Fig. 5.

A scheme of the photoperiodic control of nymphal development in the cricket Modicogryllus siamensis. NSC; neurosecretory cells. Dark red and blue lines indicate long-day (LD) and short-day (SD) pathways, respectively. LDs stimulate Ms’myo expression during the fifth to seventh instar stage, which suppresses Ms’jhamt expression and reduces JH synthesis, leading to adult emergence. SDs suppress Ms’myo expression and stimulate Ms’jhamt expression during the same stage, which increases JH production, resulting in nymphal molts, hence leading to slow nymphal development. Temperature regulates the growth rate through the insulin/TOR signaling pathway to accelerate or slow down at higher or lower temperatures, respectively. Slow development for overwintering is most likely maintained by short photoperiods and cold temperatures during autumn to winter. For further explanations, see text.