Ontogenesis of the cricket Gryllus argentinus Sauss. (Orthoptera, Gryllidae)

The development of Gryllus argentinus Sauss. was studied under stable laboratory conditions: the temperature of 26°C, the air humidity of 60%, and the photoperiod of 12h light: 12 h dark. The life cycle of Gryllus argentinus includes four stages: egg, pronymph, nymph, and adult. The duration of embryonic development is 18 days. The depth of egg bedding in the peat is 9.63 ± 0.12 mm (n =145), the clutch containing 2–4 eggs. A female can lay over 1100 viable eggs during the entire oviposition period. Nymphal development includes 9 instars and lasts 97 days. The duration of nymphal instars (days) is: I—5; II—6; III—6; IV—6; V—8; VI—10; VII—13; VIII—14; IX—29. The duration of the adult life is 51 days in males and 69 days, in females. In the imaginal ontogenesis of males and females, three periods can be distinguished: pre-reproductive, reproductive, and postreproductive. Males start to emit the aggressive signal on the 6th (5–8th) day (the pre-reproductive period). They enter the reproductive period (start to emit the calling song) on the 9th (8–13th) day. Females enter the reproductive period (become capable of responding to the calling song and of copulation) on the 9th (8–10th) day. Oviposition starts on the day after the first copulation. The reproductive period lasts about 40 (15–59) days in males and 58 (21–70) days in females. The post-reproductive period starts in females at the moment of finishing the egg laying period and in males, with disappearance of reproductive behavior. The period ends in the animal’s death.