RELATIONSHIPS AMONG PHEROMONE TRAP CATCHES OF MALE CORN EARWORM MOTHS (LEPIDOPTERA: NOCTUIDAE), EGG NUMBERS, AND PHENOLOGY IN CORN
1991; Cambridge University Press; Volume: 123; Issue: 2 Linguagem: Inglês
10.4039/ent123271-2
ISSN1918-3240
AutoresM. A. Latheef, J. A. Witz, J. D. López,
Tópico(s)Insect and Pesticide Research
ResumoAbstract Relationships among catches of corn earworm moths, Helicoverpa (= Heliothis ) zea (Boddie), in pheromone traps, numbers of corn earworm eggs, and corn ears with fresh silks were investigated in eight corn fields during a 2-year period in Brazos River Valley, Texas. Cross-correlation analysis indicated that the catches of corn earworm moths in pheromone traps were closely associated with egg numbers in seven of eight fields with a time differential varying between −1 to +2 days. Cross-correlation peaks for new silks versus eggs occurred with time differentials being mostly positive, indicating that corn earworm egg numbers reached a maximum after corn produced large numbers of fresh silks on ears. There was a weak but significant linear relationship between egg numbers and corn earworm catches in pheromone traps when corn was in the whorl stage of growth. A stepwise regression model of the form: log (eggs/ha + 1) = 3.71 + 0.22*log( S + 1)*log( T + 1) − 0.3*log( S + 1), where S = numbers of corn ears with new silks per hectare, and T = mean corn earworm moths per trap, explained 52.5% of the variance. These results emphasize the mediating effects of fresh silks on corn earworm oviposition on corn.
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