Biocontrol introduction
Target pest: Heliothrips haemorrhoidalis (Thysanoptera: Thripidae), Greenhouse thrips
Agent introduced: Thripoctenus javae (Hymenoptera: Eulophidae) = Thripobius semiluteus, Thripobius javae
Imported:
1995, 2000
Import source:
California, USA (originally from Australia and Brazil) (1995); USA via Israel via Italy (2000)
Import notes:
Froud & Stevens (2004) - Thripoctenus javae [as Thripobius semiluteus] was imported from F.A.R. Inc. insectaries in Corona, California, USA in 1995 [this was prior to the Hazardous Substances and New Organisms Act (1996) requiring Environmental Protection Authority approval to import and/or release ‘new’ organisms] into the HortResearch [subsequently Plant and Food Research] insect quarantine facility in Auckland for host preference testing. Thripoctenus javae had been introduced into California from Australia and Brazil as a biocontrol agent for H. haemorrhoidalis.
Jamieson et al. (2008) - following approval to release T. javae [see EPA (2000b) entry in the ‘EPA applications’ section], attempts were made to obtain it from commercial insectaries in California, the source of the parasitoid for host testing. However, these insectaries had ceased production of T. javae. Therefore, in December 2000 T. javae pupae were imported into the HortResearch [subsequently Plant and Food Research] invertebrate quarantine facility in Auckland from a laboratory colony in Italy, which was sourced from a colony in Israel, which had, in turn, been sourced from the United States. The colony was reared on H. haemorrhoidalis and two months after importation there were sufficient numbers to begin releases.
Released:
2001
Release details:
Jamieson et al. (2008) - releases were made in the upper half of the North Island in citrus, avocados, shrubs and hedge plants as follows: Kerikeri (Northland) (4 sites), Whangarei (Northland) (4), Auckland (1), Bay of Plenty (8) and Gisborne (Poverty Bay) (4). Releases at Gisborne occurred November-December 2001 (other than one release in May 2001, at a site that also received a release in November); releases at the other sites occurred January-March 2001. At each site, cards with 1,000-10,000 T. javae pupae were hung at a height of 1-2 m in the canopy of trees or shrubs with H. haemorrhoidalis damage. In total, over 110,600 individuals were released at the 21 sites. In addition to these releases, HortResearch [subsequently Plant and Food Research] supplied 5,720 T. javae to 27 owners/managers of orchards, botanical and home gardens throughout the North Island and to Christchurch Botanical Gardens in the South Island from 2002 to 2005, and a private company currently has T. javae in commercial production.
Establishment:
Froud & Stevens (2004) - monitoring in late-summer of 2002-03 at release sites showed that T. javae is locally established at several sites. However, so far there has been very little spread of the parasitoid, which has generally only been found at release sites and directly adjacent orchards.
Jamieson et al. (2008) - each release site was monitored 1-4 times in autumn (March - May) between 2002 and 2007. In 2007-08, landowners at Taipa (Northland), Drury and Balmoral (Auckland) and Mt Maunganui (Bay of Plenty) (not at release sites) provided leaves infested with thrips and suspected T. javae pupae for assessment. The release site monitoring recovered T. javae from three of four sites at both Kerikeri and Whangarei, one of the four Gisborne sites and the Auckland site. Recoveries at some sites were as early as 2002, but were inconsistent from year to year and appeared related to host density. They were mostly recovered in association with heavy H. haemorrhoidalis infestations, usually in gardens or shelter trees around orchards rather than in orchards, where thrips numbers were typically low. The material provided from Taipa, Drury, Balmoral and Mt Maunganui also confirmed establishment at those locations. The Taipa location was 60 km from the nearest release site. Thripoctenus javae has successfully established in all major citrus and avocado growing regions and has dispersed from release sites. The most likely mode of dispersal, particularly long distances, is via human assisted transportation of plants, rather than natural dispersal.
Morales-Rodriguez et al. (2022) - surveys in autumn (March-May) 2017 at all but one (at Gisborne) of the original 2001 release sites recorded the presence of T. javae at 16 of the 20 sites (80%) visited. The parasitoid was found at all sites in Whangarei and Bay of Plenty, two of four of sites in Kerikeri, one of three sites in Gisborne as well as the single site in Auckland. (It has also been found in five Auckland home gardens and a public park demonstrating dispersal from the original release site.) At the two Kerikeri and two Gisborne sites where T. javae was not found, the host, H. haemorrhoidalis, was not found either. This survey demonstrates a higher rate of establishment than the previous estimate of 52% (Jamieson et al. 2008) [see entry above], perhaps due to the wider range of host plants searched in the current survey. In addition to the release site survey, cryptomeria (Cryptomeria japonica) shelterbelts at 65 kiwifruit orchards were surveyed across the Bay of Plenty from late-March to May 2018. Thripoctenus javae were found at 32 (49.2%) of these orchards; the furthest distance it was found from an original release site was 55.4 km in Edgecumbe.
Impacts on target:
Jamieson et al. (2008) - garden shrubs and shelterbelts, where T. javae is often recovered in association with heavy infestations of H. haemorrhoidalis, seem to act as parasitoid reservoirs and may be important in assisting T. javae to reduce H. haemorrhoidalis numbers in orchards.
Morales-Rodriguez et al. (2022) - seventeen years after release, T. javae has dispersed from the release sites and has been found on cryptomeria shelterbelts in kiwifruit orchards in Bay of Plenty. However, its effectiveness on H. haemorrhoidalis populations is still unknown.
Impacts on non-targets:
Stevens & Froud (1999) - world-wide, T. javae has only been recorded as parasitising five thrips species in the subfamily Panchaetothripinae. Of those five species, only H. haemorrhoidalis is present in New Zealand. However, three other species in the subfamily Panchaetothripinae are present in New Zealand and can be considered as potential hosts for T. javae; two are introduced pests or potential pests, the other is the endemic Sigmothrips aotearoana. Host preference tests were carried out in the laboratory with H. haemorrhoidalis, S. aotearoana and Heliothrips bicinctus (present in the wild in New Zealand and also in Australia, along with H. haemorrhoidalis and T. javae). The trials indicated that T. javae could complete its development on S. aotearoana and H. bicinctus, but that H. haemorrhoidalis is the preferred host. In trials with S. aotearoana and H. haemorrhoidalis, only a few S. aotearoana were parasitised in both choice and no-choice tests. With H. bicinctus and H. haemorrhoidalis there was no difference in levels of parasitism of in the no-choice tests, though H. haemorrhoidalis was preferred in choice tests. Given that H. bicinctus is not recorded as a host of T. javae in the wild in Australia, despite occurring there in the same environments as H. haemorrhoidalis, these results suggest the parasitism of S. aotearoana and H. bicinctus is an artefact of confinement and that it is unlikely S. aotearoana will be parasitised in the wild. Furthermore, habitat separation between H. haemorrhoidalis and S. aotearoana and certain S. aotearoana life history parameters, such as overwintering as adults, should decrease the chances of S. aotearoana being exposed to T. javae.
General comments:
Taxonomic note (21 November 2022) - Thripobius semiluteus (the name under which this parasitoid was introduced into New Zealand) was described by Bouček (1976). Triapitsyn (2005) proposed Thripobius javae as a new combination for Epomphale javae Girault 1917 and synonymised Thripobius semiluteus with Thripobius javae. Doğanlar & Doğanlar (2013) reinstated Thripoctenus and Epomphale as a valid genera, synonymised Thripobius under Thripoctenus, and included Thripoctenus javae (synonymous with for Epomphale javae) in the genus Thripoctenus.
EPA Applications:
EPA (2000b) - 16 April 1999: application by New Zealand Citrus Growers Inc. and Avocado Industry Council to import for release the biological control agent Thripobius semiluteus [subsequently reclassified as Thripoctenus javae - see taxonomic note in the 'General comments' section], giving citrus and avocado growers an alternative option for controlling greenhouse thrips (Heliothrips haemorrhoidalis). EPA Application # NOR99002, approved without controls 24 June 2000.
References
Bouček Z (1976). Taxonomic studies on some Eulophidae [Hym.] of economic interest, mainly from Africa. Entomophaga 21: 401-414 https://doi.org/10.1007/BF02371639
Doğanlar M, Doğanlar O (2013). Systematics of the genera with reduced mandible of Eulophidae (Hymenoptera: Chalcidoidea): parasitoids of thrips (Thysanoptera). Entomofauna 34(33): 457-516 https://www.researchgate.net/profile/Mikdat-Doganlar/publication/236605419_Doganlar_MS_Entomophauna/links/0046351836ed60eb64000000/Doganlar-MS-Entomophauna.pdf
EPA (2000b). Application to EPA (NOR99002) to import for release the biological control agent Thripobius semiluteus (Boucek), giving citrus and avocado growers an alternative option for controlling green house thrips (Heliothrips haemorrhoidalis) (Bouche). Environmental Protection Authority website https://www.epa.govt.nz/database-search/hsno-application-register/view/NOR99002
Froud KJ, Stevens PS (2004). Assessing host ranges for parasitoids and predators used for classical biological control: A guide to best practice. Chapter 8: Estimating the host range of a thrips parasitoid. Forest Health Technology Enterprise Team, USDA Forest Service, Morgantown, West Virginia: pp 90-102 https://www.invasive.org/hostrange/ch8.pdf
Jamieson L, Froud K, Edwards R, Stevens P (2008). Establishment of Thripobius javae (=semiluteus) in New Zealand. New Zealand Plant Protection 61: 17-23 https://journal.nzpps.org/index.php/nzpp/article/view/6827/6655
Morales-Rodriguez A, Rowe C, Chhagan A, Poulton J, Dobson S, Astill M, Mauchline N, Puketapu A, Rogers P, Herrick J, Stannard K, McKenzie C, McKenna C (2022). Update on the establishment of Thripoctenus javae in New Zealand and new locality records in Bay of Plenty kiwifruit orchards. New Zealand Plant Protection 75: 19-24 https://journal.nzpps.org/index.php/nzpp/article/view/11752/11608
Stevens P, Froud K (1999). Application to EPA (NOR99002) to import for release, or release from containment, the insect parasitoid, Thripobius semiluteus. Environmental Protection Authority website https://www.epa.govt.nz/assets/FileAPI/hsno-ar/NOR99002/15d686075f/APPLICATION-NOR99002.pdf
Triapitsyn SV (2005). Revision of Ceranisus and the related thrips-attacking entedonine genera (Hymenoptera: Eulophidae) of the world. African Invertebrates 46: 261-315 https://hdl.handle.net/10520/EJC84540
