Diel flight periodicity of Graminella nigrifrons (Homoptera: Cicadellidae)

The effect of light intensity, temperature, and host-plant age on the diel flight periodicity of Graminella nigrifrons (Forbes) was evaluated under controlled laboratory conditions and in the field. In a controlled environment, leafhoppers reared on young and mature oats responded similarly to changes in light intensity when temperature was held at a constant 26.6 plus or minus 1 degree C. Most leafhoppers were trapped under low light that simulated dusk and dawn. Activity was low at midday and at night. Temperature altered this flight pattern. When day temperature was 26.6 plus or minus 1 degree C and night was 18.3 plus or minus 1 degree C, most leafhoppers were trapped late in the day and peaked at dusk. Few leafhoppers flew at night, but there was a small speak at dawn. It these laboratory experiments, numbers of females and males trapped did not differ greatly. In the field, many more leafhoppers were trapped in July than in June or August.