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Breadfruit from Samoa potentially host the Pacific fruit fly (Bactrocera xanthodes) and so their export to New Zealand requires a disinfestation treatment. Heat treatments by air (HAT) or water (HWT) are common fruit-fly disinfestation treatments for tropical crops. Two breadfruit cultivars – Puou and Ma’afala – were subjected to three heat treatments, HAT-1 (minimum 47.2oC for 20 min at core), HAT-2 (49.0oC for 100 min at core) and HWT (47.2oC for 20 min at core), and an untreated control was also included. Fruit were stored for one week at 15oC followed by three days at 25oC. Disorders observed were heat damage to the skin (blackening) and increased decay on the body and stem-end. Heat damage was at an acceptably low level following HAT-1 but was unacceptable following HAT-2 or HWT. Initial results suggest that a HAT can be tolerated, but the effect of ramp rate and the potential of using a two-step HWT system should be examined.

The controlled atmosphere temperature treatment system (CATTS) was assessed as a disinfestation tool to control codling moth (CM; Cydia pomonella) larvae inside apples. Codling moth mortality and apple quality were assessed after exposure to one of 10 treatments, which were combinations of five variables, namely, O2 concentration (air 20.9%, 1, 2 or 3%); CO2 concentrations (air 0.04% or 15%); 12 or 24˚C/h ramp rate up to 46˚C; air speed 1.3 m/s; and either 2.5- or 3-h treatment time. CATTS treatments resulted in higher CM mortality than equivalent hot air treatments. The treatments involving 1 or 2% O2 combined with 15% CO2 and a ramp of 12˚C/h or 24˚C/h to 46˚C, with a total treatment time of 3 h or 2.5 h and a 1.3 m/s air speed resulted in 100% mortality of CM. However, all CATTS and hot air treatments compromised apple quality. High CM mortality can be achieved using CATTS, but refinement of the protocol is needed to improve fruit quality outcomes.

Most taro imported from the Pacific are currently fumigated with toxic methyl bromide to kill pests, predominantly mites and nematodes that are generally found on the surface of taro. Combined high-pressure washing (HPW) and hot water treatment (HWT) were examined as alternative methods for disinfesting taro. Taro mites (Rhizoglyphus sp.) and root knot nematodes (Meloidogyne sp.) were exposed to a range of HWT and HPW conditions separately or together. At 47˚C, mean lethal times of 2.6—2.9 mins and 3.9—4.1 mins were estimated to control 99% and 99.99% of nymph and adult mites, respectively. Mite nymphs and adults were more tolerant to HWT than mite eggs. The mean lethal time estimate to control 99% of juvenile nematodes was 4.5 mins. Nematode eggs were the most tolerant life stage with only 10% mortality after a 4-min 47˚C HWT. HPW+HWT reduced heavy infestations of mobile pests on taro (n=30—117/taro) by 100%. HPW followed by HWT 50˚C for 12.5 mins reduced viable egg infestation by 95.8%. HPW followed by HWT can control surface pests on taro while maintaining taro quality.

Ethyl formate (EF) is a Generally Recognised As Safe (GRAS) alternative to methyl bromide, with potential to control surface pests on New Zealand avocados before export. "Hass" avocados, two-spotted spider mites (TSM) and oleander scale (OS) insects were fumigated with 1.2% EF (240 g VAPORMATE™/m3) at 6 °C for 1, 2 or 4 h. Fruit were then stored at 5 °C for 3 weeks before external and internal fruit quality assessment. Survival of pest species was assessed 1 or 7 days later. Fumigation with 1.2% EF + 10% CO2 for 2 or 4 h controlled all life stages of non-diapausing TSM and all life stages of OS, apart from crawlers (0.3-0.7% survivorship). Diapausing TSM were harder to control (17% ± 4.8% mortality; 4-h treatment). Ethyl formate treatment resulted in damage to avocado skins (41% ± 5.3% – 91% ± 2.0%), and an increase in vascular browning and rots. The EF fumigations of avocado fruit at doses used here have potential to control non-diapausing mites and scale insects, but treated fruit were of unacceptable quality. Future studies could examine whether prior cool storage could reduce fruit damage.

New Zealand apples infested with apple leafcurling midge (ALCM) cocoons are a quarantine issue for growers exporting to many markets. The presence of ALCM on apples in these markets requires fumigation with methyl bromide, which decreases fruit quality. The effectiveness of various forms of heat treatments on ALCM were evaluated as alternatives. Apples infested with ALCM cocoons were subjected to one of the following heat treatments: Controlled Atmosphere Temperature Treatment System (CATTS; 1% O2, 15% CO2, 46˚C, 3 h), hot air (46˚C, 3 h), hot water high pressure washing (hot-HPW; 55˚C, 100 psi, 15—20 s), or hot water drench (HWD; 55˚C, 40 psi, 15—20 s). ALCM removal and mortality were assessed 7-days post-treatment. The hot-air and CATTS treatments provided the greatest control, with 82.2 and 92.2% mortality respectively. More cocoons were removed with hot-HPW (46.6%) compared with ambient-HPW (27.1%). Neither HWD nor hot-HPW increased mortality of cocooned ALCM over that in untreated controls. ALCM cocoons are particularly difficult pests to remove/kill; further research should focus on incorporating multiple control measures into the current systems approach.

Export markets require highquality fruit free from insects and mites of quarantine significance and with minimal or no agrichemical residues This presents a challenge for New Zealands pipfruit sector when developing novel pest management systems to meet these market requirements Brushbed apple washers are an important component of a systems approach to remove insects and mites in packhouses before fruit are exported A new apple washer using multinozzle rotors significantly reduced the incidence of insects and mites on apples Weathered residues of kaolin and hydrated lime were similarly reduced by this apple washer Assessment of fruit quality after apple washing and cool storage did not identify any commercially significant quality issues on the three apple cultivars examined Apple washer design to optimise pest removal from all locations on the fruit is discussed

The presence of live pests on packed apples is a concern for many of New Zealand's export markets. Greedy and latania scale, onion thrips, apple leafcurling midge (diapausing larvae) and obscure mealybug were subjected to hot water treatments (HWT) of 49.5, 51.0 or 52.5°C for either 1, 2 or 3 min. Latania, greedy scale and onion thrips were the most susceptible pests to HWT, with either 2-3 min at 49.5°C or ≥ 1 min at 51.0 or 52.5°C achieving >80% mortality. HWT of 52.5°C for 1-3 min consistently achieved >90% mortality of apple leaf curling midge diapausing larvae. Obscure mealybug was the most tolerant species tested, with mortalities of 60-70% at 51.0 or 52.5°C for 2 or 3 min. A HWT of 51°C for 2 min did not affect quality of 'Royal Gala', 'Fuji' and 'Braeburn' apples. There is potential for short-duration HWTs to achieve high mortalities of a range of insects, while resulting in minimal damage to apple fruit.

Methyl bromide fumigation became mandatory for capsicums and truss tomatoes exported to Australia after tomato potato psyllid (TPP) was detected in 2006 in New Zealand. Methyl bromide detrimentally affects product quality by increasing rots and the browning of the green stems. An alternative being tested is ethyl formate (EF) and carbon dioxide, commercially available as VAPORMATE®. This study examined the tolerances of different life stages of TPP to EF. Eggs were considerably more tolerant of EF than adults and nymphs. Complete elimination of egg hatch was achieved after a 1-h exposure to 1.19% EF. In contrast, all nymphs and adults were killed after a 1-h exposure to 0.12% and 0.06% EF, respectively. Assessment of egg mortality was altered to better reflect the post-hatch treatment effects on nymph survival. In a subsequent egg age tolerance trial, mean lethal concentrations for 99% mortality ranged from ca 1% EF for young and older eggs to ca 1.5% EF for mid-aged eggs.

Pests on capsicum fruit can cause market access issues resulting in costly methyl bromide fumigation. High pressure washing (HPW) removes insects and other surface contaminants and has been commercialised for capsicums. This paper reports on performance of a commercial HPW system and compares it to an experimental HPW system that the commercial system was based on. The experimental high-pressure washing system operated at 75 or 100 psi (517 or 689 kPa, respectively) resulted in complete removal of aphids on capsicum fruit. The commercial washer at the same pressures removed 98.1-98.9% of aphids resulting in 85-95% clean fruit. HPW treatment increased incidence of soft rot and stem blackening with higher rot blackening at 100 psi. These results indicate the potential of HPW to be included as a mitigation measure in a systems approach to improve market access for capsicum. However, further optimisation in a commercial setting and evidence for efficacy against other pests of capsicum, such as tomato potato psyllid is required.

Bull’s eye rot (BER) of apples is caused by a postharvest fungal pathogen (Phlyctema vagabunda syn. Neofabraea alba). Previous laboratory experiments found hot water treatments (HWT) resulted in a significant reduction of BER incidence for artificially inoculated fruit so the feasibility of HWT to control naturally infected fruit in a semi-commercial trial was tested. One bin (1934 fruit) of naturally infected ‘Scired’ apples was harvested from a Hawke’s Bay orchard with a known high incidence of BER, then placed in a coolstore for 1 week until treated. All fruit were passed through a high-pressure water blaster then air dried. Approximately half the contents of the bin (1034 fruit) were packed into Friday trays in apple boxes with a plastic polyliner. The other half (900 fruit) were treated for 2 min with hot water at 51°C in a semi-commercial hot water bath before packing. All fruit were then coolstored for 20 weeks before assessment for BER. This HWT resulted in a 6-fold reduction of BER incidence so was an effective treatment for BER in a semi-commercial test.

New Zealand lower thrips (NZFT, Thrips obscuratus (Crawford)) were exposed to a range of ethyl formate (EF) and pyrethrum-based postharvest treatments on apricots. Research showed that EF+CO 2 or EF+N 2 were effective treatments against NZFT and caused negligible damage to apricot fruit quality. However, pyrethrum dipping did not effectively control NZFT and caused signiicant internal damage to apricot fruit. Lethal concentration (LC 99 ) estimates were developed for adult and larval NZFT using a range of EF concentrations (0-1.27% EF+CO 2 ) and temperatures (5, 15 and 25°C). It is estimated that treatments of 1% (30.7 g/m 3 ) EF at 5 or 25°C or a higher concentration of 1.5% (46.3 g/m 3 ) at 15°C will achieve 99% mortality of NZFT adults and larvae on apricot fruit with 95% conidence.

Global use of phosphine as a fumigant has increased in response to the need to replace methyl bromide, and with the improved formulations, ECO2FUME® and VAPORPH3OS®. Phosphine is registered as a postharvest fumigant on kiwifruit in New Zealand and has been used commercially to reduce the risk of detecting live pests. Scale insects, mealybugs and diapausing twospotted spider mites were exposed to a range of phosphine treatments. A 48-h low temperature (1.7-4.6°C) fumigation (6408-3311 ppm) achieved 100% mortality of all life stages of oleander scale insects, while a 12-h exposure killed all longtailed mealybug life stages. A 36-h low temperature (2.5-3.3°C) fumigation (4332-2712 ppm) treatment achieved 100% mortality of all greedy scale insect life stages. A 48- to 96-h treatment (3600-1200 ppm) at 1-15°C caused 91.3-100% mortality of diapausing twospotted spider mite adults. Use of phosphine as a commercial treatment for kiwifruit is discussed.

Insect removal from kiwifruit is important for improving access to overseas markets. Insect removal from kiwifruit by physical treatments such as high pressure washing is hugely successful but kiwifruit packing is carried out “dry”. Therefore, one potential option is the use of ‘air-knife’ blowers to remove insects. A system with air-knives from the sides and top that was mounted over a single-lane Compac grader was able to remove over 90% of artificially inoculated diapausing two-spotted mites (≈ 85/fruit). The difference in pest levels between untreated ‘Hayward’ kiwifruit fruit naturally infested with a wide range of insects (n=2194) and fruit exposed to air-knives (n=2204) was: mealybug 100%, beetle/weevils 91—100%, oribatid mites 93%, tuckerellid mites 98%, unidentified mites 88% , booklice 86%, thrips 74— 100%, Collembola 63%, cockroaches 100%, spiders 43%, scale insects 40%. Air-knives had no noticeable effect on ‘Hayward’ or ‘Zesy002’ (Gold3) fruit quality. These results indicate that air-knives using a high air-flow/low-pressure system can effectively remove high rates of “mobile” insects and first-instar scale insects, and can probably be implemented logistically and economically from a commercial perspective.

The presence of apple leafcurling midge (ALCM) on apples is of concern for many of New Zealand’s export apple markets. High pressure washing (HPW) systems have been implemented in export packhouses to reduce the risks associated with various pests; however, higher removal rates of ALCM are required to improve access to challenging markets. A range of pre-treatment dips to improve ALCM removal efficacy when applied before HPW were tested, and the impact of these pre-treatment dips on pest viability determined. Removal of ALCM cocoons by HPW alone was 41%, compared with pre- treatments of hot water at 51˚C (66%), Saturate® (58%), Prospect oil® (57%), malic acid (53%), citric acid (48%), lactic acid (46%), acetic acid (39%), HarvestCide® (37%) or sodium bicarbonate (37%). However, only the hot-water treatment significantly enhanced removal compared with HPW alone. In a second trial, removal of ALCM cocoons with HPW was 69% and hot water + UV-C increased removal to 76%, although this difference was not statistically significant. Overall, none of the pre-treatment dips was found to reduce ALCM viability significantly compared with HPW alone.

The potential for highpressure waterblasting to remove leafroller egg rafts from the surface of Hass avocados after harvest was investigated Water pressures from 400 to 1000 psi were tested Pressures of 800 and 1000 psi removed 96999 of greenheaded leafroller (Planotortrix octo) egg rafts in two consecutive seasons Equal numbers of brownheaded leafroller (Ctenopseustis obliquana) egg rafts were also removed at pressures of 800 psi Natural infestations of thrips mites and leafroller larvae were completely removed at pressures from 400 to 1000 psi but armoured scale pests remained on the fruit Waterblasted fruit met current industry quality standards