Effect of photoperiod and temperature on the intensity of pupal diapause in the cotton bollworm,Helicoverpa armigera(Lepidoptera: Noctuidae)

Abstract

The intensity of pupal diapause in the cotton bollworm, Helicoverpa armigera (Hübner) was investigated under both laboratory and natural conditions. By transferring diapausing pupae induced under LD 11:13, LD 12:12 and LD 13:11 at 20, 22 and 25 °C to 25 °C combined with LD 15:9 to terminate diapause the rearing day length of 11 h evoked greater intensity of diapause than did 12 and 13 h at 25 °C; whereas the rearing temperature of 25 °C evoked more intense diapause than did 20 and 22 °C under LD 11:13. By transferring diapausing pupae induced under LD 12:12 at 20 and 22 °C to six temperatures of 18, 20, 22, 25, 28 and 31 °C combined with LD 15:9 to terminate diapause, the duration of diapause was significantly shortened from 146 days at 18 °C to 24 days at 31 °C, showing that high temperatures significantly accelerate diapause development. Furthermore, the duration of diapause was significantly longer at the rearing temperature of 22 °C than that at 20 °C when the diapause-terminating temperatures were 20 and 22 °C. Chilling at 5 °C did not shorten the duration of diapause but lengthened it when chilling period was included. However, chilling plays an important role in synchronizing adult emergence. Rearing temperature of 22 °C also evoked more intense diapause than did 20 °C in most chilling treatments. When the overwintering pupae were transferred at different times from natural temperatures to 25 °C, it was found that the earlier the transfer took place, the earlier the adults emerged when the time spent under natural conditions was included. However, cool temperatures before March showed an enhanced effect on diapause development at 20 °C, suggesting that the high diapause-terminating temperature can offset the effect of chilling on diapause development. The result of diapause termination under natural conditions suggests that the developmental threshold for post-diapause development in H. armigera should be around 17.5 °C.

Predicting performance and survival across topographically heterogeneous landscapes: the global pest insect Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae)

“…, ; Chen et al . ). Although we have not set a period of diapause in this model, as it is presently unclear if H. armigera undergo diapause in South Africa, a similar pattern of arrested development during cold conditions is reflected in the model's outputs.…”

Local and regional climate variables driving spring phenology of tortricid pests: a 36 year study

“…At the FREC, there have been anecdotal sightings of active tortricid larvae during uncharacteristically warm winters, indicating that during warm autumns and winters, development can continue and potentially lead to earlier spring flight. and possibly extend its length (Tauber & Tauber, 1976;Collier & Finch, 1983;Bale & Hayward, 2010;Chen et al, 2014). This resulted in less intensive diapause, with fewer thermal accumulations needed for termination (Denlinger & Iv, 1981;McWatters & Saunders, 1998;Fantinou & Kagkou, 2000;Bale & Hayward, 2010).…”

“…[Colour figure can be viewed at wileyonlinelibrary.com]. and possibly extend its length (Tauber & Tauber, 1976;Collier & Finch, 1983;Bale & Hayward, 2010;Chen et al, 2014). For insects in diapause, warmer temperatures can increase the insect's metabolic rates and lead to depletion of nutrient reserves and early termination of diapause (Han & Bauce, 1998).…”

Diapause in Stingless Bees (Hymenoptera: Apidae)

“…Temperature is also a significant environmental cue, although it may fluctuate seasonally from year to year (Tauber & Tauber, 1976;Tauber & Kyriacou, 2001;Saunders, 2012Saunders, , 2014. Nevertheless, both photoperiod and temperature often exert significant synergistic power influencing an insect's response (Kimura, 1988;Vaz Nunes & Saunders, 1989;Chen et al, 2014;Saunders, 2014).…”