado para una determinada explotación frutícola requiere considerar dos aspectos fundamentales. En primer lugar, el fruticultor debe valorar la conveniencia económica de la adquisición frente a la posibilidad de contratar a empresas de servicios (sino en todas, sí para aquellas operaciones de mayor coste); en segundo lugar, la potencia del tractor deberá ser coherente en relación a las máquinas agrícolas que se le acoplen.

Nuevos neumáticos para tractores agrícolas

El neumático agrícola condiciona de forma determinante el rendimiento del tractor. Es necesario, por tanto, que el agricultar conozca las prestaciones de los neumáticos actuales. Ello le permitirá elegir el equipamiento más adecuado a sus necesidades.

Tractores especiales: viñeros y fruteros

A la hora de adquirir un tractor el viticultor y el fruticultor han de tener en cuenta sus necesidades, las características técnicas de la máquina y la utilidad de las innovaciones tecnológicas del mismo.

Occurrence and biology of Tolype innocens (Burmeister) on blueberry

Tolype innocens (Burmeister, 1878) is reported for the first time damaging blueberry (Vaccinium ashei) plants in Brazil having the caterpillars feeding on leaves and new shoots. T. innocens biology was studied on blueberry leaves in laboratory conditions and then a fertility life table was elaborated. Developmental time and viability of egg, larval and pupal stages and egg-adult period were 15.0 and 35.3, 33.3 and 84.5, 20.6 and 100, and 69.2 days and 45%, respectively. Average pupal weight was 0.840g for the females and 0.580g for the males. The sex ratio was 0.5. Pre-oviposition and oviposition time lasted 6.34 and 12.1 days, respectively. Mean fecundity was 251 eggs per female. Eggs were laid either individually or in masses. Longevity was 19.0 and 20.0 days for males and females, respectively. T. innocens population increased 47 times per generation, with a mean generation time of 77 days, and a finite rate of increase of 1.02. This data on biological parameters will be useful for establishing control strategies.