Journal ArticleDOI
A method of computing the effectiveness of an insecticide
TLDR
In order to make experimental studies comparable and statistically meaningful, the article recommends the following formula: per cent control = 100(X - Y)/X, which eliminates errors due to deaths in the control sample which were not due to the insecticide.Abstract:
There are several statistical methods used in biology (entomology) for computing the effectiveness of an insecticide, based on relating the number of dead insects in the treated plat to the number of live ones in the untreated plat. In order to make experimental studies comparable and statistically meaningful, the article recommends the following formula: per cent control = 100(X - Y)/X, where X = % living in the untreated check sample and Y = % living in the treated sample. Calculation using this method eliminates errors due to deaths in the control sample which were not due to the insecticide. An example based on treatments of San Jose scale includes computation of probable errors for X and Y, and the significance of the difference between the two counts. Common biometric convention holds that when the difference between the results of two experiments is greater than three times its probable error, the results are significant and due to the treatment applied.read more
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Fitness costs limit the development of resistance to indoxacarb and deltamethrin in Heliothis virescens (Lepidoptera: Noctuidae).
TL;DR: Comparison of life traits between the selected and unselected populations revealed that the selected populations laid a significantly lower number of eggs and that a lower percentage of eggs hatched, which was reflected in both the net replacement rate and the intrinsic rate of population increase, which were both lower for theselected populations.
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2‐Undecanone, a constituent of the glandular trichomes of Lycopersicon hirsutum f. glabratum: Effects on Heliothis zea and Manduca sexta growth and survival
TL;DR: The effects of 2‐undecanone, a compound found in the glandular trichomes of the wild tomato, Lycopersicon hirsutum f.
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Comparative susceptibility of European corn borer, southwestern corn borer, and sugarcane borer (Lepidoptera: Crambidae) to Cry1Ab protein in a commercial Bacillus thuringiensis corn hybrid.
TL;DR: The lower susceptibility of D. saccharalis to Cry1Ab protein suggests that it is necessary to verify if a high-dose Bt corn for O. grandiosella is also a high dose for D.saccharalis, whereas O. nubilalis was most susceptible.
Journal ArticleDOI
Laboratory evaluation of a phytosteroid compound of mature leaves of Day Jasmine (Solanaceae: Solanales) against larvae of Culex quinquefasciatus (Diptera: Culicidae) and nontarget organisms
TL;DR: Qualitative and chromatographic analysis of the crude extract of C. diurnum revealed the presence of many bioactive phytochemicals, and the bioassay experiment with the third-instar larval form established that the presenceof a steroid compound was responsible for mosquitocidal activity.
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Studies on larvicidal and pupicidal activity of Leucas aspera Willd. (Lamiaceae) and bacterial insecticide, Bacillus sphaericus, against malarial vector, Anopheles stephensi Liston. (Diptera: Culicidae)
TL;DR: The present results suggest that the ethanolic extracts of L. aspera and B. sphaericus provided an excellent potential for controlling of malarial vector, A. stephensi.