Influence of Different Crops on the Population Dynamics of the Western Corn Rootworm, Diabrotica Virgifera Virgifera LeConte, in East Central Illinois

The long-term rotation of maize and soybean has caused a significant change in the ovipositional behavior of the western corn rootworm, Diabrotica virgifera virgifera LeConte, which is implicated in the decrease of effectiveness of the soybean-maize rotation as a pest management strategy in east central Illinois and northern Indiana. The influences of maize (Zea mays L.), soybean (Glycine max L.), oat stubble (Avena sativa L.), and alfalfa ( Medicago sativa L.) on adult densities, ovary development, and oviposition of the new strain of western corn rootworm was studied. The influence of different planting dates on oviposition and emergence also were evaluated. Five cropping system treatments were arranged in a five by five Latin square experimental design. Maize planted on different dates surrounded the treatments to enhance the continuous presence of adult corn rootworms within the plots. Information also is included regarding the influence of these crops on the adult densities and oviposition of northern and southern corn rootworms, Diabrotica barberi Smith and Lawrence and Diabrotica undecimpunctata howardi Barber, respectively. Results from the experiments indicated that western, northern, and southern corn rootworm adults are common inhabitants of maize, soybean, oat stubble, and alfalfa throughout the growing season as measured by PheroconRTMAM and vial traps. Densities of female western corn rootworm adults frequently exceeded published economic thresholds across my crop treatments regardless of trap type used. Densities of males were typically greatest in maize and lowest in the other crop treatments. Oviposition by western corn rootworms occurred in all crop treatments. Western corn rootworm ovarial development in maize lagged behind the other crops during the initial sampling period. By season's end, ovarial development was generally delayed in maize as compared with the other crops. Gravid females were present for a long period of time in each of the four crops. Overall results suggest that longer term and more complex rotation strategies will have to be employed to minimize economic injury caused by western corn rootworms to rotated maize in east central Illinois.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Crop Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Rondon, Silvia Ivette

Contributors dc:contributor

• Michael Eugene Gray

• Agriculture, Agronomy

Language dc:language

eng

Identifier

(MiAaPQ)AAI3044210

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85002