ACTION OF MOUTHPARTS DURING FEEDING IN THE DARK-SIDED CUTWORM, EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE)

1985 ◽  
Vol 117 (3) ◽  
pp. 343-349 ◽  
Author(s):  
B.D. Devitt ◽  
J.J.B. Smith
Keyword(s):  
Initial Contact ◽  
Leaf Sampling ◽  
Plant Test ◽  
Euxoa Messoria ◽  
Continuous Feeding ◽  
Lepidoptera Noctuidae ◽  
Maxillary Palps

AbstractFilm records of cutworms feeding on cabbage showed that in sampling and continuous feeding, the mandibles, maxillary palps, galeae, labial palps, and labrum contacted the leaf. Sampling involves palpation with the maxillary palps; this is followed by test biting, during which the galeae, labrum, and labial palps make initial contact with the plant. Test biting may be followed by continuous feeding in which all of the mouthparts contact the leaf in characteristic patterns. The actions of the mouthparts are discussed in relation to the function of their chemosensilla.

Effects of the sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta (Lepidoptera, Noctuidae)

2001 ◽  
Vol 204 (22) ◽  
pp. 3935-3942 ◽  
Author(s):  
Seong Eun Jeong ◽  
Yun Lee ◽  
Jeong Hee Hwang ◽  
Douglas C. Knipple
Keyword(s):  
Male Fertility ◽  
Chemical Constituents ◽  
Direct Injection ◽  
Arginine Decarboxylase ◽  
Tobacco Budworm ◽  
Polyamine Metabolism ◽  
Helicoverpa Assulta ◽  
Continuous Feeding ◽  
The Common ◽  
Lepidoptera Noctuidae

SUMMARY We investigated the effects of sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta. We found that continuous feeding of oleander sap during the larval period significantly affects fertility in males but not in females. This effect was also induced by direct injection of oleander sap into the hemocoel of 2-day-old pupae. Histological analyses of developing testes following oleander injection revealed a developmental delay and progressively more severe morphological abnormalities in the later stages of development. The effects of oleander sap on spermatogenesis in H. assulta were associated with greatly reduced levels of the two major polyamines, spermidine and spermine, in testis compared with saline-injected controls. In contrast, levels of putrescine, which is a precursor of both spermidine and spermine, and the activities of the enzymes ornithine decarboxylase and arginine decarboxylase, which are involved in the biosynthesis of putrescine, were initially elevated following oleander injection, but subsequently failed to undergo the induction that normally occurs during late pupal development. The effects of oleander sap on spermidine and spermine levels could be the result of direct inhibition by chemical constituents of the oleander sap of one of the enzymes used in common in the conversions of putrescine to spermidine and spermidine to spermine; alternatively, these effects on polyamine metabolism could be secondary to the disruption of a more fundamental process in the developmental program guiding spermatogenesis in H. assulta.

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.

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.

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.

FIELD STUDIES ON THE CHEMICAL CONTROL OF THE DARK-SIDED CUTWORM (LEPIDOPTERA: NOCTUIDAE) ON TOBACCO IN ONTARIO, WITH PARTICULAR REFERENCE TO DURSBAN®

1971 ◽  
Vol 103 (5) ◽  
pp. 649-653 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
Chemical Control ◽  
Large Scale ◽  
Field Studies ◽  
Effective Control ◽  
Split Application ◽  
Significant Difference ◽  
Untreated Check ◽  
Euxoa Messoria ◽  
Scale Test ◽  
Lepidoptera Noctuidae

AbstractDDT, carbaryl, Dursban® (0,0-diethyl 0-3,5,6-trichloro-2-pyridyl phosphorothioate), and AC-47031 (cyclic ethylene (diethoxyphosphinyl) dithioimidocarbonate) were applied at different rates on rye and/or soil for control of the dark-sided cutworm, Euxoa messoria (Harris), attacking flue-cured tobacco in Ontario. All insecticides tested caused significant reductions in cutworm damage in comparison with the untreated check. Dursban at 1/2 lb/ac on rye, or 1 lb/ac incorporated in the soil tended to give better control than DDT at 4 lb/ac on soil and showed a significant difference from split applications of DDT at 11/4 lb/ac on rye and 4 lb/ac on soil in the large scale test. Carbaryl and AC-47031 showed less effect than DDT. There was no advantage in the split application of DDT or Dursban on rye and on soil since each treatment singly could provide effective control of this pest. Rye treatment is more economic than soil treatment and could apparently provide adequate control. Dursban showed promise as a substitute for DDT for control of the dark-sided cutworm in tobacco fields.

MORTALITY IN LARVAE OF EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE) COLLECTED FROM THE TOBACCO AREA OF ONTARIO

1971 ◽  
Vol 103 (6) ◽  
pp. 888-892 ◽  
Author(s):  
G. E. Bucher ◽  
H. H. Cheng
Keyword(s):  
Bacterial Infection ◽  
Fourth Instar ◽  
Stable Population ◽  
Virus Diseases ◽  
Adult Females ◽  
Causes Of Mortality ◽  
Trap Plants ◽  
Euxoa Messoria ◽  
Lepidoptera Noctuidae

AbstractLarvae of the dark-sided cutworm were collected from trap plants of tobacco set in a field of rye at Delhi, Ont., in 1969. They were reared individually to pupation to determine the degree of survival and the causes of mortality from the fourth instar to maturity. About 36% pupated and the greatest amount of mortality was caused by insect parasitism, a microsporidial disease, and bacterial infection. Fungus and virus diseases were virtually absent. As adult females are capable of laying a large number of eggs, mortality in eggs and young larvae must reach at least 98% to maintain a stable population. Introduction of virus pathogens to attack larvae might well be expected to result in regulating the population at a lower density.

LABORATORY AND FIELD TESTS WITH BACILLUS THURINGIENSIS AGAINST THE DARK-SIDED CUTWORM, EUXOA MESSORIA (LEPIDOPTERA: NOCTUIDAE), ON TOBACCO

1973 ◽  
Vol 105 (7) ◽  
pp. 941-945 ◽  
Author(s):  
H. H. Cheng
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Test ◽  
Cover Crop ◽  
Laboratory Tests ◽  
Field Tests ◽  
Tobacco Leaves ◽  
Larval Stages ◽  
Euxoa Messoria ◽  
Lepidoptera Noctuidae ◽  
Third Instar Larvae

AbstractLaboratory tests were conducted to determine the susceptibility of the various larval stages of Euxoa messoria (Harris) in Ontario to four commercial preparations of Bacillus thuringiensis Berliner: Thuricide® 90TS, Thuricide®-HP, Biotrol® BTB 183, and Dipel. A field test was made to determine whether these preparations could be as effective as Dursban® (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate) for control of this species when applied on the rye cover crop in spring.In laboratory tests first to third instar larvae that fed on rye leaves treated with all four B. thuringiensis preparations, were found to be susceptible regardless of the rates applied. Mortality of fourth to seventh instar larvae fed treated tobacco leaves was low. Thuricide 90TS and Biotrol BTB 183 as applied in the field for control of E. messoria populations were relatively ineffective as compared with Dursban.

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.

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