TOXICITY AND PERSISTENCE OF PYRETHROID INSECTICIDES AS FOLIAR SPRAYS AGAINST DARKSIDED CUTWORM (LEPIDOPTERA: NOCTUIDAE) ON TOBACCO IN ONTARIO

1980 ◽  
Vol 112 (5) ◽  
pp. 451-456 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
Winter Rye ◽  
Organophosphorus Insecticides ◽  
Tobacco Plants ◽  
Pyrethroid Insecticides ◽  
Foliar Sprays ◽  
Tobacco Seedlings ◽  
Euxoa Messoria ◽  
Lepidoptera Noctuidae

AbstractToxicity and persistence of six insecticides, including three pyrethroids and three organophosphorus insecticides, against Euxoa messoria (Harris) larvae were evaluated. These insecticides were applied to winter rye or tobacco seedlings in the field, and the residues on the foliage were bioassayed in the laboratory. The pyrethroids, cypermethrin, fenvalerate and permethrin, were more effective and persistent, and killed the larvae more rapidly than the organophosphorus insecticides, sulfopros, chlorpyrifos and trichlorfon. The higher rate of cypermethrin and fenvalerate gave a longer period of protection than the lower rate of the same materials and both materials were persistent longer than permethrin. No visible phytotoxicity was found on the tobacco plants treated directly with sulfopros, trichlorfon, cypermethrin, fenvalerate, and permethrin in the 3 years of tests.

CUTWORMS (LEPIDOPTERA: NOCTUIDAE) OF TOBACCO IN NOVA SCOTIA: II. FALL RYE AND WINTER FALLOW EFFECTS ON A FIELD POPULATION

1974 ◽  
Vol 106 (1) ◽  
pp. 73-77
Author(s):  
H. B. Specht
Keyword(s):  
Nova Scotia ◽  
Winter Rye ◽  
Tobacco Plants ◽  
Peridroma Saucia ◽  
Cultural Methods ◽  
Variegated Cutworm ◽  
Euxoa Messoria ◽  
Field Plots ◽  
Lepidoptera Noctuidae ◽  
Winter Fallow

AbstractTwice as many larvae of the dark-sided cutworm, Euxoa messoria Harr., were found in rye fall-seeded tobacco field plots than in winter-fallowed tobacco field plots. There were corresponding differences in numbers of injured tobacco plants. Cutworm aggregations were more prominent in the winter rye than in the winter fallowed area of the tobacco field with low populations of dark-sided cutworms.Larvae of the variegated cutworm, Peridroma saucia Hbn., appeared 2 to 4 weeks later than dark-sided cutworm larvae and winter cultural methods had little effect on their numbers.

RESIDUAL TOXICITY OF SIX PYRETHROID AND TWO ORGANOPHOSPHOROUS INSECTICIDES ON SOIL SURFACE AGAINST DARKSIDED CUTWORM (LEPIDOPTERA: NOCTUIDAE) ON TOBACCO IN ONTARIO

1984 ◽  
Vol 116 (1) ◽  
pp. 11-17 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
Soil Moisture ◽  
Soil Surface ◽  
Moist Soil ◽  
Pyrethroid Insecticides ◽  
Treated Soil ◽  
Residual Toxicity ◽  
Euxoa Messoria ◽  
Dry Soil ◽  
Organophosphorous Insecticides ◽  
Lepidoptera Noctuidae

AbstractSix pyrethroids, cyfluthrin, cypermethrin, deltamethrin, fenvalerate, flucythrinate and permethrin, and two organophosphorous insecticides, acephate and chlorpyrifos, were applied to the soil surface in the greenhouse and field to evaluate their effectiveness and residual toxicity against the darksided cutworm, Euxoa messoria (Harris), in Ontario.Four years of tests indicated that the pyrethroid insecticides were consistently similar in effectiveness and residual toxicity at the rates applied. On air-dry soil surfaces in the greenhouse, the pyrethroids were significantly more toxic and persistent than was chlorpyrifos. On moderately moist soil surfaces in the field, chlorpyrifos was as toxic to the cutworm larvae as were the pyrethroid insecticides, but less persistent. None of the pyrethroids was affected by soil moisture to the same extent as was chlorpyrifos. Acephate-treated soil surfaces, regardless of indoor or outdoor conditions, were less toxic and the toxicity less persistent than with chlorpyrifos-treated soil. Although not statistically different, the high rates of pyrethroids were consistently more toxic and persistent to the cutworm larvae than the low rates of the same materials. All the pyrethroid insecticides have excellent potential as soil treatments for controlling cutworms on tobacco.

OBSERVATIONS ON THE BIONOMICS OF THE DARK-SIDED CUTWORM, EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE), IN ONTARIO

1973 ◽  
Vol 105 (2) ◽  
pp. 311-322 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
North American ◽  
Head Width ◽  
Natural Mortality ◽  
Mortality Factors ◽  
Tobacco Seedlings ◽  
Euxoa Messoria ◽  
Width Measurements ◽  
Pass Through ◽  
Rotation Crop ◽  
Lepidoptera Noctuidae

AbstractThe dark-sided cutworm, Euxoa messoria (Harris), has a North American distribution and is commonly found in tobacco fields in Ontario. It has one generation a year, and overwinters as an egg in the soil. Hatching takes place in early April and the young larvae feed on the rye rotation crop; later they attack newly transplanted tobacco seedlings. Head width measurements of larvae collected from the field show seven instars, but individual rearing data of E. messoria larvae reveal that small numbers pass through six and an occasional larva passes through eight; however, the eighth instar has the same head width as the seventh. Pupation occurs from late July to mid-August in the soil. The adult emerges from mid-August to October, and oviposition occurs in this same period. Eggs are completely developed before winter. Behaviour and duration of the different stages are described. Natural mortality factors of the species are given.

ASSESSMENT OF TOBACCO LOSSES CAUSED BY THE DARK-SIDED CUTWORM, EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE), DELHI, ONTARIO

1971 ◽  
Vol 103 (4) ◽  
pp. 534-541 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
Population Density ◽  
Tobacco Plant ◽  
New Method ◽  
Crop Losses ◽  
Euxoa Messoria ◽  
Average Current ◽  
Lepidoptera Noctuidae

AbstractIntensive studies on the damage and losses of flue-cured tobacco caused by the dark-sided cutworm, Euxoa messoria (Harris), were carried out in the field at Delhi, Ont., during 1967 and 1968. A new method for estimating the accurate tobacco crop losses is illustrated. Assessment of damage of the tobacco plant and the population density in relation to the yield are described. The yield was significantly related, negatively, to the dark-sided cutworm density, and was reduced in the cutworm-damaged blocks in comparison with the yield in the undamaged check blocks. Assessment of average losses caused by the species was 17% of marketable tobacco, which, based on the average current prices, would amount to 200 dollars per acre or approximately 25 million dollars over the country as a whole every year.

scholarly journals Susceptibility of African Bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae) to selected pyrethroid Insecticides on Cotton

2021 ◽  
Author(s):  
Zemedkun Alemu
Keyword(s):  
Helicoverpa Armigera ◽  
Agricultural Research ◽  
Pure Water ◽  
Synthetic Pyrethroids ◽  
Cotton Production ◽  
Pyrethroid Insecticides ◽  
Lambda Cyhalothrin ◽  
Helicoverpa Armígera ◽  
Production Areas ◽  
Lepidoptera Noctuidae

Abstract AbstractHelicoverpa armigera is a major threat for all cotton production areas in Ethiopia. Pests control with insecticides from a single chemistry group is common practice in most cotton farms, which may help to the development of insecticide resistance. The studies aimed to determine the susceptibility of the field population of H. armigera to pyrethroid insecticides. The experiment was carried out at Werer Agricultural Research Center under the laboratory condition using larva immersion and square dip methods. The selected insecticides were tested in seven dilutions levels. In each dilution 30 larvae of 3rd instars, H. armigera were treated in three replications along with pure water. A low level of resistance was detected for all tested locations to alphacypermethrin and a high resistance ratio to lambda-cyhalothrin and deltamethrin for Gewane and Werer populations. Aplhacypermethrin was the most toxic insecticide and its LC50 was low compared to other tested synthetic pyrethroids. Whereas, deltamethrin was the least toxic insecticide with high LC50. The LC50 value of the Goffa-Sawla population was significantly different among the populations for Werer, Upper-Awash, and Gewane in both bioassay methods. The study concluded that Helicoverpa armigera might have resistant to deltamethrin in Werer and Gewane populations. Further studies on the monitoring of resistance are recommended.

OVIPOSITION AND LONGEVITY OF THE DARK-SIDED CUTWORM, EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE), IN THE LABORATORY

1972 ◽  
Vol 104 (6) ◽  
pp. 919-925 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
Oviposition Period ◽  
Male And Female ◽  
Significant Difference ◽  
Euxoa Messoria ◽  
The Mean ◽  
Honey Solution ◽  
Lepidoptera Noctuidae ◽  
Adult Food

AbstractIn the laboratory, the mean number of eggs laid per female of the dark-sided cutworm, Euxoa messoria (Harris), fed on honey solution was 1303.8; when given water alone 261.3; and 86.4 when held without food or water. Adult food significantly increased the longevity and oviposition period and reduced the pre-oviposition period. There was no significant difference between the weight of male and female pupae. The weight of the female pupae was significantly correlated with: the oviposition period; the number of eggs laid; the longevity, except moths fed on honey solution; but not the pre-oviposition period, regardless of food taken as adults. Females fed on honey solution mated successfully, 30% of them more than once. When given water or nothing the number of mated females was reduced. Dissections showed that adult food accelerated the development of eggs and increased the fecundity potential.

INSECT PARASITES OF THE DARKSIDED CUTWORM, EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE), IN ONTARIO

1977 ◽  
Vol 109 (1) ◽  
pp. 137-142 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
Internal Parasites ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Euxoa Messoria ◽  
Host Parasite ◽  
Lepidoptera Noctuidae ◽  
Insect Parasites

AbstractIn the study of insect parasites of the darksided cutworm, Euxoa messoria (Harris), fourth- to seventh-instar larvae were collected from a field at Delhi, Ont., and reared in the laboratory. A total of 701 insect parasites including six species of Hymenoptera and four of Diptera, were reared from the 3970 darksided cutworm larvae collected in 1973 and 1974.Thirteen species of insect parasites of E. messoria are listed. Ten of these species were reared in the present study from E. messoria in Ontario and all of them are primary and internal parasites. Of the 10, only two have previously been reported as parasites of E. messoria. Host–parasite relationship and the degree of parasitism are given for the 10 species reared in Ontario.

A Description of a Necrotic Virus Disease affecting Tobacco and Other Plants

Parasitology ◽  
1935 ◽  
Vol 27 (2) ◽  
pp. 231-245 ◽  
Author(s):  
Kenneth M. Smith ◽  
J. G. Bald
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Virus Disease ◽  
Insect Vector ◽  
Tobacco Plants ◽  
Thermal Death ◽  
Tobacco Seedlings ◽  
Ultra Filtration ◽  
Thermal Death Point ◽  
Chief Characteristic

An account is given of an apparently undescribed virus disease. The virus appears spontaneously in the glasshouse affecting tobacco seedlings in the seed boxes. The symptoms on a number of hosts are described. The chief characteristic of the virus is its failure to become systemic in any host plant so far tested. It is, however, occasionally found in the roots of young tobacco plants, usually in the case of those naturally infected. Certain physical properties of the virus have been investigated. Its dilution end-point appears to be about 1:10,000; its longevity in extracted sap is about 20 days, the thermal death-point is 72° C. The virus shows a strong resistance to alcohol, remaining viable in 99 per cent, alcohol for 71 hours so far as tested.It is not known how the virus is transmitted in nature, and no insect vector has as yet been identified.The virus has been transmitted to healthy cowpeas by spraying them with a suspension of the virus by means of an atomiser.By the Elford method of ultra-filtration the particle size is found to be 20–30μμ.The virus is compared with that of the American tobacco ringspot, and methods of differentiating the two are indicated.

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