Daily rhythms in the sorghum shootfly, Atherigona soccata: oviposition, egg‐hatch and adult eclosion

Abstract

Daily rhythms controlling oviposition, egg-hatching and adult eclosion in the sorghum shootfly, Atherigona soccata Rondani, were investigated. Eggs were laid only during the photophase of a LD 12 : 12 cycle, in two peaks.Under continuous light, this oviposition was considerably attenuated but not made immediately arrhythmic. Egg-hatching and adult eclosion both commenced just before dawn. Some feature of the scotophase during or immediately after black-head formation apparently acts as a signal for hatching. Eclosion was controlled by light but its timing in the field was modified by temperature. The last 2-3 days of the pupal period constituted the most sensitive stage, and light signals received during this period determined the time of eclosion. Ecological advantages of these rhythms to the shootfly are discussed.

Daily Temperature Cycle Induces Daily Hatching Rhythm in Eastern Lubber Grasshoppers,Romalea microptera

“…Some insect species only hatch at night (Beck 1980;Raina 1982), some during the day (Michiyo 1989;Ramachandran 1989), some primarily at or just before dawn (Beck 1980;Itoh & Sumi 2000;Schilman et al 2009), and others mainly at or just after dusk (Corbet 1962). In other species, hatching time is random, or it varies over the 24-h period, based on some non-rhythmic environmental factor (Chapman 1998;Vitek & Livdahl 2009).…”

Hatching pattern and survival of first instars of Ectropis excursaria (Guenee) (Geometridae: Lepidoptera)

“…The winter afternoon peak was spread over nearly 6 hr, probably due to lower temperatures (Raina, 1982), while the summer afternoon peaks tended to be bigger and sharper. The winter afternoon peak was spread over nearly 6 hr, probably due to lower temperatures (Raina, 1982), while the summer afternoon peaks tended to be bigger and sharper.…”

“…Sorghum shootfly egg hatching has also been reported to start before the onset of photophase and continue to early part of photophase (Raina, 1982). As the temperature was increased or decreased from this optimum, hatching started before the start of photophase and continued till sometime after.…”

“…Sorghum shootfly egg hatching has also been reported to start before the onset of photophase and continue to early part of photophase (Raina, 1982). In the case of sorghum shootfly some aspect of last scotophase has been suggested to trigger egg hatching (Raina, 1982). In sorghum stem borer, Chilo partellus (Swinhoe), hatching of eggs has been reported to be due to "lights-on" stimulus if eggs have developed for 180 to 350 hr-degrees after blackheading (Chapman et al, 1983).…”

“…Hatching of eggs in the morning has been suggested to have important bearing on the survival and establishment of first instar larvae (Raina, 1982;Chapman et. al., 1983).…”