Enhancement of cold hardiness by acclimation is stage-specific in the non-diapausing pupae of onion maggot Delia antiqua (Diptera: Anthomyiidae)

Abstract

Abstract. When puparia of the onion maggot Delia antiqua were preexposed to 5°C for 5 days starting at different time points after pupariation, a large increase in survival after exposure to -20°C for 5 days was observed only when pre-exposure was initiated at 3-6 days after pupariation. The increase in cold hardiness was not associated with a large increase in the trehalose content of the puparia. The supercooling point of the puparia naturally decreased from -18 to -27°C in the first three days after pupariation, and pre-exposure to 5°C did not have an additional effect. Thus, factors responsible for the enhancement of cold hardiness by acclimation other than trehalose and supercooling point should be sought. The period of responsiveness to cold acclimation coincided with the time soon after head evagination, which corresponds to "pupation" in lepidopteran insects. The puparia appear to be physiologically flexible for a short time after head evagination, and able to adapt their physiology to the contemporary cold environment.

Cold tolerance and trehalose accumulation in overwintering larvae of the codling moth, Cydia pomonella (Lepidoptera: Tortricidae)

“…This relationship suggests that trehalose plays an important role in the overwintering strategy of the codling moth. Trehalose, the major insect blood sugar, has previously been considered a cryoprotectant in some insect species (Storey & Storey, 1991;Rojas et al, 1994;Koš ál & Šimek, 1995Koš ál & Šimek, , 1996Goto et al, 2001;Koš ál et al, 2001;Nomura & Ishikawa, 2001), but not in others (Naeemullah et al, 1999;Miyazaki et al, 2006). Despite widespread interest in cryoprotection, the mechanism by which trehalose confers cryoprotection is unknown.…”

Upregulation of a desaturase is associated with the enhancement of cold hardiness in the onion maggot, Delia antiqua

“…In D. antiqua, the increase in cold hardiness was not associated with a large increase of cryoprotectants, including trehalose, in the puparia (Miyazaki et al, 2006). Recently, Chen et al (2005Chen et al ( , 2006 reported that heat shock proteins (HSP90 and HSP70), which facilitate renaturation of proteins after stress, are upregulated in SD and WD pupae.…”

“…The survival rate of summer-diapause (SD) and winter-diapause (WD) pupae after a 5 days exposure to À20 1C exceeds 75%. Meanwhile, non-diapausing pupae also show a significantly increased survival rate when they are pre-exposed to 5 1C (cold-acclimated non-diapause pupae, CA) Miyazaki et al, 2006). We have long been interested in the mechanism of strong cold hardiness in this species.…”

Chaperonin Contributes to Cold Hardiness of the Onion Maggot Delia antiqua through Repression of Depolymerization of Actin at Low Temperatures

“…Meanwhile, non-diapausing pupae also show a significantly increased survival rate when they are preexposed to 5°C (cold-acclimated non-diapause pupae, CA) ( Fig. 1 ) [25] , [26] . To explore the molecular mechanisms underlying the strong hardiness in D. antiqua , we sought for differentially expressed genes in the cold-acclimated and diapause pupae.…”