[ Original Article ]

Journal of Apiculture - Vol. 30, No. 1, pp.1-5

ISSN: 1225-0252 (Print)

Print publication date Apr 2015

Received 08 Jan 2015 Revised 28 Mar 2015 Accepted 30 Mar 2015

DOI: https://doi.org/10.17519/apiculture.2015.04.30.1.1

Comparative Analysis on the Nest Structures of the Korean Yellowjacket, Vespula koreensis and the Yellow Hornet, Vespa simillima simillima

Kil Won Kim

Division of Life Sciences, Incheon National University, Incheon, 406-772, Republic of Korea

Correspondence to: E-mail: kilwon@inu.ac.kr

Abstract

This study compared the nest structure of the Korean yellowjacket, Vespula koreensis and the yellow hornet, Vespa simillima simillima, both belonging to the subfamily Vespinae which contains the largest and best-known eusocial wasps. Vespula and Vespa are considered as same category in major design of nest architecture among eusocial wasps. Four nests of V. koreensis and three nests of V. simillima simillima were examined. The nest of V. simillima simillima was 3.26 times bigger than that of V. koreensis, and nest envelope of V. simillima simillima was 1.3 times thicker than that of V. koreensis. The comb of V. koreensis contained 2.4 times more cells than that of V. simillima simillima: on average 647 cells vs. 269 cells within a comb. On the whole, mean diameter of the cell was almost two times greater in V. simillima simillima: 4.7mm vs. 8.9mm. In V. simillima simillima, cell size was bigger in larger comb. More vigorous researches should be done on life history traits of V. koreensis, a Korean endemic species which is almost unknown, while social wasp population seems to be dramatically increasing in temperate regions.

Keywords:

Nest structure, Korean yellowjacket, Vespula koreensis, Yellow hornet, Vespa simillima simillima

INTRODUCTION

The architecture of nest made by animals is an important source of information about behavioral evolution. Unlike most behavior, construction leaves behind a physical trace that can be measured, stored and later reexamined (Wenzel, 1991). In social wasps, nest construction is probably the most complex task of the workers. From collecting materials to the structural architecture, simple things done by each individual with presumably limited intelligence gather and interact, and finally show great structural architectures (Jeanne, 1975).

The subfamily Vespinae contains the largest and bestknown eusocial wasps, including true hornets (the genus Vespa), and the yellowjackets (genera Dolichovespula and Vespula). Vespa and Vespula are most often observed eusocial wasps in East Asia, with recently increasing population densities in residential sections on the outskirts of cities (Jeanne, 1975; Matsuura and Yamane, 1984; Choi and Moon, 2005; Choi et al., 2012). Out of 18 species of Vespinae found in South Korea, 10 species belong to the genus Vespa, 6 species to the genus Vespula and 2 species to the genus DolichoVespula (Choi et al., 2013). Using same nest materials and food source the genus Vespula and Vespa show a similar ecological niche and life history traits (Ross and Matthews, 1991).

The nest sites preferred by Vespa wasps are above the ground in the open or in an enclosed space, below the ground in a cavity, or some combination of these feature depending on the species (Matsuura and Yamane, 1984). Vespa simillima is the only Vespa species known that shows adaptability to a wide range of nest site in both and enclosed situations aboveground and underground (Matsuura, 1991). Vespula species, in contrast, mainly nest in cavities underground. Wenzel (1991) classified the Vespula and Vespa as same category in major design of nest architecture among eusocial wasps. The queens make an ordinary pedicellate first comb, but later workerinitiated combs may be built directly from the substrate without pedicels (Matsuura and Yamane, 1984; Jung and Burgett, 2009). Both of Vespula and Vespa construct their nests using wood pulp. Brood cells are constructed, arranged in a honeycombed pattern, and surrounded by a multi-layered envelope.

In this study I conducted comparative analysis on the nest structure of the yellow hornet, Vespa simillima simillima and the Korean yellowjacket, Vespula koreensis, a Korean native species. Volume of the nests, thickness of nest envelope, the number of cells within combs, cell diameter etc. were compared between species.

MATERIALS AND METHODS

Building behaviors of Vespa simillima simillima and Vespula koreensis

Queens of both species initially builds a series of cells. The cells are arranged in horizontal layers named combs, an egg is then laid in each cell. As the colonies grow new combs are added by the workers and the nest envelop is enlarged so that it covers the comb entirely. In Vespula species the bottom part of the nest is opened to serve as a nest entrance. But the envelope of V. simillima simillima completely covers the comb whether nesting occurs in an open or an enclosed situation (Matsuura, 1991). On the basis of this characteristic it seems probable that this species evolved from ancestors that nested exclusively in the open environment (Matsuura, 1991).

The pulp, nest material, is either collected from external sources of fibers or taken from the nest inner envelop, which must be continually removed in many places to accommodate comb expansion. Cells are built almost entirely from the recycled paper, while incoming pulp from the field is usually applied to the outer envelope (Duncan, 1939; Akre et al., 1976).

Nest collection and analysis

Nests of V. simillima simillima measured in this study were obtained under roofs of buildings during summer season. Nests of V. koreensis were carefully collected to dig up from underground as much as possible so as not to damage the envelope. Four nests of V. koreensis and three nests of V. simillima simillima were collected and studied. Measurements on the nest components were conducted under laboratory conditions.

Parameters on the structure and composition of the nests were determined as follows: After measuring a longer diameter and shorter diameter of the nest, volume of the nest was calculated by 4π((R+r)/2)³/3. ‘R’ is longer radius and ‘r’ is shorter radius. Number of combs was considered as the order of construction. Number of cells within each comb was counted. Diameter of the cell was considered as a longer diameter of cells. The measurements were carried out with a vernier caliper and ruler.

The relationship between the number of cells within comb and diameter of cells in the comb was estimated by regression analysis using SigmaPlot 12.3 (Systat, 2012).

RESULTS

Nests of the two species measured in this study were all right globular shape. V. simillima simillima had a nest 3.26 times larger than that of V. koreensis: 1782±6974 mm³ on average in V. koreensis vs. 2156±7036 mm³ in V. simillima simillima. Nest envelope of V. simillima simillima was 1.3 times thicker than that of V. koreensis: 27.1 ±2.8 mm in V. simillima simillima vs. 20.7±2.5 mm in V. koreensis.

Table 1 presents the nest volume, and the number and diameter of cells in each comb in V. koreensis and V. simillima simillima. The number of cells within comb varied strongly from the first comb to the last one. For both of the species the number of cells was constantly higher in second comb than in the first comb, and the last comb had less cells than previous combs except the first comb.

Nest of V. koreensis contained 2.4 times more cells than that of V. simillima simillima: on average 647 cells within a comb in the nest of V. koreensis vs. 269 cells within a comb of V. simillima simillima (Table 1). Mean of the cell diameter was constantly smaller in the first comb than that of the second comb in the two species. On the whole, mean diameter of the cell was almost two times greater in V. simillima simillima: 4.7mm in V. koreensis vs. 8.9mm in V. simillima simillima (Table 1; Fig. 1).

Table 1.

Comparison of the nest volume, and the number and diameter of cells in each comb between Vespula koreensis and Vespa simillima simillima

Fig. 1.

Combs of Vespa simillima simillima (A) and Vespula koreensis (B). The figures shows an example of the second comb in the nest, and the black bar on each figure corresponds to 1cm of length.

In V. simillima simillima the number of cells within comb showed a positive relationship with mean diameter of cells in the comb (Anova test for regression analysis, R² =0.5888, y=0.0022x+8.3710, F_1,10=5.3075, P=0.0440), while there was no relationship found in V. koreensis in this case (Fig. 2).

Fig. 2.

Relationship between the number of cells within comb and mean diameter of cells in the comb of the nest in Vespula koreensis and Vespa simillima simillima.

DISCUSSION

There is few quantitative data on life history traits of V. koreensis which is a Korean endemic species. This study provides limited information on the nest structure of V. koreensis comparing to V. simillima simillima which shows similar ecological niche and eusociality.

Within the genus Vespula, 2 species groups have been recognized: the V. vulgaris group, the members of which exist in large colonies, build large nests and whose workers scavenge for meat in addition to capturing live prey to feed their larvae; and the V. rufa group, the members of which exist in much smaller colonies, build small nests and whose workers are strictly predacious (MacDonald et al., 1976). Carpenter (1987) made the cladogram based on analysis of 39 characters (Matsuura and Yamane, 1984), and established Vespula species groups as V. koreensis and V. vulgaris groups are sister-taxa. The nest size of V. koreensis seems to be smaller than V. vulgaris which shows 3,000 up to 15,000 workers within a nest. The cell diameter of V. koreensis appeared also smaller than that of V. vulgaris: 4.7mm in this study vs. 6mm in V. vulgaris (Jung and Burgett, 2009).

Including true hornets (the genus Vespa), and the yellowjackets (genera Dolichovespula and Vespula), the subfamily Vespinae are the dominant social wasps in temperate areas and have profound effects on the ecology of vast regions (Jeanne, 1975; Akre, 1991; Dejean et al., 2011). These wasps have been introduced into many areas of the world where they do not naturally occur, and the population seems to be dramatically increasing in temperate regions (Choi and Moon, 2005; Masciocchi, 2010; Choi et al., 2012). It might need more robust studies on the Korea endemic species.

Acknowledgments

For help in data collection I thank Keounghye Kim. This study was conducted in compliance with ethical standards of animal treatment according to the Association for the Study of Animal Behaviour Society Guidelines for the use of animals in research. This work was supported by Incheon National University Research Grant (2013).

LITERATURE CITED

Akre, R.D., (1991), Wasp research: strengths, weaknesses, and future directions, New Zealand J. Zool, 18, p223-227. [https://doi.org/10.1080/03014223.1991.10757970]
Akre, R.D., W.B. Garnett, J.F. Mac Donald, A. Greene, and P. Landolt, (1976), Behavior and colony development of Vespula pensylvanica and V. atropilosa (Hymenoptera: Vespidae), J. Kans. Entomol. Soc, 49, p63-84.
Carpenter, J., (1987), Phylogenetic relationships and classification of the Vespinae (Hymenoptera: Vespidae), Syst. Entomol, 2, p413-431. [https://doi.org/10.1111/j.1365-3113.1987.tb00213.x]
Choi, M.B., and T.Y. Moon, (2005), Predominant distribution of Vespa simillima simillima Smith in the urbanized central Busan areas, Korean J. Nat. Sci, 12, p49-54.
Choi, M.B., J.M. Kim, and J.W. Lee, (2012), Increase trend of social hymenoptera (wasps and honeybees) in urban area, inferred from moving-out case by 119 rescure services in Seoul of South Korea, Entomol. Res, 42, p308-319. [https://doi.org/10.1111/j.1748-5967.2012.00472.x]
Choi, M.B., J.K. Kim, and J.W. Lee, (2013), Checklist and distribution of Korean Vespidae revisited, Korean J. Appl. Entomol, 52, p85-91. [https://doi.org/10.5656/KSAE.2013.02.1.072]
Dejean, A., R. Cereghino, J.M. Carpenter, B. Corbara, B. Herault, V. Rossi, M. Leponce, J. Orivel1, and D. Bonal, (2011), Climate change impact on neotropical social wasps, PLoS ONE, 6(6), pe27004. [https://doi.org/10.1371/journal.pone.0027004]
Duncan, C.D., (1939), A contribution to the biology of North American vespine wasps, Stanford University Publications in Biology, 8, p1-272.
Jeanne, R.L., (1975), The adaptiveness of social wasp nest architecture The Quarterly Rev, Biol, 50, p267-287. [https://doi.org/10.1086/408564]
Jung, C., and M. Burgett, (2009), Nest Structures of Two Yellowjackets, Vespula pensylvanica and Dolichovespula maculate (Hymenoptera: Vespidae), Korean J. Apiculture, 24, p201-210.
MacDonald, J.F., R.D. Akre, and R.W. Matthews, (1976), Evaluation of yellowjacket abatement in the United States, Bull. Entomol. Soc. Am, 22, p397-401. [https://doi.org/10.1093/besa/22.4.397]
Masciocchi, M., (2010), Competition for food between the exotic wasp Vespula germanica and the native ant assemblage of NW Patagonia: evidence of biotic resistance, Biological Invasions, 12, p625-631. [https://doi.org/10.1007/s10530-009-9469-5]
Matsuura, M., (1991), Vespa and Provespa, in The social biology of wasps, eds. by K. G. Ross, and R. W. Matthews, p232-262, Ithaca, NY, Comstock Publishing Associates.
Matsuura, M., and S. Yamane, (1984), Biology of the Vespine wasps, p320, Hokkaido University Press, Japan.
Ross, K.G., and R.W. Matthews, (1991), The social biology of wasps, p678, Ithaca, NY, Comstock Publishing Associates.
Systat, (2012), SigmaPlot 12.3, Systat Software Inc.
Wenzel, J.W., (1991), Evolution of nest architecture, in The social biology of wasps, eds. by K. G. Ross, and R. W. Matthews, p480-519, Ithaca, NY, Comstock Publishing Associates.