Kojima, Jun-ichi

Makino, Shun'ichi

Saito-Morooka, Fuki

Sayama, Katsuhiko

English

Sydney eScholarship

 Rapid expansion of range and population  in the social-parasitic hornet  Katsuhiko Sayama1, Jun-ichi Kojima2, Fuki Saito-Morooka2, Shun’ichi Makino1 1 Hokkaido Research Center, Forestry and Forest Products Research Institute, Sapporo, Japan 2 Faculty of Science, Ibaraki University, Mito, Japan Vespa dybowskii is the only social-parasitic hornet, that usurps a nest and workers of its host species, V. crabro or V. simillima, to produce their own workers, males and gynes. This species was a rare species in Japan, the number of its occurrence records has recently been drastically increasing. In this study, we analyzed the trends of the expansion of the distribution range and population size of this hornet in Japan.  Conclusion Vespa dybowskii has expanded its distribution range rapidly and increased its population size since the second half of 1990s. Recent host records showed that more than half of the host-identified nests originally belonged to V. simillima, which is more common than V. crabro in many parts of Japan. Therefore, a possible shift in the major host from V. crabro to V. simillima is one of the factors underlying the rapid range expansion and increase in the population size of V. dybowskii.  ・The number of records has increased rapidly in the 2000s in each region. About 30 examples reported in Sakagami & Fukushima (1957) are not included. (2) The number of records in each decade and region  Trends:    (1) Distributional range in Japan and Hokkaido  Factors:   (2) Shift from usurping host nests to founding own nests?:       A facultative parasite or an obligatory parasite?  ・First appearance of overwintered queens of V. dybowskii was later than that of two host species. However, solitary period of overwintered queens of V. dybowskii was significantly longer  than that of two host species (Mann-Whitney U-test). Thus, V. dybowskii is suggested to be an obligatory temporary social parasite. (1) Host shift from V. crabro to V. simillima? (2) Cladogram of Vespa species                     (after Perrard et al., 2013) Distribution range,  population size, host records: ・We collected  these data based on the information extracted from literatures and internet  web sites, and on personal communication, in addition to our own research. First appearance and solitary period of overwintered queens: ・Study site: The Hitsujigaoka  Experimental  Forest of the Forestry and Forest Products Research Institute in Sapporo, Hokkaido, northern Japan. ・We collected  hornets using baited traps once a week  from 2001 to 2013.    (3) Methods (1) Life cycle of V. dybowskii 2 3 2 2 518412301120501001502002501930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010sNo. of records 5026488719020406080100120Hokkaido Tohoku Kanto Central Kinki and westwardNo. of recordsRegions in Japan2000s（N=230）1990s（N=41）1980s（N=18）1437283100% 20% 40% 60% 80% 100%Kinki and westwardCentralKantoHokkaidoV. crabro V. simillima・In the 1930s-50s, major host species was V. crabro. Recent host records showed that more than half of the host-identified nests belonged to V. simillima. 211220514410% 20% 40% 60% 80% 100%2010s2000s1980s～90s1930s～50s (Sakagami & Fukushima, 1957)V. crabro V. simillima6249 48010203040506070V. dybowskii V. crabro V. simillimaSolitary period (days)Species Queen（N=12） Worker（N=13）V. dybowskii 6 June ± 1.2 7 Aug. ± 2.2V. crabro 23 May ± 2.1 10 July ± 2.3V. simillima 20 May ± 2.0   8 July ± 2.1First appearance（Mean date ± SE）P=0.0022 P=0.0018 IUSSI2014 P122 Matsuura (1995) 17 prefectures in Japan (Blue) 2013 30 prefectures  in Japan (Blue & Red) Matsuura (1995) 11 municipalities  in Hokkaido (Blue) 2013 31 municipalities in Hokkaido  (Blue & Red) Emerging fromoverwintering May June Oct.July Aug. Sept.OverwinteringQueenWorkerMaleGyne (new queen)Usurpationof host nestV. simillimaV. crabroHost and own workers↓Own workers

Rapid expansion of range and population in the social-parasitic hornet

https://ses.library.usyd.edu.au/bitstream/2123/11306/4/Poster122.pdf

Rapid expansion of range and population in the social-parasitic hornet

Abstract

Similar works

Full text

Available Versions

Sydney eScholarship