Academic literature on the topic 'Queensland fruit fly'

Weekly data from the urban and rural environments of numerous Australian inland towns were used to assess the impact of urban environments on the potential growth rate of the Queensland fruit fly. The urban environments were warmer and more moist than adjacent rural environments, making rural landscapes less attractive for fruit fly. Further analysis of climatic data revealed an acute negative water balance during the summer season. Under this harsh environment, the health and greenness of urban backyards and parks is maintained with frequent use of urban irrigation. This study aims to quantify the impact of urban hydrology on environmental conditions for the population potential of Queensland fruit fly in south-eastern New South Wales. CLIMEX, a climate-driven simulation model, was used in this study. Results indicated that throughout the winter season, low temperatures kept the Queensland fruit fly under control, irrespective of any other factor, including favourable moisture conditions. During summer, moisture was the major limiting factor. Even partial irrigation reduced the limiting effects of the deficiency of rainfall often experienced during midsummer. Irrigation also resulted in a large increase in the duration of the favourable period for the potential growth of fruit fly and an almost complete removal of unfavourable periods. When irrigation water was applied at optimal or excessive levels, the duration of favourable conditions for the Queensland fruit fly extended beyond the summer season. For the Queensland fruit fly, towns appear to be oases compared with the surrounding rural desert. Queensland fruit fly is unlikely to travel freely between towns, minimising chances of reinvasion once a resident population has been eliminated.

Abstract The surveillance and management of Dacini fruit fly pests are commonly split by fly gender: male trapping focuses on the dacine ‘male-lures’, whereas female trapping focuses on lures based on host-fruit volatiles. Although the males of several Dacini species have been reported to be attracted to host fruit volatiles, the option of using host-fruit traps for males has, to date, been ignored. Males of the cue-lure responsive fruit fly Bactrocera tryoni (Froggatt) have been recorded as responding to host-fruit volatile blends, but it is not known how frequently this happens, if it is age-dependent, or the strength of the response relative to cue-lure throughout the year. Here, we conducted an olfactometer experiment to test the lifetime (weeks 1–15) response of B. tryoni males to the odor of tomato, a known host of this fly, and compare catches of wild males to tomato-based traps and cue-lure traps in the field. Bactrocera tryoni males started to respond to tomato odor as they sexually matured (2 to 3 wk olds) and thereafter showed consistent olfactory response until advanced age (15 wk). In the field, wild males were captured by tomato-based traps throughout the year at a level not significantly different from cue-lure traps. The reason for the consistent B. tryoni male response to host fruit odor at this stage is not known, but it certainly occurs at a level greater than can be continued to be ignored for both basic and applied research.

Bactrocera tryoni (Froggatt) (Queensland fruit fly, or “Qfly”) is a highly polyphagous tephritid fruit fly and a serious economic pest in Australia. Qfly biology is intimately linked to the bacteria and fungi of its microbiome. While there are numerous studies of the microbiome in larvae and adults, the transition of the microbiome through the pupal stage remains unknown. To address this knowledge gap, we used high-throughput Next-Generation Sequencing (NGS) to examine microbial communities at each developmental stage in the Qfly life cycle, targeting the bacterial 16S rRNA and fungal ITS regions. We found that microbial communities were similar at the larval and pupal stage and were also similar between adult males and females, yet there were marked differences between the larval and adult stages. Specific bacterial and fungal taxa are present in the larvae and adults (fed hydrolyzed yeast with sugar) which is likely related to differences in nutritional biology of these life stages. We observed a significant abundance of the Acetobacteraceae at the family level, both in the larval and pupal stages. Conversely, Enterobacteriaceae was highly abundant (>80%) only in the adults. The majority of fungal taxa present in Qfly were yeasts or yeast-like fungi. In addition to elucidating changes in the microbiome through developmental stages, this study characterizes the Qfly microbiome present at the establishment of laboratory colonies as they enter the domestication process.

Abstract The multibillion-dollar United States fresh fruit and vegetable industries are under threat because of actual or potential quarantines that may be imposed within hours or days if any one of many insect pests are introduced (40; P.V. Vail, personal communication). California, Florida, Texas, and Hawaii are particularly vulnerable because their climates are favorable for fruit fly species, and important shares of their produce enter into interstate and international trade. The 1980-82 California infestation by the Mediterranean fruit fly, Ceratitis capitata (Wied.), was eradicated. The Caribbean fruit fly, Anastrepha suspensa (Loew), is currently being fought in Florida and the Mexican fruit fly, Anastrepha ludens (Loew), poses a problem in Texas. In Hawaii, 3 fruit flies are endemic. They are the Oriental fruit fly, Dacus dorsalis (Hend.), the melon fly, Dacus cucurhitae (Coq.), as well as the Mediterranean fruit fly. The Queensland fruit fly, Strumeta tryoni (Froggatt), is endemic in parts of Australia and threatens to become much more widely distributed.

When 5-day-old laboratory-raised Queensland fruit flies (Dacus tryoni) were fed a dinitrogen-fixing bacterial strain of Klebsiella oxytoca isolated from the crop of a wild fly, acetylene reduction (nitrogenase) activity associated with the flies was detected after 2 to 3 days and persisted for at least 22 days. Flies not fed the dinitrogen-fixing strain were negative for acetylene reduction until 21 days after emergence. Presumably such dinitrogen-fixing bacteria are able to supply some Queensland fruit flies with a small part of their nitrogen requirements, but its importance is unknown.

The vulnerability of horticultural industries in Australia to the Queensland fruit fly Bactrocera (Dacus) tryoni under climate change is examined. Vulnerability is defined in terms of sensitivity and adaptation options. Regional estimates of fruit fly density are fed into an economic model that takes account of costs of damage, management, regulation and research. Sensitivity analyses are used to estimate potential future costs under climate change by recalculating costs with increases in temperature of 0.5˚C, 1.0˚C and 2˚C. It is assumed that irrigation will automatically compensate for any changes in rainfall. The current national, annual cost of Queensland fruit fly is estimated to be $AU28.5 million/year ($25.7–49.9 million), with 60% of the cost borne by commercial growers. Climatic warming threatens the sustainability of area freedom in the Fruit Fly Exclusion Zone (FFEZ) and is likely to increase damage and control costs to commercial growers in endemic areas, except in northern Australia. Costs to mainland apple, orange, and pear growers are estimated to increase by $3.1, $4.7, and $12.0 million with increases of 0.5˚C, 1.0˚C, and 2˚C, respectively. These represent increases of 25%, 38%, and 95%, respectively, but do not reflect the greatly increased risks of failure to maintain area freedom in the FFEZ. Growers in endemic Queensland fruit fly areas can expect their costs to increase 42–82%, compared with 24–83% in the FFEZ. Increased damage to backyard growers is likely, especially in South Australia and Victoria. Thus the fly poses a real threat to southern States under modest projected increases in temperatures. The extent of the likely cost increases raises questions about the industries’ ability to pay and remain competitive. The current analysis illustrates the potential benefits of taking a national and strategic approach to the management of insect pests in Australia. A combination of CLIMEX modelling, sensitivity analysis and mapping provided valuable insights into both industry and regional vulnerabilities. Adaptation options require further quantification, but that awaits a credible population model of Queensland fruit fly. Costs need to be discounted, depending on the expected timing of the temperature increases.

AbstractSince 1985, a new and serious fruit fly pest has been reported in northwestern Australia. It has been unclear whether this pest was the supposedly benign endemic species, Bactrocera aquilonis, or a recent introduction of the morphologically near-identical Queensland fruit fly, B. tryoni. B. tryoni is a major pest throughout eastern Australia but is isolated from the northwest region by an arid zone. In the present study, we sought to clarify the species status of these new pests using an extensive DNA microsatellite survey across the entire northwest region of Australia. Population differentiation tests and clustering analyses revealed a high degree of homogeneity within the northwest samples, suggesting that just one species is present in the region. That northwestern population showed minimal genetic differentiation from B. tryoni from Queensland (FST=0.015). Since 2000, new outbreaks of this pest fruit fly have occurred to the west of the region, and clustering analysis suggested recurrent migration from the northwest region rather than Queensland. Mitochondrial DNA sequencing also showed no evidence for the existence of a distinct species in the northwest region. We conclude that the new pest fruit fly in the northwest is the endemic population of B. aquilonis but that there is no genetic evidence supporting the separation of B. aquilonis and B. tryoni as distinct species.

Tephritid fruit flies have been comparatively well studied because of the damage they cause to horticultural crops in affected countries New Zealand benefits from this knowledge as it continues to exclude economically damaging fruit fly species For example fruit fly development models are used for biosecurity risk analysis and decision making during incursion responses Here the literature was searched for development times for three species of particular concern to New Zealand the Mediterranean fruit fly the Queensland fruit fly and the oriental fruit fly The published data were reanalysed to fit development models to the different life stages and the generation time The new models were then compared with previously published models for these species The generation time models were found to give reasonably accurate predictions when validated against published estimates of field voltinism overseas This paper presents the most comprehensive analysis to date of fruit fly development times and degree day models

Outbreaks of insect pests pose a serious threat to local economies and global food production, with as much as 15% of global crop production lost to herbivorous insects annually. Outbreaks of transboundary pests and diseases that affect food crops have increased in frequency in conjunction with globalization, international trade and the impacts of climate change. Indeed, increasing global temperatures are predicted to increase the distribution, rate of development, survival and population density of many pest insects. Such changes have important ramifications for host plant exploitation. The Queensland fruit fly (Bactrocera tryoni) is Australia’s worst horticultural pest, and is feared by international buyers of Australian produce. Like other Tephritid fruit fly species, B. tryoni has the potential to breach quarantine barriers via human mediated transport, and can rapidly establish in ‘new’ environments. This pest species is responsible for an estimated AU$28.5 million in annual yield loss, management costs and loss to domestic and international markets. Increasing and ongoing outbreaks of B. tryoni in Australia’s major growing regions has put international trade in jeopardy.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
Full Text

Queensland fruit fly is Australia's most serious insect pest of horticulture. The fly lays its eggs into fruit, where they hatch into maggots which destroy the fruit. Understanding egg laying behaviour, known as oviposition, is a critical but under-researched aspect of fruit fly biology. This thesis focused on three aspects of oviposition: the role of fruit peel as a physical barrier to oviposition; the quality of fruit for maggot development; and the structure and wear of the egg laying organ – the ovipositor. Results showed that flies selected fruit based on their suitability for offspring survival, not because of the softness or hardness of fruit peel. Previously reported use of holes or wounds in fruit peel by ovipositing females was determined to be a mechanism which saved the female time, not a mechanism to reduce ovipositor wear. The results offer insights into the evolution of host use by fruit flies and their sustainable management.

Bactrocera tryoni, the Queensland fruit fly, is established along the entire Australian east coast. It is a major pest of horticulture and arguably the worst horticultural insect pest in Australia. Adult flies lay eggs into fruit and resultant larvae feed on the flesh of the fruit. The population biology of B. tryoni has been well studied in temperate regions, where it has been established that climatic factors, particularly temperature and rainfall, limit population growth. In contrast, in subtropical and tropical regions, the population dynamics of the fly have been little studied. This thesis investigates the fly's phenology and abundance changes across subtropical and tropical Queensland and asks what factors govern the population cycles of B. tryoni in this state. Winter breeding and abundance of the fly, a component of the seasonal cycle which in south-east Queensland is fundamentally different from that observed in temperate Australia, is also investigated. A historical, extensive multi-year and multi-site trapping data set with from across Queensland was analysed to look at the effects of temperature, rainfall and relative humidity on B. tryoni trap catch. Trap data was further compared with the predicted phenology data generated by a DYMEX® based B. tryoni population phenology model. The phenology model used was based on a previously published model, but was also modified to more explicitly look at the effects of host plant availability and the presence or absence of non-reproductive over-wintering flies. Over-wintering field cage studies and a winter-spring field trapping study, both carried out in Brisbane, supplied additional data on B. tryoni's population abundance and capacity to breed during winter in the subtropics. Results show significant variation of monthly fly abundance for nine sites across Queensland. Abundance changed across sites in non-predictable ways. Annual population phenology within a site was, for some sites, highly consistent from year to year, but inconsistent for other sites. All sites in the subtropics showed some form of population depression during the cooler months, but breeding was continuous, albeit reduced at nearly all sites. Some tropical sites, where the climate is regarded as highly favourable for B. tryoni, still showed dramatic peaks and troughs in annual population abundance. There were relatively few significant correlations observed between weather factors and fly populations for any site. Output from the DYMEX population model suggested that fruit availability is a major driver of population dynamics in the tropical north of the state, while weather is more important in the subtropical south. The population dynamics of B. tryoni at sites along the central Queensland coast, where it is assumed that a mix of both weather and host fruit availability drive local populations, were poorly captured by the population model. Field cage results showed that B. tryoni successfully bred during winter in Brisbane, with pupal emergence starting in mid-winter (1st week of August), peaking in early spring (2nd week of September). Trap catch at orchards in Brisbane increased with increasing temperature and fruit availability, but diminished with decreasing temperature and fruit availability. The results suggest that B. tryoni has an optimal climate for population growth in the tropics, but fruit availability for offspring production limits population growth. In the subtropics however, both climate and fruit availability determine the population size. Winter temperatures are marginal for B. tryoni population growth in the subtropics.

Bactrocera tryoni, the Queensland fruit fly, is established along the entire Australian east coast. It is a major pest of horticulture and arguably the worst horticultural insect pest in Australia. Adult flies lay eggs into fruit and resultant larvae feed on the flesh of the fruit. The population biology of B. tryoni has been well studied in temperate regions, where it has been established that climatic factors, particularly temperature and rainfall, limit population growth. In contrast, in subtropical and tropical regions, the population dynamics of the fly have been little studied. This thesis investigates the fly's phenology and abundance changes across subtropical and tropical Queensland and asks what factors govern the population cycles of B. tryoni in this state. Winter breeding and abundance of the fly, a component of the seasonal cycle which in south-east Queensland is fundamentally different from that observed in temperate Australia, is also investigated. A historical, extensive multi-year and multi-site trapping data set with from across Queensland was analysed to look at the effects of temperature, rainfall and relative humidity on B. tryoni trap catch. Trap data was further compared with the predicted phenology data generated by a DYMEX® based B. tryoni population phenology model. The phenology model used was based on a previously published model, but was also modified to more explicitly look at the effects of host plant availability and the presence or absence of non-reproductive over-wintering flies. Over-wintering field cage studies and a winter-spring field trapping study, both carried out in Brisbane, supplied additional data on B. tryoni's population abundance and capacity to breed during winter in the subtropics. Results show significant variation of monthly fly abundance for nine sites across Queensland. Abundance changed across sites in non-predictable ways. Annual population phenology within a site was, for some sites, highly consistent from year to year, but inconsistent for other sites. All sites in the subtropics showed some form of population depression during the cooler months, but breeding was continuous, albeit reduced at nearly all sites. Some tropical sites, where the climate is regarded as highly favourable for B. tryoni, still showed dramatic peaks and troughs in annual population abundance. There were relatively few significant correlations observed between weather factors and fly populations for any site. Output from the DYMEX population model suggested that fruit availability is a major driver of population dynamics in the tropical north of the state, while weather is more important in the subtropical south. The population dynamics of B. tryoni at sites along the central Queensland coast, where it is assumed that a mix of both weather and host fruit availability drive local populations, were poorly captured by the population model. Field cage results showed that B. tryoni successfully bred during winter in Brisbane, with pupal emergence starting in mid-winter (1st week of August), peaking in early spring (2nd week of September). Trap catch at orchards in Brisbane increased with increasing temperature and fruit availability, but diminished with decreasing temperature and fruit availability. The results suggest that B. tryoni has an optimal climate for population growth in the tropics, but fruit availability for offspring production limits population growth. In the subtropics however, both climate and fruit availability determine the population size. Winter temperatures are marginal for B. tryoni population growth in the subtropics.

Fruit flies are the insects which cause maggots in your backyard fruit and vegetables. They are not just a nuisance to gardeners, but the single greatest insect threat to commercial and subsistence fruit growers throughout Asia, Australia and the Pacific. Queensland fruit fly, the focus of this PhD, costs Australia an estimated $100million per year. I focused specifically on how Queensland fruit fly uses different commercial citrus varieties. I identified specific plant related mechanisms which increase a fruit’s resistance to fruit fly attack. This information can be used by plant breeders to make fruit less prone to fruit fly damage.

Queensland fruit fly is Australia’s most destructive horticultural insect pest. The flies need to mate to successfully reproduce, but there remained significant gaps in knowledge about how they find and select mates. I showed that male and female flies likely use physical landmarks to find each other in the environment. Having found potential mates, I described their fine-scale courtship behaviour and demonstrated that young, large male flies are most successful at securing a mate. I also made significant advances in our understanding of the potential for close-range chemical communication to play a role in mate identification and selection. This research directly informs sustainable management strategies against this pest.

Queensland fruit fly is a destructive horticultural insect pest. Knowing the age-structure of fly populations, that is the relative proportion of young, middle-age, and old-age flies within a population at a given time, is critical for effective management. The thesis combined behavioural ecology with a novel mathematical analysis to identify the seasonal changes in the age of a wild Queensland fruit fly population. The study showed that the abundance and age-structure of the fly changed predictably with the season, strongly suggestive of an endogenous mechanism that helps the fly cope with seasonal changes in resource availability.

Fruit flies are major pests to a wide range of fruits and vegetables as their larvae cause damage and yield loss. To replace pesticide-based controls with more sustainable management approaches, we need to develop new generation technologies. This thesis focuses on molecular and whole-organism studies to investigate the interactions between Queensland fruit fly larvae and tomato fruit. Through molecular analysis, different mechanisms were identified to determine the susceptibility of various tomato varieties to fruit fly damage. The results pave the way for future studies on breeding for fruit resistance to fruit fly attack and sustainable pest management.

The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), a major pest of horticulture in eastern Australia, is a relatively poor coloniser of new habitat. This thesis examines behavioural properties that might limit the ability of B. tryoni to establish new populations. As the potential for B. tryoni to establish an outbreak population may be most directly limited by mechanisms associated with dispersal and mating behaviour, these two factors were the focus of this research project. The relevance of dispersal and mating behaviour for control of outbreak populations was assessed. Dispersal (i) Dispersal patterns of males and females are not different. Dispersal of post-teneral male B. tryoni from a point within an orchard near Richmond, New South Wales, was monitored following temporally replicated releases. Application of sterile insect technique (SIT) requires knowledge of dispersal from a release point so that effective release rates can be determined. In addition, dispersal following introduction to new habitat can lead to low or negative population growth and an Allee effect. In Spring and Autumn, 2001 – 2003, three different strains of B. tryoni were released: (1) wild flies reared from infested fruit collected in the Sydney Basin; (2) a laboratory-reared strain with a colour mutation (white marks); and (3) sterile flies obtained by gamma-irradiation of a mass-reared strain. Dispersal was monitored using a grid of traps baited with the male attractant, cuelure. During the majority of releases, flies were massmarked using a self-marking technique and fluorescent pigment powder to enable identification of recaptured flies. A preliminary study found that fluorescent pigment marks had no effect on adult survival and marks did not fade significantly in the laboratory over a period of five weeks after eclosion. As cuelure repels inseminated sexually mature female B. tryoni, unbaited, coloured flat sticky traps, and black and yellow sticky sphere traps baited with a food lure (protein autolysate solution) were used to supplement traps baited with cuelure. The effectiveness of these two sticky trap types was assessed, and recaptures used to compare patterns of dispersal from a release point by male and female B. tryoni. Fluorescent yellow (chartreuse), green, and clear unbaited flat sticky traps were relatively ineffective for monitoring dispersal of sterile male and female B. tryoni, recapturing only 0.1% of released sterile flies. Monitoring dispersal with sticky ball traps baited with protein autolysate solution was more successful, with yellow spheres and black spheres recapturing 1.7% and 1.5%, respectively. Trap colour had no effect on recaptures on flat sticky traps or sticky spheres. Equal recapture rates on yellow and black sticky sphere traps suggests that the odour of yeast autolysate solution was more important than colour for attraction of post-teneral flies to traps. Using the results of recaptures on odoriferous black and yellow sticky sphere traps within one week of release, regression equations of male and female recaptures per trap were found to be similar (Figure 4-3). This is the first study to clearly indicate that post-teneral dispersal patterns of male and female B. tryoni released from a point do not differ, enabling the use of existing models to predict density of both sexes of B. tryoni following post-teneral dispersal. (ii) Males disperse further in Spring than in Autumn, but this is not temperature-related. Analysis of replicated recaptures in traps baited with cuelure revealed that dispersal of male B. tryoni in an orchard near Richmond, New South Wales, was higher in Spring than in Autumn (Figure 5-6). As the maximum daily temperature was significantly higher in Spring than in Autumn this result was unexpected, since earlier studies have found that B. tryoni disperse at the onset of cool weather in search of sheltered over-wintering sites. Dispersal of post-teneral B. tryoni may have been affected by habitat suitability; it was found that seasonal trends in dispersal could have been influenced by local habitat variables. Low mean dispersal distances in Autumn may be explained by the presence of fruiting hosts in the orchard, or the availability of resources required by over-wintering flies. There was no significant correlation between temperature and mean dispersal distance, suggesting that higher rates of dispersal cannot be explained by temperature-related increases in activity. Recapture rate per trap was significantly negatively correlated with increasing daily maximum and average temperature. This may have consequences for detection of B. tryoni outbreaks in quarantine areas due to reduced cuelure trap efficiency. (iii) Maturity and source variation affect dispersal and response to cuelure. This research indicated that most male and female B. tryoni do not disperse far from a release point, suggesting that an invading propagule would not spread far in the first generation. However, there is considerable variation in flight capability among individuals. Comparison of wild, laboratory-reared white marks, and gamma-irradiated sterile male B. tryoni indicated that mean dispersal distance and redistribution patterns were not significantly affected by fly origin. Despite no difference in dispersal distance from the release point, recaptures of wild and sterile males per Lynfield trap baited with cuelure were highest within one week after release, whereas recaptures of white marks males per trap increased in the second week. This result may offer evidence to support the hypothesis that sterile male B. tryoni respond to cuelure at an earlier age. Rearing conditions used to produce large quantities of males for sterilisation by gamma-irradiation may select for earlier sexual maturity. Mating Behaviour (i) Density and sex ratio do not affect mating, except at low densities. Demographic stochasticity in the form of sex ratio fluctuations at low population density can lead to an observed Allee effect. The effect of local group density and sex ratio on mating behaviour and male mating success of a laboratory-adapted strain of B. tryoni was examined in laboratory cages. In the laboratory-adapted strain of B. tryoni used in this study, a group of one female and one male was sufficient for a good chance of mating success. The proportion of females mated and male mating success was not significantly affected by density or sex ratio, although variability in male mating success was higher at low density. This could indicate that mating success of B. tryoni can be reduced when local group density is low owing to decreased frequency in encounters between males and females. (ii) Mass-reared males exhibit aberrant mating behaviour, but this does not reduce mating success. Strong artificial selection in mass-rearing facilities may lead to decreased competitiveness of sterile males released in SIT programs as a result of alteration or loss of ecological and behavioural traits required in the field. The effects of domestication and irradiation on the mating behaviour of males of B. tryoni were investigated by caging wild, mass-reared and sterile (mass-reared and gammairradiated) males with wild females. Mating behaviour of mass-reared males was different from that of wild males, but behaviour of wild and sterile males was similar. Mass-reared males were found to engage in mounting of other males much more frequently than wild and sterile males, and began calling significantly earlier before darkness. Male calling did not appear to be associated with female choice of mating partners, although this does not exclude the possibility that calling is a cue used by females to discriminate between mating partners. Conditions used to domesticate and rear large quantities of B. tryoni for SIT may select for an alternative male mating strategy, with mass-reared males calling earlier and exercising less discrimination between potential mating partners. Despite differences in behaviour of wild, mass-reared and sterile males, frequency of successful copulations and mating success were similar. (iii) Pheromone-calling by males was increased in larger aggregations but this did not result in significantly more female visits. Finally, large laboratory cages with artificial leks were used to investigate the importance in B. tryoni of male group size for female visitation at lek sites and initiation of male pheromone-calling. Calling propensity of male B. tryoni was increased by the presence of conspecific males. Females visited the largest lek more frequently than single males, but there was no correlation between lek size and female visitation. Female B. tryoni had a limited capacity to perceive a difference between the number of calling males; female visitation at leks was only weakly associated with male calling, suggesting that lek size and the number of pheromone-calling males may not be the only factor important in locating mates in B. tryoni. The weak, but positive correlation between male calling and female visitation may indicate that passive attraction maintains lek-mating in B. tryoni. Further studies are essential on mating behaviour of B. tryoni, including identification of male mating aggregations in the field, measurement of habitat variables associated with male aggregations, the influence of density on wild B. tryoni mating success, and the role of pheromone-calling, in order to optimise use of SIT for control of this pest.

The campaign to eradicate the papaya fruit fly from north Queensland has been widely acknowledged by international scientists as a significant technical achievement that equals any similar control program world-wide. Fruit Fly Fighters is a highly readable and practical account of the whole campaign from 1995 when the papaya fruit fly was first discovered until 1999 when eradication was formally declared. Key aspects covered include: The emergency response; Campaign management; The growers' perspective; Monitoring, eradication, data management; quarantine, traffic control points; market access for fruit from infected areas; public relations; and research and development. The operating manuals and other reports are in a CD-ROM that accompanies this book.

The Queensland fruit fly (Bactrocera tryoni) is a significant horticultural pest in Australia, and has also established in other parts of the Pacific. There is a significant risk to New Zealand of invasion by this species, and several recent incursions have occurred. The potential effects of climate change on the distribution and impacts of invasive species are well known. This paper uses species distribution modelling using Maxent to predict the suitability of New Zealand to the Queensland fruit fly based on known occurrences worldwide and Bioclim climatic layers. Under current climatic conditions the majority of the country was generally in the lower range, with some areas in the medium range. Suitability prediction maps under future climate change conditions in 2050 and 2070, at lower emission (RCP 2.6) and higher emission (RCP 8.5) scenarios generally show an increase in suitability in both the North and South Islands. Calculations of the shift of suitable areas show a general movement of the centroid towards the south-east, with the higher emission scenario showing a greater magnitude of movement.