Assessment of the Impact of the European Corn Borer at Three Locations in South Dakota

<p>The European corn borer (Lepidoptera: Pyralidae) varies as an</p> <p>economically significant pest in South Dakota from south to north. In</p> <p>the northern part of the state the European corn borer (ECB) is limited</p> <p>to one generation per year. In contrast, there are localized sites</p> <p>along the Missouri River in southern South Dakota which usually</p> <p>experience a substantial second brood population. Infestation by</p> <p>either first or second brood ECB occurs at different stages in the</p> <p>developmental sequence of the corn plant. As such, each brood must be</p> <p>considered separately when assessing relationships between yield loss</p> <p>and ECB larval cavities within the plant. Berry and Campbell (1978)</p> <p>reported that plants .infested by both first and second generation ECB</p> <p>incurred greater yield reductions than did plants infested by only the</p> <p>first brood. On a yield loss per cavity basis, the first brood had a</p> <p>greater impact on yield than did the second. Contrary to this, Lynch</p> <p>(1980) observed a loss of 4.2 Bu/A/cavity with plants infested during</p> <p>the pollen shedding stage of development, compared to a 3.4 Bu/A/cavity</p> <p>loss for plants infested during the whorl stage. Under equal infestation</p> <p>levels Jarvis et al. (1961) found the first brood to cause more</p> <p>damage than the second. Further investigation by Lynch et al. (1980)</p> <p>revealed greater yield losses due to infestation during the pollen</p> <p>shedding stage (second brood). Differences in varieties and larval</p> <p>survival may partially explain these contradictory results. Jarvis et al. (1961) observed no synergistic relationship between</p> <p>first and second brood induced yield reductions when plants were infested by both generations. In Prince Edward Island, Canada,Thompson and White (1977) showed differences in grain yield but no</p> <p>significant difference in silage yield between insecticide treated and</p> <p>control plots. The impact of first or second brood ECB at any location</p> <p>is dependent on the relative population levels present. Kwolek and</p> <p>Brindley (1959) illustrated this point by reporting on the inconsistency</p> <p>from state to state with regard to the different impact of the</p> <p>two broods. In Ohio the second brood was found to be the most influential</p> <p>with only a small first brood population present. First brood had</p> <p>a greater impact on yield in Minnesota while Iowa corn was subject to</p> <p>approximately equal infestation by both generations. Chiang et al. (1960) noted that the ECB females prefer to oviposit</p> <p>on the most vigorous plants in the area. First brood females</p> <p>prefer the earlier planted, taller corn, while the second brood females</p> <p>actively select the later planted more succulent plants that are</p> <p>shedding pollen. The production and use of irrigated long season corn</p> <p>hybrids, early planting and heavy fertilization requires monitoring for</p> <p>both first and second generation ECB.</p> <p>Artificial infestation studies have elucidated the relationships</p> <p>between generation of attack, cavity counts and yield. To</p> <p>date, however, no quantitative studies have been conducted to ascertain these relationships with naturally occurring populations of the ECB in South Dakota. The objective of this study was to assess the impact of first and second generation ECB on total plant weight and grain yield. Studies were conducted at three locations in South Dakota. Analyses were made on either grain yield or total plant weight (cut 4" aboveground) recorded both at the time of harvest and on a dry matter basis.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Entomology-Zoology

Year dc:date.available

1982

Author dc:creator

• Raemisch, David R.

Contributors dc:contributor

• David D. Walgenbach

• Entomology

Statement dc:rights

• <p>No Copyright - Non-Commercial Use Only<br /><a href="http://rightsstatements.org/vocab/InC-EDU/1.0/">http://rightsstatements.org/vocab/NoC-NC/1.0/</a></p>

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/261

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1263