Insect Growth Regulators: Some Effects of Methoprene and Hydroprene on Productivity of Several Stored Grain Insects.

1977 ◽  
Vol 25 (2) ◽  
pp. 201 ◽  
Author(s):  
TG Amos ◽  
P Williams
Keyword(s):  
Growth Regulators ◽  
Sitophilus Oryzae ◽  
Adult Mortality ◽  
Rhyzopertha Dominica ◽  
Stored Grain ◽  
Insect Growth Regulators ◽  
Insect Growth ◽  
Stored Grain Insects

The effects of two insect growth regulators on the productivity of Rhyzopertha dominica, Sitophilus oryzae and S. granarius were studied by exposing insects to wheat treated with methoprene (isopropyl 11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate) or hydroprene (ethyl 3,7,11-trimethyldodeca-2,4-dienoate) at concentrations of 1, 5, 10 and 20 ppm. Parental adult mortality was generally higher on wheat treated with methoprene than with hydroprene, and this effect was usually enhanced under unventilated conditions. The productivity of the three species was markedly reduced, in some instances suppressed, under unventilated conditions, whereas only R. dominica productivity was depressed under ventilated conditions. When progeny were produced, their productivity was, in general, lower than normal.

Control of Main Stored-Grain Insects with New Formulations of Entomopathogenic Fungi in Diatomaceous Earth Dusts

2008 ◽  
Vol 4 (1) ◽  
Author(s):  
Yacoub Ahmad Batta
Keyword(s):  
Entomopathogenic Fungi ◽  
Diatomaceous Earth ◽  
Sitophilus Oryzae ◽  
Germination Percentage ◽  
Fungal Species ◽  
Rhyzopertha Dominica ◽  
Stored Grain ◽  
High Loss ◽  
Mortality Percentage ◽  
Stored Grain Insects

The present research is aimed at a formulation of the entomopathogenic fungi, Beauveria bassiana (Bal.) Vuillemin and Metarhizium anisopliae (Metch.) Sorokin, in two types of diatomaceous earth dusts, fossil shield and Silico-Sec, are then applied against the adults of three species of stored-grain insects: Sitophilus oryzae L., Rhyzopertha dominica Fab. and Tribolium castaneum Herbs. Effect of the treatment was assessed by comparing the mortality percentage of the adults of the three insect species exposed to the formulated fungi with that of the adults exposed to the unformulated fungi or the diatomaceous earth dusts or the undisturbed control. Results obtained from these exposures have indicated that treatment of the adults with the formulated fungi resulted in a significantly higher mean mortality percentage compared to the treatment with the unformulated fungi or the diatomaceous earth dusts or the undisturbed control. A synergistic interaction between the effect of fungal species and the diatomaceous earth dusts was shown. Viability of conidia of both fungal species in diatomaceous earth dusts was assessed by calculating the germination percentage of the conidia over time. Results indicated a small loss of mean germination percentage for formulated conidia of both fungal species versus a high loss of mean germination percentage for the unformulated conidia, thus the diatomaceous earth dusts used in the formulation of both fungi demonstrated a negligible effect on the viability of formulated conidia compared to the unformulated.

The importance of formulating insect growth regulators with surfactants and their blends for the control of the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

1985 ◽  
Vol 6 (2) ◽  
pp. 183-186 ◽  
Author(s):  
J. N. Mkhize ◽  
A. P. Gupta
Keyword(s):  
Growth Regulators ◽  
Half Life ◽  
Sitophilus Oryzae ◽  
Residual Activity ◽  
Tween 80 ◽  
Insect Growth Regulators ◽  
Sorbitan Monooleate ◽  
Insect Growth ◽  
Span 80 ◽  
Wheat Kernels

AbstractThe use of surfactants and their blends to improve the penetration of two insect growth regulators (IGRs; hydroprene and R-20458) into wheat kernels was investigated. It was found that formulation of IGRs with a surfactant, Tween-85 (polyoxyethylene trioleate), increased mortality and/or effectiveness of the IGRs. Formulation of hydroprene with a blend of Span-80 (sorbitan monooleate) with Tween-80 (polyoxyethylene monooleate) produced results comparable to those by hydroprene with Tween-85. However, formulations of IGRs with surfactants with high or low hydrophile-lipophile balance (HLB), failed to provide suitable control of the weevil, probably due to the type of emulsions formed. The same results were obtained with hydroprene formulations with blends of Spans and Tweens, even though their HLBs were close to that of Tween-85. Residual half-life for hydroprene was about three months; formulations with Tween-85 or a blend of Span-80 did not enhance the residual activity for hydroprene in wheat.

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