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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Changes in egg size of the diamondback moth Plutella xylostella (Lepidoptera: Yponomeutidae) treated with fenvalerate at sublethal doses and viability of the eggs
TL;DR: The treatment of a sublethal dose against the parent affected the development and survival of offspring at immature stages of males, and the hatchability of smaller eggs laid by treated females at LD 2 5 tended to be lower than those of controls under different humidity conditions.
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Field-evolved resistance of Helicoverpa zea (Boddie) to transgenic maize expressing pyramided Cry1A.105/Cry2Ab2 proteins in northeast Louisiana, the United States.
Gagandeep Kaur,Jianguo Guo,Sebe Brown,Graham P. Head,Paula A. Price,Silvana V. Paula-Moraes,Xinzhi Ni,Marcelo Dimase,Fangneng Huang +8 more
TL;DR: It is documented that the observed field control problems of Cry1A.105/Cry2Ab2 maize against H. zea in northeast Louisiana were due to resistance development of the insect to the Bt proteins in plants.
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Impacts of the pesticides imidacloprid, propargite, and pymetrozine on Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae): IOBC and life table assays
TL;DR: Life table assays revealed that imidacloprid and propargite had no significant effects on the intrinsic rate of natural increase, while pymetrozine caused a 34% reduction in rm value (p < 0.05).
Journal ArticleDOI
Lethal and behavioural effects of three synthetic repellents (DEET, IR3535 and KBR 3023) on Aedes aegypti mosquitoes in laboratory assays
TL;DR: All three repellents had a significant effect on mosquitoes, but DEET exhibited a more complex mode of action than the others due to its insecticidal properties.
Journal ArticleDOI
Hemodynamic dysfunction and cytochrome P4501A mRNA expression induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin during embryonic stages of lake trout development.
TL;DR: It is concluded that subtle, ultrastructural changes in vascular endothelial cells consistently precede increases in vascular permeability and sac fry mortality; however, induction of CYP1A mRNA occurs prior to any observable morphological lesions, changes inascular permeability, or sac Fry mortality.