Corn Earworm Oviposition and the Effect of DDT on the Egg Predator Complex in Corn Silk1

Harrison, Floyd P.

doi:10.1093/jee/53.6.1088

Cited by 9 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…I n the United States Orius insidiosus is outstanding as a predator on eggs and young larvae of Lepidoptera, especially Heliothis xea on cotton and maize (Barber, 1936;Fletcher & Thomas, 1943;Harrison, 1960;Newsom & Smith, 1949;Oatman, 1966). I n the United States Orius insidiosus is outstanding as a predator on eggs and young larvae of Lepidoptera, especially Heliothis xea on cotton and maize (Barber, 1936;Fletcher & Thomas, 1943;Harrison, 1960;Newsom & Smith, 1949;Oatman, 1966).…”

Section: Introductionmentioning

confidence: 99%

The action of some systemic aphicides on the eggs of Anthocoris nemorum (L.) and A. confusus Reut

Elliott

Way

1968

Annals of Applied Biology

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

The action of some systemic aphicides on the eggs of Anthocoris nemorum (L.) and A. confusus Reut

Elliott

Way

1968

Annals of Applied Biology

View full text Add to dashboard Cite

show abstract

“…Despite their low abundance during anthesis, removal and exclusion of C. maculata larvae still resulted in higher pest survival, suggesting the importance of predation by immatures even at low densities. Helicoverpa zea in sweet corn is a difficult target for biological control, but in our experiments placed eggs were totally eliminated by predators at significantly more stations in the treatments where C. maculata larvae were present over 48 h. Helicoverpa zea eggs in many landscapes are laid on developing sweet corn during very concentrated time windows (2Á3 days) (Harrison 1960) and it is this group of eggs that needs to be eliminated by natural enemies on some portion of ears to have biological control. Our results (e.g., the total elimination of placed eggs from ears over 48 h) suggest that the presence of immature C. maculata may contribute to lowering crop damage by this pest.…”

Section: Discussionmentioning

confidence: 85%

“…Most oviposition occurs on or very near the silks and upon hatching larvae migrate into the ear tip within 8Á98 min (Barber 1941;Harrison 1960). Once inside very little non-cannibalism biotic mortality occurs (Archer and Bynum 1994).…”

Section: Introductionmentioning

confidence: 99%

Importance of predation byColeomegilla maculatalarvae in the natural control of the corn earworm in sweet corn

Seagraves

Yeargan

2009

Biocontrol Science and Technology

View full text Add to dashboard Cite

The corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) is a serious pest of many crops in North America, particularly sweet corn. The larvae of Coleomegilla maculata (DeGeer) (Coleoptera: Coccinellidae) are the most frequently observed predators of H. zea eggs in sweet corn. Companion cropping strategies have been developed to augment densities of C. maculata in sweet corn plantings. In this study, the importance of predation by C. maculata larvae was evaluated in experiments when larval abundance was manipulated using hand removal and physical exclusion. In 2003 and 2004, sentinel H. zea eggs were exposed on corn for 48 h. Egg mortality was 13.8% greater in the treatment where C. maculata larvae were present. In 2004 and 2005 eggs were exposed on corn under the same hand removal and physical exclusion techniques and monitored at 3-h intervals for 24 h to directly observe predation on sentinel eggs. Coleomegilla maculata larvae were the most frequently observed predators of the eggs, accounting for 45.9% of 85 total observed predation events in the control. Whereas in the treatment where C. maculata larvae were reduced, egg survival was 26.13% greater and only 37 total predation events were observed. All pest eggs were eliminated from individual ears 22.1% more often when C. maculata larvae were present at natural densities indicating that predation by this predator stage lessens crop damage by H. zea. The results of this study suggest that C. maculata larvae are an irreplaceable source of natural mortality for H. zea eggs on sweet corn.

show abstract

“…Eggs were examined at 2 and 4 days (13 and 15 August) with the aid of a 10 x magnification hand lens. Eggs were categorized as unhatched, hatched, sucked out (teepee shaped), chewed on (crown shaped), parasitized (black), or missing (Harrison, 1960). Observations of common CEW egg predators feeding on eggs were made in the laboratory prior to initiation of field studies.…”

Section: Methodsmentioning

confidence: 99%

“…Chewing insects, Coleomegilla maculata (DeGeer), Hippodamia convergens Guerin and larvae of Chrysopa spp., left a crown of egg shell or consumed the entire egg. Hatched eggs had a large exit hole with ragged edges, initiated on one side of the egg (Bell & Witcomb, 1964;Harrison, 1960).…”

Section: Methodsmentioning

confidence: 99%

Relationship of Heliothis zea predators, parasitoids and entomopathogens to canopy development in soybean as affected by Heterodera glycines and weeds

Alston

Bradley

Schmitt

et al. 1991

Entomologia Exp Applicata

View full text Add to dashboard Cite

The influence of canopy development in soybean on the survival of corn earworm, Heliothis zea (Boddie) (Lepidoptera: Noctuidae), egg and larval stages and population dynamics of arthropod fauna were evaluated in field trials during 1986–88 in eastern North Carolina. Soybean canopy size decreased as soybean cyst nematode, Heterodera glycines Ichinohe (Nematoda: Heteroderidae), initial population densities increased. Plant species composition of the soybean canopy was affected by weed population densities. Mortality of H. zea larvae due to parasitism and infection with entomopathogens was greater in closed canopy and (or) weedy soybeans than in very open and (or) weed free soybeans. Predation and parasitism of corn earworm eggs were similar across nematode and weed density treatments. Natural enemy populations increased to highest levels during July in closed canopy and (or) weedy soybeans, coinciding with availability of largest prey population reservoirs. A delay in colonization of very open and (or) weed free soybeans by beneficial arthropods until mid to late August allowed greater H. zea larval survival than in closed canopy and (or) weedy soybeans. Arthropod species richness was generally greatest in closed canopy and (or) weedy soybeans during mid to late July, with differences becoming nonsignificant in August and early September. Mean and maximum ambient temperatures were higher and relative humidities lower in open canopy than in closed canopy plots. These conditions were less favorable for development of pathogens and natural enemies.

show abstract

Corn Earworm Oviposition and the Effect of DDT on the Egg Predator Complex in Corn Silk1

Cited by 9 publications

References 0 publications

The action of some systemic aphicides on the eggs of Anthocoris nemorum (L.) and A. confusus Reut

The action of some systemic aphicides on the eggs of Anthocoris nemorum (L.) and A. confusus Reut

Importance of predation byColeomegilla maculatalarvae in the natural control of the corn earworm in sweet corn

Relationship of Heliothis zea predators, parasitoids and entomopathogens to canopy development in soybean as affected by Heterodera glycines and weeds

Contact Info

Product

Resources

About