Chilled Galleria mellonella larvae: mechanism of supernumerary moulting

Abstract

ABSTRACT. Supernumerary larval instars were produced when Galleria mellonella L. (Lepidoptera) larvae were chilled at 0°C. Although sensitivity to cooling stress of the last instar and younger larvae were generally the same, only penultimate and the last instar larvae showed a significant correlation between their age and the number of additional larval moults. Chilling stress induced a rapid and persistent increase in the JH titre of the last instar larvae. Severing the ventral nerve cord resulted in a predictable loss of the ability to produce supernumerary moults in chilled last instar larvae. The data suggest that sensory input stimulates allatotropic hormone secretion by the brain of chilled larvae. The possible mechanism controlling supernumerary moulting is discussed.

Larval development, developmental arrest, and hormone levels in the couple Galleria mellonella (lepidoptera‐pyralidae)—Pseudoperichaeta nigrolineata (diptera‐tachinidae)

“…However, there is a very active synthesis of JH or a diminution of its degradation during that period. G. mellonellu is particularly sensitive to exposure to chilling, which induces supernumerary molts [16, by increasing the JH level [23]. The latter increase is probably caused by a stimulation of the corpora allata by the brain [24] and by a decrease in the specific JH-esterase activity [25,26].…”

The neuroendocrine stress-response in insects: the history of the development of the concept

“…Гормональный статус насекомых со сверхчисленными линьками в неблагоприятных условиях среды последовательно изучали Б. Цимборовский и М.И. Богус (Cymborowski, Bogus, 1976;Bogus, Cymborowski, 1981). Б. Цимборовский предложил схему стрессорной реакции, возникающей у личинок Galleria mellonella в условиях холодового стресса (Cymborowski, 1988).…”

Juvenile hormone regulation and developmental expression of a Tenebrio desiccation stress protein gene

“…First, increases in J H titre have been reported in various insect species following starvation, injury, and exposure to cold temperatures or short photoperiod [Cymborowski et al, 1982;Bogus et al, 1986;Bogus and Cymborowski, 1981;Xu et ul., 19921. However, several observations suggest that J H may mediate the expression of dsp28 following cold or desiccation stress and injury.…”

“…However, several observations suggest that J H may mediate the expression of dsp28 following cold or desiccation stress and injury. First, increases in J H titre have been reported in various insect species following starvation, injury, and exposure to cold temperatures or short photoperiod [Cymborowski et al, 1982;Bogus et al, 1986;Bogus and Cymborowski, 1981;Xu et ul., 19921. Second, photoperiod and environmental stress can induce diapause or quiescence and in some larval insects, J H also induces diapause [Chippendale, 19831. Third, desiccation and cold stress induces quiescence in the larval stage of Tenebrio, when dsp2S levels are high, but development proceeds if pupae are subjected to these conditions.…”