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ABSTRACT
Studying yellowjackets is challenging due to their cryptic nesting behaviour, short field season, and extreme variation in population density. Developing or perfecting techniques for rearing yellowjackets would greatly increase the opportunity of studying the communication ecology of yellowjackets and the evolution of eusociality in the Hymenoptera. Our objective was to assess a method for rearing the five Vespula congeners V. acadica (Sladen), V. alascensis (Packard), V. atropilosa (Sladen), V. germanica (F.), and V. pensylvanica (Saussure). In early spring 2014, we collected queens of each of the five species from the field and placed them singly in a plywood nest box connected to a mesh cylinder that served as a foraging arena and provided constant access to water and food (honey, live flies, and live caterpillars). For each queen, we recorded nest initiation, the attachment site of the nest pedicel, and the stage of nest development at the end of the experiment, nine weeks after the last collection date of queens. Queens of V. germanica (n=18), V. alascensis (n=11), V. acadica (n=4), V. pensylanica (n=23), and V. atropilosa (n=11) had nest-inititation rates of 61%, 50%, 25%, 17%, and 0%, respectively. The mean number of nest cells built by queens of V. germanica, V. alascensis, V. acadica, V. pensylvanica, and V. atroplisoa were 21.6 ± 4.6, 17.8 ± 6.3, 8.0, 26.5 ± 8.3, and 0, respectively. Two V. germanica queens and one V. pensylvanica queens established nests that produced a few worker wasps. Although our rearing method compares favorably to, and in some aspects improves, previous rearing methods, further refinements are needed to generate the large numbers of wasp workers that are essential for experimental testing of hypotheses pertinent to life-history traits of yellowjackets.
Key Words: Yellowjacket, Vespula, rearing, nesting
INTRODUCTION
Yellowjackets and hornets are intensely studied because they can be (i) invasive and pestiferous species in many ecosystems (Landolt 1998; D'Adamo et al. 2001; Day and Jeanne 2001; Landolt et al. 2005; Brown et al. 2014), (ii) potential biological control agents (Hoffmann et al. 2000), (iii) vectors of microorganisms (Davis et al. 2012; Stefanini et al. 2012), and (iv) threats to citizens with venom (hyper)sensitivity (Nakajima 1986; Schmidt 1986; Ono et al. 2003). Furthermore, wasps are model organisms for studying the evolution of...