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Borer
Kinds of Borer Terms modified by Borer Selected AbstractsEFFECTS OF FIVE NEW COMPOUNDS ON THE LARVAL GROWTH AND DIGESTIVE PHYSIOLOGY OF THE ASIATIC CORN BORER, OSTRINIA FURNACALIS LARVAEINSECT SCIENCE, Issue 3 2003Jia He Abstract Five new compounds were tested on the growth and antifeeding activity compared with toosendanin against fifth instar larvae Ostrinia furnacalis. The activities of two proteases, a weak alkaline trypsine-like enzyme and a chymotrypsin-like enzyme, in the midgut of Ostrinia furnacalis larvae were also measured. Experimental results suggest that when incorporated into an artificial diet at the concentration of 500mg/kg, the antifeeding activities of toosendanin, C19, C23, C24, C26, C28 were 51.16%, 57.61%, 4.28%, 51.08%, 36.73% and 51.67%, respectively, C19, C24, C28 had no significant difference with toosendanin. At 20mg/kg, the larval growth were remarkably suppressed by C19, C26, C28, the inhibition of C28 was close to toosendanin in 48 h. The two proteases were activated by toosendanin and C28 while they were inhibited in 48 h but activated in 24 h by C19, C24 and C26. In this paper, the related functions and mechanisms were discussed. [source] Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of SugarcaneENTOMOLOGICAL RESEARCH, Issue 3 2005Abdul KHALIQ ABSTRACT Sugarcane (Saccharum officinarum L.) varieties CP-43/33 and L-118 susceptible, BF-162 and SPSG-26 resistant while CP-72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho-physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations. The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co-efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan®, removal of dead hearts + spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval. [source] An econometric analysis of regional adoption patterns of Bt maize in GermanyAGRICULTURAL ECONOMICS, Issue 3-4 2010Nicola Consmüller Bt maize; Genetically modified organisms (GMO); Germany; Panel data analysis Abstract In this study, our goal is to identify and explain the underlying factors that drive regional adoption of Bt maize MON810 in Germany. Since regional differences cannot be explained by the occurrence of the target pest alone, we assume that under the given regulatory framework for genetically modified (GM) crop production in Germany, farm structures as well as the sociopolitical environment have also influenced regional adoption rates during the past years. Following a description of the relevant legal and economic framework in Germany, we develop theoretical hypotheses for regional variation in Bt maize adoption and test them econometrically with unique data at the federal state (Laender) and county (Landkreis) level. According to our analysis at the federal state level, the maize acreage per farm is the main driver of Bt maize adoption. In addition, there are signs that public opposition to GM cultivation as measured by membership in the German Friends of the Earth association significantly dampens GM cultivation. At the level of Brandenburg counties, the regional infestation frequency of the European Corn Borer, the target pest of Bt-Maize, is the major determinant of adoption. Although Bt maize is a scale-neutral technology for controlling damages caused by the Corn Borer, additional fixed costs due to regulation make the technology scale dependent. [source] Faithful to Fenway: Believing in Boston, Baseball, and America's Most Beloved Ballpark by Michael BorerAMERICAN ETHNOLOGIST, Issue 4 2009PETER BENSON No abstract is available for this article. [source] Twig-Nesting Ants: The Hidden Predators of the Coffee Berry Borer in Chiapas, MexicoBIOTROPICA, Issue 3 2010Ashley Larsen ABSTRACT Coffee is a globally important crop that is subject to numerous pest problems, many of which are partially controlled by predatory ants. Yet several studies have proposed that these ecosystem services may be reduced where agricultural systems are more intensively managed. Here we investigate the predatory ability of twig-nesting ants on the main pest of coffee, the coffee berry borer (Hypothenemus hampei) under different management systems in southwest Chiapas, Mexico. We conducted both laboratory and field experiments to examine which twig-nesting ant species, if any, can prey on free-living borers or can remove borers embedded in coffee fruits and whether the effects of the twig-nesting ant community differ with habitat type. Results indicate that several species of twig-nesting ants are effective predators of both free-living borers and those embedded in coffee fruits. In the lab, Pseudomyrmex ejectus, Pseudomyrmex simplex, and Pseudomyrmex PSW-53 effectively removed free-living and embedded borers. In the field, abundance, but not diversity, of twig-nesting ant colonies was influenced by shade management techniques, with the highest colony abundance present in the sites where shade trees were recently pruned. However, borer removal rates in the field were significant only in the shadiest site, but not in more intensively managed sites. This study provides evidence that twig-nesting ants can act as predators of the coffee berry borer and that the presence of twig-nesting ants may not be strongly linked to shade management intensity, as has been suggested for other arthropod predators of the borer. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp [source] Species richness and parasitism in an assemblage of parasitoids attacking maize stem borers in coastal KenyaECOLOGICAL ENTOMOLOGY, Issue 1 2003Guofa Zhou Abstract. 1. Parasitoids were reared from four species of lepidopteran stem borer collected in maize in southern coastal Kenya from 1992 to 1999. The stem borers included three native species, Sesamia calamistis Hampson, Busseola fusca Fuller, and Chilo orichalcociliellus (Strand), and one exotic borer, Chilo partellus (Swinhoe). A total of 174 663 caterpillars was collected, of which 12 645 were parasitised. 2. Twenty-six primary parasitoid species were reared from the exotic borer, C. partellus, indicating a rapid accumulation of native parasitoids on the alien borer. 3. The three most abundant parasitoids were the larval parasitoids Cotesia sesamiae Cameron, Cotesia flavipes (Cameron), and the pupal parasitoid Pediobius furvus Gahan. The pupal parasitoid Dentichasmias busseolae Heinrich and the larval parasitoid Goniozus indicus Ashmead were also common. All used an ingress-and-sting method of attack. 4. Cotesia flavipes, introduced into Kenya in 1993, was found in all seasons from 1997 onwards, and has become the most abundant stem borer larval parasitoid in the area. A native congener, Cotesia sesamiae, appeared in all seasons from 1992 to 1999. Together, these two parasitoids accounted for 83.3% of the parasitised borers. 5. Thirty parasitoid species were recovered in Kilifi district, 27 in Kwale, and 15 in Taita Taveta. Parasitism was much greater in Taita Taveta district than in Kilifi or Kwale districts. [source] Dispersal capacity in the Mediterranean corn borer, Sesamia nonagrioidesENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2004M. Eizaguirre Abstract Corn (Zea mays L.) borers are the primary target of Bacillus thuringiensis Berliner (Bt) transgenic maize. Management of corn borer resistance to Bt requires information on larval and adult dispersal capacities, a feature that is particularly unknown in Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae), the most damaging corn borer in Spain. Larval dispersal was studied over a 3 year period by infesting plants with egg masses and dissecting the neighbouring plants 7, 14, and 32 days later to measure larval dispersal at several ages. The number and age of larvae were recorded in the dissected plants. Only mature larvae dispersed in significant numbers; they moved at least to rows adjacent to those containing the infested plant, and down the row five plants. The percentage of larvae that dispersed from the infested plant was density-dependent. Adult dispersal was studied with directional light and pheromone uni-traps over 5 and 3 year periods, respectively. Directional light traps were placed in the margins between Bt and non-Bt maize fields, half oriented towards each of the two kinds of maize field. Pheromone traps were placed in the Bt and non-Bt fields at increasing distances (0,100 m) from the border. The numbers of males and females caught in directional light traps were not different in traps oriented towards Bt or non-Bt fields, but the number of males caught in the third flight in Bt fields was lower than in non-Bt fields. These results suggest that males from adjacent Bt and non-Bt fields mate indiscriminately with females emerging in any of the two kinds of maize fields. However, male movement in the third flight may not be sufficient to randomly distribute males between the two fields. [source] Ancestral feeding and survival of offspring in European corn borerENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2002D.A. Andow Abstract Experiments were conducted to evaluate the influence of ancestral adult feeding by European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), on larval survival in the field and neonate movement behavior in laboratory. Larval survival was higher when either the grandparental or parental generation had fed, but the feeding sites of the surviving larvae were not affected by ancestral feeding condition. This is the first evidence that grandparental feeding could influence larval survival in the field. Larval movement was observed in the laboratory. Silking speed of neonates was faster when either grandparents or parents had fed, while walking speed was faster only when parents had fed. No broad-sense genetic correlation was found between silking speed and walking speed. Broad-sense heritability among feeding histories were not significant for silking speed, but was significantly greater than zero for walking speed when grandparents fed and parents did not. These intergenerational effects could induce complex population dynamics in this species. [source] Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of SugarcaneENTOMOLOGICAL RESEARCH, Issue 3 2005Abdul KHALIQ ABSTRACT Sugarcane (Saccharum officinarum L.) varieties CP-43/33 and L-118 susceptible, BF-162 and SPSG-26 resistant while CP-72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho-physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations. The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co-efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan®, removal of dead hearts + spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval. [source] A new stem-borer of the genus Bucculatrix (Lepidoptera: Bucculatricidae) from Japan, with description of the life historyENTOMOLOGICAL SCIENCE, Issue 1 2009Shigeki KOBAYASHI Abstract A new species of bucculaticid moth, Bucculatrix hamaboella sp. nov. (Host plant: Hibiscus hamabo, Malvaceae) is described from Wakayama Prefecture, Japan. The feeding habit of the new species is unique in that: (i) the young larva is a leaf miner forming a long red linear mine but in the later instars the larva becomes a stem borer; (ii) later instar larvae undergo double molts within a cocoonet (molting cocoon); and (iii) penultimate and final instars appear on the surface of the leaf as non-feeding stages. The external non-feeding larvae of B. hamaboella undergoing double molts within one cocoonet are considered to be an abbreviated form of the external feeding instars of other bucculatricids typically making first and second cocoonets, undergoing a single molt within each cocoonet. On the basis of morphological characters, this species is related to the species of Sections I and II (Host: Asteraceae) of Braun (1963), rather than to the species of Section VIII (Host: Malvaceae). [source] Difference in the time of mating activity between host-associated populations of the rice stem borer, Chilo suppressalis (Walker)ENTOMOLOGICAL SCIENCE, Issue 3 2006Hideki UENO Abstract Mating activities of the rice stem borer, Chilo suppressalis, were compared between rice- and wateroat-feeding populations, and two potential temporal factors that may act as reproductive barriers were examined. Seasonal data of the number of moths attracted to pheromone traps showed that the peak of emergence at the rice field was approximately 10 days earlier than that at the wateroat vegetation in the first flight season, although there was a broad overlap of emergence at the two locations. Both field observations and a laboratory experiment showed that moths from the rice field started mating earlier than those from the wateroat vegetation. However, whereas the difference was distinctive in the laboratory experiment, mating activity at the wateroat vegetation shifted significantly to an earlier time phase than that observed in the laboratory. Body size data showed that the male moths attracted to the pheromone traps at the wateroat vegetation were significantly larger than those at the rice field, suggesting that the traps at the two locations mainly attracted moths originating from different host plants. However, pheromone-trapped males at the rice field were significantly larger than those reared from overwintering samples. These results support the idea that males from the wateroat vegetation migrate to the rice field. The differences in seasonal and temporal mating activity and their effects on development of reproductive isolation between host-associated populations are discussed. [source] Biology and damage traits of emerald ash borer (Agrilus planipennis Fairmaire) in ChinaINSECT SCIENCE, Issue 5 2007XIA WEI Abstract Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a major stem borer of ash (Fraxinus spp.). It is univoltine in Tianjin, while it is semivoltine in Heilongjiang Province, and both univoltine and semivoltine in Changchun, Jilin Province, where the majority is univoltine. The longevity of emerald ash borer adults is 17.2 ± 4.6 days (n= 45), eggs 9.0 ± 1.1 days (n= 103), univoltine larvae 308 days, semivoltine larvae 673 days, and pupae 61.2±1.6 days (n= 45). It takes about 100 days from the time larvae bore into the phloem to when they complete the pupal cell. In a 10-year-old velvet ash (Fraxinus velutina Torr.) plantation in Tianjin, emerald ash borer preferred to oviposit on the regions of boles from 50-150 cm above ground, accounting for 76.7% of the total girdling. Girdling on the south side of the tree boles accounted for 43.40% of the total girdling. The emerald ash borer population density is higher at the edge of the plantation compared with the center. [source] Effects of predatory ants on lower trophic levels across a gradient of coffee management complexityJOURNAL OF ANIMAL ECOLOGY, Issue 3 2008S. M. Philpott Summary 1Ants are important predators in agricultural systems, and have complex and often strong effects on lower trophic levels. Agricultural intensification reduces habitat complexity, food web diversity and structure, and affects predator communities. Theory predicts that strong top-down cascades are less likely to occur as habitat and food web complexity decrease. 2To examine relationships between habitat complexity and predator effects, we excluded ants from coffee plants in coffee agroecosystems varying in vegetation complexity. Specifically, we studied the effects of eliminating ants on arthropod assemblages, herbivory, damage by the coffee berry borer and coffee yields in four sites differing in management intensification. We also sampled ant assemblages in each management type to see whether changes in ant assemblages relate to any observed changes in top-down effects. 3Removing ants did not change total arthropod densities, herbivory, coffee berry borer damage or coffee yields. Ants did affect densities of some arthropod orders, but did not affect densities of different feeding groups. The effects of ants on lower trophic levels did not change with coffee management intensity. 4Diversity and activity of ants on experimental plants did not change with coffee intensification, but the ant species composition differed. 5Although variation in habitat complexity may affect trophic cascades, manipulating predatory ants across a range of coffee agroecosystems varying in management intensity did not result in differing effects on arthropod assemblages, herbivory, coffee berry borer attack or coffee yields. Thus, there is no clear pattern that top-down effects of ants in coffee agroecosystems intensify or dampen with decreased habitat complexity. [source] Efficacy of trap and lure types for detection of Agrilus planipennis (Col., Buprestidae) at low densityJOURNAL OF APPLIED ENTOMOLOGY, Issue 4 2010J. M. Marshall Abstract Development of effective trapping tools for forest pests and evaluating the key components of these tools is necessary to locate early-stage infestations and develop management responses to them. Agrilus planipennis Fairmaire (emerald ash borer) is an introduced pest of ash (Fraxinus spp. L.) in North America. The effectiveness of different trap and lure combinations were tested in areas with low and high density populations of A. planipennis. At low density sites, purple prism traps outperformed green traps and girdled ash trap trees in capture rates (adults per day) and rates of detection of A. planipennis. Also, manuka oil lures, used as a standard lure in a national survey programme, captured higher rates of A. planipennis than did previous standards of girdled ash trap trees. There was no logistic relationship between the detection of A. planipennis on a trap and the diameter of the ash tree from which the trap was suspended, possibly because of the use of artificial lures with these traps. There was also no difference in the mean number of A. lanipennis captured per day between ash species and between vigour rating of ash associated with the traps. However, traps placed in open grown and dominant trees captured more beetles than traps placed in lower canopy class trees. At sites defined as low and high density, there was no difference in the larval density per cm3 of phloem. This suggests that exposure time to A. planipennis has been shorter at those low density sites. By exploiting the trap and tree characteristics that improve A. planipennis capture rates and detection efficacy, there can be future improvement in management of this pest. If detection can occur before infested ash trees exhibit signs and symptoms, there may be a potential for reducing the mortality of ash within stands. [source] Geostatistical characterization of the spatial distribution of Grapholita molesta and Anarsia lineatella males in an agricultural landscapeJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2006A. Sciarretta Abstract:, The results obtained in spatial analysis of pheromone trap catches of oriental fruit moth, Grapholita molesta (Busck) and Peach twig borer, Anarsia lineatella (Zeller), are reported. The studies were performed in the Molise region, central Italy, during 2002 and 2003. Local distributions of oriental fruit moth and peach twig borer males were considered in a heterogeneous landscape. The aim of the study was to determine the temporal and spatial variation in distribution and abundance of the insect pests inside small plots of fruit orchards (apple, kiwi, peach, pear and plum fruits) and outside (in field crops, irrigation channels, hedgerows and a river), and to evaluate the importance of the host plants in relation to the adult distributions. Results showed that the main ,hot spot' for both lepidopterous pests was in a stone fruit orchard in the northern zone of the study area; other infested areas were in stone orchards and, in the case of A. lineatella, also in plum orchards. The river seems to act as a barrier rather than an ecological corridor. The observed spatio-temporal distributions of G. molesta and A. lineatella differed and were determined mainly by the location of the most important host plants and by the tendency of males to move in the environment, i.e. inside and outside the breeding and mating sites. Adequate knowledge of these spatial processes should be considered as an essential prerequisite for integrated pest management programmes in a precision farming approach. [source] Antixenosis mechanism of resistance in pigeonpea to the pod borer, Helicoverpa armigeraJOURNAL OF APPLIED ENTOMOLOGY, Issue 1 2006D. A. Kumari Abstract:, The noctuid pod borer, Helicoverpa armigera, is one of the most important pests of pigeonpea, and plant resistance is an important component for minimizing the extent of losses caused by this pest. To develop insect-resistant cultivars, it is important to understand the contributions of different components of resistance, and therefore, we studied the antixenosis mechanism of resistance to H. armigera in a diverse array of pigeonpea genotypes under no-choice, dual-choice, and multi-choice conditions. Antixenosis for oviposition was observed in case of ICPL 187-1, ICP 7203-1, ICPL 88039, T 21, ICPL 84060, and ICPL 332 under no-choice, dual-choice and multi-choice conditions. However, the number of eggs laid on ICPL 88039, T 21 and ICP 7203-1 did not differ significantly from those on ICPL 87 under dual-choice conditions. The susceptible check, ICPL 87 was highly preferred for oviposition. The genotypes ICP 7203-1, ICPL 187-1, T 21, ICPL 332, and ICPL 84060 can be used as sources of non-preference mechanism of resistance in pigeonpea improvement programs to breed for resistance to H. armigera. [source] Determination of baseline susceptibility to Cry1Ab protein for Asian corn borer (Lep., Crambidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2005K. He Abstract:, Although transgenic Bacillus thuringiensis (Bt) corn can provide a new tool for control of the Asian corn borer (ACB), Ostrinia furnacalis (Guenée), concern has been raised regarding the possibility of the target insect evolving resistance to the Bt protein under intensive selection pressure from Bt corn. Therefore, it is necessary to establish baseline data to enable detection of changes in susceptibility in field populations after prolonged exposure to Bt corn. Susceptibility to purified Cry1Ab protein from Bt was determined for 10 populations of ACB from the major corn-growing regions of China, ranging geographically from Heilongjiang Province in the northeast to Shaanxi Province in the east-central part. Neonate ACB were exposed to semi-artificial diet incorporated with increasing Cry1Ab protein concentrations, and mortality and growth inhibition were evaluated after 7 days. The range of LC50 (50% lethal concentration) among the populations was 0.10 to 0.81 ,g/g (Cry1Ab protein/diet). Differences (P < 0.05) in susceptibility among the populations were significant. LC50s generated from the Huanghuaihai Summer Corn Region were higher than those from the Spring Corn Regions. Bt was one of the significant natural biomortality factors of overwintering generation ACB. There was a significant correlation between percentage of the larvae infected with Bt and their LC50 values to Cry1Ab protein in geographic distinct populations (r = 0.7350*, d.f. = 8, r0.05 = 0.632). Based on the background of Bt formulations used for corn insect pests control in these areas, these differences were not caused by prior exposure to Bt insecticides. Instead, the small differences likely reflect natural Bt selection pressure. Because the variation in susceptibility to Cry1Ab was small (<10-fold), the ACB apparently is susceptible to Cry1Ab across its range within China. [source] (11Z)-hexadec-11-enal enhances the attractiveness of Diatraea saccharalis main pheromone component in wind tunnel experimentsJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2005B. Kalinová Abstract:, GC-EAD and GC-MS analysis of pheromone gland extracts of sugarcane borer, Diatraea saccharalis, revealed two antennally active compounds, (9Z,11E)-hexadeca-9,1-dienal and (11Z)-hexadec-11-enal, in approximately 10 : 1 ratio. Various doses of identified compounds were investigated in wind tunnel experiments individually and in a 10 : 1 ratio. At all tested doses (9Z,11E)-hexadeca-9,1-dienal alone elicited upwind orientation and source location only in a minority of tested males. An admixture of (11Z)-hex-11-enal enhanced the attractiveness of (9Z,11E)-hexadeca-9,11-dienal significantly. This two-component blend (100 pg) was as attractive as natural pheromone extracted from three female pheromone glands. The data suggest that (11Z)-hexadec-11-enal is a part of the D. saccharalis sex pheromone. [source] Field efficacy of transgenic cotton containing single and double toxin genes against the Asian corn borer (Lep., Pyralidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2004K. He Abstract:, Insect resistant transgenic cotton (Gossypium hirsutum L.) is expected to provide satisfactory control of lepidopteran species in the cotton field. The Asian corn borer, Ostrinia furnacalis (Guenée) (Lep., Pyralidae), is an important component of the lepidopteran pest complex of cotton in China. Insect resistant transgenic cotton cultivars GK2, carrying cry1A gene, and SGK321, carrying both cry1A and CpTI genes, were evaluated for resistance to Asian corn borer. Field trials were conducted with artificial infestation of Asian corn borer at squaring, flowering and flowering-boll cotton plants, which coincided with the generations of natural Asian corn borer occurrence. Damage ratings were significantly reduced in transgenic cotton cultivars both GK2 and SGK321 compared with their parental non-transgenic cotton cultivars Simian3 and Shiyuan321, respectively. In addition, percentage of plants stem bored and number of tunnels per plant were significantly higher on GK2 than on SGK321 in the second generation. Laboratory bioassays were carried out by exposing neonates to plant tissues collected from the field. Tissues assayed included the new leaves, match-head squares and white flowers, which are the tissues initially attacked by the neonates in the field. Low larval survival rates were observed on SGK321 and GK2, contrasting greatly to the high number of survivors found on their non-transgenic cotton tissue isolated throughout the season. However, larval survival was higher on new leaves isolated from late-season transgenic cotton plants and fruit tissues than on early-season. In addition, higher larval survival was observed on GK2 than SGK321 in assays with the late season tissues. This may be associated with reduced levels of available toxin in plant tissues as they age. Both laboratory and field data indicated that SGK321 and GK2 were highly resistant to Asian corn borer. The high level of efficacy for insect resistant transgenic cotton against Asian corn borer offers the potential for season-long control. [source] Bioefficacy and mode of action of rocaglamide from Aglaia elaeagnoidea (syn. A. roxburghiana) against gram pod borer, Helicoverpa armigera (Hübner)JOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2004O. Koul Abstract:, Rocaglamide, a highly substituted benzofuran, was isolated and identified as the main biologically active component in Aglaia elaeagnoidea (syn. A. roxburghiana) for gram pod borer Helicoverpa armigera (Hübner). Addition of rocaglamide to an artificial diet retarded the growth of neonate larvae in a dose-dependent manner with EC50 values of 0.76 p.p.m. These values compared favourably with azadirachtin (EC50 = 0.23 p.p.m.). However, azadirachtin was apparently more potent than rocaglamide in inducing growth inhibition via oral administration to these first stadium larvae. The candidate compound was found to have LD50 and LD95 values of 0.40 and 1.02 ,g per larva, respectively, in topical application against third instar larvae 96 h post-treatment. However, these values for azadirachtin were 8.16 and 25.8 ,g per larva for the same period. This shows that azadirachtin was less effective against third instar H. armigera larvae in inducing acute toxicity via topical treatment in comparison with rocaglamide. However, severe morphological larval deformities were observed in such azadirachtin-treated larvae during the process of ecdysis. The cytotoxic nature of rocaglamide was established by evaluating dietary utilization and the results did not implicate any antifeedant effect but the toxicity-mediated effect due to reduced efficiency of conversion of ingested food. It was obvious that feeding deterrence is not the primary mode of action but a centrally mediated effect, which could be due to the induced cytotoxicity at non-specific cellular levels. [source] Dispersal of the emerald ash borer, Agrilus planipennis, in newly-colonized sitesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2009Rodrigo J. Mercader Abstract 1Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive forest insect pest threatening more than 8 billion ash (Fraxinus spp.) trees in North America. Development of effective survey methods and strategies to slow the spread of A. planipennis requires an understanding of dispersal, particularly in recently established satellite populations. 2We assessed the dispersal of A. planipennis beetles over a single generation at two sites by intensively sampling ash trees at known distances from infested ash logs, the point source of the infestations. Larval density was recorded from more than 100 trees at each site. 3Density of A. planipennis larvae by distance for one site was fit to the Ricker function, inverse power function, and the negative exponential function using a maximum likelihood approach. The prediction of the best model, a negative exponential function, was compared with the results from both sites. 4The present study demonstrates that larval densities rapidly declined with distance, and that most larvae (88.9 and 90.3%) were on trees within 100 m of the emergence point of the adults at each site. The larval distribution pattern observed at both sites was adequately described by the negative exponential function. [source] Non-target habitat exploitation by Trichogramma brassicae (Hym. Trichogrammatidae): what are the risks for endemic butterflies?AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2003D. Babendreier Abstract 1,Trichogramma brassicae Bezdenko is inundatively released against the European corn borer in Switzerland. Because parasitoids dispersing from the release fields might pose a threat to native butterflies, the searching efficiency of T. brassicae was investigated in nontarget habitats. 2,In field studies, T. brassicae was released at rates of 120 000 females/ha. Parasitism of sentinel Ephestia kuehniella egg clusters was 1.6,3.6% in meadows and 2.0,4.0% in flower strips. The respective figures were 57.6,66.7% and 19.2,46.9% in maize, significantly higher than the parasitism rates in the nontarget habitats. Experiments carried out in small field cages confirmed these results: Again, significantly higher parasitism rates were found in maize compared to meadows and flower strips, and also compared to hedgerows (in sleeve cages). 3,To elucidate potential factors underlying the low searching efficiency in nontarget habitats, the behaviour of individual T. brassicae females was investigated on four meadow plants comparatively to maize and a filter paper control. Mean (±SE) walking speed on maize was 2.2 ± 0.2 mm/s, similar to three of the plants tested and filter paper but significantly higher than on Trifolium pratense (0.85 mm/s). A higher turning rate was found on T. pratense, Viola wittrockiana and Plantago lanceolata, in contrast to the longer leaved maize and Alopecurus pratensis. The number of wasps leaving the plant within the observation period differed significantly between plant species, and was twice as high for T. pratense (and the filter paper control) compared to the other plant species. 4,In a choice experiment carried out in a climate cabinet with all five host plant species in cages, we obtained the highest parasitism rates on maize and the lowest parasitism on T. pratense, thus confirming the behavioural observations. 5,In conclusion, there is evidence for a decreased searching efficiency on plants in nontarget habitats compared to maize. However, the data explain only part of the differences found between parasitism in maize compared to nontarget habitats. Other factors, such as the structural complexity of a habitat, may also play a role. We conclude that the risk for butterfly populations in the tested nontarget habitat due to mass released T. brassicae is low. [source] Insect growth-reducing and antifeedant activity in Eastern North America hardwood species and bioassay-guided isolation of active principles from Prunus serotinaAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2000S. Omar Abstract 1 Thirty extracts of wood and bark of hardwood trees from Eastern North America were examined for insect growth-reducing activity in a bioassay with European corn borer, Ostrinia nubilalis, and an antifeedant bioassay with the rice weevil, Sitophilus oryzae. 2 Nine of the bark extracts and four of the wood extracts showed significant growth reducing effects at 0.5% in meridic diets, whereas only two bark extracts and one wood extract showed significant antifeedant effect at the same concentration. 3 Slower growing tree species were more biologically active than fast growing ones. Isolation of the bioactive compounds in one of the active species, Prunus serotina, showed that naringenin, its derivative methoxynaringenin, and eriodictyol were responsible for the antifeedant effects. [source] Accumulated thermal time, a key factor in affecting generation initiation and duration of top borer, Scirpophaga excerptalis Walker of sugarcane for its model-based chemical controlMETEOROLOGICAL APPLICATIONS, Issue 1 2010Arun K. Srivastava Abstract The seasonal variation in the initiation and duration of the I,III generations of the top borer was observed and analysed during five crop cycles from 2002,2003 to 2006,2007 at Lucknow in central Uttar Pradesh. The durations of the I,III generations were significantly correlated with the accumulated thermal time (Tbase = 10°C). Relatively higher temperature and consequently higher accumulated thermal time shortened the brood duration and early initiation of successive generations and vice versa. Based on these correlations, models were developed for predicting the initiation and duration of these generations. These models were validated for 2007,2008 crop cycle. The differences between observed and predicted duration of the I,III generation of the pest were 3, 1 and 3 days respectively reflecting high precision of the models. As the current management strategy for the chemical control of the pest is based on a calendar week, the shift of III generation initiation due to seasonal fluctuations could lead to escape from insecticide and render the chemical application pointless. The model-based control strategy is more precise and foretells the time of application of chemical against III generation of top borer which is most damaging to sugarcane crop. Copyright © 2009 Royal Meteorological Society [source] Isolation and characterization of microsatellite markers from Teretrius nigrescens Lewis (Coleoptera: Histeridae), predator of the storage pest Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)MOLECULAR ECOLOGY RESOURCES, Issue 4 2009A. B. OMONDI Abstract Teretrius nigrescens is a predator of the larger grain borer (LGB) Prostephanus truncatus, an invasive post-harvest pest in Africa. We describe the isolation and characterization of 24 novel polymorphic microsatellite markers and their testing on a population from Honduras. Alleles per locus ranged between 2 and 12, and observed heterozygosity between 0.037 and 0.646. Six loci deviated significantly from Hardy,Weinberg equilibrium and showed evidence of null alleles. These markers will be useful for studies of the predator's population structure and characterizing populations for control of LGB. [source] Development of insect-resistant transgenic rice with Cry1C*-free endospermPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 9 2009Rongjian Ye Abstract BACKGROUND: Yellow stem borer (Tryporyza incertulas Walker), striped stem borer (Chilo suppressalis Walker) and leaf folder (Cnaphalocrocis medinalis Guenec) are three lepidopteran pests that cause severe damage to rice in many areas of the world. In this study, novel insect-resistant transgenic rice was developed in which Bt protein expression was nearly absent in the endosperm. The resistant gene, cry1C*, driven by the rice rbcS promoter (small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase), was introduced into Zhonghua 11 (Oryza sativa L. ssp. japonica) by Agrobacterium -mediated transformation. RESULTS: A total of 83 independent transformants were obtained, 19 of which were characterised as single-copy foreign gene insertion. After preliminary screening of the T1 families of these 19 transformants in the field, six highly insect-resistant homozygous lines were selected. These six homozygous transgenic lines were field tested for resistance to leaf folders and stem borers, and for their agronomic performance. The Cry1C* protein levels in leaves and endosperm were measured by ELISA. Subsequently, the elite transgenic line RJ5 was selected; this line not only possessed high resistance to leaf folders and stem borers, normal agronomic performance, but also Cry1C* expression was only 2.6 ng g,1 in the endosperm. CONCLUSION: These results indicated that RJ5 has the potential for widespread utility in rice production. Copyright © 2009 Society of Chemical Industry [source] Risk assessment of thiacloprid and its chemical decontamination on eggplant, Solanum melongena L.PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 2 2009Jayakrishnan Saimandir Abstract BACKGROUND: Thiacloprid [(Z)-3-(6-chloro-3-pyridylmethyl)-1,3-thiazolidin-2-ylidenecyanamide; CalypsoÔ] is a systemic insecticide having persistence in the plant system. It was chosen for the management of the eggplant shoot and fruit borer, Leucinodes orbonalis Guen. Management of this insect pest is difficult because it harbours inside the shoot and fruit portions of eggplant. The persistence of thiacloprid on eggplant has not been studied in India. The Food and Agriculture Organisation (FAO) has proposed its maximum residue limit (MRL) on eggplant as 0.7 mg kg,1, and there is a need to validate this value. Since residues were found to be above this level, five different decontamination agents were tested for the decontamination of thiacloprid from eggplant. RESULTS: The half-life of thiacloprid was 11.1 and 11.6 days from trials in 2 years. Safety factors such as theoretical maximum daily intake (TMDI) and maximum permissible intake (MPI) were used to arrive at a risk assessment to human health from the analytical data obtained from the field trials. Thiacloprid at the doses tested (30 and 60 g AI ha,1) was not effective in managing eggplant fruit borer. A waiting period of 3 days before harvest of the fruits after insecticide application and a processing factor (PF) could not ensure a sufficient margin of safety (MOS). Subjecting the data to a processing factor of 60% could not bring the residues below the proposed MRL. CONCLUSION: Thiacloprid is not found to be an appropriate and effective agent for application to eggplant. Either the proposed MRL needs to be revised or good agricultural practice involving thiacloprid for plant protection in eggplant cultivation is required. Copyright © 2008 Society of Chemical Industry [source] Comparison of dose responses and resistance ratios in four populations of the rice stem borer, Chilo suppressalis (Lepidoptera: Pyralidae), to 20 insecticidesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 3 2008Yue Ping He Abstract BACKGROUND: Chemical control is a major strategy for suppressing the rice stem borer, Chilo suppressalis (Walker). Owing to their high toxicity and increasing resistance development in the target insect, many insecticides will be phased out entirely in 2007 in China. Alternatives with relatively low toxicity are urgently needed to replace traditional chemicals for rice stem borer control. In this study, the authors examined four field populations of C. suppressalis for their toxicological responses to more than 20 insecticides, including a few low-toxicity organophosphates and many novel pesticides. Interpopulation resistance levels to 12 conventional insecticides were also compared. RESULTS: Based on LD50 values, the rice stem borer was most sensitive to avermectins and fipronil (LD50 < 1 ng larva,1). The stem borers exhibited the least sensitivity to endosulfan (LD50 > 100 ng larva,1) and monosultap (LD50 > 1000 ng larva,1). Insect growth regulators and chitin synthase inhibitors showed great efficacy against C. suppressalis, especially against populations that had developed resistance to conventional insecticides. Four field populations showed variable tolerance levels to many insecticides. LYG05 was the most susceptible population, only with a low level of resistance to monosultap (RR = 6.6). NC05 and GL05 populations exhibited intermediate tolerance levels with RR values up to 20.4 and 52.8 respectively. RA05 was the most resistant population to many insecticides, with resistance ratios up to 76.2. CONCLUSION: The results from this study provide valuable information for selection and adoption of new alternative insecticides and for resistance management of the rice stem borer. Copyright © 2008 Society of Chemical Industry [source] Activity of Bacillus thuringiensis toxins against cocoa pod borer larvaePEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2004Djoko Santoso Abstract Twelve Cry proteins from Bacillus thuringiensis Berliner were tested in bioassays on cacao plantations in Indonesia for activity against the larvae of cocoa pod borer (Conopomorpha cramerella (Snellen)), an insect pest of the cacao tree. Through the damage caused by their feeding, the larvae of cocoa pod borer cause the pods of the cocoa tree to ripen prematurely. They are difficult to control with conventional measures. Preliminary assays identified five toxins that were more active than others. In two subsequent bioassays the activity of selected toxins was determined more accurately. Three Cry1 proteins with relatively little homology were all found to be toxic, opening perspectives for controlling cocoa pod borer by expression of Cry proteins in transgenic plants. Copyright © 2004 Society of Chemical Industry [source] Fumigation toxicity of volatile natural and synthetic cyanohydrins to stored-product pests and activity as soil fumigantsPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2004Dong-Sik Park Abstract Insecticidal fumigation toxicity of natural and synthetic cyanohydrins was evaluated with four stored-product pests: the lesser grain borer, Rhyzopertha dominica (F), the red flour beetle, Tribolium castaneum Herbst, the saw-toothed grain beetle Oryzaephilus surinamensis L, the maize weevil, Sitophilus zeamais (Motsch) and the house fly, Musca domestica L. The fumigation LC50 values were calculated by probit analysis. For house flies, all but one of the cyanohydrins tested were more potent than 1,3-dichloropropene (Telone®). Three were as efficacious as chloropicrin. For the lesser grain borer, all cyanohydrins tested were more insecticidal than dichloropropene, and all but one were more potent than chloropicrin. Four were as insecticidal as dichlorvos. The acetate of 1-cyano-1-hydroxy-2-propene (CHP-ace) was also tested in soil for antifungal and antibacterial activity, and inhibition of weed seed germination. CHP-ace reduced the total soil bacterial and fungal counts significantly, and was effective in inhibiting the germination of weed seeds in soil, indicating a broad spectrum of activity as a soil fumigant. Copyright © 2004 Society of Chemical Industry [source] | |||||||||||||||||||||||||||||||||||||