Use of Pyrethroids, Methomyl, and Chlorpyrifos to Control Fall Armyworm (Lepidoptera: Noctuidae) in Whorl Stage Field Corn, Sweet Corn, and Sorghum

1991 ◽  
Vol 74 (2) ◽  
pp. 261 ◽  
Author(s):  
L. P. Guillebeau ◽  
J. N. All
Keyword(s):  
Sweet Corn ◽  
Fall Armyworm ◽  
Field Corn ◽  
Lepidoptera Noctuidae

Resistance in Maize to Euxesta stigmatias Loew (Diptera: Otitidae)2

2000 ◽  
Vol 35 (4) ◽  
pp. 432-443 ◽  
Author(s):  
B. T. Scully ◽  
G. S. Nuessly ◽  
R. L. Beiriger
Keyword(s):  
Spodoptera Frugiperda ◽  
Sweet Corn ◽  
Insect Pests ◽  
Empirical Relationship ◽  
Fall Armyworm ◽  
Maize Germplasm ◽  
Corn Silk ◽  
Field Corn ◽  
Maize Genotypes ◽  
Lepidoptera Noctuidae

The corn silk fly, Euxesta stigmatias Loew (Diptera: Otitidae), and related otitid species can cause severe crop losses to sweet corn, Zea mays L., grown in tropical and subtropical regions. In Florida, the fall armyworm, Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), and E. stigmatias are two debilitating insect pests on the sweet corn ear that are considered the most costly and difficult to control. Our purpose was to search for resistance to the corn silk fly in a diverse set of maize germplasm that included sweet, floury, field and popcorn, and to determine if any empirical relationship existed between E. stigmatias damage and S. frugiperda infestation in corn ears. The overall means across two sites, 3 yrs and 16 genotypes was 1.77 for corn silk fly damage, rated on a 0 to 4 prototype scale, and 30.1% for fall armyworm infestation. Clear differences existed between the sweet and popcorn types when compared to the field and floury types. The field and floury corns sustained significantly less damage by the corn silk fly than the sweet and popcorn types (0.91 vs 3.33). Five of these genotypes, CEW-R58, DDSB, GT-RI4, Mp704 and ‘Zapalote Chico 2451’, had both lower corn silk fly damage ratings and lower levels of fall armyworm infestation. Across this broad germplasm base no statistical relationship was identified between corn silk fly damage and fall armyworm infestation, suggesting that each insect species responds independently to different maize genotypes. Husk extension was partly related to reduced S. frugiperda infestation, and tip tightness was partly related to reduced E. stigmatias damage. These results indicate that field corn could possibly serve as source of resistance to the corn silk fly for the improvement of sweet corn.

scholarly journals Larval and pupal stage of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in sweet and field corn genotypes

2003 ◽  
Vol 63 (4) ◽  
pp. 627-633 ◽  
Author(s):  
L. M. Santos ◽  
L. R. Redaelli ◽  
L. M. G. Diefenbach ◽  
C. F. S. Efrom
Keyword(s):  
Sex Ratio ◽  
Spodoptera Frugiperda ◽  
Sweet Corn ◽  
Fall Armyworm ◽  
Pupal Stage ◽  
Phase Duration ◽  
Larval Phase ◽  
Field Corn ◽  
Lack Of Information ◽  
And Control

Spodoptera frugiperda, the fall armyworm, is a very significant polyphagous pest due to the damages it causes, and control difficulties. Lack of information about its impact on sweet corn motivated a comparison of its biology, with respect to the larval and pupal stages, among the genotypes ELISA, BR 400 (sweet corns), and BR PAMPA (field corn). In laboratory conditions (25 ± 1ºC; 70 ± 10% RH; photophase 12 hours), 35 caterpillars were individualized and fed daily with 3.14 cm² sections of corn leaves from the referred-to genotypes, cultivated in plots in the experimental area of the Departament of Fitossanidade, UFRGS, Porto Alegre, RS from October to November 2000. The caterpillars were weighed daily; after each molt, the cephalic capsules were collected and measured (in width), to establish growth rate; pupae were weighed and sexed when 24 hours old. The duration of the larval instars, the pupal sex ratio, and the mortality of larvae and pupae were evaluated. In the first three instars there were no differences registered in capsule width. In the fourth and fifth instars, capsules of caterpillars kept in BR 400 were smaller. The weight of caterpillars and pupae, instar duration and sex ratio did not differ among the genotypes. Pupal phase duration was less in females kept in BR 400. Mortality was greater in the larval phase in ELISA and in the pupal phase in BR PAMPA.

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