Mitochondrial COI and II Provide Useful Markers for Wiseana (Lepidoptera: Hepialidae) Species Identification
Total Page:16
File Type:pdf, Size:1020Kb
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Lincoln University Research Archive Bulletin of Entomological Research (1999) 89, 287–293 287 Mitochondrial COI and II provide useful markers for Wiseana (Lepidoptera: Hepialidae) species identification B. Brown*, R.M. Emberson and A.M. Paterson Ecology and Entomology Group, PO Box 84, Lincoln University, Lincoln, Canterbury, New Zealand Abstract A method for identifying the members of the endemic genus Wiseana Viette from New Zealand is described. Seven species have been described in the genus: W. cervinata (Walker), W. copularis (Meyrick), W. fuliginea (Butler), W. jocosa (Meyrick), W. mimica (Philpott), W. signata (Walker) and W. umbraculata (Guenée). No morphological characters have been identified to distinguish between the larvae of each species and adult females exhibit high levels of intra and interspecific morphological variation making identification difficult or impossible. Adult males can be distinguished by a combination of scale, antennal and genital characters, but this requires considerable taxonomic experience. Molecular markers were generated via amplification of the cytochrome oxidase subunit I and II (COI and II) of the mitochondrial DNA by the polymerase chain reaction (PCR). Amplified DNA was digested with restriction enzymes to give characteristic fragment patterns. Fourteen restriction enzymes were surveyed and a combination of four of these distinguish all Wiseana taxa except W. fuliginea and W. mimica. Introduction and W. fuliginea on South Island. Dugdale (1994) also lists W. mimica as a damaging species. Wiseana Viette is one of five endemic genera in the Wiseana taxa are difficult to distinguish using adult ‘Oxycanus’ lineage of hepialid moths (Lepidoptera: morphological characters. Males of all species can be Hepialidae) (Dugdale, 1994) from New Zealand. Using a identified but this requires dissection and interpretation of morphological species concept, Dugdale (1994) recognized genitalia and experience in interpreting antennal and scale seven species in the genus: W. cervinata (Walker), W. copularis characters (table 1). (Meyrick), W. fuliginea (Butler), W. jocosa (Meyrick), W. Females of all species have been found to have mimica (Philpott), W. signata (Walker) and W. umbraculata continuous, overlapping external morphological characteris- (Guenée). tics (MacArthur, 1986; Herbert, 1995) and are only reliably The larvae of Wiseana, commonly referred to as ‘porina’ identified using characters from the bursa copulatrix in the (an old, preoccupied generic name), are important pasture female genitalia (Dugdale, 1994). External characters to pests in New Zealand causing significant economic losses distinguish between W. cervinata and W. copularis females are (French, 1973; Barratt et al., 1990, Johnston, 1994; Herbert, being tested (E.G. White, personal communication). Herbert 1995). The larvae build vertical tunnels in the soil and feed (1995) found the larvae of each species, reared in the nocturnally, defoliating pasture grasses, clover and lucerne laboratory from positively identified adults, to be morpho- (Barratt et al., 1990). Barlow (1985) estimated that porina logically very similar. Further morphological work to densities of 40–120 m–2 resulted in 20–80% loss of pasture distinguish between larvae of the different species is in production. Herbert (1995) found larvae of W. cervinata and progress (J. Dugdale, personal communication). W. copularis in damaged pastures throughout New Zealand Intra and interspecific character variation has created difficulties in finding stable morphological characters to identify taxa in this genus and has resulted in a history *FAX: 64 3 325 3844 of taxonomic instability (Hudson, 1928; Dumbleton, 1966; E-mail: [email protected] Archibald, 1984; Dugdale, 1988). Research on control 288 B. Brown et al. measures has previously treated ‘porina’ pests as a gin one-species problem, principally dealing with the W. cervinata ‘complex’ (e.g. Farrell et al., 1974). Failure to accurately identify the taxa under study may have confounded ecological studies (e.g. Dumbleton, 1945; Fenemore & Allen, 1969; French, 1973; Barlow et al., 1986). ge . umbraculata Few variable characters were identified for Wiseana taxa oval in mid-section, apiculate W lar x=0.44 mm, SD=0.04 bowed outer mar pale in a cladistic analysis of a morphological data set (Brown et al., 1999) and relationships within the genus, apart from gin between W. signata and W. umbraculata, were not resolved. ounded Brown et al. (in press) identified ten lineages of Wiseana from mitochondrial DNA COI and II sequences. These lineages corresponded to the seven currently described species, plus an additional haplotype for W. cervinata, . signata W. copularis and W. signata. Phylogenetic relationships for oval in mid-section, tapering to a r apex W small x=0.05 mm, SD=0.03 bowed outer mar pale the genus Wiseana were inferred from the mitochondrial DNA sequences (fig. 1). The mtDNA data set produced a gin more resolved phylogeny for Wiseana in comparison to the morphological, but lack of synapomorphies deeper in uptly to the clade, a predominance of transitional nucleotide , substitutions and the presence of many autapomorphic characters for Wiseana haplotypes suggests recent and rapid radiation. This result is consistent with the dearth of . mimica oval in mid-section, tapering abr an acute apex W small x=0.12 mm, SD=0.05 bowed outer mar triangular longer than deep morphological features that define the Wiseana taxa. Where morphological characters cannot distinguish gin between taxa, other methods may be useful. Herbert (1995) , Wiseana uncate resolved the seven recognized species using isoenzyme electrophoresis and developed a key. The seven ounded species showed unique combinations of fixed differences at the Acp-1, Gp-2, Me-1, 6pg-1 and Pep-1 loci. Additional . jocosa fixed or frequency differences at other loci also very short, tr x=0.18 mm, SD=0.06 W small bowed outer mar dark, triangular apices r distinguished each species. However, new molecular taxa. gin techniques such as amplification of a fragment of DNA by the polymerase chain reaction (PCR) followed by cleavage iseana , long with restriction enzymes to produce diagnostic patterns W , ow from length and site polymorphisms (RFLPs) offer ounded advantages over allozymes. DNA is less sensitive to . fuliginea sharp apex long, narr x=0.07 mm, SD=0.02 W small bowed outer mar triangular apices r ow gin ectangular ge . copularis ounded apex r parallel sided, narr x=0.33 mm, SD=0.04 W lar bowed outer mar long and r uncate om adult males used to distinguish between uncate ow tr oad tr , ounded ge, elongate . cervinata (northern populations) tapering, narr x=0.4 mm, SD=0.04 W lar parallel sided triangular apices r tapering, br (southern populations) Fig. 1. Strict consensus cladogram of the six most parsimonious trees from the analysis of mtDNA COI and II sequence data gin for the single species lineages within the genus Wiseana Morphological characters fr ocesses (Lepidoptera: Hepialidae) from New Zealand. Branch lengths 1. are proportional to the number of unambiguous nucleotide ewing discal changes. Decay values are shown above the branches and win pr able for cell T Character Genitalia T Pseudotegumen outer mar Antennae Pectination shape Scales White scales, bootstrap proportions (>50%) below. Molecular markers for Wiseana taxa 289 degradation, in the short term, allowing specimens to be Table 2. Locations of populations sampled for each Wiseana stored in alcohol before DNA extraction. taxon. Furthermore, any life cycle stage can be used, only a Population Codea Grid refb n small amount of DNA is required and the restriction patterns are unambiguous and reproducible (Szalanski & W. fuliginea Powers, 1996; Armstrong et al., 1997). The technique is also Birdlings Flat MC M37 860-090 2 relatively inexpensive in comparison to sequencing, Dunedin DN I44 133-783 1 allowing more specimens to be processed. W. mimica The mitochondrial genome is relatively small and has a Cass NC K34 963-090 2 combination of conserved and variable regions (Simon et al., Mackenzie Country MK H38 802-615 1 1994; Mills, 1996) which is useful for the development of diagnostic tests to discriminate between races and sibling W. copularis ‘northern’ species. The polymerase chain reaction (PCR) and restriction Opouri Saddle MB P27 713-073 2 fragment length polymorphisms (RFLPs) of mtDNA Greens Beach WD I34 118-974 2 have produced diagnostic tests for Aedes mosquitoes Pohara NN N25 012-421 5 (Kambhampati & Rai, 1991), Anopheles mosquitoes (Diptera: Cobb Ridge NN M26 843-113 2 Culicidae) (Mitchell et al., 1992), gypsy moths Lymantria Queenstown OL E41 690-668 3 dispar (Linnaeus) (Lepidoptera: Lymantriidae) (Bogdano- W. signata ‘southern’ wicz et al., 1993), root knot nematodes Meloidogyne spp. Waimea NN N27 182-844 1 (Hugall et al., 1994), ermine moths of the Yponomeuta Pohara NN N25 012-421 2 padella (Linnaeus) complex (Lepidoptera: Yponomeutidiae) (Sperling et al., 1995), tobacco budworm Heliothis virescens W. signata ‘northern’ (Fabricius) and corn earworm Helicoverpa zea (Boddie) Mangapehi WO S17 116-960 2 (Lepidoptera: Noctuidae) (Roehrdanz, 1997). Woodhill Forest AK Q10 367-934 2 In this paper we report a method for distinguishing Levin WN S25 997-496 2 between Wiseana taxa using the polymerase chain reaction W. cervinata ‘ southern’ and restriction fragment length polymorphisms on the Birdlings Flat MC M37 860-090 5 mitochondrial DNA cytochrome oxidase I and II (COI and Nelson NN N27 182-844 2 II) regions. Goulter MB N28 288-581 2 Otaio SC J39 621-248 2 Material and methods W. cervinata ‘northern’ Mangapehi WO S17 116-960 2 Collections Ohakune RI S20 162-958 2 Hawera TK Q21 290-790 2 This study is based on adult Wiseana males that were Levin WN S25 997-496 1 collected by light trapping, placed directly into 96% ethanol and stored at 4°C before identification (see table 1) and DNA W. copularis ‘southern’ extraction. Wiseana taxa have overlapping distributions Christchurch MC M35 792-433 2 within New Zealand with W.