Composition and Abundance of Stink Bugs (Heteroptera: Pentatomidae) in Corn
ABSTRACT The species composition and abundance of stink bugs (Heteroptera: Pentatomidae) in corn, Zea mays L., was determined in this on-farm study in Georgia. Seven species of phytophagous stink bugs were found on corn with the predominant species being Nezara viridula (L.) and Euschistus servus (Say). All developmental stages of these two pests were found, indicating they were developing on the corn crop. The remaining five species, Oebalus pugnax pugnax (F.), Euschistus quadrator (Rolston), Euschistus tristigmus (Say), Euschistus ictericus (L.), and Acrosternum hilare (Say), were found in relatively low numbers. Adult N. viridula were parasitized by the tachinid parasitoid Trichopoda pennipes (F.). There was a pronounced edge effect in distribution of stink bugs in corn. Population dynamics of N. viridula and E. servus were different on early and late-planted corn. Oviposition by females of both stink bug species occurred in mid-to-late-May and again mid-to-late-June in corn, regardless of planting date. In early planted fields, if stink bug females oviposited on corn in mid-July, the resulting nymphs did not survive to the adult stage in corn because ears were close to physiological maturity and leaves were senescing. Density of stink bug adults in early planted corn was relatively low throughout the growing season. In late-planted corn, females of both stink bug species consistently laid eggs in mid-to-late-July on corn with developing ears. This habitat favored continued nymph development, and the resulting adult population reached high levels. These results indicate that corn management practices play a key role in the ecology of stink bugs in corn agroecosystems and provide information for designing management strategies to suppress stink bugs in farmscapes with corn.
SourceAvailable from: Xinzhi Ni[Show abstract] [Hide abstract]
ABSTRACT: Phytopathogen infections are frequently influenced by both biotic and abiotic factors in a crop field. The effect of brown stink bug, Euschistus servus (Hemiptera: Pentatomidae), feeding and planting date and sampling time on common smut (Ustilago maydis) infection percentage of maize plants was examined in 2005 and 2006, and 2010 and 2011, respectively. Brown stink bug adult feeding on maize hybrid ‘DKC6971’ at flowering in 2005 and 2006 did not influence smut infection percentage when examined using three treatments (i.e., 0 adult, 5 adults, and 5 adults mixed with the smut spores). The smut infection percentages were < 3% (n = 12) in the three treatments. The smut infection percentage among the four weekly samplings was the same, so was natural aflatoxin contamination at harvest among the treatments. The second experiment showed that planting date did not affect the smut infection percentage in either 2010 or 2011. But, the smut infection percentage from the post-flowering sampling was greater than pre-flowering sampling in both years. The smut infection percentage varied among the germplasm lines in 2010, but not in 2011. This study demonstrated that brown stink bug feeding at flowering had no effect on smut infection in maize, and the best time for smut evaluation would be after flowering. The temperature and precipitation might have also influenced the percentage of smut infected maize plants during the four years when the experiments were conducted. The similarity between kernel-colonizing U. maydis and Aspergillus flavus infections and genotype × environment interaction were also discussed.This article is protected by copyright. All rights reserved.Insect Science 06/2014; 21(5). DOI:10.1111/1744-7917.12149 · 1.51 Impact Factor
Article: The Tachinid Times[Show abstract] [Hide abstract]
ABSTRACT: Welcome to the 25th anniversary issue of The Tachinid Times. Twenty-four years have passed since this newsletter first appeared in print. I was expecting it to last for a few years through the support of several kind con-tributors, but I did not hold high hopes for its longevity. A few lean years and it would be gone. Yet here we are in 2012, at issue 25 and the newsletter has endured. Its continuance is perhaps a sign that this informal venue for news on the Tachinidae has a small but stable niche within the broad spectrum of scientific endeavour. In the article that follows I give a brief history of The Tachinid Times and explain what motivated its start nearly a quarter of a century ago. There would be no newsletter without submissions, and in this issue there is a wide range of articles to satisfy every taste. I would like to thank all the contributors for making this 25th issue a memorable one. As I explain each year in this foreword, The Tachinid Times is primarily an online newsletter but a printed copy can still be sent to anyone would who like one. Hardcopies are also distributed to several libraries to provide a perman-ent record of this publication. Both online and print ver-sions are based on the same PDF and thus have the same pagination and appearance. submissions on all aspects of tachinid biology and sys-tematics, but please keep in mind that this is not a peer-reviewed journal and is mainly intended for shorter news items that are of special interest to persons involved in tachinid research. Student submissions are particularly wel-come, especially abstracts of theses and accounts of studies in progress or about to begin. I encourage authors to illus-trate their articles with colour images, since these add to the visual appeal of the newsletter and are easily incorporated into the final PDF document. Please send images as se-parate image files apart from the text.
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ABSTRACT: The local dispersal of polyphagous, mobile insects within agricultural systems impacts pest management. In the mid-Atlantic region of the United States, stink bugs, especially the invasive Halyomorpha halys (Stål 1855), contribute to economic losses across a range of cropping systems. Here, we characterized the density of stink bugs along the field edges of field corn and soybean at different study sites. Specifically, we examined the influence of adjacent managed and natural habitats on the density of stink bugs in corn and soybean fields at different distances along transects from the field edge. We also quantified damage to corn grain, and to soybean pods and seeds, and measured yield in relation to the observed stink bug densities at different distances from field edge. Highest density of stink bugs was limited to the edge of both corn and soybean fields. Fields adjacent to wooded, crop and building habitats harbored higher densities of stink bugs than those adjacent to open habitats. Damage to corn kernels and to soybean pods and seeds increased with stink bug density in plots and was highest at the field edges. Stink bug density was also negatively associated with yield per plant in soybean. The spatial pattern of stink bugs in both corn and soybeans, with significant edge effects, suggests the use of pest management strategies for crop placement in the landscape, as well as spatially targeted pest suppression within fields.PLoS ONE 10/2014; 9. DOI:10.1371/journal.pone.0109917 · 3.53 Impact Factor