National Brown Marmorated Stink Bug Pilot Surveillance Programme annual report The Brown Marmorated Stink Bug (BMSB) pilot Surveillance been shown that both methods are effective for detection of programme was initiated during the 2018–2019 high-risk BMSB (Morrison et al., 2015). As this was a pilot programme, season for the monitoring of Halyomorpha halys (: surveyors were asked to regularly inspect potential host trees ), a pentatomid bug from Asia that is now a outside the designated 5 m search area when time permitted, significant pest in the US, Europe and Georgia. BMSB is a as BMSB may be attracted to the lure but not be trapped, or high-impact pest that feeds on a wide variety of horticultural not be found within 5 m of the trap. The manufacturers of the and amenity , causing significant economic losses in lure stated that the effectiveness of the BMSB lures extended many horticultural crops. BMSB is also a significant nuisance further than 5 m, so it was considered prudent to occasionally pest owing to its habit of aggregating in very large numbers widen the search when time permitted. The lure used was the (thousands) during winter in dwellings and other structures. Trece® Pherocon BMSB dual lure, which has two components: a high-dose 4x lure of 20 mg of BMSB pheromone and 200 mg MPI recognises that import pathways for BMSB are not limited of the aggregation component, and one sticky card trap was to particular commodities. Rather, high-risk pathways exist for also used for the duration of trapping. This lure is designed the accidental importation of BMSB, associated with inanimate to attract adult and nymph BMSB and is currently considered objects thought to be of low risk, such as international shipping, imported used vehicles and containers from BMSB-infested countries. MPI established a pilot BMSB surveillance programme to provide an early warning of BMSB incursions, both to facilitate eradication and to provide assurances of New Zealand’s freedom from this unwanted organism. The programme consisted of seasonal monitoring for BMSB using lure traps placed on or near specific hosts at 25 targeted Transitional Facility locations in Auckland (16) and Christchurch (9) (Figures 1 & 2). The Transitional Facilities were selected using import and BMSB interception data to provide a list of high-risk sites. Any suspect specimens caught were sent to the MPI Health and Environment Laboratory for diagnostic identification. All sites were ground-surveyed for the presence of potential host trees prior to trap establishment. MPI decided to include several native flowering and fruiting trees (e.g. titoki, Alectryon excelsus and karaka, Corynocarpus laevigatus) as potential host trees, because of the wide host range of BMSB (Leskey et al., 2012) (> 100 host plants in 45 families). This effort included placing traps on wooden stakes, or host plants and a small number of unknown hosts, to help provide information on the influence of host type on detection using lures and traps. All trap sites were established by 26 October 2018 and the programme was run for 24 weeks, concluding on 12 April 2019. The programme included one lure change after 12 weeks. Lure traps and visual inspection methods were applied at each site. Site inspections consisted of a combination of trap servicing and vegetation searches within 5 m of the Figure 1: Location of nominated risk sites for the BMSB pilot programme in Auckland, showing pilot trap, using beating sheets (Figure 3). It has site numbers Surveillance 46 (3) 2019 | 95 to be the best lure available. Traps were inspected every 10 +/- 1 working days for signs of suspect pentatomids. During the pilot programme, three separate MPI BMSB investigations were undertaken to deal with possible incursions of BMSB at different locations around New Zealand. Trapping and vegetation searches were implemented using the same procedures as the pilot programme, but for a 12- week period. These results have also been included in this report.

Results A total of 264 samples were collected from BMSB trap sites, from both traps and vegetation searches. Of that total, 258 were pentatomid specimens and six were non-pentatomids. No BMSB were found during the pilot or investigation field activities. Sixty-three percent (162/258) of all submissions were from native hosts. The most common pentatomid identified from these samples was viridula (green vegetable bug), with 97 specimens. However, Glaucias amyoti (Australasian green shield bug) was the most common pentatomid in the sticky traps (21 specimens). Cermatulus nasalis (brown soldier bug) was one of the least common species, with four specimens, and only one specimen of Oncacontias vittatus (forest shield bug) was collected (Table 1).

Table 1: Pentatomid species sampled from BMSB pilot and MPI investigation trap sites, and type of sample collection

Figure 2: Location of nominated risk sites for the BMSB pilot programme in Christchurch, showing pilot site numbers Pentatomid

species number of Total samples Samples collected from trap Samples collected from vegetation < 5 m from lure Samples collected from vegetation > 5 m from lure Nezara viridula 97 7 68 22 Glaucias amyoti 78 21 45 12 Montethiella 52 2 32 18 humeralis Cuspicona simplex 26 0 16 10 Cermatulus nasalis 4 2 1 1 Oncacontias 1 0 1 0 vittatus Total 258 32 163 63

Figure 3: BMSB sticky trap and lure (on tree at right), with associated foliage-beating inspection 96 | Surveillance 46 (3) 2019 Table 2: Pentatomid species sampled during BMSB pilot and investigation which provided sufficient opportunity to conduct additional surveillance, and phenology of associated plant host inspections on suitable hosts. More than 50 percent of all Phenology of plant host specimens collected (154/258) were adult , and nymphs made up a large proportion of the remainder. Egg masses were rarely found and only collected for Cuspicona simplex and Glaucias amyoti, making these species the only pentatomids

Pentatomid species Flowering Immature fruit Mature fruit Ripening fruit Vegetative to have all three life stages sampled. The only sample of Cermatulus nasalis 0 0 1 0 3 Oncacontias vittatus (forest shield bug) collected was an adult. Cuspicona simplex 1 4 7 9 5 Adult Nezara viridula (Australasian green vegetable bug) was Glaucias amyoti 7 5 9 20 37 the most collected pentatomid species and life-stage. Montethiella humeralis 2 6 22 17 5 The highest number of samples collected was over the Nezara viridula 16 6 13 26 36 period January to March (Figure 4, following page). This Oncacontias vittatus 0 0 0 0 1 was consistent across the pilot programme and active MPI Total 26 21 52 72 87 investigations over this time, as would be expected during the warmest months. Both the pilot programme and the Table 3: Summary of trap numbers and type of BMSB surveillance, showing total investigation sites showed a notable decrease in samples samples taken and proportion collected outside 5 m radius of trap sites collected in April compared with March. Number of samples and Bioregion Number of Surveillance percentage collected Almost half of all trap clearances (48 percent) were carried (Crosby codes)* traps type/s more than 5 m from trap out in sunny conditions, although cloudy conditions were also Pilot, commonly recorded (Table 4). Rainy and windy conditions Auckland (AK) 26 225 (21%) Investigation were the least frequent, partly because trappers avoiding Investigation conditions when vegetation searches and sheet-beating were Bay of Plenty (BOP) 16 28 (50%) only impractical. This is also reflected in the likelihood of collecting Mid Canterbury (MC) 9 Pilot only 10 (30%) samples in rainy and windy weather. Almost 30 percent of trap Investigation Southland (SD) 5 1 (0%) clearances carried out in sunny weather resulted in a sample only collection. The average time a sample was collected (11:39 AM) *Crosby (1998) was similar to the average time a trap clearance was carried out Table 4: Summary of samples collect for all weather condition categories, for BMSB (11:46 AM). pilot and investigation trap clearances Quality-assurance checks were carried out to evaluate the performance of the trappers. All trappers undertook compliance checks during the surveillance monitoring. These audits were carried out to ensure that the trappers were undertaking the inspections, sample submissions and reporting for BMSB field activities to meet the standard required. Compliance checks were also carried out on trappers used for Weather condition Weather Number of pentatomid- positive samples Number of pentatomid- negative samples Number of trap clearances with no sample taken Number of trap clearances with samples taken Proportion of clearances that resulted in sampling trap clearances Total the MPI investigation activities, although only trappers used Cloudy 44 3 284 36 11.3% 320 for the pilot programme received marked specimen audits. Five Rain 8 0 69 5 6.7% 74 marked specimens were placed during the programme and Sunny 204 3 303 120 28.4% 423 only one was not received by the diagnostic laboratory. Weather Windy 2 0 58 2 3.3% 60 conditions may have played a role in the loss of this specimen, as rain and wind may have removed it from the sticky board. Pentatomid samples were collected from all five categories of Follow-up investigation found the marked specimen was not plant host phenology (Table 2). The data indicate that four present on the trap after the trap clearance was completed. of the species collected exhibited a preference for mature and In conclusion, the BMSB pilot surveillance programme ripening fruit as well as vegetative parts of the plant. Too few processes and procedures enabled delivery of results that specimens of C. nasalis and O. vittatus were collected to draw were robust and carried out within budgetary constraints. It is any conclusions as to their preferences. recommended that a national BMSB surveillance programme The highest numbers of samples (225, 85 percent) were be implemented in the upcoming 2019–2020 monitoring collected in the Auckland bioregion (Table 3). This region had season and beyond. the highest number of traps and was also the only bioregion with both pilot and investigation traps. Proportionally, the Bay of Plenty had the most samples collected outside the 5 m radius search area, partly due to the sites being orchards and parks,

Surveillance 46 (3) 2019 | 97 Figure 4: Samples taken during BMSB pilot surveillance programme and MPI investigations, showing totals for each month

References Vinni Pather Incursion Investigator Crosby TK, Dugdale JS, Watt JC (1998). Area codes for recording specimen Biosecurity Surveillance and Incursion Investigation localities in the New Zealand subregion. New Zealand Journal of Zoology (Plant Health) (25), 175–183. Diagnostic and Surveillance Directorate Morrison WR, Cullum JP, Leskey TC (2015). Evaluation of Trap Designs Biosecurity New Zealand and Deployment Strategies for Capturing Halyomorpha halys (Hemiptera: Ministry for Primary Industries Pentatomidae). . 108(4), 1683–1692. J Econ Entomol [email protected] Leskey TC, Short BD, Butler BR, Wright SE (2012). Impact of the Invasive Brown Marmorated Stink Bug, Halyomorpha halys (Stål), in Mid-Atlantic Rory MacLellan Tree Fruit Orchards in the United States: Case Studies of Commercial Principal Adviser Management. Psyche. 2012. 10.1155/2012/535062. Surveillance and Incursion Investigation (Plant Health) Diagnostic and Surveillance Directorate Biosecurity New Zealand Ministry for Primary Industries [email protected] Sophie Melles National Operations Manager SPS Biosecurity Limited [email protected]

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