Development of the Spittlebug Mahanarva fimbriolata under Varying Photophase Conditions

The effects of varying photophase conditions on biological parameters of Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae), nymphs and adults were evaluated. Eggs of a late developmental stage were placed near sugarcane roots (cultivar RB739735) maintained in a greenhouse (21 ± 7° C, 90 ± 10% RH). Nymphs and adults were exposed to the following photophase conditions: a) 13:11 L:D as nymphs and adults, b) 13:11 as nymphs and 12:12 as adults, c) 12:12 as nymphs and adults, and d) 12:12 as nymphs and 13:11 as adults. Exposure of nymphs to 13 hr of light significantly reduced the duration of the nymphal stage and the number of nymphs that matured to adults. The duration of the nymphal stage was longer in individuals developing into females than in those developing into males. There was an increase in the longevity of adults kept at 13 hr of light since the nymphal stage. The average longevity of adult males and females was approximately the same. The sex ratio was similar under all photophase conditions. The life cycle of insects kept at 12 and 13 hr of light during nymphal and adult stages respectively was extended. The total life cycle was significantly longer in M. fimbriolata females than males. The different photophase conditions did not affect the reproductive potential of M. fimbriolata. Females produced more diapausing than non-diapausing eggs, except when under 13- and 12-hr light conditions. There was no significant difference in the number of diapausing and non-diapausing eggs produced by females under the other photophase conditions.