Rubidium Marking to Detect Dispersal of Pest and Predator from Corn into Sorghum and Cotton in Georgia

2007 ◽  
Vol 42 (3) ◽  
pp. 383-391 ◽  
Author(s):  
P. G. Tillman ◽  
J. R. Prasifka ◽  
K. M. Heinz
Keyword(s):  
Field Study ◽  
Helicoverpa Zea ◽  
Cotton Field ◽  
Orius Insidiosus ◽  
Field Site ◽  
Rubidium Chloride ◽  
Common Boundary ◽  
Field Plots

This field study evaluated marking both the pest [Helicoverpa zea (Boddie)] and its predator [Orius insidiosus (Say)] with rubidium chloride (RbCI) in corn to detect dispersal of these insects from this crop into sorghum and cotton. Sorghum and cotton were planted in small plots at the interface, or common boundary, of a commercial corn and cotton field. The cotton field adjacent to these interface plots was divided into cotton field plots. Foliar solutions of RbCI were applied to corn at field site 1 when the ears were infested with 4th through 6th instars of H. zea and at site 2 when corn silks were infested with eggs and 1st instars of H. zea and nymphs and adults of O. insidiosus. Insects were collected at various times after RbCI application from the sorghum interface plots, cotton interface plots, and cotton field plots. Both H. zea eggs and O. insidiosus females were successfully marked in corn treated with RbCI, and marking success for both insects ranged from 15–33%. Data on rubidium-marked insects indicated that H. zea females from the generation feeding on rubidium-treated corn dispersed into sorghum interface plots at both treated sites and into cotton interface plots at one site and that O. insidiosus females dispersed from corn into sorghum interface plots and cotton field plots at one site.

Bacillus thuringiensis Alone and in Mixtures with Chemical Insecticides against Heliothines and Effects on Predator Densities in Cotton

1997 ◽  
Vol 32 (2) ◽  
pp. 183-191 ◽  
Author(s):  
S. Y. Young ◽  
T. J. Kring ◽  
D. R. Johnson ◽  
C. D. Klein
Keyword(s):  
Bacillus Thuringiensis ◽  
Species Composition ◽  
Helicoverpa Zea ◽  
Cotton Field ◽  
Predator Density ◽  
Chemical Insecticide ◽  
Delayed Effects ◽  
Arthropod Predators ◽  
Developmental Rates ◽  
Delayed Mortality

Tests were conducted in a cotton field in 1994 and 1995 to evaluate the efficacy of Bacillus thuringiensis var. kurstaki Berliner alone and in mixtures with thiodicarb and cyhalothrin against heliothines and to evaluate the survival of predators on cotton. The heliothine population treated in both years was almost entirely Helicoverpa zea (Boddie) (>97%). In both years, B. thuringiensis alone failed to reduce larval populations over the control plots (P > 0.05). Larval densities were similarly reduced in thiodicarb and thiodicarb-B. thuringiensis treatments. Treatments that contained cyhalothrin and/or profenofos provided the best control. Bacillus thuringiensis treatment of plots did not have any delayed effects on H. zea such as reductions in developmental rates or delayed mortality beyond 3 days after application. In addition, heliothine egg mortality in the 1994 collection 3 days after application did not differ significantly among treatments. Predator density in the B. thuringiensis alone treatment was similar to the untreated control. All treatments that contained conventional chemical insecticides, including thiodicarb at the ovicidal rate, reduced predator densities to low numbers. These data indicate that B. thuringiensis did not provide control of H. zea in cotton fields and did not improve control of H. zea when used in mixtures with an ovicide or larvacide. Therefore, caution should be urged in recommending B. thuringiensis when the heliothine species composition is skewed toward H. zea. Furthermore, when B. thuringiensis was used in mixtures with chemical insecticides, there was no conservation of arthropod predators relative to use of traditional chemical insecticide treatments.

scholarly journals Plant age, crop stage and surrounding habitats: their impact on sucking pests and predators complex in cotton (Gossypium hirsutum L.) field plots in arid climate at district Layyah, Punjab, Pakistan

2022 ◽  
Vol 82 ◽  
Author(s):  
A. Nadeem ◽  
H. M. Tahir ◽  
A. A. Khan
Keyword(s):  
Insect Pests ◽  
Abiotic Factors ◽  
Threshold Level ◽  
Plant Age ◽  
Cotton Field ◽  
Strong Positive Correlation ◽  
Green Lacewings ◽  
Arthropod Predators ◽  
Trap Cropping ◽  
Field Plots

Abstract Sucking pests are major threat to cotton field crop which cause unbearable losses to the crop yield. Aim of the current study was to record seasonal dynamics of major sucking insect pests including whitefly, jassid, thrips and their natural arthropod predators i.e. green lacewings and spiders in cotton field plots. The effects of surrounding field crops on pests’ density and predatory efficiency of predators were also recorded. For sampling and survey of insects, the visual counting was found to be the most efficient method for recording the abundance of insects, trailed by net sweeping and tapping. Whitefly was the most dominant sucking pest found on the vegetative stage of cotton, followed by jassid and thrips. Fluctuated populations of predatory arthropods, spiders and green lacewings were also recorded during whole cropping season however, the densities of pests and predators varied with crop phenology. Spiders’ population was encouraging at both vegetative and flowering stage and also the same trend of jassid and whitefly were observed at both stages of the crop. Surrounding habitats showed non-significant effect on population densities of insect pests and predators. For abiotic factors, the spiders showed strong positive correlation with humidity and temperature. However, green lacewing was only positively correlated with humidity. On the other hand, the populations of whitefly, jassid and thrips showed non-significant correlation with both temperature and humidity. Overall densities of sucking insect pests were found above economic threshold level. The plant age, crop stage and surrounding habitats effect on the population fluctuation of pests as well as the predators’ abundance. The future studies are also warranted to investigate the altered habitats and multiple trap cropping to find out their impact on unattended insect predators and parasitoids in cotton crop.

scholarly journals Bermudagrass Resistance to Spring Dead Spot Caused by Ophiosphaerella herpotricha

Plant Disease ◽  
1998 ◽  
Vol 82 (7) ◽  
pp. 771-774 ◽  
Author(s):  
J. H. Baird ◽  
D. L. Martin ◽  
C. M. Taliaferro ◽  
M. E. Payton ◽  
N. A. Tisserat
Keyword(s):  
Field Study ◽  
Disease Severity ◽  
Shoot Density ◽  
Root Weight ◽  
Spring Dead Spot ◽  
Ophiosphaerella Herpotricha ◽  
Cynodon Transvaalensis ◽  
Field Plots

Field and greenhouse studies were conducted to evaluate the resistance of seed- and vegetatively propagated bermudagrass entries (Cynodon spp.) to spring dead spot caused by Ophiosphaerella herpotricha. In Kansas greenhouse studies, O. herpotricha caused root discoloration and root weight reductions in all entries tested. However, in Kansas field plots, root weight reductions were not different among entries and were not correlated with disease severity ratings. In an inoculated field study in Oklahoma, diseased areas ranged from 47 cm2 for the entry Jackpot to 262 cm2 for Poco Verde in 1995, and from 121 to 1,810 cm2 for the entries Guymon and Common in 1996. African bermudagrass (Cynodon transvaalensis) exhibited the greatest number of live shoots per diseased area in both years, due in part to its greater shoot density, but also indicating greater potential to recover from the disease. African bermudagrass, Guymon, Sundevil, Midlawn, Midfield, Ft. Reno, Mirage, and several experimental seed-propagated entries were most resistant to spring dead spot, having the lowest diseased area and greatest number of live shoots within diseased areas. In Oklahoma, severity of spring dead spot among bermudagrass entries was correlated with feeeze injury that occurred during the first winter after planting.

scholarly journals EVALUASI LAPANG TERHADAP DAMPAK APLIKASI INSEKTISIDA ISOPROCARB PADA SERANGGA PREDATOR DAN HAMA KUTU PERISAI AULACASPIS TEGALENSIS Zhnt. (HOMOPTERA: DIASPIDIDAE) DI PERTANAMAN TEBU

2004 ◽  
Vol 4 (2) ◽  
pp. 69-74
Author(s):  
Rosma Hasibuan
Keyword(s):  
Field Study ◽  
Field Evaluation ◽  
Chemical Insecticide ◽  
Insecticide Application ◽  
Sugarcane Field ◽  
Carbamate Insecticide ◽  
Predacious Species ◽  
The Impact ◽  
Field Plots ◽  
Aulacaspis Tegalensis

Field evaluation of isoprocarb insecticide-application-effects on predacious insects and scale pest Aulacaspis tegalensis Zhnt. (Homoptera: Diaspididae) in sugarcane plantations.  The sugarcane scale, Aulacaspis tegalensis Zehntner,  is a new  serious pest of sugarcane in Lampung Province.  Over the years, most control practices against A. tegalensis  rely on the use of chemical insecticide.  A  field  study was conducted to assess  the  impact of  isoprocarb (carbamate-insecticide) on sugarcane scale pests  and  their natural predators in sugarcane  plantation.  The results indicated  that the application of  isoprocarb  (at recommended  concentration = 1.25 mg/L) in sugarcane field failed to cause  a significant reduction on  scale pest  populations.  In contrast, the numbers of  predacious insects was significantly reduced  in isoprocarb-treated-field plots.     The  predacious insects  in association with scale pests in sugarcane fields were predominantly  coccinellids.  Four species of primary predacious coccinellids attacking scale pests were: Chilocorus melanophthalmus, Chilocorus sp.,  Scymnus sp, and Telsimia sp.  This field study indicated that the predacious species were more susceptible to isoprocarb than their prey.

scholarly journals Efficacy of Three Insecticides for Controlling Corn Earworm, Helicoverpa zea (Boddie) in Maize

2013 ◽  
Vol 20 (1-2) ◽  
pp. 43-47
Author(s):  
MA Uddin ◽  
M Jahan ◽  
MM Uddin ◽  
MM Rahman
Keyword(s):  
Field Study ◽  
Helicoverpa Zea ◽  
Yield Loss ◽  
Corn Earworm ◽  
Time Intervals ◽  
Field Laboratory ◽  
Insecticidal Toxicity ◽  
Different Doses

A field study was conducted to test the efficacy of three insecticides viz. Dursban 20 EC, Decis 2.5 EC and Lebaycid 50 EC with three different doses @ 0.1%, 0.2% and 0.3% in controlling the Helicoverpa zea in maize (cv. BARI Hybrid Bhutta-5) at Entomology Field Laboratory, BAU, Mymensingh. The results showed that the lowest percent of cob infestation was 1.72%, 1.90% and 2.75% at 3 DAT, 7 DAT and 12 DAT in 0.3% Decis treated plots, respectively. The highest percent of cob infestation was observed in untreated plots. The lowest mean number of kernel damage (2.10) and yield loss (1.40 kg/ha) were found with 0.3% Decis 2.5 EC treated plots. The efficacy of insecticides were Decis 2.5 EC (0.3%) > Decis 2.5 EC (0.2%) > Dursban 20 EC (0.3%) > Lebaycid 50 EC (0.3%). The efficacy of all insecticides on cob infestation at different time intervals indicated that insecticidal toxicity decreases with the increasing time after application.DOI: http://dx.doi.org/10.3329/pa.v20i1-2.16848 Progress. Agric. 20(1 & 2): 43 – 47, 2009

scholarly journals Gene Flow Between Bt and Non-Bt Plants in a Seed Mixture Increases Dominance of Resistance to Pyramided Bt Corn in Helicoverpa zea (Lepidoptera: Noctuidae)

2020 ◽  
Vol 113 (5) ◽  
pp. 2041-2051 ◽  
Author(s):  
Yves Carrière ◽  
Ben A Degain ◽  
Virginia S Harpold ◽  
Gopalan C Unnithan ◽  
Bruce E Tabashnik
Keyword(s):  
Helicoverpa Zea ◽  
Relative Survival ◽  
Bt Corn ◽  
Bt Toxins ◽  
F1 Progeny ◽  
Survival And Development ◽  
Seed Mixture ◽  
Field Plots ◽  
Lepidoptera Noctuidae ◽  
Seed Mixtures

Abstract For delaying evolution of pest resistance to transgenic corn producing Bacillus thuringiensis (Bt) toxins, limited data are available to compare the effectiveness of refuges of non-Bt corn planted in seed mixtures versus blocks. Here we addressed this issue in the ear-feeding pest Helicoverpa zea Boddie by measuring its survival and development in the laboratory on ears from field plots with 90% Cry1A.105 + Cry2Ab corn and 10% non-Bt corn planted in a seed mixture or blocks. We compared a strain of H. zea selected for resistance to Cry1Ac in the laboratory, its parent strain not selected in the laboratory, and their F1 progeny. The relative survival of the F1 progeny and dominance of resistance were higher on ears from Bt plants in the seed mixture than the block. Half of the kernels in ears from non-Bt plants in the seed mixture produced both Cry1A.105 and Cry2Ab. However, survival on ears from non-Bt plants did not differ between the block and seed mixture. In simulations based on the observed survival, resistance to Cry1A.105 + Cry2Ab corn evolved faster with the seed mixture than the blocks, because of the higher dominance of resistance in the seed mixture. Increasing the refuge percentage improved durability of Cry1A.105 + Cry2Ab corn more for the blocks than the seed mixture. These findings imply that, for a given percentage of non-Bt corn, resistance of H. zea and other ear-feeding pests to multi-toxin Bt corn is likely to evolve faster for seed mixtures than blocks.

scholarly journals Study on Nature and Extent of Damage of Corn Earworm, Helicoverpa zea (Boddie) in Maize

2013 ◽  
Vol 20 (1-2) ◽  
pp. 49-55
Author(s):  
MA Uddin ◽  
M Jahan ◽  
MM Uddin
Keyword(s):  
Field Study ◽  
Helicoverpa Zea ◽  
Yield Loss ◽  
Corn Earworm ◽  
Infestation Rate ◽  
Average Yield ◽  
Faecal Matter ◽  
Maize Varieties ◽  
The Mean ◽  
Extent Of Damage

A field study was conducted on the nature and extent of damage of corn earworm, Helicoverpa zea (Boddie) in two maize varieties viz. BARI Hybrid Bhutta-5 and BARI Bhutta-7. The larvae caused damage by feeding on the ear tip at silk stage and then to kernel, the larvae were mainly confined to the ear tip and excreted faecal matter. It was found that the cob infestation rate was in linear progress and the mean cob infestation was 6.50% and 6.69% in BARI Hybrid Bhutta-5 and BARI Bhutta-7, respectively. The mean length of cob infestation was 24.90% and 25.07% and the mean number of kernel damage was 24.30 and 25.43 in BARI Hybrid Bhutta-5 and BARI Bhutta-7, respectively. The average yield loss was 0.016 t/ha in BARI Hybrid Bhutta-5 and 0.017 t/ha in BARI Bhutta-7. It was revealed from the results that BARI Bhutta-7 was more susceptible to this pest.DOI: http://dx.doi.org/10.3329/pa.v20i1-2.16849 Progress. Agric. 20(1 & 2): 49 – 55, 2009

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