Review of the impact of the TriState community fruit fly awareness programme on road travellers - 1999/2000

Travellers entering the Fruit Fly Exclusion Zone at Kamarah, the Sturt highway, and Broken Hill were asked questions about their knowledge of fruit fl y issues and their vehicles were examined for fruit. Of the travellers examined 90.2% had heard of the Zone before entering, and of those 97.3% knew not to carry fruit or to dispose of fruit before entering the Zone. Only 4.3% of travellers who had heard of the Zone prior to entry carried fruit, while 24.7% of travellers who had not heard of the Zone carried fruit. There was a highly significant negative relationship between the proportion of travellers found with fruit and the frequency of travel. In this roadside survey, 96% of travellers recalled seeing the road signs, while 15% learnt about the zone by 'word of mouth' or 'local knowledge' and 10.7% and 3.1% of respondents obtained their information from television and radio respectively. There were, however, differences between sites. Only 31.8% of travellers could correctly recall the value of the two penalties advertised on the road signs however 44.5% and 34.5% recalled the two individual amounts. 18.4% of those who claimed not to know about the fines carried fruit compared with about 3.5% for those who remembered some penalty. Tomatoes were frequently not thought of as being fruit and this confusion needs to be addressed. Different risk groups were affected by different awareness tools and a variety of awareness tools need to be used in a public awareness campaign. Any travel or risk group which recalled an awareness message invariably were less likely to carry fruit. Any improvement in the delivery of the community awareness campaign will improve the overall management of the quarantine zone.7 page(s

Field performance of Lynfield and McPhail traps for monitoring male and female sterile Bactocera tryoni (Froggatt) and wild Dacus newmani (Perkins)

Backgroud: McPhail traps, baited with protein food lure, are used worldwide for surveillance of many species of fruit flies. Queensland fruit fly (Qfly) Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) is a native Australian fruit fly and normally monitored using Lynfield traps baited with cuelure. On some occasions, McPhail traps with wet food lures are deployed to detect female flies or to find the incursion epicentre. This paper reviews field results on the merits of Lynfield and McPhail traps for detection of male and female Qfly. Results: Following release of equal numbers of sterile males and females, Lynfield traps baited with cuelure captured more Qfly males than protein autolysate or orange concentrate in McPhail traps. Significantly more male than female Qfly were captured in McPhail traps baited with protein autolysate or orange. There was no significant difference between orange concentrate lure and protein autolysate lure in attracting either males or females. Another Australian native fruit fly, Dacus newmani (Perkins), was attracted to cuelure in Lynfield traps but not to either lure in McPhail traps. Conclusions: The data obtained run counter to the reputation of McPhail traps baited with protein autolysate or orange concentrate as a specialist lure/trap combination for female Qfly.4 page(s

Queensland fruit fly (Bactrocera tryoni froggatt) attraction to and chemical analysis of male annihilation blocks using three concentrations of cuelure at dubbo, New South Wales, Australia

Three rates of cuelure were compared in male annihilation blocks to assess the attraction of male Queensland fruit fly. There were no significant differences in trap captures of fruit fly between 2, 8 or 18 mL of cuelure in chipboard based male annihilation blocks. There was no repellent effect at the high cuelure rate, even in the first inspection period. At the end of the trial, chemical analysis was conducted on the core and edge positions of blocks. Cuelure, maldison and raspberry ketone were significantly related to the weight of the blocks. Cuelure levels were significantly higher in surface layers while maldison levels were significantly higher in the core position. Implications for the male annihilation technique are discussed.4 page(s

Effects of Radiation, Dye, Day of Larval Hopping and Vibration on Eclosion of Queensland Fruit Fly, Bactrocera Tryoni (Froggatt) (Diptera: Tephritidae)

5 page(s

Effect of conditions in sealed plastic bags on eclosion of mass-reared Queensland fruit fly, Bactrocera tryoni

The sterile insect technique has been used for more than 50 years to control a range of insects around the world. Sterile insect technique is rapidly becoming a major component of many area-wide fruit fly management programmes. Irradiation of immature life stages induces sterility in adults, which are then distributed over large areas to mate with wild flies, resulting in no viable offspring. However, irradiation in normal air results in declining adult quality. To optimize the quality of sterile adult flies, several techniques are available to lower the levels of oxygen in fruit fly tissues prior to irradiation. The simplest method is to seal pupae in plastic bags and allow the oxygen consumption of pupae to minimize oxygen in both the air and pupal tissue. Some fruit fly species have rapid decreases in eclosion as a result of low oxygen atmospheres. We tested the tolerance of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), to low oxygen for the first time. In the first two experiments, unirradiated B. tryoni pupae were tested for different periods in sealed plastic bags at 17, 21, and 26°C. Optimum eclosion occurred at 21°C with the lowest eclosion at 26°C. In general, mean full eclosion declined at ca. 0.1% eclosion per hour sealed in plastic bags during the first 96h for all temperatures. In the third and fourth experiments at 17°C, there was a decline in average eclosion for irradiated and unirradiated pupae of about 13.4% after they were sealed in plastic bags for 192h. In general, B. tryoni eclosion declined at 0.1% per hour inside sealed plastic bags for periods up to 192h at 17°C. Queensland fruit flies can tolerate long periods of conditions found inside sealed plastic bags and current practices for sterile B. tryoni release programmes will result in minimum decrease in eclosion. The possible evolution of tolerance of these conditions is discussed.6 page(s

Economics of Surveillance: a Bioeconomic Assessment of Queensland Fruit Fly

Regional management of endemic pests of trade significance typically requires a surveillance system, border controls, eradication protocols and conditions for market closure and reopening. An example is the systems for managing Queensland fruit fly (Qfly) in south east Australia where the preferred approach for intensive production areas is an Area Wide Management (AWM) scheme. An AWM, such as the Greater Sunraysia PFA (GSPFA) in northern Victoria and western New South Wales, depends for its recognition amongst trade partners on an effective and credible surveillance system that identifies outbreaks rapidly, notifies exporters of trade restrictions and initiates eradication. These ‘market rules’ are fundamental to the economics of surveillance: they define an outbreak and thus the probability of market closure, the expected time to eradication, and consequent time to market reopening. This paper uses a spatial and dynamic bioeconomic model of Qfly infestation and spread to determine the expected optimal investment in surveillance and eradication capacity of the AWM

Economics of surveillance : a bioeconomic assessment of Queensland fruit fly

Regional management of endemic pests of trade significance typically requires a surveillance system, border controls, eradication protocols and conditions for market closure and reopening. An example is the systems for managing Queensland fruit fly (Qfly) in south east Australia where the preferred approach for intensive production areas is an Area Wide Management (AWM) scheme. An AWM, such as the Greater Sunraysia PFA (GSPFA) in northern Victoria and western New South Wales, depends for its recognition amongst trade partners on an effective and credible surveillance system that identifies outbreaks rapidly, notifies exporters of trade restrictions and initiates eradication. These ‘market rules’ are fundamental to the economics of surveillance: they define an outbreak and thus the probability of market closure, the expected time to eradication, and consequent time to market reopening. This paper uses a spatial and dynamic bioeconomic model of Qfly infestation and spread to determine the expected optimal investment in surveillance and eradication capacity of the AWM.21 page(s

Pupal release of the Queensland fruit fly, Bactrocera tyroni (Froggatt) (Diptera: Tephritidae), in the sterile insect technique : seasonal variation in Eclosion and Flight

The Queensland fruit fly, Bactrocera tryoni (Froggatt), is the most significant pest of edible fruit in Australia. For the control of B. tryoni using sterile insect technique (SIT), either pupae or adults may be released. Using pupal release, this study tested the seasonal effect of different pupal loadings on eclosion and the flight of sterile B. tryoni. Pupal eclosion boxes were loaded with either 200, 350, 500, 650 or 800 g of pupae during five periods of the fruit fly season (August, October, December, February and April). Adult flies were allowed to emerge and the remaining pupal debris was sampled to determine the per cent emergence and per cent fliers. The duration of emergence, dye retention on the ptilinum of the flies, and temperature and relative humidity externally and internally of the eclosion boxes were recorded. The percentage of emergence was influenced by both pupal loading and the period of release. Overall, the percentage of emergence was lower for loadings of 200 and 350 g of pupae in August, October and April as compared with the 500 g or higher loadings. This difference was not apparent in December or February. The mean percentage of emergence for each pupal loading in December, February and April was well above 65%, the minimum required emergence parameter for successful sterile B. tryoni release. Across all pupal loadings, the percentage of fliers was greater than 99.3% in December, 87.8% in February and 80.8% in April. A high percentage of fliers (>92.7%) was recorded in October, but the percentage of emergence in August and October was below 65% for all pupal loadings; thus pupal release is a suboptimal SIT method during this period of time. Dye on the ptilinum was detected on every fruit fly sampled across all pupal loadings and release periods. Minimum temperature for optimal pupal emergence should not fall below 10°C, and the maximum should not exceed 35°C. Minimum temperature for successful flight should not fall below approximately 6°C while the maximum temperature should exceed 16°C. The described pupal release system is considered a possible option for use as part of an SIT program against B. tryoni under suitable environmental conditions in Australia.10 page(s

Impact of marking dye, transport and irradiation on eclosion of mass produced Queensland fruit fly Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)

In Sterile Insect Technique (SIT) programs, released flies are commonly marked with fluorescent dye prior to irradiation to assist subsequent identification. The impacts of dye, transport and irradiation on adult eclosion of Queensland fruit fly were investigated. Eclosion in the non-dyed, non-transported, nonirradiated pupae was 84.64%. Dyeing, transport and irradiation processes significantly reduced the adult eclosion rate to 72.88%. This reduction in adult eclosion was accompanied by a 10.2% increase in partially eclosed adults. In an additional treatment, the dye was removed from pupae following irradiation by rinsing with water. These pupae were allowed to eclose in a humid container, whereas the pupae from the other treatments were allowed to eclose in glass Petri dishes. The percentage of fully eclosed flies was 81.54% - a significant improvement compared with standard dyed transported irradiated pupae and very close to that found in untreated controls - and the percentage of partially eclosed flies was not significantly different from the control pupae. Both irradiation treatments had more uneclosed pupae compared to the control treatment although the three treatments differed by only 2.1% variation. Based on these results, it appears that dye and/or the eclosion environment have considerable impacts on the viability of Queensland fruit flies produced for SIT. There appears to be substantial room for improvement in either the marking system and/or the eclosion environment used prior to release.3 page(s