Research Article |
Corresponding author: Krzysztof Bartosz Kozyra ( kozyra_k@amu.edu.pl ) Academic editor: Jack Neff
© 2016 Krzysztof Bartosz Kozyra, Edward Baraniak, Marek Kasprowicz.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kozyra KB, Baraniak E, Kasprowicz M (2016) Nesting ecology of Polistes nimpha (Hymenoptera, Vespidae): a preliminary study in western Poland. Journal of Hymenoptera Research 51: 187-201. https://doi.org/10.3897/jhr.51.7508
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In 2014 and 2015 we investigated the nesting ecology of Polistes nimpha, one of the paper wasp species common in western Poland. In three selected study plots we collected data about plant species on which P. nimpha foundresses initiate nests, nest height above ground, and nest azimuth. We have observed some preferences of foundresses in relation to these three parameters. Nests are most often initiated on Hypericum, Tanacetum, Daucus and Achillea plants. The preferred range of nest height above ground is 15 to 25 cm, while the preferred nest azimuth is about 110°.
Nesting ecology, host plant species, Polistes nimpha , Poland
Most of the available information on nesting sites of the paper wasp Polistes nimpha (Christ, 1791) (Hymenoptera: Vespidae) and its host plant species and nest height above ground is scattered in various publications and usually placed in the description of the study area (
Polistes nimpha is one of three species of the genus Polistes Latreille, 1802 found in Poland (
The available data on the nesting ecology of Polistes nimpha are mostly very brief descriptions of the general vegetation types where the nests were found, although some cited earlier lists of plant species. Only two studies of the paper wasp P. chinensis antennalis Pérez, 1905 from Japan and P. nimpha from Ukraine included a list of host plant species and precise numbers of nests on individual plant species (
This study’s focus was to determine on which plant species the paper wasps of this species build their nests and to identify the possible preferred features of the plant species during nesting site selection by the foundress. We also took into account the height at which the nest was located and its orientation in relation to the north (azimuth). Additionally, our objective was to verify tentatively whether paper wasp colony survival depends on the plant species on which the nest is located. The collected data allowed us to analyse the nesting ecology by means of determining the wasps’ preferences regarding host plant species and nest height above ground and its orientation in relation to the north. This is the first study to analyse the effect of host plant species selection on the survival rate of paper wasp colonies at the pre-emergence phase.
We tested the hypothesis that selection of the plant species on which the nest is located and nest height above ground and its orientation in relation to the north were not accidental, but rather served to maximize the chances of colony survival by improving the thermoregulatory capacity of the wasp nest. The population described in this paper is located at the edge of the general range of this species in Europe, although we know of at least one population of Polistes nimpha located on the Baltic Sea coast (about 250 km north of Poznań) (
We conducted field research in 2014–2015 in three permanent plots located near Suchy Las, at the edges of the military training area in Biedrusko: plot A (52.495892°N, 16.874196°E, 17,400 m2), plot B (52.493527°N, 16.873038°E, 5,300 m2), and plot C (52.495657°N, 16.867265°E, 14,200 m2). We selected these plots because of the favourable conditions for paper wasp nesting (sunny grasslands abandoned for several years), as in similar habitats Polistes nimpha particularly frequents (
We started our field research in late April. Initially, we searched for nests along line transects spaced 2 m apart and marked each nest with a numbered flag. Next, we recorded the host plant species and measured two major parameters of the nests: height at which the nest was located and its orientation in relation to the north (azimuth). We measured nest height as the distance between the ground surface below the nest and its petiole. With a portable magnetic compass, we measured the azimuth as the angle between a line oriented toward the magnetic north and the axis of the wasp nest petiole. We measured (to the nearest 5°) the azimuth of each nest three times and took the mean into account. To calculate the geographic azimuth, we added the local magnetic declination (
Paper wasp colony survival was studied in 2014. We controlled the observed nests weekly to determine their condition. We regarded a colony as dead if at least one of the following criteria was met:
lack of a comb in a place where it was observed before;
colony destruction (e.g., due to ant predation; without appearance of any new eggs, larvae, and pupae within 2 weeks after predation).
Colony causes of mortality and patterns of changes of Polistes nest numbers are the subject of a separate paper (
We analysed survival rate in the period between the first record of each nest until the first week of June (inclusive). This period spanned nearly the whole pre-emergence phase (i.e., before the appearance of the first worker wasps). We identified wasps’ species when we found a nest for the first time or later during measurements or plant identification.
We performed all statistical analyses using GraphPad Prism 5 software. Because the distributions of azimuth and nest height values were not normal, we used nonparametric Kruskal-Wallis and Mann-Whitney tests. We compared the numbers of nests built on different plant species with the chi-squared test.
During field research in the study area we found 157 nests of P. nimpha in 2014 and 127 nests in 2015. In 2014, we assessed nest azimuth and height for 124 nests and plant species for 129 nests, and in another 14 species, identified only the plant family (Poaceae, true grasses). In 2015, we assessed azimuth for 120 nests, height for 127 nests, and plant species for 121 nests.
In total, for both seasons, we found paper wasp nests on 30 plant species (Table
List of plant species on which we found paper wasp nests of Polistes nimpha in 2014–2015.
Plant species | Family | Number of nests | |
---|---|---|---|
2014 | 2015 | ||
Hypericum perforatum L. | Clusiaceae | 57 | 24 |
Daucus carota L. | Apiaceae | 20 | 7 |
Tanacetum vulgare L. | Asteraceae | 5 | 20 |
Achillea millefolium L. | Asteraceae | 9 | 9 |
Artemisia vulgaris L. | Asteraceae | 12 | 3 |
Juncus effusus L. | Juncaceae | 0 | 11 |
Holcus lanatus L. | Poaceae | 1 | 8 |
Dactylis glomerata L. | Poaceae | 7 | 2 |
Rosa canina L. | Rosaceae | 7 | 1 |
Galium verum L. | Rubiaceae | 0 | 7 |
Picris hieracioides L. | Asteraceae | 0 | 5 |
Rumex acetosa L. | Polygonaceae | 0 | 4 |
Artemisia campestris L. | Asteraceae | 2 | 2 |
Centaurea stoebe L. | Asteraceae | 0 | 3 |
Prunus domestica ssp. syriaca (Borkh.) Janch. | Rosaceae | 0 | 3 |
Elymus repens (L.) Gould | Poaceae | 3 | 0 |
Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl | Poaceae | 0 | 2 |
Festuca rubra L. | Poaceae | 0 | 2 |
Poa angustifolia L. | Poaceae | 0 | 2 |
Pyrus pyraster (L.) Burgsd | Rosaceae | 0 | 2 |
Agrimonia eupatoria L. | Asteraceae | 0 | 1 |
Galium album Mill. | Rubiaceae | 0 | 1 |
Lupinus polyphyllus Lindl. | Fabaceae | 0 | 1 |
Phleum hubbardii D. Kováts | Poaceae | 0 | 1 |
Calamagrostis epigejos (L.) Roth. | Poaceae | 1 | 0 |
Festuca trachyphylla (Hack.) Krajina | Poaceae | 1 | 0 |
Pinus sylvestris L. | Pinaceae | 1 | 0 |
Populus sp. | Salicaceae | 1 | 0 |
Quercus robur L. | Fagaceae | 1 | 0 |
Senecio jacobaea L. | Asteraceae | 1 | 0 |
Number of species | 16 | 23 | |
Total number of nests | 129 | 121 |
Survival rate of colonies of Polistes nimpha, depending on the plant species on which the comb was built in 2014.
Plant species | Number of nests | Survival [%] | |
---|---|---|---|
Initiated | Survived until worker emergence | ||
Hypericum perforatum | 57 | 11 | 19 |
Daucus carota | 20 | 4 | 20 |
Artemisia vulgaris | 12 | 2 | 17 |
Achillea millefolium | 9 | 0 | 0 |
Dactylis glomerata | 7 | 0 | 0 |
Rosa canina | 7 | 0 | 0 |
Tanacetum vulgare | 5 | 0 | 0 |
Elymus repens | 3 | 1 | 33 |
Artemisia campestris | 2 | 0 | 0 |
Holcus lanatus | 1 | 0 | 0 |
Calamagrostis epigejos | 1 | 0 | 0 |
Festuca trachyphylla | 1 | 0 | 0 |
Pinus sylvestris | 1 | 0 | 0 |
Populus sp. | 1 | 0 | 0 |
Quercus robur | 1 | 0 | 0 |
Senecio jacobaea | 1 | 0 | 0 |
Total | 129 | 18 | 14 |
The geographic orientation of combs was nearly identical and did not differ significantly between the years (Mann-Whitney test, U = 6,899; P = 0.326) (Fig.
Nest height above ground was similar in both years, although the difference between years was significant (Mann-Whitney test, U = 5,663; P = 0.0001). The mean height in 2014 was 19.6 cm, whereas it was about 17 cm in 2015 (Fig.
Nest azimuth on the most frequent plant species was similar in both years (Fig.
Values of the azimuth of nests of P. nimpha, depending on the plant species on which they were built in 2014–2015. Abbreviations: Hp—Hypericum perforatum; Tv—Tanacetum vulgare; Am—Achillea millefolium; Je—Juncus effusus; Dc—Daucus carota; Dg—Dactylis glomerata; Hl—Holcus lanatus; Rc—Rosa canina; Gv—Galium verum.
Height at which the nests of P. nimpha were built in 2014–2015, depending on plant species. *Dunn’s post hoc test, p < 0.05. Abbreviations: Hp—Hypericum perforatum; Tv—Tanacetum vulgare; Am—Achillea millefolium; Je—Juncus effusus; Dc—Daucus carota; Dg—Dactylis glomerata; Hl—Holcus lanatus; Rc—Rosa canina; Gv—Galium verum.
The plant species composition and numbers of nests on plants of individual species differed between the two years (Fig.
The species composition of host plants of Polistes nimpha, especially in the upper part of Table
The wasps also built many nests on culms of various grasses (e.g., Holcus lanatus, Dactylis glomerata, Elymus repens, and Calamagrostis epigejos (Table
The pattern of colony mortality during the season we observed in Poland is very similar to results of studies conducted in Italy for Polistes nimpha (
Nest height above ground generally did not differ significantly between host plant species (in 2014, no differences; in 2015, a difference between only Juncus effusus and Holcus lanatus) (Fig.
Changes in host plant species composition which may alter the wasps’ preferences for some species as nesting sites (Table
The third parameter we analysed was the geographic orientation of the comb. In many social insects, such as ants and termites, the geographic orientation of nests is not accidental and is of great significance for their thermoregulation (for a review, see
In conclusion, this study shows that foundresses of P. nimpha demonstrate specific preferences for nesting sites regarding their host plant species, nest height above ground, and geographic orientation (azimuth) of the combs. The first 2 factors are important to maximize the chances of colony survival in preemergence phase, the most dangerous, initial part of the colony life cycle, while azimuth most likely functions as a passive mechanism of nest thermoregulation at an early stage of its development, when the surrounding vegetation is still low and allows direct access of sunlight to the comb. Although the nests were built on plants of more than 10 species (Table
Both height above ground and azimuth seem to play important roles in the passive thermoregulation of paper wasp colonies. In some Polistes species spectacular adaptations to cold climates have been found, such as life cycle plasticity (
We would like to express special thanks for reviewers Lidya Rusina and Christopher K. Starr and editor Jack Neff for valuable comments on the manuscript and great help during processing of the manuscript.