The Use of Spider Silk in the Nests of Small Birds, With Particular Reference to the Chaffinch (Fringilla coelebs)

A very wide range of smaller passerine birds employ silk, from spiders and other arthropods, as a nesting material. The nest is an important feature of bird breeding behaviour, success being dependent in part upon the structure of the nest and the timing of construction of the nest. Spiders can spin many different types of silk, with varying properties, but all spider silks are remarkably strong and extensible. In addition, web silk is adhesive and represents a renewable resource. This study has shown that the chaffinch uses spider web and cocoon silk. Cocoon silk attaches lichen to the outside of the nest, and holds together the moss structure. Web silk is used in more general roles, and usually to a lesser extent; it appears to be an all purpose bonding material, attaching a range of materials to the outside of the nest, and binding together other structural materials. Web silk is also used to attach the nest to the twigs of the bush or tree in which it is built. Using scanning electron microscopy, it has not been possible to identify with any certainty the spider families which spin the cocoon silk used, but all web silk found in chaffinch nests appears to belong to the family Amaurobiidae. These webs are spun flat against rough tree bark and on fences etc. , and trap insects by entangling them in extremely fine fibrils. The amount of this silk present at Garscube Estate, on the edge of Glasgow, starts to rise just before the onset of chaffinch nest building. It is proposed that nest-building is not restricted in location by the availability of this common silk-type, but the birds may be prevented from building earlier in the season by a lack of these webs in the environment. However, the use of silk appears to enable them to breed in areas where the sites and materials available for nest-building are not ideal. It may be possible to generalise these findings for the chaffinch to other temperate, and tropical, passerines that employ silk as a nesting material. Compared with chaffinch nests, the extent of silk usage can be far greater, and the number of functions it fulfils far wider, in nests of other birds. The birds may consequently find themselves more restricted in time and place of breeding where the types of silk needed are not in abundance

Long-term Benefits of GM crops: Potential for Diabrotica Suppression in Europe using Bt Maize

Transgenic crops producing insecticidal proteins from _Bacillus thuringiensis_ (Bt) have been widely adopted since 1996 in the United States of America to combat important pests of maize and cotton. There is growing evidence that several target pest populations have been dramatically reduced in areas where the Bt crops have been most intensively adopted over multiple years. The evidence is most dramatic for nonmigratory monophagous and oligophagous species that show high mortality on Bt crops, such as European corn borer (_Ostrinia nubilalis_), and tobacco budworm (_Heliothis virescens_). Bt cotton is currently being used in the southwestern USA as part of an area-wide eradication program for pink bollworm (_Pectinophora gossypiella_). Single, stacked, and pyramided Bt maize lines producing coleopteran-active insecticidal proteins have been shown in some cases to cause >99% mortality of western corn rootworm (_Diabrotica virgifera virgifera_) larvae every year. Simulation models suggest that long-term area-wide cultivation of these Bt corn lines can lead to dramatic population reduction, and even local extinction, of corn rootworms. An eradication program for this economically important pest, based around Bt maize and incorporating a combination of other tools, would benefit European agriculture and the environment. Post-commercial monitoring programs should be designed to investigate long-term benefits to agricultural production systems that can be reasonably expected from the widespread cultivation of Bt crops in Europe

Parameters for Successful Parental RNAi as An Insect Pest Management Tool in Western Corn Rootworm, \u3ci\u3eDiabrotica virgifera virgifera\u3c/i\u3e

Parental RNAi (pRNAi) is an RNA interference response where the gene knockdown phenotype is observed in the progeny of the treated organism. pRNAi has been demonstrated in female western corn rootworms (WCR) via diet applications and has been described as a potential approach for rootworm pest management. However, it is not clear if plant-expressed pRNAi can provide effective control of next generation WCR larvae in the field. In this study, we evaluated parameters required to generate a successful pRNAi response in WCR for the genes brahma and hunchback. The parameters tested included a concentration response, duration of the dsRNA exposure, timing of the dsRNA exposure with respect to the mating status in WCR females, and the effects of pRNAi on males. Results indicate that all of the above parameters affect the strength of pRNAi phenotype in females. Results are interpreted in terms of how this technology will perform in the field and the potential role for pRNAi in pest and resistance management strategies. More broadly, the described approaches enable examination of the dynamics of RNAi response in insects beyond pRNAi and crop pests

Parameters for Successful Parental RNAi as An Insect Pest Management Tool in Western Corn Rootworm, \u3ci\u3eDiabrotica virgifera virgifera\u3c/i\u3e

Parental RNAi (pRNAi) is an RNA interference response where the gene knockdown phenotype is observed in the progeny of the treated organism. pRNAi has been demonstrated in female western corn rootworms (WCR) via diet applications and has been described as a potential approach for rootworm pest management. However, it is not clear if plant-expressed pRNAi can provide effective control of next generation WCR larvae in the field. In this study, we evaluated parameters required to generate a successful pRNAi response in WCR for the genes brahma and hunchback. The parameters tested included a concentration response, duration of the dsRNA exposure, timing of the dsRNA exposure with respect to the mating status in WCR females, and the effects of pRNAi on males. Results indicate that all of the above parameters affect the strength of pRNAi phenotype in females. Results are interpreted in terms of how this technology will perform in the field and the potential role for pRNAi in pest and resistance management strategies. More broadly, the described approaches enable examination of the dynamics of RNAi response in insects beyond pRNAi and crop pests

Evaluation of SmartStax and SmartStax PRO Maize against Western Corn Rootworm and Northern Corn Rootworm: Efficacy and Resistance Management

Background: Cases of western corn rootworm (WCR) field-evolved resistance to Cry3Bb1 and other corn rootworm (CRW) control traits have been reported. Pyramid products expressing multiple CRW traits can delay resistance compared to single trait products. We used field studies to assess the pyramid CRW corn products, SmartStax (expressing Cry3Bb1 and Cry34Ab1/Cry35Ab1) and SmartStax PRO (expressing Cry3Bb1, Cry34Ab1/Cry35Ab1 and DvSnf7), at locations with high WCR densities and possible Cry3Bb1 resistance, and to assess the reduction in adult emergence attributable to DvSnf7 and other traits. Insect resistance models were used to assess durability of SmartStax and SmartStax PRO to WCR resistance. Results: SmartStax significantly reduced root injury compared to non-CRW-trait controls at all but one location with measurable WCR pressure, while SmartStax PRO significantly reduced root injury at all locations, despite evidence of Cry3Bb1 resistance at some locations. The advantage of SmartStax PRO over SmartStax in reducing root damage was positively correlated with root damage on non-CRW-trait controls. DvSnf7 was estimated to reduce WCR emergence by approximately 80–95%, which modeling indicated will improve durability of Cry3Bb1 and Cry34Ab1/Cry35Ab1 compared to SmartStax. Conclusion: The addition of DvSnf7 in SmartStax PRO can reduce root damage under high WCR densities and prolong Cry3Bb1 and Cry34Ab1/Cry35Ab1 durability

RNAi as a management tool for the western corn rootworm, \u3ci\u3eDiabrotica virgifera virgifera\u3c/i\u3e

The western corn rootworm (WCR), Diabrotica virgifera virgifera, is the most important pest of corn in the US Corn Belt. Economic estimates indicate that costs of control and yield loss associated with WCR damage exceed $US 1 billion annually. Historically, corn rootworm management has been extremely difficult because of its ability to evolve resistance to both chemical insecticides and cultural control practices. Since 2003, the only novel commercialized developments in rootworm management have been transgenic plants expressing Bt insecticidal proteins. Four transgenic insecticidal proteins are currently registered for rootworm management, and field resistance to proteins from the Cry3 family highlights the importance of developing traits with new modes of action. One of the newest approaches for controlling rootworm pests involves RNA interference (RNAi). This review describes the current understanding of the RNAi mechanisms in WCR and the use of this technology for WCR management. Further, the review addresses ecological risk assessment of RNAi and insect resistance management of RNAi for corn rootworm

RNAi as a management tool for the western corn rootworm, \u3ci\u3eDiabrotica virgifera virgifera\u3c/i\u3e

The western corn rootworm (WCR), Diabrotica virgifera virgifera, is the most important pest of corn in the US Corn Belt. Economic estimates indicate that costs of control and yield loss associated with WCR damage exceed $US 1 billion annually. Historically, corn rootworm management has been extremely difficult because of its ability to evolve resistance to both chemical insecticides and cultural control practices. Since 2003, the only novel commercialized developments in rootworm management have been transgenic plants expressing Bt insecticidal proteins. Four transgenic insecticidal proteins are currently registered for rootworm management, and field resistance to proteins from the Cry3 family highlights the importance of developing traits with new modes of action. One of the newest approaches for controlling rootworm pests involves RNA interference (RNAi). This review describes the current understanding of the RNAi mechanisms in WCR and the use of this technology for WCR management. Further, the review addresses ecological risk assessment of RNAi and insect resistance management of RNAi for corn rootworm

PARENTAL RNAI SUPPRESSION OF KRUPPEL GENE TO CONTROL HEMIPTERAN PESTS

This disclosure concerns nucleic acid molecules and methods of use thereof for control of hemipteran pests through RNA interference - mediated inhibition of target coding and transcribed non - coding sequences in hemipteran pests. The disclosure also concerns methods for making transgenic plants that express nucleic acid molecules useful for the control of hemipteran pests, and the plant cells and plants obtained thereby

PARENTAL RNAI SUPPRESSION OF HUNCHBACK GENE TO CONTROL HEMIPTERAN PESTS

This disclosure concerns nucleic acid molecules and methods of use thereof for control of hemipteran pests through RNA interference-mediated inhibition of target coding and transcribed non-coding sequences in hemipteran pests. The dis closure also concerns methods for making transgenic plants that express nucleic acid molecules useful for the control of hemipteran pests, and the plant cells and plants obtained thereby

PARENTAL RNAI SUPPRESSION OF HUNCHBACK GENE TO CONTROL HEMIPTERAN PESTS

This disclosure concerns nucleic acid molecules and methods of use thereof for control of hemipteran pests through RNA interference-mediated inhibition of target coding and transcribed non-coding sequences in hemipteran pests. The dis closure also concerns methods for making transgenic plants that express nucleic acid molecules useful for the control of hemipteran pests, and the plant cells and plants obtained thereby