Timm Karisch Lepidoptera Report 2018
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Darwin-Plus Project DPLUS040 Securing the future for St Helena’s endemic invertebrates Report Lepidoptera The endemic plume moth Agdistis marionae, feeding nectar on flower of Scrubwood; Man and Horse cliff (09.IV.2018, photo: A.-J. DUTTON) Timm Karisch Museum für Naturkunde und Vorgeschichte Dessau Dessau, 31.08.2018 Contents 1 Introduction 3 1.1 Knowledge on Lepidoptera of St Helena 3 1.2 The project 4 2 Material 5 2.1 Methods 5 2.2 Studied areas 6 2.3 Presentation of the results 7 3 Results 8 3.1 Moths and butterflies of the main habitats of the island 8 3.1.1 Habitats formed by indigenous or endemic plants 8 3.1.1.1 Cloud forest 8 3.1.1.2 Gumwood-woodlands 13 3.1.1.3 Scrubwood-shrubland 17 3.1.1.4 Samphire semi-deserts 20 3.1.2 Non-indigenous habitats 25 3.1.2.1 Forests 25 3.1.2.2 Shrubland 30 3.1.2.3 Opuntia- and Aloe-Vegetation 36 3.1.2.4 Meadows and pastures 38 3.1.3 rural areas 39 3.2 Habitat-linked moths 41 3.3 Lepidoptera species 42 4 Recommendations of habitat management 61 4.1 Introduction 61 4.2 Cloud forest zone 61 4.3 Gumwood-woodland 61 4.4 Scrubwood shrubland 62 4.5 Forests 62 4.6 Non-indigenous, open shrub vegetation 62 4.7 Semi-deserts 63 5 Outstanding works 64 6 Summary 66 7 Acknowlegements 67 8 References 68 2 1 Introduction 1.1 Knowledge on Lepidoptera of St Helena Allthough there are probably more than 50 endemic species occuring nowhere else than on the island, the Lepidoptera have not attained much attention during the last centuries. The most comprehensive study on butterflies and moths of St Helena was undertaken by Mrs. EDITH WOLLASTON. She visited together with her husband THOMAS VERNON WOLLASTON St Helena Island between 7th September, 1875 and 20th February, 1876. Her outstanding paper on Lepidoptera was published in 1879 and was a significant contribution to the fauna since the first reports on moths and butterflies written by WALKER in MELLISS (1875). Since WOLLASTON there were only occasionally publications (f. e. BERIO 1972 or HARDWICK 1965) about one or a few Lepidoptera species from St Helena. Some of them are founded on material collected by the large Belgian expeditions between 1965 and 1967, but moths and butterflies were not in the main focus of these expeditions. Valuable information is available from the compehensive and detailed Lepidoptera material collected by Professor ARTHUR LOVERIDGE between 1957 and his death in 1980. This material is now housed in The Natural History Museum London, the Museum of Comparative Zoology of the Harvard-University, Cambridge, and in the Royal Museum for Middle Africa (MRAC) in Tervuren. A small collection still exists on St Helena. In the 1950s and 1960s and in 1994, 1995 and 2003 as well as from 2005 – 2006 PHILIP and MYRTLE ASHMOLE stayed on the island and undertook research on the endemic fauna. During this research they also collected some Lepidoptera specimens, now stored in the collection of the Natural History Museum in London. For one week in December 1995 the author of this study collected moths together with Dr. WIELAND RÖHRICHT, Wriezen. The results of this short investigation were published in KARISCH (2001, 2003, 2007). For the Macroheterocera the material collected by the Belgians and stored in the MRAC was included. 3 1.2 The project The aim of the project was to improve the knowledge on Lepidoptera of the island in several ways: - distribution of the species on the island with special focus on the endemics; - taxonomy of the Opogona-moths (not included in KARISCH 2001, 2003, 2007 because of the lack of material), a genus with a particular radiation on this island; - habitats of the moths; - biology and food plants of endemic and non-endemic moths; - risk factors for endemic species. The project was part of DarwinPlus „Securing the future for St Helena’s endemic invertebrates“ (DPLUS040). The fieldwork was undertaken by T. KARISCH with technical and logistical help of members of the Trust (especially D. PRYCE, DR. R. CAIRNS-WICKS, S. BARGO, A.-J. DUTTON, L. FOWLER) and H. MENDEL (Natural History Museum London). It was not possible to cover a whole season for several reasons. In 2017 it was intended to do the fieldwork for five weeks between the end of February and beginning of April, but because of technical problems of the R. M. S. „St. Helena“ the stay was shortened to three weeks. In 2018 a four weeks field work was undertaken between the end of March and end of April. In 2017 the weather conditions for the first two weeks were quite good with only short periods of rain. This was around the new moon and so light trapping was conducted almost every evening. After two weeks the weather changed to very humid conditions, especially in medium and higher altitudes. This was the time around full-moon, therefore the daytime activities for the search for moths and caterpillars were hindered and the outcome was not as good as expected. In 2018 the weather was quite similar with more sunshine in the first two weeks and partially rainy or windy weather in the second period. Originally it was intended by the author to rear the caterpillars until pupation on the island. The shortage of the stay prevented this in 2017, the very quick decay of the food because of the hot weather in 2018. As it was not possible for biosecurity reasons to take the caterpillars and necessary living plant material off the island, breeding was finished by members of the St Helena National Trust and ANRD. The descriptions of vegetation at the collecting points have initial character. They were produced by the author of the report with the help of the accompanying members of the National Trust. The final characterisation should be done when the vegetation map of the island is completed and published by the Darwin project DPLUS052 lead by S. CHERRETT. On 15th March 2017 a training was provided for members of the St Helena National Trust and ANRD. The main focus was to introduce into the preparation of moths and the examination of genitalia structures for identification purposes. All participants got the chance to spread some moths and to do the first steps for a genitalia dissection. On 4th April 2018 a workshop was held for identification of moths. In the morning an introduction was given, in the afternoon the participants were able to identify some common, recently collected moths. 4 2 Material 2.1 Methods The majority of the adult moths were collected using a mercury vapour lamp during the first hours of a night. During the first two nights in 2017 a blended lamp was additionally used. Because it was observed, that the bulb of the mercury vapour lamp had no impact on the arriving insects, it was subsequently used at nearly all other localities. Additionally a small UV-trap was used on a few localities. Fig. 1 Light trap at Joan Hill (27.II.2017, photo: T. KARISCH) During daytime the moths were caught with a net, identified and released, if it was not necessary to study the specimens more carefully in the laboratory. The majority of the collected moths were pinned and stored in boxes. Very small moths (e. g. Tineidae, Cosmopterigidae, Praydidae, Gele- chiidae, Glyphipterigidae) were collected in small tubes and spread immediately after death in the evening or during the following day to obtain a high-quality material for taxonomic studies. Caterpillars were collected mainly during daytime excursions. They were put into small plastic con- tainers together with material from their host plants. A number of these caterpillars were reared in these boxes until pupation and the hatching of the moths. If possible, a number of caterpillars from one sample was transferred into a tube with absolute pure ethanol to enable genetic studies later on. The name of the host plant of the caterpillar was noted, when the identification was possible on-site. If not, a sample of the plant was collected and herbarized for later identification. Some parts of plants were also herbarized for documentation of the caterpillar activity. When possible, photographs were taken from moths and caterpillars to show them in situ. 5 2.2 Studied areas The study sites for the field work were proposed by the Trust after discussion of the needs to obtain results to fulfill the aims of the project. These are the main sites (vegetation zones based on CRONK 1989): • Cloud forest zone (tree fern thicket/Cabbage tree woodland): Near Black Gate Nursery, between Black Gate Nursery and Mt Actaeon, SW-slope of Mt Actaeon* • Moist Gumwood woodland Peak Dale*, Thompson’s Wood* • Dry Gumwood woodland Piccolo Hill, Millenium Forest • Scrubwood scrub Man and Horse at Joan Hill*, Pipe Path • Woodland or shrubland of the uplands Burnt Rock, Casons Forest, Napoleon’s Tomb*, Hooper’s Rock* • Open scrubland (Schinus terebinthifolius, Chrysanthemoides monilifera etc.) with rocky cliffs Sandy Bay Valley near chapel* • Opuntia-scrub Ebony Cottage in Sandy Bay Valley • Semidesert Gregory’s Battery*, Mole Spider Hill, lower Rupert’s Valley*, Egg Island A planting with different endemic shrubs between an New Zealand-Flax-plantation and a non- natural wood was studied at the Ginger Patch at High Peak. The localities indicated with an asterisk (*) are rich with Lichens or Mosses. 6 2.3 Presentation of the results This report gives a list of all species of Lepidoptera with exception of members of the genus Opo- gona, which have been observed during the field work activities in 2017 and 2018 at the study localities.