Southern Spread of Moths in New Zealand
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32 The Weta 40: 32-38 (2010) Southern spread of moths in New Zealand Brian Patrick Central Stories Museum & Art Gallery, Box 308, Alexandra. ([email protected]) Introduction and Results Dugdale (1988) notes 73 moth and butterfly species, particularly Australian, that have become established in New Zealand since European settlement as the result of human assistance. Hoare (2001) recorded and illustrated a further 27 species that had become established in the intervening years to 2001. While most of these 100 species have not yet become established in southern New Zealand, here I note six species of these exotic moths that have, in recent years, spread south to Otago and Southland joining earlier invasions that have generally gone unrecorded. All specimens cited are either stored pinned and dry in the Otago Museum, Dunedin or since 2006, in the Central Stories Museum, Alexandra. Figure 1. Adults of the casemoth Lepidoscia heliocharis (left) and Achrya affinitalis (right). Photo B. Patrick. Inevitably only a fragment of information is available on the southward spread of these species. What I present here is indicative only. The six species in question and my observations of a southern spread are as follows: Achyra affinitalis (Lederer, 1863) Dugdale (1988) lists the adventive Australian moth Achyra affinitalis (Lederer, Southern spread of moths 33 1863), (Crambidae: Pyraustinae) as being established in the Hawkes Bay and Auckland areas since 1970. Since then it has spread south to the northern South Island and continues that spread further south to southern Canterbury and Otago in more recent years. I found the species in 1990 at Kaitorete Spit, Mid Canterbury and in 1998 at Farewell Spit, Northwest Nelson. More recently it has moved south to southern Canterbury and Otago particularly the dry interior of the Mackenzie Country and Central Otago. Interestingly it was not collected by White (2002) during his intensive 1991-2000 light-trapping programme at 43 sites in the Mackenzie Country. Many of these trapping sites were within the altitudinal range the species now occupies. My first Otago record is 19 March 2008 at Conroys Road, 300m., near Alexandra CO, captured at light; followed by 7 November 2008 with two adults to light as above. In the Mackenzie Basin the first records are 28 March 2009, Haldon Arm, 380m., Lake Benmore, Mackenzie Basin MK, three at light. I think we can be reasonably certain that in the years 2001 to 2009 the species entered the Mackenzie Basin for the first time based on the exhaustive work of White (2002), who did not find it. Since then it has increased in range and numbers so that by April and May 2010, at several sites, it was the commonest moth species found at light. Latest records point to its increasing population and range: 1 November 2009 one by day Conroys Road 300m., near Alexandra CO 3 December 2009 one by day Chapman Road Scientific Reserve - saline area, near Alexandra CO 11 April 2010 32 adults at light Conroys Road, 300m., near Alexandra CO 11 April 2010 three adults at Gorge Creek, 300m., Alexandra-Roxburgh HighwayCO 22 April six at light Conroys Road, 300m., near AlexandrCO 6 May 2010 four adults at light 340m., Little Valley Road, Knobby Range CO In Australia the species is found throughout mainland Australia (Common, 1990) and is considered likely to be involved in long-distance movements. Common also notes that larval outbreaks occur at irregular intervals and are mostly in drier areas when “native and introduced weeds and crop plants belonging to many families are webbed and defoliated”. These plant families include Fabaceae, Malvaceae and Asteraceae. This information provides an insight into what has been observed in New Zealand regarding movement, fondness for dry areas and its probable life history here. It signals the possible pest status of this species in New Zealand. Research is required to confirm what its life history is here in its new homeland. Barea aff. confusella (Walker, 1864) 34 Brian Patrick Another species of Australian origin, Barea aff. confusella (Oecophoridae) (Dugdale, 1988) was first detected in the south on 24 November 2000 at Osbourne, eastern Otago, on 4 November 2005 further south in Dunedin and 20 November 2005 in Alexandra, Central Otago. The species does not appear to be established in Central Otago yet, but is more common in eastern Otago although by no means commonly found there yet. Its wing pattern is distinct from that of Barea codrella as illustrated by Hoare (2001). Dialectica scalariella (Zeller, 1850) The tiny adults and distinctive feeding damage of the southern European Dialectica scalariella (Gracillariidae) were first identified at Atawhai near Nelson, New Zealand in February 1997 from reared adults (Hoare, 2001). Larvae are leaf miners in various Boraginaceae particularly Echium species. Hoare (2001) notes its discovery in the Auckland area in 1998-2000 and also notes my discoveries south to Rangitata Island, South Canterbury in November 1999. Given its small size and inconspicuousness it is impossible to know where it first became established. My records for the South Island date from November 1999 when I found adults at the mouth of the Ashburton River, Mid Canterbury within rosettes of Echium. Later that same year I found adults at Kaitorete Spit and then further south at Rangitata River mouth in South Canterbury. Adults were also found in 2005 in Cloudy Bay, Waima Mouth and Acheron River - 750m, Marlborough. Since then I kept a special lookout for the adults or larval damage in Otago suspecting that it may spread that far south given the hot dry summers, similar to its new found habitat in Marlborough. It took till 5 March 2005 for larval damage, and 13 March 2005 for adults to appear in Central Otago. Since then adults have become common in the period March-May each year, flying by day in calm weather or found within the host plant‟s foliage. It is now common and widespread in Central Otago with larvae or adults known from Kawarau Gorge, Dunstan Gorge, Old Man Range (1500m), Alexandra township and surrounding localities such as Airport Terrace, Molyneaux Estate and Conroys Road. Lepidoscia heliochares (Meyrick, 1893) The casemoth species Lepidoscia heliochares (Pyschidae) has been known from New Zealand for several decades, particularly in its northern parts. The species is naturally endemic to Australia being described from Sydney and Melbourne, where it was recorded as common in July and August, with adults flying “freely in sunshine”. Southern spread of moths 35 From 1987 to 2000, I recorded adults of the species several times from various parts of Christchurch with a record in 1996 from Kaitorete Spit south of Christchurch from late July to mid September. In 1994 and 1995 I found one female and three males in the Waitaki Valley, in Kurow township and at Fettercairn, much further to the south on the border between Canterbury and Otago. These adults were found between 14 and 21 September. The first Central Otago adults were detected on the 16 August 2006, with over 100 males and females found by the winter of 2009. Maybe the species had made Alexandra its home slightly earlier than 2006, but that was my first winter there as a resident. Previous to that I had intensively surveyed for moths for the past 20 years at all seasons as a holiday-maker and visitor (Patrick, 1994; Patrick, unpublished data). Results for Alexandra are: 2006; 41 males - 16 August to 25 September; most at light with many found on windows where they had come to light the previous night. 2007; 41 males and one female – 30 July to 10 October; as above most at light. Female was active in the late afternoon on a shop window on a 16⁰C day on 7 September. 2008; 6 males as above. Collecting season curtailed by overseas trip. 2009; 30 males and females, mostly at light but some bred from cases. 2010; males found from 15 August onwards on shop windows and walls close to lights. One male active on wet morning on shop window. Larvae feed on leaf litter from within a larval case. Observations in Alexandra suggest that lavender and other dense plants provide an ideal habitat for larvae. Adults emerge from late July through to the end of September, with peak emergence from late August to mid September based on over 200 individuals found in Alexandra. Mature larvae wander from larval feeding sites onto fences, house walls, under pot plants and paths to fix their cases to hard surface in a sheltered place, where they pupate. Pupal cases were found under window ledges and pot plants. Although many more males are found at light, from breeding records females emerge in about equal numbers to males. Females have slightly reduced wings, but can fly. It is interesting that the species appears to be nocturnal in New Zealand but was described as diurnal in its original description in Australia. Further observations in Australia are necessary to clear up this obvious behavioural difference Opogona comptella Walker, 1864 The pretty Australian tineid Opogona comptella (Tineidae) has been in New Zealand at least 100 years (Dugdale, 1988). I did not find in the southern South Island in the late 1960s or early to mid 1970s, but it was common in North Otago by 1978, Dunedin by 1983, further south at Milton by 1987, Invercargill by 1990, while my 36 Brian Patrick first records for Central Otago were not till 1991. Since then it has established throughout the South and is reasonably commonly found in human- induced habitats where larvae have been found feeding on dead wood. Tachystola acroxantha (Meyrick, 1885) The dull orange-coloured Tachystola acroxantha (Oecophoridae) is a species of Australian origin that was first found in New Zealand in 1886 (Dugdale, 1988).