Effect of pre-wintering and wintering temperature regimes on weight loss, survival, and emergence time in the mason bee Osmia cornuta (Hymenoptera: Megachilidae)

Apidologie, Jul 2018

Jordi Bosch, William P. Kemp

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

http://www.apidologie.org/articles/apido/pdf/2004/05/M4025.pdf

Effect of pre-wintering and wintering temperature regimes on weight loss, survival, and emergence time in the mason bee Osmia cornuta (Hymenoptera: Megachilidae)

Apidologie Effect of pre-wintering and wintering temperature regimes on weight loss, survival, and emergence time in the mason bee Osmia cornuta (Hymenoptera: Megachilidae) Jordi BOSCH 1 William P. KEMP 0 0 USDA-Agricultural Research Service, Bee Biology and Systematics Laboratory , Logan, UT 84322-5310 , USA 1 Biology Department, Utah State University , Logan, UT 84322-5310 , USA - Osmia cornuta adults require exposure to wintering temperatures followed by incubation in the spring to emerge. We studied winter survival, weight loss, emergence time, and post-emergence longevity in O. cornuta exposed to a variety of pre-wintering and wintering treatments. Few bees emerged after exposure to wintering durations <30 days. Maximum survival and longevity were obtained with wintering durations of 90-150 days. Time to emergence following incubation declined with increasing wintering duration and increasing wintering temperature. Pre-wintering treatment had a dramatic effect on bee fitness. Bees pre-wintered for 15 days lost less weight, had higher survival and lived longer than bees pre-wintered for 45 or 75 days. In general, larger bees were more likely to survive the winter and lived longer than smaller bees. We discuss the relevance of these results to survival in wild O. cornuta populations and the management of populations used in orchard pollination. 1. INTRODUCTION Osmia cornuta (Latreille) is a solitary, uni voltine, spring-flying mason bee distributed throughout most of central and southern Europe and parts of the Middle East (Peters, 1977) . Adult females are active for approximately 20 days in the spring, during which time they build one or more nests in abandoned beetle burrows in dead timber or vacant nests of other bees (mainly Anthophora) in clay embankments. In addition to foraging for pollen and nectar to provision their nests, females also collect mud to build cell partitions and to seal completed nests. Eggs hatch in approximately one week, immature development proceeds through the spring-summer period, and adulthood occurs in late-summer or early autumn. Eclosed adults remain in their cocoons through the winter, and emerge the next spring as temperatures rise. Respirometry studies with the closely-related species Osmia lignaria Say (Kemp et al., 2004) indicate that this winter dormancy is diapause-mediated (sensu Tauber et al., 1986) . Wintering in the adult stage appears to be a derived trait within the family Megachilidae and the genus Osmia (Bosch et al., 2001) , and is probably associated with the early seasonal activity period of O. cornuta. Most other Megachilidae winter as prepupae and adults are active later in the year (Bosch et al., 2001) . Osmia cornuta is an excellent pollinator of fruit trees, and has been studied as an orchard pollinator in several countries (Asensio, 1984; Torchio et al., 1987; Krunic et al., 1991; Bosch, 1994a; Maccagnani et al., 2003) . As a result, its foraging and nesting behavior are relatively well known (Taséi, 1973a; Maddocks and Paulus, 1987; Jacob-Rémacle, 1990; Bosch, 1994b; Bosch and Blas, 1994a; Vicens and Bosch, 2000a) , and methods to manage O. cornuta populations have been developed, including preferred nesting materials and nesting cavity sizes, releasing methods, and number of bees required per orchard area (Bosch, 1994b, c, 1995; Vicens and Bosch, 2000b) . There is, however, much less information available on the developmental biology and wintering requirements of O. cornuta populations (Taséi, 1973b; Bosch and Blas, 1994b) . Previous studies indicate that winter survival in O. cornuta from NE Spain is high (> 95%) when bees are artificially wintered (3–5 ºC) for a period of 100–120 days, beginning in October to earlyNovember (Bosch, 1994a; Bosch and Blas, 1994b) . Populations artificially wintered later in the year (late-November) for shorter periods (75 days) have lower winter survival (< 86%) (Bosch, 1994a, 1995) . Some bees from the latter populations actually survive the winter, but are not vigorous enough to chew their way out of their cocoons the following spring (Bosch, 1994a) . These results suggest a strong effect of pre-wintering periods (defined as the period from adult eclosion to initiation of wintering) and/or wintering periods (period from initiation of wintering to spring incubation) on O. cornuta survival and vigor. Previous studies also demonstrate a strong effect of wintering periods on emergence time. Bees wintered for 75 days have protracted emergence periods following spring incubation (exposure to warm temperatures that elicit emergence) compared with bees wintered for longer periods (Bosch and Blas, 1994b) . To our knowledge, there is no information available on the effect of different wintering temperatures on emergence in this species. The objective of this study was to investigate the effect of pre-wintering and wintering duration and temperature on O. cornuta survival, emergence tim (...truncated)


This is a preview of a remote PDF: http://www.apidologie.org/articles/apido/pdf/2004/05/M4025.pdf

Jordi Bosch, William P. Kemp. Effect of pre-wintering and wintering temperature regimes on weight loss, survival, and emergence time in the mason bee Osmia cornuta (Hymenoptera: Megachilidae), Apidologie, pp. 469-479, Volume 35, Issue 5, DOI: doi:10.1051/apido:2004035