Differences in fitness traits between E and Z pheromone races of European corn borer, Ostrinia nubilalis, on different host plants

Life-history traits can have a direct impact on an organism’s overall fitness. By looking at differences in life-history traits of closely related insect groups we can better understand what drives these changes and how they affect fitness. The European corn borer (ECB), Ostrinia nubilalis (Hübner), is a polyphagous insect species native to Europe, where it is widespread. ECB is considered a major economic pest of corn in the United States and Canada. ECBs have two distinct pheromone races, the E and Z races, which produce different ratios of two isomers in their pheromone blends. The pheromone races also can exhibit variation in emergence behavior and host plant selection.  This research focuses on how E and Z ECB larvae differ in fitness due to changes in life-history traits on a range of host plant based diets. Assessment includes ECB larvae from both laboratory colony and wild captured populations. Identification of pheromone race of ECB individuals is done using a PCR and restriction enzyme method. ECB larvae are reared on either a Cry1F Bt corn, non-Bt corn, sweet corn, tomato, or hops variety plant-incorporated diet.  Larvae are then measured for variations in: (1) growth and development, (2) pheromone production, (3) fecundity, and (4) survival. Data are analyzed using two-way ANOVA to determine if there are significant differences in life-history traits between the pheromone races.