APP202663: import and release the moth, Lathronympha strigana and the beetle, Chrysolina abchasica, as biocontrol agents for tutsan, (Hypericum androsaemum) David Havell Technical Advisor, Northern Threats Team, Department of Conservation.

2 Tutsan Bicontrol Programmes The Department of Conservation supports biocontrol programmes where the agents have a targeted impact and do not adversely impact on native species. We support the release of Lathronympha strigana for the control of tutsan. We have concerns about releasing the beetle Chrysolina abchasica.

3 (a) (b) (c ) Will Chrysolinia abchasica cause Significant Displacement of any native species within its natural habitat? (Minimum Standards, HSNO Act, section 36) Habitat overlap, between nationally critical species and St John’s wort. Habitat overlap between native hypericum and Tutsan, Puhoi Tutsan alone, Rangitoto (d) Native Hypericum alone.

4 Self Sustaining populations Distribution of Tutsan and St JW, from both DOC and the NZ Virtual Herbarium Tutsan cliff site, Taumaranui Rest area Could C. abchasica form self-sustaining populations in NZ? We think where Tutsan and St John’s wort are present,a self sustaining population will occur and any release should assume so, so that a precautionary approach should be used.

5 Concerns re Chrysolina species 1.Are known to have reduced St JW from a widespread invasive species to occasional patches in NZ and elsewhere 2.Use Hypericum species across a range of Hypercium sections, including taxonomic sections found in NZ. Chrysolina abchasica will have one main host (tutsan), as well as two other limited hosts (St JW and H. humifusum ) from which spillover and limited grazing may occur. 3.Spillover attacks of Chrysolina species on non target species are known, for example Groenteman, lists records of severe spillover attacks of Chrysolina species on tutsan in NZ, even though the Chrysolinia species concerned did not complete development on tutsan in trials

6 Concerns re Chrysolina species 4.If the effectiveness of biocontrol was carried across to non target species, significant declines in native and valued Hypericum species could be expected. 5.Tutsan and other exotic hypericums overlap in range with native hypericums. 6.New Zealand has native hypericums which are valued and threatened.

7 Hypericum phylogenies Published phylogenies of hypericum, with known Chrysolina hosts indicated. Hosts occur across sections, though the best host tends to be 1 species. Three, possibly 4 native species are likely to be used as hosts to varying degrees. Published phylogenies of hypericum, with known Chrysolina hosts indicated. Hosts occur across sections, though the best host tends to be 1 species. Three, possibly 4 native species are likely to be used as hosts to varying degrees.

8 NZ Threat System If hypercium natives declined at the rate St JW did, a species threat ranking would significantly worsen

9 This table shows categories factored into threat rankings: population losses affect threat rankings

10 Chrysolinia grazing on Hypericums Current biocontrol agents for St John’s Wort, (Groenteman,2011) These tables show the evidence of Chrysolina species feeding on native hypericums and feeding instances. They graze with intensity from medium to high. C. abchasica (Landcare response to submission)

11 Chrysolina as vectors of plant disease As noted by Landcare Research, Chrysolina spread anthracnose disease which contributes to the biocontrol of St John’s wort. Chrysolina species in NZ including C. abchasica graze native Hypericums and could spread disease via grazing damage. Although unlikely disease carrying C. abchasica will be released, beetles could become infected after release with disease present in NZ.

12 Do Hypericum species overlap in range? Hyperciums, Central North Island Yes. And this is demonstrated with just a small sampling of sites. Yes. And this is demonstrated with just a small sampling of sites.

13 Matea Road H. minutiflorum H. pusillum St John’s wort

14 Pureora, Hypericum minutiflorum site

15 South Island Sites

16 What does the Department of Conservation want? We would like additional testing similar to that published for other Chrysolinia species. and more extensive reporting on potential severe spillover impacts on non target plants. In order to be confident that there is not going to be native species declines in areas where C.abchasica hosts occur.

17 Conclusions 1.Native hypericums, especially H. pusillum grow in regions where tutsan and other (albeit weaker) Chrysolinia hosts grow. 2.Native hyperciums are grazed by Chrysolinia and some support limited larvae development. 3.There is risk posed to native hypericums by C.abchasica.

18 Conclusions 4.The impact of C. abchasica and other Chrysolinia species on native hyperciums needs further research, before a full release is carried out. 5.Research should determine in what ways all native Hypericums are affected by C. abchasica, including whether there are local declines of native species, the extent of decline, and plant damage in response to the number of Chrysolinia individuals.