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.
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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
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ABSTRACT: Phytophagous stink bugs are economically important pests of annual and perennial crops in the southeastern United States. Because of insecticide resistance and risk of secondary pest outbreaks, there is interest in identifying cultural practices that could lead to reduced insecticide applications. The objective of this project was to assess the importance of cotton planting date on stink bug damage to cotton. Unsprayed cotton plots with biweekly planting dates were established at three locations in southern Georgia in each of two crop years. During the bloom cycle, stink bug-induced boll injury was estimated weekly in each plot. Plots were subsequently defoliated, mechanically harvested, and ginned to assess differences in fiber yield and quality attributable to stink bug injury. Results show that the rate of boll damage generally increased more rapidly through the bloom cycle for planting dates in June compared with May. Similarly, estimates of boll damage from June-planted cotton more frequently exceeded the stink bug treatment threshold compared with May-planted cotton. In 2011, mean lint yield and economic returns from May planting dates were significantly greater than June planting dates. In 2012, lint yield and economic returns were greater in plots established in early May compared with later planting dates. Estimates of HVI color + b, a measure of fiber yellowness, were lower in early May-planted cotton compared with June planting. These data show that growers need to be aware of increased stink bug damage potential when planting late.Journal of Economic Entomology 04/2014; 107(2):646-53. DOI:10.1603/EC13395 · 1.61 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.