Dissertation

with Nilaparvata lugens (Stål) damaged, mechanically damaged and undamaged rice plants.Moreover, S. litura females avoided plants infested with N. lugens in a dual-choice flight tunnelbioassay. In our study utilizing S. frugiperda damaged plants, L. oryzophilus females avoidedovipositing on previously damaged plants when given a choice in greenhouse experiments.Table 2.1. Mean number of L. oryzophilus eggs and larvae per plant (± SE) in field samplesusing rice variety ‘Jackson.’ Egg samples were taken 13 and 19 days after exogenous JAapplications. Core samples were taken 19 and 27 days after permanent flood wasestablished. Means within the same column followed by different letters indicate asignificant difference (P ≤ 0.05).Egg SamplesCore SamplesFirst Second First SecondTreatmentControl1 mM JAEggs/Plant0.83 ± 0.74a0.17 ± 0.16aEggs/Plant2.17 ± 1.48a1.82 ± 0.8aLarvae/Plant4.84 ± 1.32a2.31± 0.50bLarvae/Plant7.4 ± 1.7a4.76 ± 0.75a5 mM JA 0.67 ± 0.33a 4.10 ± 1.8a 1.92 ± 0.50b 6.32 ± 1.1aTable 2.2. Mean number of L. oryzophilus eggs and larvae per plant (± SE) in field samplesusing variety ‘Rosemont.‘ Egg samples were taken 3 days after exogenous JA applications.Core samples were taken 14 and 19 days after permanent flood was established. Meanswithin the same column followed by different letters indicate a significant difference (P ≤0.05).TreatmentControlEgg SampleCore SamplesFirst First Core Sample Second Core SampleEggs/Plant2.18 ± 0.7aLarvae/Plant2.88 ± 0.68aLarvae/Plant8.12 ± 2.56a5 mM JA 0.88 ± 0.43a 1.46 ± 0.34b 6.54 ± 1.33aThe ability of JA to induce resistance to L. oryzophilus in greenhouse experiments led usto hypothesize that exogenous JA would induce resistance in field grown plants. Although adultrice water weevils can be found in rice fields both before flooding, oviposition and larvalinfestations largely commence after flooding (Everett and Trahan, 1967). Densities of eggs in26