Biodiversity Data Journal :
Research Article
|
Corresponding author: Renate Wöger (renate.nowicki@web.de)
Academic editor: John-James Wilson
Received: 27 Mar 2020 | Accepted: 17 Jun 2020 | Published: 07 Jul 2020
© 2020 Renate Wöger, Roland Wöger, Matthias Nuss
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:
Wöger R, Wöger R, Nuss M (2020) Spatial and temporal sex ratio bias and Wolbachia-infection in New Zealand Crambidae (Lepidoptera: Pyraloidea). Biodiversity Data Journal 8: e52621. https://doi.org/10.3897/BDJ.8.e52621
|
The New Zealand fauna of snout moths (Pyraloidea) predominantly consists of endemic species. During 2017 and 2018, 56 species of Pyraloidea in 1,749 individuals were collected at 14 localities. All species were screened for Wolbachia-infection, with specimens of eight species (14%) being positive, of which six species belong to Scopariinae. This is the first record of Wolbachia-infection amongst New Zealand Lepidoptera. The most common pyraloid species, Eudonia submarginalis and Orocrambus flexuosellus, were analysed for a larger set of individuals looking for sex ratio and Wolbachia-infection. There is a sex ratio bias towards females in both species, but it varies in space and time. Wolbachia is found in all populations of E. submarginalis with 10–80% of the tested individuals being positive, depending on locality. No Wolbachia-infection has been found in O. flexuosellus. Thus, sex ratio bias might be linked to Wolbachia-infection in E. submarginalis, but not in O. flexuosellus.
Pyraloidea, Crambidae, Wolbachia-infection, sex ratio bias, New Zealand
Snout moths (Pyraloidea) are one of the megadiverse subgroups of Lepidoptera, occurring worldwide with more than 16,000 described species (
A sex ratio bias can be caused by different factors. One is a sexual dimorphism in timing of emergence (
A sex ratio bias can be also caused by Wolbachia-infection (
Based on molecular data (multi-locus sequence typing), 16 supergroups of Wolbachia (A-Q) are currently recognised (
Wolbachia-infection rates vary inter- and intraspecifically (e.g.
Wolbachia is typically transmitted maternally through the cytoplasm of the eggs (
Though there is a comprehensive bibliography about Wolbachia, there are still gaps in surveying Wolbachia amongst taxa and regions. For New Zealand, it has been first recorded just recently from Orthoptera, Psocoptera, Diptera and Hymenoptera (
A survey of Pyraloidea in New Zealand has been undertaken during January and February of the years 2017 and 2018. A total of 56 species in 1,749 specimens were collected both during the day and also attracted to artificial UV light for 3–4 hours after nightfall. Collecting localities were visited one to six times, depending on travel logistics and weather conditions. The moths were collected from 14 localities, three of them being situated in Taranaki (North Island) and 11 localities scattered over the South Island. At each locality, all pyraloid individuals attracted by the UV light were collected. Specimens were killed using cyanide or ethyl acetate, pinned and dried for transportation. After fieldwork, moths were labelled and sorted to morpho-species. Specimens were identified by the authors using the database of the Landcare research Auckland (landcareresearch.co.nz) (
Nomenclature and taxonomy are based on the Global Information System on Pyraloidea (GlobIZ) (
The sex ratio was identified in the two most commonly collected species Eudonia submarginalis and Orocrambus flexuosellus. To distinguish males and females, we dissected the abdomen. The dissection followed
Record data of E. submarginalis and O. flexuosellus were separated into location and year. If we visited a locality more than once, the collected individuals were pooled. We tested for a significant departure from a 1:1 sex ratio by chi-square-tests using SPSS (Statistical Package for Social Science, IBM®) at all localities where more than 15 individuals were collected.
Phenograms are generated using Brian Patrick’s records from iNaturalist (iNaturalist.org) (
Genomic DNA was extracted from dried abdomens using the Genomic DNA from tissue kit (Macherey-Nagel, Düren, Germany), following the manufacturer‘s standard protocol for animal tissue.
PCR was performed to amplify the mitochondrial cytochrome oxidase I gene (COI) from the extracted DNA using the primer pair HybHCO/HybLCO. These primers contain a universal primer tail (T7), which is also used for sequencing (
To determine amplicon presence and size, we examined PCR results via gel electrophoresis on a 1% agarose gel and GelRed as dye agent.
The samples with successful PCR were sequenced and tested for presence of Wolbachia DNA. If the COI Barcode PCR failed, we excluded the sample. For sequencing work, we mandated Macrogen Europe, Amsterdam, Netherlands.
Sequences were aligned manually using the programme BioEdit version 7.2.6.1 (
For a screening over all collected species, at least one specimen was tested for the presence of Wolbachia-infection. From the two species E. submarginalis and O. flexuosellus, at least 15 specimens per locality were tested. This number of 15 individuals results from GPower (
We tested extracted DNA for the presence of Wolbachia-infection with PCR using two primer combinations. An approximately 1000 bp fragment is expected by the pair of primers 16sf 5´-TTG TAG CCT GCT ATG GTA TAA CT-3´/16sr 5´GAA TAG GTA TGA TTT TCA TGT-3´ (
The PCR was performed for both primer pairs simultaneously in 20 µl reactions, containing 10 pmol of each primer, 10mM dNTPs, PCR buffer, 50mM MgCl2 and 1U taq DNA Polymerase (ampliTaq, Thermo Fisher Scientific). After an initial phase at 95ºC for 5 min, the temperature profile was 95ºC for 30 sec, 50ºC for 45 sec and 72ºC for 1 min for a total of 38 cycles. The final elongation temperature was 72ºC for 10 minutes, followed by a cooling phase at 8ºC. To ascertain the results, every PCR contained a positive sample and a negative sample as well. PCR reactions that produced ambiguous results were re-run.
PCR products were visualised on 1% agarose gel and GelRed as dye agent. Specimens tested positive for Wolbachia-infection were determined by referring to positive control in each PCR reaction. For sequencing the Wolbachia DNA by using the primer pairs mentioned above, we mandated Macrogen Europe, Amsterdam, Netherlands. The wsp sequences obtained were matched to public sequences in Genbank database, based on sequence similarity of at least 95%. Sequences have been analysed via the Wolbachia PubMLST Databases (
During the surveys, 41 pyraloid species were obtained by 1–10 individuals, seven species by 11–50 individuals, five species by 51–200 individuals, as well as three species by more than 200 individuals.
Eudonia submarginalis was found at seven localities, with more than 15 individuals at four localities, each on South Island (Figs
Sex ratio at different localities. Number of males (black) and females (grey) in Orocrambus flexuosellus . * samples with significant difference to an equal ratio of sexes with p ≤ 0.05, ** samples with significant difference to an equal ratio of sexes with p ≤ 0.001 (chi-square-test: χ 2 = 0.00011) .
Sex ratio at different localities. Number of males (black) and females (grey) in Eudonia submarginalis. * samples with significant difference to an equal ratio of sexes with p ≤ 0.05, ** samples with significant difference to an equal ratio of sexes with p ≤ 0.001 (chi-square-test: χ 2 = 0.00011) .
The sex ratios are significantly (p ≤ 0.05) biased towards females in populations of E. submarginalis at four out of five localities, as well as of O. flexuosellus at five out of seven localities (Figs
We screened 56 pyraloid species for Wolbachia-infection. Specimens of eight species (14%) tested positive, of which six species belong to Scopariinae and two to Crambinae and Spilomelinae, respectively. Altogether, 13 males and 22 females tested Wolbachia positive (Table
Screening for Wolbachia amongst pyraloid species collected in 2017 and 2018.
Family |
species |
Individuals total number |
N Individuals tested for Wolbachia |
N Individuals tested positive for Wolbachia |
Acentropinae |
Argyra strophaea |
1 |
1 |
0 |
Acentropinae |
Hygraula nitens |
32 |
1 |
0 |
Crambinae |
Gadira acarella |
5 |
3 |
0 |
Crambinae |
Glaucocharis auriscriptella |
3 |
1 |
0 |
Crambinae |
Glaucocharis chrysochyta |
2 |
1 |
0 |
Crambinae |
Glaucocharis elaina |
2 |
1 |
0 |
Crambinae |
Glaucocharis interrupta |
1 |
1 |
0 |
Crambinae |
Glaucocharis lepidella |
5 |
3 |
0 |
Crambinae |
Glaucocharis selenaea |
4 |
1 |
0 |
Crambinae |
Orocrambus angustipennis |
3 |
2 |
0 |
Crambinae |
Orocrambus apicellus |
12 |
2 |
0 |
Crambinae |
Orocrambus creneus |
56 |
6 |
0 |
Crambinae |
Orocrambus enchephorus |
1 |
1 |
1 |
Crambinae |
Orocrambus flexuosellus |
358 |
72 |
0 |
Crambinae |
Orocrambus ordishi |
4 |
4 |
0 |
Crambinae |
Orocrambus ramosellus |
190 |
14 |
0 |
Crambinae |
Orocrambus vitellus |
242 |
16 |
0 |
Crambinae |
Orocrambus vulgaris |
51 |
8 |
0 |
Musotiminae |
Musotima nitidalis |
1 |
1 |
0 |
Phycitinae |
Crocydophora cinigarella |
1 |
1 |
0 |
Phycitinae |
Delogenes limodoxa |
1 |
1 |
0 |
Phycitinae |
Patagoniodes farinaria |
9 |
2 |
0 |
Pyraustinae |
Uresiphita ornitopteralis |
2 |
1 |
0 |
Pyraustinae |
Uresiphita polygonalis |
12 |
2 |
0 |
Scoparinae |
Antiscopa elaphra |
1 |
1 |
0 |
Scoparinae |
Eudonia aspidota |
3 |
1 |
0 |
Scoparinae |
Eudonia cataxesta |
3 |
1 |
0 |
Scoparinae |
Eudonia chlamydota |
5 |
2 |
1 |
Scoparinae |
Eudonia colpota |
4 |
1 |
0 |
Scoparinae |
Eudonia cymatias |
17 |
4 |
0 |
Scoparinae |
Eudonia cyptastis |
2 |
1 |
0 |
Scoparinae |
Eudonia dinodes |
2 |
2 |
2 |
Scoparinae |
Eudonia diphteralis |
3 |
3 |
0 |
Scoparinae |
Eudonia dochmia |
3 |
1 |
0 |
Scoparinae |
Eudonia feredayi |
6 |
1 |
0 |
Scoparinae |
Eudonia leptalea |
159 |
3 |
0 |
Scoparinae |
Eudonia manganeutis |
1 |
1 |
0 |
Scoparinae |
Eudonia minualis |
16 |
1 |
0 |
Scoparinae |
Eudonia minusculalis |
10 |
1 |
0 |
Scoparinae |
Eudonia octophora |
8 |
2 |
0 |
Scoparinae |
Eudonia philerga |
13 |
1 |
0 |
Scoparinae |
Eudonia rakaiensis |
20 |
8 |
1 |
Scoparinae |
Eudonia sabulosella |
126 |
4 |
0 |
Scoparinae |
Eudonia submarginalis |
300 |
60 |
23 |
Scoparinae |
Eudonia trivirgata |
1 |
1 |
0 |
Scoparinae |
Scoparia animosa |
2 |
1 |
0 |
Scoparinae |
Scoparia chalicodes |
10 |
6 |
3 |
Scoparinae |
Scoparia cyameuta |
1 |
1 |
0 |
Scoparinae |
Scoparia halopis |
9 |
1 |
0 |
Scoparinae |
Scoparia rotuella |
9 |
3 |
1 |
Scoparinae |
Scoparia sp. |
6 |
3 |
0 |
Scoparinae |
Scoparia ustimacula |
2 |
2 |
0 |
Spilomelinae |
Deana hybreasalis |
1 |
1 |
0 |
Spilomelinae |
Leucinodes cordalis |
1 |
1 |
0 |
Spilomelinae |
Mnesictena flavidalis |
5 |
4 |
3 |
Spilomelinae |
Mnesictena marmarina |
3 |
1 |
0 |
The more detailed screening of E. submarginalis and O. flexuosellus revealed a percentage of Wolbachia positive tested specimens in E. submarginalis of up to 80% depending on locality (N males tested = 18, infected = 8; N females tested = 38, infected = 14). No Wolbachia infection has been found in O. flexuosellus (N males tested = 23, females tested = 49 (Table
Wolbachia screening between E. submarginalis and O. flexuosellus. Significant difference of sex ratio to an equal distribution with p ≤ 0.05 (chi-square-test : χ 2 = 0.00011) is given in bold.
Locality (see Fig. 1) |
sex ratio (N male / N total) (total number of collected individuals in brackets) |
N individuals tested for Wolbachia |
N individuals tested positive for Wolbachia (in percent) |
E. submarginalis |
|||
Karamea 2017 (1) |
0.02 (81) |
12 |
2 (16.7) |
Methven 2017 (2) |
0.22 (23) |
7 |
1 (14.3) |
Nelson 2017 (3) |
0.09 (44) |
7 |
2 (28.6) |
Methven 2018 (2) |
0.48 (31) |
10 |
1 (10.0) |
Cambrians 2018 (4) |
0.33 (108) |
20 |
16 (80.0) |
total |
0.22 (287) |
56 |
22 (39.3) |
O. flexuosellus |
|||
Taranaki Hollard Garden 2017 (5) |
0.13 (65) |
9 |
0 (0.0) |
Nelson 2017 (3) |
0.16 (31) |
9 |
0 (0.0) |
Methven 2017 (2) |
0.29 (24) |
9 |
0 (0.0) |
Methven 2018 (2) |
0.53 (51) |
10 |
0 (0.0) |
Cambrians 2018 (4) |
0.43 (88) |
9 |
0 (0.0) |
Lawrence 2018 (6) |
0.23 (48) |
9 |
0 (0.0) |
Waikawa 2018 (7) |
0.29 (42) |
8 |
0 (0.0) |
Total |
031 (348) |
72 |
0 (0.0) |
The highest number of infected specimens of E. submarginalis is found at the Cambrians with 16 infected and four non-infected specimens, but this does not correlate with the strongest shift in sex ratio bias towards females which is found in Karamea. Furthermore, the percentage of Wolbachia positive tested specimens does not correlate with the sex ratio bias in general. For instance, there are 10% Wolbachia positive tested specimens of E. submarginalis at Methven in 2018 with no indication of sex ratio bias and 14.3% at Methven in 2017 with a sex ratio bias of 0.22 in favour of females (Table
The data of our survey show sex ratio deviation towards females in Eudonia submarginalis and Orocrambus flexuosellus - two of the most common pyraloid moths in New Zealand - at some, but not all localities. Although both species are synchronous and syntopic, there are seasonal and species specific differences as well, for example, a sex ratio bias is found for both species in Methven in 2017, but not in 2018 and at the Cambrians for E. submarginalis, but not for O. flexuosellus.
Interpretation of records for protandry or protogyny is impossible, because the sampled pyraloid specimens represent only temporal fractions of the populations, which becomes evident when being compared with the data by
The occurrence of Wolbachia in New Zealand insects has been discovered just very recently (
Looking at several populations of E. submarginalis, the percentage of positively tested individuals varies from 10 to 80%. A similar wide range of infection rate is also reported for Japanese populations of Zizina emelina (
Comparing the two most common pyraloid species E. submarginalis and O. flexuosellus with reference to a Wolbachia infection, only E. submarginalis tested positive and all its investigated populations show at least one infected specimen. Thus, Wolbachia infection may contribute to the sex ratio bias in E. submarginalis, but not in O. flexuosellus. In conclusion, there is no congruent pattern between unequal distribution of sexes and Wolbachia-infection.
We thank Robert Hoare from Landcareresearch Auckland for assistance on-site and from afar. We thank Klaus Reinhardt from the Technical University Dresden for revision and commenting on a draft of the manuscript. Two anonymous referees provided useful comments that improved the paper, for which we are grateful.
We are grateful for collecting permissions received by the Department of Conservation (DOC) New Zealand. Staff, particularly Manuela Bartel and resources provided by Senckenberg Naturhistorische Sammlungen Dresden are gratefully acknowledged. We thank Taranaki Regional Council for making the Hollard Gardens available. Special thanks go to the members of Forest and Bird Te Wairoa reserve and Peter and Margaret from Dolly’s Farm Taranaki for a very cordial welcome.
Senckenberg Museum of Zoology, Dresden, Germany