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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Insect Genetics and Biochemistry Research » Research » Publications at this Location » Publication #332553
Title: Pre-wintering conditions and post-winter performance in a solitary bee

Author
item SGOLASTRA, FABIO - University Of Bologna, Italy
item ARNAN, XAVIER - Federal University Of Pernambuco
item Pitts Singer, Theresa
item MAINI, STEFANO - University Of Bologna, Italy
item Kemp, William - Bill
item BOSCH, JORDI - Autonomous University Of Barcelona

Submitted to: International Congress of Entomology
Publication Type: Abstract Only
Publication Acceptance Date: 8/25/2016
Publication Date: 9/25/2016
Citation: Sgolastra, F., Arnan, X., Pitts Singer, T., Maini, S., Kemp, W.P., Bosch, J. 2016. Pre-wintering conditions and post-winter performance in a solitary bee [abstract]. 2016 XXV International Congress of Entomology. 09/25/2016-09/30/2016. Orlando, FL. Talk #3520.

Interpretive Summary: .

Technical Abstract: Notwithstanding lowered metabolism, and because diapausing insects have no access to food, diapause has an energetic cost that may affect post-diapause performance. Previous studies on the solitary bee Osmia lignaria have shown that prolonged pre-wintering periods (the time during which individuals already in diapause remain at warm temperatures) are associated with elevated lipid consumption, fat body depletion, and body weight loss. More recently, we investigated whether prolonged pre-wintering also affects reproduction, i.e. whether the costs associated with diapause could have an effect on post-diapause performance in this species. Females were exposed to a range of pre-wintering conditions, and ovary development and individual post-wintering performance were monitored throughout their adult life span. No evidence of an effect of pre-wintering duration on post-diapause reproductive success was found. Expected differences in the timing of establishment were not observed because ovary maturation was, surprisingly, not arrested during pre-wintering. Prolonged pre-wintering duration did not result in decreased life span, probably because emerging females could rapidly replenish their metabolic reserves through feeding. These results are important in view of the delays in winter onset under the current scenario of climate change. However, there was a very strong effect of the duration of the pre-emergence period on the likelihood of nest establishment. Females that took longer to emerge were less likely to establish. Longevity emerges as the main factor determining fecundity in Osmia, and its intrinsic variability is so large that it may override the effects of any other potential factors, including pre-wintering duration.