Publicly available Investigation into New Zealand endemic leaf beetles (Chrysomelinae and Galerucinae) and attempts to locate species in Kahurangi National Park for host testing against Eadya daenerys, a potential biocontrol agent Carl Wardhaugh, Andrew Pugh, Matt Scott, and Toni Withers Report information sheet Report title Investigation into New Zealand endemic leaf beetles (Chrysomelinae and Galerucinae) and attempts to locate species in Kahurangi National Park for host testing against Eadya daenerys, a potential biocontrol agent Authors Carl Wardhaugh, Andrew Pugh, Matt Scott, and Toni Withers, Scion Client Department of Conservation SIDNEY output 60686 number Report Number 23807 Signed off by S. Pawson Date 29 June 2018 Confidentiality Publically available requirement Intellectual © New Zealand Forest Research Institute Limited. All rights reserved. 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Published by: Scion, 49 Sala Street, Private Bag 3020, Rotorua 3046, New Zealand. www.scionresearch.com (ii) Executive summary Introduction Native chrysomeline leaf beetles need to be tested against the braconid parasitoid wasp Eadya daenerys (hereafter referred to as Eadya), a proposed biological control agent for the invasive eucalypt tortoise beetle, Paropsis charybdis. Eadya attacks the larval stages of diurnal, exposed, leaf-feeding chrysomelines that are active during the early summer (December). At least nine leaf beetle species were identified as high-priority species to test with Eadya (two exotic pests, six exotic weed biocontrol agents, and at least one native species). By 2017 host-range testing with Eadya had been successfully completed for the two pests and six weed biological control agents on the host specificity testing list. Results to date are promising and suggestive that Eadya is host specific to the tribe paropsini, as presented in the Scion Technote: (https://www.scionresearch.com/__data/assets/pdf_file/0014/64004/ParopsisTechNote.pdf ). Arguably representatives of our native chrysomeline fauna are the most important species for host testing, however little is known about the larval stages, or host plants, of these species. This project Our aim was to locate and study these beetles to determine their potential vulnerability to Eadya, and to identify sources of beetles for host range testing if needed. The best outcome would be locating a few species for testing, and collecting sufficient larvae that they could be transferred to the containment facility in Rotorua for host testing against Eadya. The first step was to examine all literature and collection records to prioritise species for host testing that may potentially be affected by Eadya. The next step was to undertake field work at the best time of year to find, collect priority species, and then conduct host specificity tests. Key results From the available information on our native NZ chrysomelid fauna (body size, distribution, larval behaviour, and phylogenetic relationship) we conclude that the vast majority of native species are unlikely to be affected by the introduction of Eadya. Most Chrysomelidae are likely to be too distantly related to attract Eadya or support its development. Of the more closely related species, most are too small to facilitate full physiological development of an Eadya larva, or live in habitats (high-elevation sites, plant roots, or leaf litter) where Eadya does not search for potential hosts. We consider that species most closely related to Paropsis (i.e. from the subfamily Chrysomelinae), that feed on Eucalyptus (Myrtaceae), that are large enough to potentially support the development of an Eadya larva (>5mm), and that have diurnal, external, leaf-feeding larvae that are present in the late spring/early summer period to be most vulnerable to attack by Eadya. Using these biological and ecological filters, we narrowed our focus to just a few of the 150+ native chrysomelid species. The most likely candidates were Chalcolampra speculifera, Cyrtonogetus crassus, or one of the larger species of Allocharis or Caccomolpus. Historical collections of beetles potentially vulnerable to Eadya attack indicated that several large chrysomeline species were present in Kahurangi National Park. A DoC permit was obtained, and subsequent field searches were made in November and December 2017, and January 2018. We located populations of what we believe to be one of the most appropriate species (Allocharis nr. tarsalis) to test against Eadya, based on its phylogenetic relatedness to Paropsis (same subfamily), its body size (second in size only to the nocturnal, refuge-building Chalcolampra speculifera), and larval biology (daytime 3 active, exposed leaf-feeding larvae present in the early summer). Host-testing trials with this species should reveal if Eadya is likely to pose any threat to other native leaf beetle species. Implications of results for the client The Department of Conservation and local iwi (Manawhenua ki Mohua) may be interested in this new information on the biology and ecology of a little known species, Allocharis nr. tarsalis. New information includes the identification of its host plant Veronica albicans, and distribution across Mount Arthur and Mount Peel in Kahurangi National Park. This will greatly add to what was previously known about this species, which was largely obtained from label information on pinned adult specimens in the National Arthropod Collection (NZAC) at Manaaki Whenua Landcare Research, Auckland. 4 Investigation into New Zealand endemic leaf beetles (Chrysomelinae and Galerucinae) and attempts to locate species in Kahurangi National Park for host testing against Eadya daenerys, a potential biocontrol agent Table of contents Executive summary ............................................................................................................................ 3 Introduction ......................................................................................................................................... 6 Information from the literature ............................................................................................................ 7 Field collection methods ................................................................................................................... 21 Results and discussion ..................................................................................................................... 22 Conclusions ...................................................................................................................................... 27 Acknowledgements .......................................................................................................................... 28 References ....................................................................................................................................... 29 Appendix A ....................................................................................................................................... 32 Appendix B ....................................................................................................................................... 33 Appendix C ....................................................................................................................................... 34 Appendix D ....................................................................................................................................... 35 Appendix E ....................................................................................................................................... 36 Appendix F ....................................................................................................................................... 37 5 Introduction The proposed biological control project New Zealand has ~150 native species of leaf beetles (Coleoptera: Chrysomelidae), while another ~30 species have been accidentally or deliberately introduced (MacFarlane et al. 2010). One of New Zealand’s most damaging exotic pests is the eucalyptus tortoise beetle, Paropsis charybdis Stål. (Chrysomelidae: Chrysomelinae: Paropsina), which has been present for over 100 years and remains the most significant insect pest of commercial eucalypt plantations (Murphy & Kay 2000; Withers & Peters 2017). The larvae and adults feed on the leaves of a range of Eucalyptus species (Myrtaceae), inhibiting growth and even, on occasion, resulting in tree mortality (Murray et al. 2008; Murray et al. 2010). Currently, expensive aerial spraying of insecticides is the primary control measure for Paropsis (Withers et al. 2013).