scholarly journals Effects of sublethal doses of contact insecticides on offspring production of different granary weevil populations

2010 ◽  
Vol 25 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Petar Kljajic ◽  
Ilija Peric
Keyword(s):  
Laboratory Population ◽  
Sitophilus Granarius ◽  
Wheat Grain ◽  
Granary Weevil ◽  
Offspring Production ◽  
Pirimiphos Methyl ◽  
Sublethal Doses ◽  
F2 Generation ◽  
Contact Insecticides ◽  
F1 Generation

The effects of prior contact of granary weevil (Sitophilus granarius L.) parents from a laboratory population, a Belgrade Port population (selected with LD70 pirimiphos-methyl) and a Bijeljina population (selected with LD70 deltamethrin) with filter paper treated with sublethal doses (LD20 and LD50) of the insecticides dichlorvos, malathion, chlorpyrifos-methyl, pirimiphos-methyl and deltamethrin on offspring production of the surviving insects in F1 generation (after 10 weeks) and F2 generation (after 16 weeks) in untreated wheat grain was examined under laboratory conditions. Offspring reduction of laboratory weevils was highest at 96% in the F1 generation after parents' contact with LD50 dichlorvos, and lowest in F2 generation after contact with LD50 pirimiphos-methyl with 84% more insects than in the control. The highest offspring reduction of selected weevils from Belgrade Port, 83%, was recorded in F1 generation after treatment with LD50 dichlorvos and chlopyrifos-methyl, and the lowest in F1 and F2 generations after contact with LD50 pirimiphos-methyl, around 44%. The highest offspring reduction of the selected weevils from Bijeljina, 100%, was found in F1 and F2 generations after contact with LD50 dichlorvos, malathion and deltamethrin, and the lowest again in F1 and F2 generations after contact with LD20 chlorpyrifos-methyl, in which case insect numbers were some 130% higher than in the control. The results indicate that sublethal insecticide doses, apart from a significant decrease in their efficacy against treated granary weevil populations, may also provoke an increase in insect numbers in the following generations.

scholarly journals Effects of 50°C temperature on Sitophilus granarius (L.), Sitophilus oryzae (L.) and Sitophilus zeamais (Motsch.)

2011 ◽  
Vol 26 (3) ◽  
pp. 221-227 ◽  
Author(s):  
Marijana Prazic-Golic ◽  
Goran Andric ◽  
Petar Kljajic
Keyword(s):  
Sitophilus Oryzae ◽  
Wheat Grain ◽  
Progeny Production ◽  
Maize Weevil ◽  
Granary Weevil ◽  
Total Period ◽  
Weevil Species ◽  
Short Term Exposure ◽  
Lethal Time ◽  
F1 Generation

Adults of laboratory populations of granary weevil (S. granarius), rice weevil (S. oryzae) and maize weevil (S. zeamais) were exposed at the temperature of 50?C to determine lethal time (parameters LT20, LT50 and LT99) and progeny production/reduction in F1 generation at mentioned temperature. For each exposure and each species 25 adults aged 2-5 weeks, in four replicates, were used. In the first treatment, the insects were exposed for 6, 10, 14, 16, 18, 20, 22, 26 and 30 min in plastic dishes (V=200 cm3) with 1.8 ? 0.2g of untreated coarse wheat. In the second treatment, in dishes with 100 g of untreated wheat grain the adults were exposed for 90, 100, 110, 120, 130, 140, 150, 165 and 180 min. After the exposure, the adults were placed in 100 g of untreated wheat grain, in four replicates, at 25 ? 1?C and 60 ? 5% r.h., for recovery. After one, two and seven days of recovery, the weevils were separated by sifting of wheat, and the mortality was determined, and after total period of eight weeks from the exposure of parents, the effect on progeny in F1 generation was determined. Lethal time for weevils was determined by probit analysis, and progeny production/reduction by analysis of variance. After weevils exposure in coarse wheat and after one, two and seven days of recovery, S. oryzae adults were the most susceptible (LT50 12.48-13.68 min), and the most tolerant were adults of S. granarius (LT50 17.79-20.89 min). After insects exposure in wheat grain, the most susceptible were S. granarius and S. oryzae (LT50 107.11-120.73 min), and the most tolerant S. zeamais (LT50 139.90-155.35 min). After exposure of parents of all three weevil species, in coarse wheat, progeny reduction at 100% level is after 22 min. However, after exposure of parents of all three weevil species in wheat grain, progeny reduction at 100% level in S. granarius is after 130 min, in S. oryzae after 150 min, and at 99.7% level in S. zeamais after 180 min. The investigations indicated that short-term exposure of weevils from Sitophilus genus at the temperature of 50?C adversely affects their survival and progeny production, as well as that there is a potential for its successful use as a physical measure in control of storage pest insects.

Observations on Males and Females of Sitophilus granarius (L.), the Granary Weevil, GG Strain, Exposed for Six Generations to Allethrin and Piperonyl Butoxide

1961 ◽  
Vol 93 (7) ◽  
pp. 545-552 ◽  
Author(s):  
C. Sevintuna ◽  
A. J. Musgrave
Keyword(s):  
Insect Resistance ◽  
Specific Resistance ◽  
Regression Line ◽  
Sitophilus Granarius ◽  
Recent Discussion ◽  
Granary Weevil ◽  
The Subject ◽  
Sublethal Doses ◽  
Males And Females ◽  
Genetic Phenomenon

In a recent discussion of the subject of insect resistance to insecticides, Brown (1958) has claimed that true resistance is characterized by a five-fold to ten-fold decrease in susceptibility. It is a genetic phenomenon arising as a result of selection. There is no evidence that insecticides are mutagenic, nor can resistance be induced by exposing insects to sublethal doses. A decrease in susceptibility that cannot be regarded as resistance is regarded as a condition of tolerance. In addition, the term “vigour tolerance”, intioduced by Hoskins and Gordon (see Brown, 1958) defines instances of enhanced tolerance due to extra vigour: true specific resistance is marked by a change of slope in the dosage-mortality regression line, while “vigour tolerance” is suggested if the regression line shifts but does not change in slope.

scholarly journals Efficacy of spinosad and abamectin against different populations of red flour beetle (Tribolium castaneum Herbst) in treated wheat grain

2013 ◽  
Vol 28 (2) ◽  
pp. 103-110
Author(s):  
Goran Andric ◽  
Petar Kljajic ◽  
Marijana Prazic-Golic
Keyword(s):  
Tribolium Castaneum ◽  
Significant Influence ◽  
Adult Mortality ◽  
Red Flour Beetle ◽  
Lower Mortality ◽  
Laboratory Population ◽  
Wheat Grain ◽  
Flour Beetle ◽  
Different Populations ◽  
Contact Insecticides

The efficacy of spinosad and abamectin against T. castaneum adults from a laboratory population with normal susceptibility to contact insecticides and against malathion-resistant populations from Nikinci and Jakovo was tested in the laboratory (25?1?C and 60?5% r.h.). The insecticides were applied to 500 g of untreated wheat grain for each of the following application doses: 0.25, 0.5, 1.0, 2.5 and 5.0 mg a.i./kg. After treatment, wheat was divided into three equal subsamples and 50 T. castaneum adults from each of the three test populations were released the next day into jars for each dose. Mortality was evaluated after 7, 14 and 21 days of exposure to treated wheat grain. Generally, higher concentrations and longer exposure periods resulted in higher efficacy of both insecticides, but abamectin was significantly more effective than spinosad against all three tested populations. After 7 days of exposure, mortality did not exceed 30% in any test variant. Fourteen days after treatment with the highest dose (5 mg/kg) of spinosad, mortality was highest (75%) in the laboratory population, while treatment with the same dose of abamectin achieved the highest mortality (58%) in the laboratory and Jakovo populations. After 21 days, spinosad applied at the rate of 5 mg/kg was most effective (97% mortality) in the laboratory population, while 88% efficacy was recorded in Jakovo population and 87% in Nikinci population. Abamectin doses of 2.5 and 5 mg/kg caused high adult mortality of 94-100% in the laboratory and Jakovo populations, and a significantly lower mortality in Nikinci population (75 and 86%, respectively). Statistically significant differences in the efficacy of spinosad, and particularly of abamectin, were detected among the three tested populations, the greatest difference being between the laboratory and Nikinci populations, which clearly indicates that resistance of T. castaneum adults to malathion had a significant influence.

Detection of granary weevil Sitophilus granarius (L.) eggs and internal stages in wheat grain using soft X-ray and image analysis

2007 ◽  
Vol 43 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Józef Fornal ◽  
Tomasz Jeliński ◽  
Jadwiga Sadowska ◽  
Stanisław Grundas ◽  
Jan Nawrot ◽  
...  
Keyword(s):  
Image Analysis ◽  
Sitophilus Granarius ◽  
Wheat Grain ◽  
Granary Weevil ◽  
X Ray

EFFECTS OF PHOTOPERIOD ON THE BIOLOGY OF THE GRANARY WEEVIL, SITOPHILUS GRANARIUS L. IN THE LABORATORY

2012 ◽  
Vol 3 (11) ◽  
pp. 1165-1171
Author(s):  
Y. Darwish ◽  
Y. Omar ◽  
R. Hassan ◽  
M. Mahmoud
Keyword(s):  
Sitophilus Granarius ◽  
Granary Weevil

The effects of cold pre-treatment on the toxicity of several contact insecticides on adults of three Sitophilus granarius (L.) populations

2014 ◽  
Vol 87 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Petar Kljajić ◽  
Goran Andrić ◽  
Marijana Pražić-Golić ◽  
Dušanka Inđić ◽  
Slavica Vuković
Keyword(s):  
Sitophilus Granarius ◽  
Pre Treatment ◽  
Contact Insecticides

Granary Weevil, Sitophilus granarius (Linnaeus) (Coleoptera: Curculionidae)

2008 ◽  
pp. 1653-1653
Author(s):  
Stewart B. Peck ◽  
Carol C. Mapes ◽  
Netta Dorchin ◽  
John B. Heppner ◽  
Eileen A. Buss ◽  
...  
Keyword(s):  
Sitophilus Granarius ◽  
Granary Weevil
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