National Brown Marmorated Stink Bug Surveillance Programme annual report

The Ministry for Primary Industries (MPI) established the included establishing two lured sticky-card traps about 125 m Brown Marmorated Stink Bug (Halyomorpha halys, BMSB) apart on host plants or on wooden stakes. All trap sites were set Pilot Surveillance Programme in 2018-2019 as a post-border up by 15 November 2019 and the programme ran for 24 weeks, seasonal early detection and monitoring programme to concluding in the week of 27 April 2020. The programme facilitate eradication and provide evidence of New Zealand’s included one lure change after 12 weeks. freedom from BMSB. Subsequently, MPI established the annual Site inspections consisted of a combination of trap servicing BMSB Surveillance Programme in 2019–2020, for which SPS and vegetation searches within 5–10 m of the trap, using Biota is the service provider. beating sheets (Figure 2). It has been shown that both methods BMSB is a high-impact economic, nuisance and environmental used together are more effective at detecting BMSB than a pest from Asia that is now a significant pest in the US, Europe single method (Morrison et al. 2015). The programme used the and Georgia. BMSB feeds on a wide variety of ornamental Trécé® Pherocon BMSB dual lure, which has two components: a plants, fruits and vegetables, causing significant economic losses high-dose 4x lure of 20 mg of BMSB pheromone and 200 mg of in many horticultural crops. It is also a significant nuisance the aggregation component, and one sticky card trap was also pest owing to its habit of aggregating in very large numbers (thousands) during winter in dwellings and other structures. If BMSB were to become established in New Zealand it could severely impact the horticulture, forest and tourism industries and potentially affect indigenous flora and become a serious nuisance pest in people’s homes. MPI recognises that import pathways for BMSB are not limited to any one commodity. Rather, a number of high- risk pathways exist for the accidental importation of BMSB, associated with international shipping of presumed low- risk inanimate objects such as imported used vehicles, machinery and containers from BMSB-infested countries. The programme consists of seasonal monitoring for BMSB using lure traps placed on or near specific hosts, and vegetation searches at targeted Transitional Facility (TF) locations around New Zealand (Figure 1). The TFs were selected using import and BMBS interception data to provide a list of high-risk sites. Any suspect specimens caught were triaged in the field by trained BMSB surveillance inspectors and, if required, were sent to the designated diagnostic laboratory, either as a photo sample or a physical sample. All sites were ground-surveyed for the presence of potential host trees before the traps were set out. BMSB has a wide host range of more than 100 host plants in 45 families (Leskey et al. 2012), so several flowering and fruiting native trees (e.g. titoki, Alectryon excelsus and karaka, Corynocarpus laevigatus) were included as potential hosts. This effort Figure 1: Locations of risk sites for the 2019–2020 BMSB surveillance programme 110 | Surveillance 47 (3) 2020 Figure 2: BMSB sticky trap and lure (on tree at right), with associated foliage-beating inspection used for the duration of trapping. This lure is designed to Surveillance & Incursion Investigation Plant Health Team for attract both adult and nymphal BMSBs and is currently follow-up. A thorough further inspection of the vegetation in considered to be the best lure available. Traps were inspected the area, including the use of an MPI BMSB detector dog with every 10 (± 3) working days. handler, did not reveal any further BMSBs and the biosecurity

The number of high-risk inspection sites was increased from 50 Table 1: species identified from BMSB Surveillance Programme trap to 80 for the 2019–2020 season because Plant & Food Research sites and type of sample collection, 2019–2020 (PFR) inspected ten high-risk sites in each of the Tauranga, Napier/Hastings and Nelson areas. This enabled PFR to gather Sample source valuable BMSB research data while helping to mitigate the risk Trap Vegetation search Free flying of BMSB establishing in New Zealand. Pentatomid ≤ 10 m >10 m Total species from trap from trap Results Cermatulus nasalis 3 2 5 In total, 596 samples were submitted from both trap clearances Cuspicona simplex 4 39 17 60 and vegetation searches. (Samples may contain more than one Dictyotus caenosus 1 6 7 specimen.) This resulted in 637 identifications of Pentatomidae. Glaucias amyoti 46 78 21 145 Another 13 specimens other than Pentatomidae were identified, all of which were from the family Acanthosomatidae (either Halyomorpha halys 1 1 Monteithiella Oncacontias vittatus or Rhopalimorpha obscura), except one 28 225 8 1 262 humeralis was a species of weevil (Coleoptera: Curculionidae). Nezara viridula 23 91 14 128 One BMSB was found on a kapuka shrub ( littoralis) Oechalia 4 3 7 at the beginning of March during a trap radius vegetation schellenbergii search in the Auckland region. The was found about Undetermined 10 9 3 22 2 m away from a BMSB lure. The find was reported to the Total 112 456 68 1 637

Surveillance 47(3) 2020 | 111 risk was considered to have been mitigated. The incursion Table 3: Summary of trap numbers and type of BMSB surveillance, showing total investigation found that a container of furniture from a BMSB- samples taken and proportion collected outside 5 m radius of trap sites infested country had been devanned a day previously and this Number of risk Rate of sampling Number of Region sites used for trap (samples per was the likely source of the bug found. This is a good example samples of the BMSB surveillance programme working well for early establishment risk site) detection. Auckland 24 284 11.8 The most common pentatomidae identified from these samples Waikato 2 20 10 was Monteithiella humeralis (Pittosporum shield bug), with Bay of Plenty 10 25 2.5 262 specimens. However, Glaucias amyoti (Australasian green Hawke’s Bay 10 101 10.1 shield bug) was the most common pentatomidae in the sticky Manawatū-Whanganui 2 7 3.5 traps (46 specimens). Cermatulus nasalis (brown soldier bug) Wellington 2 2 1 was one of the least common species, with five specimens Nelson 10 102 10.2 (Table 1). Canterbury 18 45 2.5 Table 2: Pentatomidae species identified from samples collected during the Dunedin 2 10 5 BMSB Surveillance Programme 2019–2020, and phenology of the hosts Total 80 596 Plant phrenology humeralis and Glaucias amyoti, making these species the only Fruit Species Pentatomidae to have all three life stages sampled; consequently Total Other these species yielded the highest numbers.

Vegetative Flowering Immature Ripening Mature/ ripe The highest numbers of samples were collected from January to C. nasalis 3 2 5 March (Figure 3). This is consistent with the 2018–2019 Pilot Cu. simplex 6 2 19 13 20 60 Surveillance Programme data and was, as expected, over the D. caenosus 5 1 1 7 warmest months of the year. Both years’ data showed a notable decrease in sample numbers collected during April, compared G. amyoti 37 2 23 39 40 4 145 to March. The sharp increase in samples for March this year H. halys 1 1 could be partly attributed to its being the second-warmest M. humeralis 41 1 45 66 107 2 262 March on record in New Zealand, as well as the inclination of N. viridula 53 3 8 15 47 2 128 trappers to spend extra time searching at trap sites after the O. schellenbergii 1 1 2 3 7 BMSB find at the start of the month. Traps remained in the field Undetermined 8 2 2 3 7 22 a few weeks later than in the 2018–2019 season, hence samples Total 155 11 98 138 227 8 637 were collected in May only during this season. Just over half of all trap clearances (51.5 percent) were carried Pentatomidae samples were collected from all five categories out in sunny conditions, although cloudy conditions were also of plant host phenology (Table 2). The data indicate that four commonly recorded (Table 4). Rainy and windy conditions of the species collected exhibited a preference for ripening, were less frequent, partly because the trappers avoided immature and mature fruit, and less preference for the conditions where vegetation searches and sheet-beating were vegetative parts of the plant. Too few specimens of C. nasalis, impractical and the likelihood of collecting samples was lower, D. caenosus and O. schellenbergii were collected to draw any as reflected inTable 4. More than 30 percent of trap clearances conclusions as to their preferences. and vegetation inspections carried out in sunny weather The highest numbers of samples (284, 47.7 percent) were resulted in a sample collection. This season, the percentage of collected in the Auckland region (Table 3). This region had the trap clearances and vegetation inspections carried out in sunny highest number of BMSB inspection sites, owing to the higher weather was higher than in 2018–2019, owing to the flexibility number of TFs in the area, although samples were collected in in trap clearance frequency, changing from an acceptable all regions where traps were established. Regions with a low rate Table 4: Summary of BMSB trap clearances and samples collected for all weather of sampling were often affected by lack of suitable vegetation at condition categories, 2019–2020 risk sites, owing to the nature of the TF environment, and this Percentage of trap limited the opportunity to collect samples. The Surveillance Weather Percentage of samples clearances and vegetation and Area Co-ordinators discussed the lack of samples from condition collected inspections carried out some regions, to ensure this was not a result of inexperience or trapper error, and confirmed that it was not. More than 50 Cloudy 37.69 33.22 percent of all specimens collected (364/637) were adult , Rainy 2.73 3.19 and nymphs made up a large proportion of the remainder. Egg Sunny 51.50 56.04 masses were rarely found and only collected for Monteithiella Windy 8.08 7.55

112 | Surveillance 47 (3) 2020 180

160

2018-2019 140 pilot surveillance season 120

100 2019-2020 surveillance season 80

Number of Samples Taken 60

40

20

0 November December January February March April May Month

Figure 4: Samples taken during BMSB pilot surveillance programme and MPI investigations, showing totals for each month variation of ± 1 day to ± 3 days either side of the 10 working References days routine. Morrison WR, Cullum JP, Leskey TC (2015). Evaluation of Trap Designs Despite the restrictions on COVID-19-related regional travel, and Deployment Strategies for Capturing Halyomorpha halys (: quality-assurance checks were able to be carried out to evaluate Pentatomidae). J. Econ. Entomol. 108(4), 1683–1692. the performance of the inspectors. All inspectors undertook Leskey TC, Short BD, Butler BR, Wright SE (2012). Impact of the Invasive compliance checks during the surveillance monitoring, using Brown Marmorated Stink Bug, Halyomorpha halys (Stål), in Mid-Atlantic video conferencing. These audits were carried out to ensure Tree Fruit Orchards in the United States: Case Studies of Commercial that the trappers met the required standard when undertaking Management. Psyche. 2012 10.1155/2012/535062 the inspections, submitting samples and reporting BMSB field activities. Owing to the COVID-19 travel restrictions, not all Rory MacLellan marked specimens were able to be placed at some inspection Principal Adviser, Surveillance, Plant Health sites, although all marked specimens that were placed during Biosecurity Surveillance & Incursion Investigation the programme were received by the diagnostic laboratory. (Plant Health) In conclusion, the BMSB surveillance programme yielded Diagnostic & Surveillance Directorate results that were robust, and was carried out within budget. Biosecurity New Zealand Large numbers of samples were collected and identified, Ministry for Primary Industries resulting in the early detection of one BMSB, showing the [email protected] benefit of the programme and demonstrating that it is Diane Anderson operating well. Senior Scientist Plant Health & Environment Laboratory Diagnostics & Surveillance Directorate Biosecurity New Zealand Ministry for Primary Industries [email protected] Sophie Melles National Operations Manager SPS Biota [email protected] Surveillance 47(3) 2020 | 113