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Full-Text Articles in Life Sciences
Stimulation Of Pheromone Biosynthesis In The Moth Helicoverpa Zea: Action Of A Brain Hormone On Pheromone Glands Involves Ca2+ And Camp As Second Messengers, Russell A. Jurenka, Emmanuelle Jacquin, Wendell L. Roelofs
Stimulation Of Pheromone Biosynthesis In The Moth Helicoverpa Zea: Action Of A Brain Hormone On Pheromone Glands Involves Ca2+ And Camp As Second Messengers, Russell A. Jurenka, Emmanuelle Jacquin, Wendell L. Roelofs
Russell A. Jurenka
Isolated abdomen and pheromone gland bioassays were utilized to determine the physiological action of the pheromone-biosynthesis-activating neuropeptide (PBAN) in the corn earworm moth Helicoverpa (= Heliothis) zea. An isolated pheromone gland bioassay showed that synthetic PBAN was active at 0.02 pmol, with maximal activity occurring at 0.5 pmol and 60 min of incubation. Second-messenger studies demonstrated that extracellular Ca2+ is necessary for PBAN activity on isolated pheromone glands. The Ca2+ ionophore A23187 stimulated pheromone biosynthesis alone, whereas the Ca2+ channel blockers La3+ and Mn2+ inhibited PBAN activity. However, the organic Ca2+ channel blockers verapamil and nifedipine did not inhibit PBAN …
Interaction Of Insecticide Resistance Genes In Field Populations Of Culex Pipiens (Diptera: Culicidae) From Italy In Response To Changing Insecticide Selection Pressure, Bryony C. Bonning, J. Hemingway, R. Romi, G. Majori
Interaction Of Insecticide Resistance Genes In Field Populations Of Culex Pipiens (Diptera: Culicidae) From Italy In Response To Changing Insecticide Selection Pressure, Bryony C. Bonning, J. Hemingway, R. Romi, G. Majori
Bryony C. Bonning
Culex pipiens Linnaeus larvae were collected from various locations in Italy and colonized as separate strains. These were analysed for elevated nonspecific esterase activity and frequency of altered acetylcholinesterase (AChE) mechanisms of insecticide resistance, and bioassayed, to define the cross-resistance spectra conferred by these to organophosphorus and carbamate insecticides. These mechanisms were further characterized by polyacrylamide gel electrophoresis. Elevated esterase A1 (formerly known as Est 3A) which predominated in C. pipiens from Italy in 1985 had been replaced by two esterases, A2 and B2. Altered acetylcholinesterase was still present at high frequencies. Altered and normal acetylcholinesterase were distinguished by differential …
Flight Times Of Africanized And European Honey Bee Drones (Hymenoptera: Apidae), Richard L. Hellmich Ii, Thomas E. Rinderer, Robert G. Danka, Anita M. Collins, D. L. Boykin
Flight Times Of Africanized And European Honey Bee Drones (Hymenoptera: Apidae), Richard L. Hellmich Ii, Thomas E. Rinderer, Robert G. Danka, Anita M. Collins, D. L. Boykin
Richard L Hellmich
Flight activities of Africanized honey bee (Apis mellifera L.) drones were compared with those of two color morphs of European drones in Venezuela. European drones departed from colonies 19 +/- (mean +/- SEM) min earlier, and flight times were more variable than those of Africanized drones. Mean flight time differences decreased as the drones aged and were similar whether drones were flying from Africanized or European colonies. Overlap of their flight distributions was > 70%, which suggests that interbreeding of the two types of bees will be substantial under most natural conditions. Black and yellow European drones flew at similar times …
Response Of Africanized And European Honey Bees To Lactose In Sucrose Syrup, H. Allen Sylvester, Richard L. Hellmich Ii, Anita M. Collins
Response Of Africanized And European Honey Bees To Lactose In Sucrose Syrup, H. Allen Sylvester, Richard L. Hellmich Ii, Anita M. Collins
Richard L Hellmich
Application of biotechnology to control Africanized honey bees may be possible by genetically engineering domestic honey bee stocks to be resistant to some agent which is toxic or debilitating to Africanized bees. The agent could then be made available to forages in an area, and susceptible wild colonies, including Africanized honey bees, would be controlled.
Depression Of Forage Quality Of Alfalfa Leaves And Stems By Acyrthosiphon Kondoi (Homoptera: Aphididae), Andrew W. Lenssen, Edgar L. Sorensen, Gerry L. Posler, Sue L. Blodgett
Depression Of Forage Quality Of Alfalfa Leaves And Stems By Acyrthosiphon Kondoi (Homoptera: Aphididae), Andrew W. Lenssen, Edgar L. Sorensen, Gerry L. Posler, Sue L. Blodgett
Andrew W. Lenssen
ACYTthosiphon kondoi Shinji is a major pest of alfalfa (Medicago sativa L.). Susceptible seedling plants are killed by A. kondoi, and established plants suffer yield loss by stunting. Information is meager on the influence of A. kondoi infestation or host plant resistance on forage quality of alfalfa leaves and stems. In a controlled environment, the forage quality (includingphenolic monomers)of alfalfagermplasmsKSI53P4and KS153BA3P4 (susceptible and resistant to A. kondoi, respectively) with and without A. kondoi infestation was compared. Leaves infested with A. kondoi had lower concentrations of crude protein and true in vitro digestible dry matter (TIVDDM) than uninfested leaves of controls, …