scholarly journals Dose-Mortality Response of the Cotton Boll Weevil to Selected Insecticides, 1995

1997 ◽  
Vol 22 (1) ◽  
pp. 416-417
Author(s):  
T. Stadler ◽  
G. H. McKibben
Keyword(s):  
Constant Temperature ◽  
Boll Weevil ◽  
Probit Analysis ◽  
Mortality Data ◽  
Cotton Boll ◽  
Light Phase ◽  
Mortality Response ◽  
Abdominal Surface ◽  
Petri Dishes ◽  
Mortality Estimates

Abstract Eight commercial insecticides were applied topically to adult laboratory-reared boll weevils. Serial dilutions were applied to the ventral abdominal surface utilizing a Hamilton repeating dispenser fitted with a 50 μl syringe calibrated to deliver a 1 jxl droplet. Insects were 5-7 d adults obtained from the USDA-ARS Gast Rearing Facility, Mississippi State, MS. Following topical application, weevils were placed in petri dishes, held at constant temperature (28°) and humidity (70-74%), at a 12 h light phase. Mortality was recorded after 24, 48, and 72 h. Mortality estimates LD50 were based on a minimum of four doses per in-secticide. Three replicates of 30 weevils each were treated. Dose-mortality data were analyzed by probit analysis. When necessary, control mortality was corrected using Abbott’s formula.

scholarly journals Mortality of the cotton boll weevil in drip and sprinkler irrigated cotton crops

2023 ◽  
Vol 83 ◽  
Author(s):  
R.F. Faustino ◽  
C.A.D. Silva ◽  
J.C. Zanuncio ◽  
J.R. Pereira ◽  
A.I.A. Pereira
Keyword(s):  
High Mortality ◽  
Irrigation System ◽  
Boll Weevil ◽  
Semiarid Region ◽  
Mortality Data ◽  
Anthonomus Grandis ◽  
Cotton Production ◽  
Cotton Boll ◽  
Organic System ◽  
Cotton Boll Weevil

Abstract The cotton boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a key cotton crop pest in Brazil. Adverse climatic factors, such as high temperatures and low soil moisture, dehydrate oviposited cotton squares (bud flowers) on the ground and cause high mortality of its offspring within these plant structures. The objective of this research was to evaluate the mortality of the cotton boll weevil in drip and sprinkler irrigated cotton crops. The experimental design was in randomized blocks with two treatments: drip (T1) and sprinkler (T2, control) irrigated cotton crops with sixteen replications. Each parcel had one emergence cage, installed between two cotton rows per irrigation system, with 37 cotton squares with opened oviposition punctures and yellowish bracts, to capture adult cotton boll weevils. The average number of boll weevils that emerged from the cotton squares and the causes of mortality at different development stages were determined per treatment. Third-generation life tables of the boll weevil were prepared using the natural mortality data in drip and sprinkler irrigation treatments and plus actual, apparent and indispensable mortality rates and the lethality of each mortality cause. We conclude that the application of water directly to the root zone of the plants in a targeted manner, using the drip irrigation system, can cause high mortality of the cotton boll weevil immature stages inside cotton squares fallen on the ground. This is because the cotton squares fallen on the drier and hotter soil between the rows of drip-irrigated cotton dehydrates causing the boll weevils to die. This is important because it can reduce its population density of the pest and, consequently, the number of applications of chemical insecticides for its control. Thus, contributing to increase the viability of cotton production, mainly in areas of the Brazilian semiarid region where the cotton is cultivated in organic system.

scholarly journals Local mortality estimates during the COVID-19 pandemic in Italy

2021 ◽  
Author(s):  
Augusto Cerqua ◽  
Roberta Di Stefano ◽  
Marco Letta ◽  
Sara Miccoli
Keyword(s):  
Machine Learning ◽  
Excess Mortality ◽  
Control Method ◽  
Local Level ◽  
Supervised Machine Learning ◽  
Machine Learning Techniques ◽  
Mortality Data ◽  
Official Method ◽  
Learning Techniques ◽  
Mortality Estimates

AbstractEstimates of the real death toll of the COVID-19 pandemic have proven to be problematic in many countries, Italy being no exception. Mortality estimates at the local level are even more uncertain as they require stringent conditions, such as granularity and accuracy of the data at hand, which are rarely met. The “official” approach adopted by public institutions to estimate the “excess mortality” during the pandemic draws on a comparison between observed all-cause mortality data for 2020 and averages of mortality figures in the past years for the same period. In this paper, we apply the recently developed machine learning control method to build a more realistic counterfactual scenario of mortality in the absence of COVID-19. We demonstrate that supervised machine learning techniques outperform the official method by substantially improving the prediction accuracy of the local mortality in “ordinary” years, especially in small- and medium-sized municipalities. We then apply the best-performing algorithms to derive estimates of local excess mortality for the period between February and September 2020. Such estimates allow us to provide insights about the demographic evolution of the first wave of the pandemic throughout the country. To help improve diagnostic and monitoring efforts, our dataset is freely available to the research community.

scholarly journals Response of Mexican Corn Rootworm to Insecticides, 1991

1995 ◽  
Vol 20 (1) ◽  
pp. 329-329
Author(s):  
E. Guerrero-Rodriguez ◽  
S. Davalos-Luna ◽  
J. Corrales-Reynaga
Keyword(s):  
Petri Dish ◽  
Mortality Data ◽  
Corn Rootworm ◽  
Field Corn ◽  
Paper Towel ◽  
Percent Mortality ◽  
Petri Dishes ◽  
Mexican Corn Rootworm ◽  
Corn Plants ◽  
Commercial Field

Abstract Populations of MCR of commercial field corn from Arenal, Jalisco were exposed to nine insecticides of organophosphorous (OP), cabamate, organo chlorinated and pyrethroid groups. Larvae were collected from the roots of corn plants daily, and confined in polyethylene black bags of two kg capacity with humidity and germinated corn as food for larvae. Insects were taken to the laboratory of Sanidad Vegetal in Guadalajara, Jalisco. Dilutions of the insecticides tested were prepared using acetone from 500 to 5000 ppm (6 to 9 dosage/product). For this study 20 larvae of last instar were selected and 1 u, liter of the solution was placed topically on the thorax, after this, each larva was placed in a petri dish with a moistened paper towel and the petri dishes confined in a cardboard box to eliminate light. Mortality counts were carried out at 24 hours. Percent mortality was corrected by Abbott’s formula. The mortality data were analyzed by probit to obtain LC50 and LC,5 values for each insecticide.

Midgut Genes Knockdown by Oral dsRNA Administration Produces a Lethal Effect on Cotton Boll Weevil

2020 ◽  
Author(s):  
Ricardo Salvador ◽  
José M. Niz ◽  
Pablo A. Nakaya ◽  
Analía Pedarros ◽  
H. Esteban Hopp
Keyword(s):  
Lethal Effect ◽  
Boll Weevil ◽  
Cotton Boll ◽  
Cotton Boll Weevil

scholarly journals Stability and tissue-specific Cry10Aa overexpression improves cotton resistance to the cotton boll weevil

2020 ◽  
Author(s):  
Thuanne Pires Ribeiro ◽  
Marcos Fernando Basso ◽  
Mayara Holanda de Carvalho ◽  
Leonardo Lima Pepino de Macedo ◽  
Dagna Maria Laurindo da Silva ◽  
...  
Keyword(s):  
Boll Weevil ◽  
Cotton Boll ◽  
Tissue Specific ◽  
Cotton Boll Weevil

scholarly journals Bioassay, Effect of Field-Aged Residue Degradation of Basillus Thuringiensis, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 351-351 ◽  
Author(s):  
J. F. Brunner ◽  
M. D. Doerr ◽  
L. O. Smith
Keyword(s):  
Constant Temperature ◽  
Petri Dish ◽  
Larval Survival ◽  
Apple Orchard ◽  
Food Storage ◽  
Storage Container ◽  
Tree Fruit ◽  
Petri Dishes ◽  
Extension Center ◽  
Neonate Larvae

Abstract Using a leaf-disk bioassay, B. thuringiensis products were evaluated for residue effects on PLR and OBLR neonate larvae. The test was conducted in an apple orchard at the Tree Fruit Research and Extension Center. The trees were 15-yr-old spur type ‘Red Delicious’ on dwarfing roots. The treatments were applied on 22 Sep at the recommended rate with a handgun sprayer at 300 psi to the point of drip, simulating a dilute spray of approximately 400 gal/acre. Each treatment was replicated three times with one tree in each. Ten leaves were collected from the interior canopy of each tree at 1, 4, 6 and 8 DAT. Two punches (2.3 cm diameter) were taken from each leaf. Four punches were placed in a petri dish (Falcon 1006, 50 × 9 mm), keeping the leaves from each replication separate. Petri dishes were chosen randomly, and five 1- to 2-d-old leafroller larvae were placed on the leaves. Five petri dishes were prepared for each tree and each leafroller species (75 larvae per treatment). The petri dishes were placed inside a food storage container and kept at 20°C constant temperature and a photoperiod of 16:8 (L:D) h. Petri dishes were examined after 7 d and larval survival recorded.

scholarly journals Changing effect of the numerator–denominator bias in unlinked data on mortality differentials by education: evidence from Estonia, 2000–2015

2020 ◽  
pp. jech-2020-214487
Author(s):  
Domantas Jasilionis ◽  
Mall Leinsalu
Keyword(s):  
High Education ◽  
Type Inequality ◽  
Mortality Data ◽  
Data Set ◽  
Inequality Measures ◽  
Death Record ◽  
Education Group ◽  
Range Type ◽  
Mortality Estimates ◽  
Mortality Inequality

BackgroundThis study highlights changing disagreement between census and death record information in the reporting of the education of the deceased and shows how these reporting differences influence a range of mortality inequality estimates.MethodsThis study uses a census-linked mortality data set for Estonia for the periods 2000–2003 and 2012–2015. The information on the education of the deceased was drawn from both the censuses and death records. Range-type, Gini-type and regression-based measures were applied to measure absolute and relative mortality inequality according to the two types of data on the education of the deceased.ResultsThe study found a small effect of the numerator–denominator bias on unlinked mortality estimates for the period 2000–2003. The effect of this bias became sizeable in the period 2012–2015: in high education group, mortality was overestimated by 23–28%, whereas the middle education group showed notable underestimation of mortality. The same effect was small for the lowest education group. These biases led to substantial distortions in range-type inequality measures, whereas unlinked and linked Gini-type measures showed somewhat closer agreement.ConclusionsThe changing distortions in the unlinked estimates reported in this study warn that this type of evidence cannot be readily used for monitoring changes in mortality inequalities.

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