In maize, the leafhopper, Dalbulus maidis (DeLong & Wolcott) is the vector of three maize pathogens: the corn stunt spiroplasma (Spiroplasma kunkelii), the maize bushy stunt phytoplasma and the maize rayado fino virus. Yield losses caused by these diseases range from nine to 90% depending on the cultivar susceptibility and the pathogen involved. The objective of this research was to study the corn leafhopper life cycle under controlled conditions, using insects and host cultivars adapted to the Brazilian conditions. Seedlings of maize and sorghum cultivated in plastic pots and covered with plastic cages, were infested with 10 adults per plant. Two independent experiments were conducted by using 10 seedlings/treatment. In the first one, the egg incubation period was recorded at constant temperatures of 17, 20, 23, 26, 29 e 32ºC ± 1ºC and using a light cycle of 12:12 h. In the second experiment the developmental period of nimphs was studied under the same light cycle and constant temperature of 26,5 ± 2ºC. The shortest incubation period was recorded at the temperatures of 26 and 29ºC, in which 70% hatching took place in nine days. At 26,5ºC the nymphs went through four (76% population) or five (18% population) instars and reached the adult stage in 15.7 days (around 3,14 days per instar). Mean adult longevity was 51.4 days and the life cycle, from egg to adult was 26.3 days in average. Therefore, in order to keep the insect colony or to conduct experiment with this insect, it is important to consider the maximum and minimum temperature limits.
Insecta; Zea mays; maize; vector; pest; disease
