Gamal El-Ghar

Joint action of benzoylphenylureas in binary mixtures against larvae of the cotton leafworm,Spodoptera littoralis

Phytoparasitica, Dec 1, 1987

In preliminary laboratory tests, the joint activity of six benzoylphenylureas (BPUs) was studied ... more In preliminary laboratory tests, the joint activity of six benzoylphenylureas (BPUs) was studied by investigating the activity of 90 of their binary mixtures against fourth-instar larvae of the cotton leaf worm, Spodoptera littoralis (Boisd.), fed for 72 h on 10 ppm BPU-treated castor bean leaves. Experimental mixing ratios were 1:1, 1:4, and 1: 9. At 10 ppm, the activity of the six BPUs was divided into two distinct groups. The first included the more active compounds (XRD-473, GR-333, and chlorfluazuron) while the second was composed of the relatively less active ones (diflubenzuron, triflumuron, and Dowco-439). Results of the assays indicated that only 18 of the 90 tested binary mixtures showed potentiation, whereas the majority, 70 mixtures, exhibited additive effects; two interacted antagonistically. Most of the potentiated pairs were at a mixing ratio of 1:9, pairing one strong BPU (at the low ratio) with a weak one (at the high ratio). The mixing ratio of 1:1 resulted in additive effects.

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Effects of insect growth regulators with juvenile hormone activity againstCallosobruchus maculatus (F.) (Coleoptera: Bruchidae)

Journal of Pest Science, Oct 1, 1992

Five insect growth regulators, CGA-29170, CGA-45128, MV-678, RO-20458, and fenoxycarb, that exhib... more Five insect growth regulators, CGA-29170, CGA-45128, MV-678, RO-20458, and fenoxycarb, that exhibit juvenile hormone activity were evaluated for biological and residual activity against the southern cowpea weevil, Callosobruchus maculatus (F.). The compounds were mixed with cowpea seeds at concentrations of 10, 25, 50, and 100mg/kg, and the residual 9 activity was evaluated at 2-week to 9-months posttreatment intervals. Most JHA-treatments showed high initial activity at the 2-week interval resulting in a significantly lower oviposition rate and showing a short residual life in this respect. CGA-45128, however, at all concentrations tested did not significantly affect oviposition at 2-week to 4-month posttreatment intervals, where was more active and caused high depression in oviposition at 6-month interval. The juvenoids had an inductive effect on the percent egg hatch at various intervals, especially CGA-29170 and CGA-45128 treatments extinding over a period of 9 months. At the lower concentration of 10mg/kg, CGA-45128 was highly effective as Fl-progeny suppressant of C. maculatus at 2-week posttreatment interval extending over 9 months. MV-678, CGA-29170, and fenoxycarb applied at 50, 50, and 25mg/kg, respectively, showed similar activity, however, the residual activity of the latter decreased after 4 months. RO-20458, however, showed high initial activity at these concentrations. Aduk emergence in all treatments was significantly suppressed, where did not exceed 29.5 % at the lower concentrations of 10 and/or 25mg/kg at 9-month posttreatment interval.

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Selective toxicity of organophosphorus insecticides to the cabbage aphid, Brevicoryne brassicae (Homoptera: Aphididae), and its parasitoid, Diaeretiella rapae (Hymenoptera: Aphidiidae)

Chromosomal Aberrations and Spermhead Abnormalities Induced by Abamectin (Avermectin B1) and its Degradates in Male Swiss Albino Mice

CYTOLOGIA, 1995

Avermectins are a complex of chemically related naturally occurring macrocyclic lactones which fi... more Avermectins are a complex of chemically related naturally occurring macrocyclic lactones which first isolated as a natural fermentation product of a soil actinomycete, Streptomyces avermitilis, in 1976 (Burg et al. 1979). The naturally occurring avermectins can be separated into four homologous pairs, of which one, abamectin (avermectin B1), which consists of 80% of avermectin B1a and 20% of avermectin B1b has been developed for use against arthropod pests of horticulture and agronomic crops (Dybas and Green 1984). Currently, it is rapidly worldwide growing in usage for many agronomic crops. They are potent chemotherapeutic agents against animal parasitic nematodes and many veterinary and agricultural arthropod pests (Putter et al. 1981, Campbell et al. 1983, Lasota and Dybas 1991). Abamectin increases calcium permeability to chloride ions, which is independent of the neurotransmitter, gamma aminobutyric acid (GABA)-mediated chloride ion channels (Calcott and Fatig 1984). The compounds' mechanism of toxicity in mammals is unknown but GABA is a mammalian central nervous system neurotransmitter and effects on GABA may be relevant to their safety in mammals (Lankas and Gordon 1989). Carcinogenicity studies with abamectin at maximum tolerated dosage levels for 22 and 24 months duration in mice and rats, respectively, have demonstrated the lack of carcinogenicity of this compound (Lanks and Gordon 1989). Also they showed the lack of genotoxic activity of abamectin in a variety of assays. Abamectin degradates were tested and found to have no adverse maternal and developmental effects in CF 1 mouse, the laboratory species/strain most sensitive to abamectin toxicity. In addition, the degradates from photolysis of thin films were negative in the microbial mutogenesis assay (Crouch et al. 1992). The specific objectives of the present study were; (1) to estimate the percentage of mitotic abnormalities in male mice bone marrow cells induced by abamectin and its degradates, (2) to measure the amount of spermhead abnormalities in male mice caused by abamectin. Materials and methods Chemical Commercially available sample of abamectin, as 'Avermectin B1', 1.8% wt/vol emulsifiable concentrate, produced by Merck, Sharp & Dohme, Three Bridge, N. J., USA., was used in the bioassays. The chemical structure is a mixture of homologous products with a minimum of 80% B1a and a maximum of 20% B1b components. The B1b component differs chemically from the B1a component by only 1 methylene (CH2) unit at the 26-carbon position; the ethyl group (C2H5) is a methyl group in the B1b form. The compound's dilutions were made in distilled water.

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Fenvalerate Penetration, Metabolism, and Excretion in Pyrethroid-Susceptible and Resistant Heliothis virescens (Lepidoptera: Noctuidae)

Journal of Economic Entomology, 1994

ABSTRACT Fenvalerate was significantly less toxic to Heliothis Virescens (F.) (PEG 87 strain) thi... more ABSTRACT Fenvalerate was significantly less toxic to Heliothis Virescens (F.) (PEG 87 strain) third instars than to pyrethroid-susceptible BCIRL-S strain third instars; the resistance ratio estimated from LD90s at 48 h was 79.2. Studies with fenvalerate-14C revealed that the toxicity differential had a pharmacokinetic component consisting of slower penetration and faster metabolism of the pyrethroid in PEG 87 larvae as compared with BCIRL-S larvae. Enhanced excretion of fenvalerate equivalents in PEG 87 larvae was of minor importance. However, the interstrain difference in fenvalerate pharmacokinetics was not sufficient to account fully for the difference in toxicity. Nerve insensitivity, which previously has been shown to be present in PEG 87 larvae, most likely was involved.

Long-term effects of insecticides on diaeretiella rapae (m'intosh), a parasite of the cabbage aphid

Pesticide Science, 1992

Five insecticides were tested in the laboratory for their selective activities between the cabbag... more Five insecticides were tested in the laboratory for their selective activities between the cabbage aphid, Brevicoryne brussicae (L.), and its associated parasitoid, Diaeretiella r a p e (M'Intosh). Based on the concentration/mortality regressions, the synthetic pyrethroids tralomethrin and cypermethrin were the most active insecticides against both the cabbage aphid and the parasitoids within the mummified aphids, whereas the carbamate methomyl was the least active. Selectivity ratios, at LC,,, for B. brassicae vs. D. r a p e in the mummified aphids showed that all insecticides tested were more active against E. brassicae than against the parasitoids. All insecticides used at the recommended field rates reduced the emergence of adult parasitoids from mummified aphids by 55-97 O h of that of control. Survival and longevity of emerged D. r a p e were significantly reduced by all insecticides and rates used. Consequently, the latent effects of these insecticides applied at and below the recommended field rates were estimated on the parasitoids through two successive generations. The recommended rates used for both methomyl and cypermethrin reduced fecundity of D. rapae recorded at the F,-generation by 75% of that of control. The emergence of F,-progeny D. rapae was not significantly affected in any treatment, whereas the survival and longevity of adult parasitoids were reduced by most treatments. At the F,-generation, the fecundity of parasitoid females was still lower than in the untreated control. Emergence and survival of adult parasitoids seemed to be slightly affected, whereas the adult longevity was highly affected in all treatments. Methomyl, tralomethrin and cypermethrin might be preferred because they had minimal adverse effects on emergence of parasitoids from the mummified aphids and their subsequent survival, longevity and fecundity, when applied at rates little below the recommended field rates.

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Impact of two synthetic pyrethroids and methomyl on management of the cabbage aphid, brevicoryne brassicae (L.) and its associated parasitoid, diaeretiella rapae (M'Intosh)

Pesticide Science, 1989

The effectiveness of two synthetic pyrethroids, cypermethrin and fenvalerate, and of methomyl app... more The effectiveness of two synthetic pyrethroids, cypermethrin and fenvalerate, and of methomyl applied to cabbage plants was tested against the cabbage aphid, Brevicoryne brassicae (L.), and its parasitoid, Diaeretiella rapae (M 'Zntosh). Dosage rates chosen were equivalent to the manufacturer'.s maximum and minimum recommendations. Methomyl was considerably more toxic to B. brassicae adults than the two synthetic pyrethroids used. Fenvalerate, at the lowest rate used (71 g h a-') , showed satisfactory effectiveness in reducing aphid adult population on treated plants by c. 77% below that of the control. All insecticides and rates used significantly reduced the emergence of parasitoid adult D. rapae f o m mumm$ed aphids compared to the control. Fenvalerate clearly had less impact on emergence than cypermethrin or methomyl at any dosage used, while methomy1 has appeared to be the most toxic compound in this respect. Longevity of parasitoid adults was highly affected by insecticide application, particularly those adults emerging from mummified aphids exposed to methomyl or cypermethrin. However, only a slight difference in longevity was seen at the lower rate of 71 g ha-' of fenvalerate. At the lowest dosage rates used, methomyl and cypermethrin reduced the F,-progeny of adult parasitoid females by 70,5% and 58.3%, respectively, of the control, whereas fenvalerate reduced the progeny by only 36,4%.

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Effects of herbicides on consumption, growth and food utilization by cotton leafwormSpodoptera littoralis (Boisd.) larvae

Anzeiger für Schädlingskunde Pflanzenschutz Umweltschutz, 1994

The deterrent effects of nine herbicides on feeding and growth of cotton leafworm, Spodoptera lit... more The deterrent effects of nine herbicides on feeding and growth of cotton leafworm, Spodoptera littoralis (Boisd.), larvae were investigated. Fourth-instar larvae were fed on castor-bean leaves treated with recommended field rates of selected herbicides. Nutritional indices were measured regularly throughout the feeding tests until pupation. The food consumed by larvae in most herbicide-treatments was below that of control. Fluazifop [500 active ingredient (AI)], bentazon (250 AI), ametryne (800, 1600 AI), flamprop (130 AI), and isoxynil (187.5 AI) treatments seemed to be the best feeding deterrents. Relative growth rates of larvae fed on leaves treated with bentazon (250 AI), ametryne (1600 AI), gluphosate (1440 AI), glufosinate (800 AI), and bromoxynil (120 AI) were significantly reduced compared to that in control. Likewise, both the efficiency of conversion of ingested food to body substance (ECI) and the efficiency of conversion of digested food to body substance (ECD) were reduced with herbicide treatments below that in control. Approximate digestibility (AD), however, was significantly increased with most herbicide treatments. Moreover, feeding on herbicide-treated leaves resulted in a significant reduction in both pupation and adult emergence compared to that in control.

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The influence of normal and low-rate application of insecticides on populations of the cotton whitefly and melon aphid and associated parasites and predators on cucumber

Anzeiger für Schädlingskunde Pflanzenschutz Umweltschutz, 1992

Studies on the application of a nuclear polyhedrosis virus to control population of the Egyptian ... more

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Knockdown Resistance Allele Frequencies in North American Head Louse (Anoplura: Pediculidae) Populations

Journal of Medical Entomology, 2014

The study examines the extent and frequency of a knockdown-type resistance allele (kdr type) in N... more The study examines the extent and frequency of a knockdown-type resistance allele (kdr type) in North American populations of human head lice. Lice were collected from 32 locations in Canada and the United States. DNA was extracted from individual lice and used to determine their zygosity using the serial invasive signal ampliÞcation technique to detect the kdr-type T917I (TI) mutation, which is most responsible for nerve insensitivity that results in the kdr phenotype and permethrin resistance. Previously sampled sites were resampled to determine if the frequency of the TI mutation was changing. The TI frequency was also reevaluated using a quantitative sequencing method on pooled DNA samples from selected sites to validate this population genotyping method. Genotyping substantiated that TI occurs at high levels in North American lice (88.4%). Overall, the TI frequency in U.S. lice was 84.4% from 1999 to 2009, increased to 99.6% from 2007 to 2009, and was 97.1% in Canadian lice in 2008. Genotyping results using the serial invasive signal ampliÞcation reaction (99.54%) and quantitative sequencing (99.45%) techniques were highly correlated. Thus, the frequencies of TI in North American head louse populations were found to be uniformly high, which may be due to the high selection pressure from the intensive and widespread use of the pyrethrins-or pyrethroid-based pediculicides over many years, and is likely a main cause of increased pediculosis and failure of pyrethrins-or permethrin-based products in Canada and the United States. Alternative approaches to treatment of head lice infestations are critically needed.

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Fenvalerate Penetration, Metabolism, and Excretion in Pyrethroid-Susceptible and Resistant Heliothis virescens (Lepidoptera: Noctuidae)

Journal of Economic Entomology, 1994

ABSTRACT Fenvalerate was significantly less toxic to Heliothis Virescens (F.) (PEG 87 strain) thi... more ABSTRACT Fenvalerate was significantly less toxic to Heliothis Virescens (F.) (PEG 87 strain) third instars than to pyrethroid-susceptible BCIRL-S strain third instars; the resistance ratio estimated from LD90s at 48 h was 79.2. Studies with fenvalerate-14C revealed that the toxicity differential had a pharmacokinetic component consisting of slower penetration and faster metabolism of the pyrethroid in PEG 87 larvae as compared with BCIRL-S larvae. Enhanced excretion of fenvalerate equivalents in PEG 87 larvae was of minor importance. However, the interstrain difference in fenvalerate pharmacokinetics was not sufficient to account fully for the difference in toxicity. Nerve insensitivity, which previously has been shown to be present in PEG 87 larvae, most likely was involved.

Long-term effects of insecticides on diaeretiella rapae (m'intosh), a parasite of the cabbage aphid

Pesticide Science, 1992

Five insecticides were tested in the laboratory for their selective activities between the cabbag... more Five insecticides were tested in the laboratory for their selective activities between the cabbage aphid, Brevicoryne brussicae (L.), and its associated parasitoid, Diaeretiella r a p e (M'Intosh). Based on the concentration/mortality regressions, the synthetic pyrethroids tralomethrin and cypermethrin were the most active insecticides against both the cabbage aphid and the parasitoids within the mummified aphids, whereas the carbamate methomyl was the least active. Selectivity ratios, at LC,,, for B. brassicae vs. D. r a p e in the mummified aphids showed that all insecticides tested were more active against E. brassicae than against the parasitoids. All insecticides used at the recommended field rates reduced the emergence of adult parasitoids from mummified aphids by 55-97 O h of that of control. Survival and longevity of emerged D. r a p e were significantly reduced by all insecticides and rates used. Consequently, the latent effects of these insecticides applied at and below the recommended field rates were estimated on the parasitoids through two successive generations. The recommended rates used for both methomyl and cypermethrin reduced fecundity of D. rapae recorded at the F,-generation by 75% of that of control. The emergence of F,-progeny D. rapae was not significantly affected in any treatment, whereas the survival and longevity of adult parasitoids were reduced by most treatments. At the F,-generation, the fecundity of parasitoid females was still lower than in the untreated control. Emergence and survival of adult parasitoids seemed to be slightly affected, whereas the adult longevity was highly affected in all treatments. Methomyl, tralomethrin and cypermethrin might be preferred because they had minimal adverse effects on emergence of parasitoids from the mummified aphids and their subsequent survival, longevity and fecundity, when applied at rates little below the recommended field rates.

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Impact of two synthetic pyrethroids and methomyl on management of the cabbage aphid, brevicoryne brassicae (L.) and its associated parasitoid, diaeretiella rapae (M'Intosh)

Pesticide Science, 1989

The effectiveness of two synthetic pyrethroids, cypermethrin and fenvalerate, and of methomyl app... more The effectiveness of two synthetic pyrethroids, cypermethrin and fenvalerate, and of methomyl applied to cabbage plants was tested against the cabbage aphid, Brevicoryne brassicae (L.), and its parasitoid, Diaeretiella rapae (M 'Zntosh). Dosage rates chosen were equivalent to the manufacturer'.s maximum and minimum recommendations. Methomyl was considerably more toxic to B. brassicae adults than the two synthetic pyrethroids used. Fenvalerate, at the lowest rate used (71 g h a-') , showed satisfactory effectiveness in reducing aphid adult population on treated plants by c. 77% below that of the control. All insecticides and rates used significantly reduced the emergence of parasitoid adult D. rapae f o m mumm$ed aphids compared to the control. Fenvalerate clearly had less impact on emergence than cypermethrin or methomyl at any dosage used, while methomy1 has appeared to be the most toxic compound in this respect. Longevity of parasitoid adults was highly affected by insecticide application, particularly those adults emerging from mummified aphids exposed to methomyl or cypermethrin. However, only a slight difference in longevity was seen at the lower rate of 71 g ha-' of fenvalerate. At the lowest dosage rates used, methomyl and cypermethrin reduced the F,-progeny of adult parasitoid females by 70,5% and 58.3%, respectively, of the control, whereas fenvalerate reduced the progeny by only 36,4%.

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Inhibitory effect of thuringiensin and abamectin on digestive enzymes and non-specific esterases of Spodoptera littoralis (Boisd.) (Lep., Noctuidae) larvae

Journal of Applied Entomology, 1995

ABSTRACT The effect of abamectin (Avermectin B1) and thuringiensin (β-exotoxin of Bacillus thurin... more ABSTRACT The effect of abamectin (Avermectin B1) and thuringiensin (β-exotoxin of Bacillus thuringiensis) on the main digestive enzymes and non-specific esterases in Spodoptera littoralis (Boisd.) larvae was determined. The fifth-instar larvae were allowed to feed for only 24 h on leaves treated with sublethal concentrations of each compound, i.e. 5, 20 and 200 ppm through three successive generations, respectively. In enzyme assays, at F1-generation, abamectin (5 ppm) caused a remarkable decrease in invertase, amylase and trehalase activities by 81, 76 and 54%, respectively, compared to those recorded in the control larvae at day 3 after treatment. The body weights of larvae fed on abamectin-treated leaves (5 ppm), generally decreased continuously during feeding periods; this decrease was directly proportional to the lower enzymatic activity. At F3-generation, abamectin (200 ppm) reduced amylase activity by 21 and 46% at 2-and 3-day feeding periods, respectively.Thuringiensin, at F1-generation (5 ppm), also caused a pronounced decrease in digestive enzyme activities, especially amylase and invertase, at which maximum inhibition, about 77 and 76%, respectively, was reached 3 days after treatment. Feeding at concentration of 200 ppm (F3-generation) also reduced amylase and trehalase activities by 53% after 2 days of treatment. In addition, abamectin at 5 ppm caused a reduction in the activities of both α-esterases and β-esterases by 28.30% and 58.66%, after 1-day feeding on leaves treated with 5 ppm (F1-generation) and 200 ppm (F3-generation), respectively. The inhibitory effect of thuringiensin on the enzymatic activities of both α-esterases and β-esterases seemed to be less than that caused by abamectin.

Effects of herbicides on consumption, growth and food utilization by cotton leafwormSpodoptera littoralis (Boisd.) larvae

Anzeiger für Schädlingskunde Pflanzenschutz Umweltschutz, 1994

The deterrent effects of nine herbicides on feeding and growth of cotton leafworm, Spodoptera lit... more The deterrent effects of nine herbicides on feeding and growth of cotton leafworm, Spodoptera littoralis (Boisd.), larvae were investigated. Fourth-instar larvae were fed on castor-bean leaves treated with recommended field rates of selected herbicides. Nutritional indices were measured regularly throughout the feeding tests until pupation. The food consumed by larvae in most herbicide-treatments was below that of control. Fluazifop [500 active ingredient (AI)], bentazon (250 AI), ametryne (800, 1600 AI), flamprop (130 AI), and isoxynil (187.5 AI) treatments seemed to be the best feeding deterrents. Relative growth rates of larvae fed on leaves treated with bentazon (250 AI), ametryne (1600 AI), gluphosate (1440 AI), glufosinate (800 AI), and bromoxynil (120 AI) were significantly reduced compared to that in control. Likewise, both the efficiency of conversion of ingested food to body substance (ECI) and the efficiency of conversion of digested food to body substance (ECD) were reduced with herbicide treatments below that in control. Approximate digestibility (AD), however, was significantly increased with most herbicide treatments. Moreover, feeding on herbicide-treated leaves resulted in a significant reduction in both pupation and adult emergence compared to that in control.

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The influence of normal and low-rate application of insecticides on populations of the cotton whitefly and melon aphid and associated parasites and predators on cucumber

Anzeiger für Schädlingskunde Pflanzenschutz Umweltschutz, 1992

Studies on the application of a nuclear polyhedrosis virus to control population of the Egyptian ... more

Download

Knockdown Resistance Allele Frequencies in North American Head Louse (Anoplura: Pediculidae) Populations

Journal of Medical Entomology, 2014

The study examines the extent and frequency of a knockdown-type resistance allele (kdr type) in N... more The study examines the extent and frequency of a knockdown-type resistance allele (kdr type) in North American populations of human head lice. Lice were collected from 32 locations in Canada and the United States. DNA was extracted from individual lice and used to determine their zygosity using the serial invasive signal ampliÞcation technique to detect the kdr-type T917I (TI) mutation, which is most responsible for nerve insensitivity that results in the kdr phenotype and permethrin resistance. Previously sampled sites were resampled to determine if the frequency of the TI mutation was changing. The TI frequency was also reevaluated using a quantitative sequencing method on pooled DNA samples from selected sites to validate this population genotyping method. Genotyping substantiated that TI occurs at high levels in North American lice (88.4%). Overall, the TI frequency in U.S. lice was 84.4% from 1999 to 2009, increased to 99.6% from 2007 to 2009, and was 97.1% in Canadian lice in 2008. Genotyping results using the serial invasive signal ampliÞcation reaction (99.54%) and quantitative sequencing (99.45%) techniques were highly correlated. Thus, the frequencies of TI in North American head louse populations were found to be uniformly high, which may be due to the high selection pressure from the intensive and widespread use of the pyrethrins-or pyrethroid-based pediculicides over many years, and is likely a main cause of increased pediculosis and failure of pyrethrins-or permethrin-based products in Canada and the United States. Alternative approaches to treatment of head lice infestations are critically needed.

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Inhibitory effect of thuringiensin and abamectin on digestive enzymes and non-specific esterases of Spodoptera littoralis (Boisd.) (Lep., Noctuidae) larvae

Journal of Applied Entomology, 1995

ABSTRACT The effect of abamectin (Avermectin B1) and thuringiensin (β-exotoxin of Bacillus thurin... more ABSTRACT The effect of abamectin (Avermectin B1) and thuringiensin (β-exotoxin of Bacillus thuringiensis) on the main digestive enzymes and non-specific esterases in Spodoptera littoralis (Boisd.) larvae was determined. The fifth-instar larvae were allowed to feed for only 24 h on leaves treated with sublethal concentrations of each compound, i.e. 5, 20 and 200 ppm through three successive generations, respectively. In enzyme assays, at F1-generation, abamectin (5 ppm) caused a remarkable decrease in invertase, amylase and trehalase activities by 81, 76 and 54%, respectively, compared to those recorded in the control larvae at day 3 after treatment. The body weights of larvae fed on abamectin-treated leaves (5 ppm), generally decreased continuously during feeding periods; this decrease was directly proportional to the lower enzymatic activity. At F3-generation, abamectin (200 ppm) reduced amylase activity by 21 and 46% at 2-and 3-day feeding periods, respectively.Thuringiensin, at F1-generation (5 ppm), also caused a pronounced decrease in digestive enzyme activities, especially amylase and invertase, at which maximum inhibition, about 77 and 76%, respectively, was reached 3 days after treatment. Feeding at concentration of 200 ppm (F3-generation) also reduced amylase and trehalase activities by 53% after 2 days of treatment. In addition, abamectin at 5 ppm caused a reduction in the activities of both α-esterases and β-esterases by 28.30% and 58.66%, after 1-day feeding on leaves treated with 5 ppm (F1-generation) and 200 ppm (F3-generation), respectively. The inhibitory effect of thuringiensin on the enzymatic activities of both α-esterases and β-esterases seemed to be less than that caused by abamectin.

Sublethal effects of Avermectin B 1 , β-Exotoxin of Bacillus thuringiensis and Diflubenzuron against cotton leafworm (Lep., Noctuidae)

Journal of Applied Entomology, 1995

... Also, the mean weight of pupae was significantly decreased, especially in the field strain, a... more

Some biochemical effects of plant extracts in the black cutworm, Agrotis ipsilon (Hufnagel) (Lep., Noctuidae)

Journal of Applied Entomology, 1996

... and cultural (health and environmental) problems involved in the use of synthetic insecticide... more

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