The Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), devastates wheat and barley production on all continents except Australia. Although D. noxia-resistant cultivars exist, virulent D. noxia populations exist in Asia, North America, and South America that have the ability to overcome resistance. In this study, synthetic hexaploid wheat genotypes created at the International Maize and Wheat Improvement Center (CIMMYT) were evaluated and characterized for resistance to North American biotype 2 (RWA2). Fewer RWA2 were produced on several genotypes, and D. noxia-induced leaf rolling and chlorosis were reduced on these genotypes as well. Aphid numbers were positively correlated with chlorosis and with leaf rolling. However, some genotypes were highly resistant to leaf rolling and chlorosis while supporting large RWA2 populations. There were negative correlations between leaf chlorosis and leaf dry weight (r = -0.267, df = 106. P = 0.006) and between aphid numbers and leaf dry weight (r = -0.297, df = 105, P = 0.002). These results indicate that chlorosis and aphid number individually explain at least 27% of the changes observed in leaf dry weights. Interestingly, there was no correlation between leaf rolling and leaf dry weight. The RWA2-resistant lines identified, which are also resistant to D. noxia populations in Mexico and to greenbug (Schizaphis graminum Rondani) biotype G, are strong candidates for use in improving the genetic diversity in bread wheat for resistance to different biotypes of both S. graminum and D. noxia.

Corn engineered to produce the Cry3Bb1 protein from Bacillus thuringiensis Berliner (Bt) has provided unprecedented control for corn rootworm (Diabrotica virgifera virgifera Le Conte). However, accumulation and persistence of plant-produced Bt protein in soils may occur where Bt crops are repeatedly grown and residues of the crop plants are incorporated into the soil. If Bt protein is released into the soil rhizosphere, it may affect soil organisms. Studies were conducted to determine the effect of Bt or non-Bt corn roots and biomass on the weight and mortality of the earthworm, Lumbricus terrestris L. with different exposure methods and times. Enzyme-linked immunosorbent assay (ELISA) was conducted to determine if the Cry3Bb1 protein was present in the soil from the gut and excreta of earthworms. Results of these studies showed that there were no significant differences in weight and percent mortality of earthworms in soil planted or not planted with Bt and non-Bt corn or in soil containing ground air-dried biomass of Bt and non-Bt plants. Cry3Bb1 protein was detected in the soil from pots and the gut and excreta of earthworms exposed to Bt roots orbiomass, whereas it was absent in soil from pot, the gut and excreta of earthworms exposed to roots or biomass of non-Bt com. There was no significant difference in the amount of the protein recovered from pots or the gut or excreta of earthworms exposed to soils containing Bt roots or biomass for 12 or 33 d.

Rhyzopertha dominica (F.), an important pest of stored grains, causes economic damage to rough rice through physical damage to the kernel, resulting in reductions in grain quality. In this test, 28 varieties of commercial rough rice (10 long grain, 11 medium grain, and 7 short grain) were examined for solid, split and cracked hulls, hull thickness, and adult emergence from neonate R. dominica introduced on each individual variety. The percentage of solid hulls ranged from 55.5% on Koshihikari variety to 92.8% on Akita variety, and the percentages of cracked and split hulls were correlated with increased susceptibility. The Dobie index for progeny production showed Wells, Jupiter, and Pirogue varieties as the most tolerant to R. dominica, while Rico and Francis were the most susceptible. The hull thickness of rough rice varied among varieties, but the tolerant varieties appeared to have thicker hulls than the susceptible varieties. There was no difference among rice types (long-, medium-, or short grain) regarding tolerance or susceptibility to R. dominica. Results show that the characteristics of the rough rice hull are important for conferring susceptibility of individual varieties to R. dominica.

Adults of Rhyzopertha dominica (F.), the lesser grain borer, were exposed on four varieties of rough rice with Dobie indices of susceptibility of 1.1 to 1.1 (low), and four varieties with Dobie indices of susceptibility of 3.4 to 3.8 (high). The varieties with low and high Dobie indices were classified as resistant and susceptible, respectively, to R. dominica. The purpose of the study was to evaluate control of R. dominica through the use of diatomaceous earth (DE) in combination with rice varieties that were either susceptible or resistant to R. dominica. The rice was treated with varying rates of the commercial DE Insecto®, up to a maximum of 1 000 mg DE/kg of rice. Adult mortality at each application rate of DE was generally greater on three of four resistant varieties compared to three of four susceptible varieties. Progeny production from the parental generation exposed on the rice was also greater in 3 of the 4 resistant varieties compared to 3 of the 4 susceptible varieties at DE rates of 500 mg/kg or more. Progeny production in rice treated with a maximum rate of 1 000 mg/kg DE ranged from 7‐44 adults on the resistant varieties compared to 75‐155 adults on the susceptible varieties. At DE rates of 500, 750, and 1 000 mg/kg, the percentage of insect‐damaged kernels (IDK) was also greater in 3/4 resistant varieties than in the susceptible varieties. Results show combining the use of DE with varietal resistance of rough rice to R. dominica could be used to limit populations of this insect in stored rice and help prevent economic damage.

Several physical and chemical attributes of rice were evaluated to determine which character would be best to use to assess multiple rice varieties for resistance to the lesser grain borer, Rhyzopertha dominica (F.). Laboratory tests were conducted on single varieties of long-, short-, and medium grain-rice to develop procedures and methodologies that could be used for large-scale screening studies. Progeny production of R. dominica was positively correlated with the percentage of broken hulls. Although kernel hardness, amylose content, neonate preference for brown rice, and adult emergence from neonates varied among the three rice varieties tested they did not appear to be valid indicators of eventual progeny production, and may not be useful predictors of resistance or susceptibility. Soundness and integrity seem to be the best characters to use for varietal screening studies with R. dominica.

A series of tests were conducted to determine the susceptibility of eggs and neonates of the lesser grain borer Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae = Bostrychidae), exposed to the insect growth regulator, methoprene, on filter paper and on rough rice. In the first test, the hatch rate of eggs exposed on filter paper treated with methoprene at the label rate of 0.003 mg [AI] / cm(2) when used as a surface treatment in structures was 52.0 +/- 7.3% compared to 93.0 +/- 3.3% on untreated controls. In the second test, eggs were exposed to a dose-response series of 0.00003 to 0.03 mg[AI]/ cm(2). Egg hatch was directly proportional to concentration and ranged from 85.0 +/- 2.0% on untreated controls to 26.7 +/- 8.3% at the highest concentration tested. In the third test, 1 ppm of methoprene was sprayed on long grain rough rice (paddy) (Cocodrie variety), and then individual kernels were cracked and an egg of R. dominica was placed directly on the kernel. On untreated rice kernels, 67.5 +/- 11.6% of the eggs hatched and were able to bore inside, and all of these larvae emerged as adults. In contrast, 40.0 +/- 5.3% of the eggs placed on treated cracked kernels were able to develop to where the larvae were visible through X-ray detection, but none emerged as adults. In the final test, newly-emerged adults were exposed on rough rice treated with 1 ppm methoprene. The number of eggs from adults on untreated rice was 52.1 +/- 4.3 eggs per female, and on treated rice the average egg production was 12.5 +/- 1.1 eggs per female. Methoprene applied on a surface or on rough rice affected development of egg hatch also reduced fecundity of parent adults exposed on the treated rough rice.

Sunflower head moth: Homoeosoma electellum (Hulst

Abstract Second-generation neonicotinoid insecticides are being used to protect seeds and seedlings against injury by early season insects on a wide variety of crops. Seed-applied insecticides have recently been commercialized in the USA for early season insect control in corn. The systemic insecticides clothianidin (Poncho®) and thiamethoxam (Cruiser®) applied as seed treatments were evaluated for their effect on corn yield in the absence of noticeable insect attack over a three year period at a number of locations representing diverse growing environments in Kansas. No consistent effect on yield was detected for either compound at either high or low rates in locations where insects were not observed at damaging populations. Controlled-environment studies detected no differences in early season growth in the absence of insect pests in response to the same two rates of both insecticides. Both compounds were evaluated for their effect on early season corn pests and were found to be effective at high and low rates on wireworm, white grub, flea beetles and chinch bugs. Higher rates of both compounds were needed to reduce feeding damage caused by black cutworm. Seed treatments with either compound would be useful where early season pests are chronic problems.

Combination treatments of diatomaceous earth (DE) (Protect-It®) and the insect growth regulator (IGR) methoprene (Diacon® II) were evaluated against Rhyzopertha dominica (F.), the lesser grain borer, on stored rough rice. Application rates of DE and methoprene ranged from 0 to 500ppm and 0 to 1ppm, respectively, in 25 treatment combinations. Tests were conducted by exposing 20 adults for 2 weeks at 32°C and 75% relative humidity on single varieties of long-, short-, and medium-grain rough rice, removing adults, and holding the rice for 8 weeks at the same conditions to collect F1 progeny. In the absence of methoprene, mortality of exposed adults increased as the concentration of DE increased, but even at the highest rate of 500ppm, mortality was only 57.5±12% and 58.8±9.7% in long and medium-grain rice, respectively, and 26.3±4.7% in short-grain rice. Mortality of R. dominica exposed on short-grain rice was lower than mortality on long-and medium-grain rice at several combinations with 375 and 500ppm DE. There was also an unexpected increase in adult mortality with the addition of methoprene so that at 1ppm methoprene and 500ppm DE, mortality in long-, medium-, and short-grain rice was 77.5±9.0%, 77.5±10.0%, and 58.5±3.0%, respectively. In the absence of methoprene, progeny produced on long- and short-grain rice ranged from 48.0±21.2 to 87.2±9.0, compared to 16.5±5.5 to 33.5±8.6 progeny produced on medium-grain rice. With the inclusion of methoprene there were few progeny produced in any of the treatment combinations, and the overall average was 0.6±0.3. Similarly, with no methoprene the range of insect-damaged kernels (IDK) was 5.2±2.7 to 12.2±3.1%, but with methoprene the overall average was reduced to 1.8±0.2%. While control of R. dominica was somewhat limited with DE, the differences among rice varieties seems to indicate that the specific type and possibly variety of rough rice may influence mortality and reproduction of R. dominica exposed to DE. With methoprene, progeny production was greatly suppressed regardless of DE concentration, but combining DE with methoprene would give some measure of adult control.

The western corn rootworm (Diabrotica virgifera virgifera LeConte) is one of the most important insect pests of corn in North America. This insect costs farmers $1 billion or more annually in reduced yields and insecticide treatment costs (Metcalf 1986). Corn rootworm larvae damage the corn root system by feeding underground. The root feeding can cause physiological yield losses and make the plants susceptible to lodging and stalk rot fungi (Palmer and Kommedahl 1969). Corn rootworm beetles also cause damage by feeding on silks, which affects pollination and seed set. Corn rootworms traditionally have been managed on a field-by-field basis using crop rotation or insecticide applications. Crop rotation works because corn rootworm beetles tend to lay their eggs in corn fields. of treated areas. They also are seeking to use timely applications of environmentally friendly insecticides to replace standard foliar insecticide treatments. The USDA and cooperating university researchers have evaluated areawide management for controlling western corn rootworm beetles in several large, 41 km2 regions (16 mi2) (Faust and Chandler 1998, Wilde et al. 1998, Chandler 2003). The objective of these projects was to reduce the frequency and number of insecticide applications needed to achieve commercially acceptable suppression of western corn rootworm. The areawide management strategy requires information on corn rootworm populations within the managed area. One method of estimating corn rootworm beetle populations is for scouts to count beetles on corn plants at numerous locations in the The eggs overwinter and hatch in the spring when corn plants are growing rapidly. Crop rotation reduces the likelihood that corn will be planted in soil where large numbers of western corn rootworm eggs have been laid. In some areas, however, the economic advantage of corn production is so large that growers plant corn year after year in the same fields (known as continuous corn). In this case, growers use soil insecticides to protect the plant roots from corn rootworm feeding or foliar insecticide treatments to kill the beetles before they can lay their eggs in the field. Scientists have proposed using an areawide management strategy to manage corn rootworms (Wilde et al. 1998, Whitworth et al. 2004) by reducing insect populations (in this case beetles) over a larger geographical area to reduce the threat of reinfestation

The effect of Dipel 4L in artificial diet on feeding behavior, occurrence on a specific diet, and growth of corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), was assessed in short-term tests. Third-, fourth-, and fifth-stage laboratory-reared and feral corn earworm larvae were evaluated. Arenas used for each assay included a non-Dipel diet, Dipel-containing diet, and a combination of the two diets. Larval activity was observed immediately after exposure to diet and at 6 and 18 h for third instars and at 6, 8, and 24 h for fourth and fifth instars, respectively. Feral and laboratory-reared third, fourth, and feral fifth instars avoided Dipel-treated diet when more suitable food was available. Third and fourth instars consistently preferred non-Dipel-containing diet when presented a choice of foods. Corn earworm growth was delayed when larvae were subjected to Dipel-treated diet in choice and no-choice assays compared with larvae provided untreated diet. Larvae presented a choice of diets grew more rapidly than those presented Dipel-treated diets in no choice arenas. Larval feeding frequency and weight gain were superior when larvae were supplied untreated diet than when restricted solely to a Dipel-treated diet. Larvae presented a choice of diets spent more time feeding and fed more frequently on untreated diet than Dipel-treated food. These data indicate that corn earworm presented a choice of Bacillus thuringiensis (Bt) and non-Bt diets may have an increased probability of completing development compared with those restricted to Bt-laced sources.

Laboratory trials were conducted to determine the effectiveness of diatomaceous earth (DE) against Rhyzopertha dominica (F.), the lesser grain borer, on stored rough rice. Two DE commercial products, Insecto™ and Protect-It®, were applied at their respective label rates of 500 and 400ppm to long grain rice by hand-mixing the DE with the rice. R. dominica were exposed for varying time intervals, mortality was assessed, and rice was held at different temperatures and relative humidities (r.h.) for 8 weeks until F1 adult emergence. There was a significant difference in mortality between the DE treatments and untreated controls (P<0.01), but no significant differences with respect to the two DE products (P⩾0.05). Mortality increased as exposure interval increased, and ranged from 15.8% to 69.2%, depending on the exposure interval. Although the general ANOVA showed a significant difference for temperature and r.h., when mortality and r.h. were compared only 5 out of 30 comparisons were significant (P<0.05). There was extensive progeny production in all treatments (including controls) and more progeny were produced at 32 than at 27°C. The overall ANOVA showed a difference for treatment and r.h., but again few comparisons were significant (P<0.05). Results showed that the two DE products did not completely suppress R. dominica on rough rice, and combination treatments with another insecticide may be necessary to give complete control.

Analysis of transcriptomes from the salivary glands and midgut of Hessian fly larvae Mayetiola destructor (say) identified a set of diverse cDNAs that encode proteins with a relatively high percentage (over 10%) of cysteinyl residues. Structural comparison of these putative proteins with known sequences in GENBANK revealed that the positions of the cysteinyl residues in the identified proteins were highly conserved within a family of proteinase inhibitors despite very little overall sequence similarity. Phylogenetic analysis sorted this set of cDNAs into five different groups. To determine if these cDNAs indeed encode proteinase inhibitors, recombinant proteins were generated with two cDNAs from two different groups. Biochemical analysis of the recombinant proteins against commercial and insect gut proteinases demonstrated that the recombinant proteins are strong proteinase inhibitors with different specificities. Northern blot and real-time PCR analysis revealed that the different genes were expressed at different developmental stages and in different tissues. The overall results indicated that M. destructor contains a complex of genes that code for proteinase inhibitors which may regulate proteinase activities in different regulatory pathways. The GENBANK accession numbers for the cDNAs in this paper were DQ232690 to DQ232718.

The western corn rootworm, Diabrotica virgifera virgifera (LeConte)(Coleoptera: Chrysomelidae), continues to be one of the most costly insect pests of corn, Zea mays L., in the United States. It is estimated that the corn rootworm complex causes approximately $1 billion in crop losses and control costs annually in the U.S. (Metcalf, 1986). This pest also has recently been introduced into Europe. Urek (1998) stated that it was discovered in Serbia as early as 1990 and has since continued to spread throughout the European continent. For these reasons, it is increasingly important to develop an efficacious, user friendly system of monitoring this pest. Several types of western corn rootworm (WCR) monitoring techniques have been in troduced and studied over the past decades (Chiang, 1973; Hein and Tollefson, 1984; Hoffman et al, 1996; Luckmann et al, 1975; Musick and Fairchild, 1970; Shaw et al, 1984). Although these techniques have scientific value, several current monitoring tech niques (such as sticky traps) have met with resistance from producers and consultants because of the inconvenience associated with handling messy, sticky materials (G. Wilde, pers. obs.). Furthermore, visual plant inspections may yield varying population estimates because of differences in scout experience (Shufran and Raney, 1989), time of day or weather conditions (Lance, 1990). Since non-sticky, kairomone-baited traps are left in the field over a longer period of time, resulting captures are not necessarily affected by fluctuations in WCR activity levels caused by changes in weather or time of day. Assuming that the traps have been deployed properly, scout experience should also have less influence on beetle captures. Turchin and Odendaal (1996) employed both a single-release-multiple-trap design and a multiple-release-single-trap design to study the effective sampling area of a pheromone trap for Dendtroctonus frontalis Zimmerman (Coleoptera: Scolytidae). They suggested the single-release design was most suited for studying the long-distance probabilities of recapturing beetles. The multiple-release design was employed for their short-range studies to avoid underestimation of recapture probabilities due to overlap of attractive areas (Elkinton and Carde, 1980). Furthermore, Turchin and Thoeny (1993) suggested that traps closest to the release point would capture many of the released beetles, reducing the recapture probability at longer distances. A commercially available kairomone-baited lure trap (Trece, Inc., Salinas, CA) has been tested in field trials in Kansas to determine its effectiveness in monitoring adult WCR. Knowledge about the sphere of influence of a lure trap is important in deploying traps in the field and to avoid lure plume overlap during studies. We sought to develop a method of determining the sphere of influence for the Trece lure trap and to determine its effective

Abstract A group of related genes has been isolated and characterized from the gut of Hessian fly larvae [Mayetiola destructor (Say)]. Members in this group appear to encode proteins with secretary signal pep tides at the N‐terminals. The mature putative proteins are small, acidic proteins with calculated molecular masses of 14.5 to 15.3 kDa, and isoelectric points from 4.56 to 4.88. Northern blot analysis revealed that these genes are expressed predominantly in the gut of Hessian fly larvae and pupae. Two related genes, G10K1 and G10K2, were isolated as tandem repeats. Both genes contain three exons and two introns. The intron/exon boundaries were conserved in terms of amino acid encoding, suggesting that they arose by gene duplication. The fact that the frequency of this group of clones in a gut cDNA library higher than that of total cDNA clones encoding digestive enzymes suggested that this group of proteins may perform an important function in the gut physiology of this insect. However, the exact functions of these proteins are as yet known since no sequence similarity could be identified between these proteins and any known sequences in public databases using standard methods.

The Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Homoptera: Aphididae), is one of the most devastating insect pests of wheat (Triticum spp.) and barley (Hordeum spp.) in the world. Yield losses and control costs are valued at several hundred million dollars each year. The use of D. noxia-resistant cultivars is an ecologically, economically, and biologically sound method of managing this pest. Several D. noxia resistance (Dn) genes from wheat have been used to develop cultivars resistant to D. noxia. However, a new U.S. D. noxia biotype (biotype 2) in Colorado is virulent to all known Dn genes except the Dn7 gene from rye (Secale spp.). Hence, there is an immediate need to identify and characterize unique sources of D. noxia resistance to biotypes. In this article, we report resistance to D. noxia biotype 2, identified in a selection from wheat cereal introduction (CItr) 2401, that is controlled by two dominant genes. CItr2401 has a strong antibiosis effect that is exhibited as a reduced intrinsic rate of increase of D. noxia biotype 2. CItr2401 plants also exhibit tolerance to leaf rolling and chlorosis. No antixenosis was detected in CItr2401.

Field and laboratory studies were conducted to determine the effect of transgenic Bacillus thuringiensis (Bt) corn, Zea mays L. (YieldGard Rootworm), expressing the Cry3Bb1 protein on aboveground nontarget insect predators (minute pirate bug, ladybird beetles, and carabids). Visual counts of adult and immature Orius insidiosus (Say), Coleomegilla maculata (DeGeer), Hippodamia convergens Gurin-Meneville, and Scymnus spp. occurring in Bt corn and its non-Bt isoline were made at Manhattan, KS, in 2002 and at Manhattan and Scandia, KS, in 2003. No significant differences were found between the Bt corn and non-Bt isoline plots in the abundance (number per plant) of O. insidiosus, C. maculata, H. convergens, and Scymnus spp. Field predation on Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) egg masses was also observed during the silking stage of corn at Manhattan and Scandia in 2003. No significant differences were observed among treatments in predation rate for predators with chewing versus sucking mouthparts. Two laboratory studies determined the effect of Cry3Bb1 protein expressed in Bt corn pollen on C. maculata and carabids. The larvae of C. maculata were reared on Bt pollen, non-Bt pollen, or greenbugs, Schizaphis graminum (Rondani). The duration of larval and pupal stages, developmental time from egg hatch to adult emergence, percentage of survival, and elytra length were compared among treatments. There were no significant differences in developmental time of larvae fed pollen or greenbugs during their first two instars. However, significantly prolonged development of the third (1 d) and fourth instars (2 d) was observed for larvae fed greenbugs only. Total time for larval development was significantly longer for larvae that fed on greenbugs versus larvae fed on pollen. No significant differences were observed among treatments in the percentage of larvae that pupated or pupal stage duration. Larvae that fed on greenbugs had higher pupal and adult weights compared with pollen-fed larvae. However, pupal and adult weights did not vary between the Bt and non-Bt pollen treatments. No significant differences occurred in longevity and elytra length of beetles among all treatments. Two carabid species, Harpalus caliginosus F. and Harpalus pensylvanicus DeGeer, were reared on moistened dog food sprinkled with Bt or non-Bt corn pollen. No significant differences in mortality of H. caliginosus and H. pensylvanicus were detected among any of the treatments. There was no significant effect of Bt pollen on fecundity and egg viability of H. caliginosus. Our studies showed that YieldGard Rootworm had no effect on the selected coleopteran predators; therefore, this Bt corn hybrid could be used in an integrated pest management system.

H9, H10, and H11 are major dominant resistance genes in wheat, expressing antibiosis against Hessian fly [(Hf) Mayetiola destructor (Say)] larvae. Previously, H9 and H10 were assigned to chromosome 5A and H11 to 1A. The objectives of this study were to identify simple-sequence-repeat (SSR) markers for fine mapping of these genes and for marker-assisted selection in wheat breeding. Contrary to previous results, H9 and H10 did not show linkage with SSR markers on chromosome 5A. Instead, H9, H10, and H11 are linked with SSR markers on the short arm of chromosome 1A. Both H9 and H10 are tightly linked to flanking markers Xbarc263 and Xcfa2153 within a genetic distance of 0.3-0.5 cM. H11 is tightly linked to flanking markers Xcfa2153 and Xbarc263 at genetic distances of 0.3 cM and 1.7 cM. Deletion bin mapping assigned these markers and genes to the distal 14% of chromosome arm 1AS, where another Hf-resistance gene, Hdic (derived from emmer wheat), was also mapped previously. Marker polymorphism results indicated that a small terminal segment of chromosome 1AS containing H9 or H10 was transferred from the donor parent to the wheat lines Iris or Joy, and a small intercalary fragment carrying H11 was transferred from the resistant donor to the wheat line Karen. Our results suggest that H9, H10, H11, Hdic, and the previously identified H9- or H11-linked genes (H3, H5, H6, H12, H14, H15, H16, H17, H19, H28, and H29) may compose a cluster (or family) of Hf-resistance genes in the distal gene-rich region of wheat chromosome 1AS; and H10 most likely is the same gene as H9.