Sterile Queensland fruit flies Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) are commonly marked with fluorescent dye to assist with subsequent identification after release and recapture. The impact of dye on adult eclosion and flight ability was tested using eight concentrations of dye (Swada, Fiesta Astral Pink) from 0 to 4.5 g/L of pupae. There was no significant difference in eclosion rates between undyed pupae (control) and pupae dyed at a concentration of 1.0 g/L. For dye concentrations of 1.5-4.5 g/L, adult eclosion rates declined from 85.7% to 77.4% and were significantly different from the control. Flight ability indices ranged from 92.1% to 83.3%. There was no significant difference in flight ability between control pupae and those dyed at 1.0 g/L and 3.5 g/L pupae, but other pupae from other dye concentrations were significantly different from the control. Pupal weight ranged from 8.3 to 10.2 mg and there was no significant relationship between pupal weight and adult eclosion or flight ability.

From 1996 to 2012, the mass‐rearing facility at Camden (NSW, Australia) has been producing Queensland fruit flies, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). During this time, the facility has regularly recorded fly quality parameters, creating a unique data set that provides an invaluable opportunity to evaluate the interrelationships among standard quality control (QC) parameters and test for redundant QC variables. Here, we conducted an exploratory data analysis to reveal relationships among the QC parameters. We found that pupal weight, adult lifespan, and longevity under nutritional stress (i.e., survival duration without food or water) had distinct monthly trends, suggesting that these QC parameters are sensitive to seasonal conditions. Furthermore, emergence percentage, flight ability, and adult lifespan were adversely affected by the dyeing/handling/irradiation process associated with sterile insect releases. Using a multivariate approach and controlling for monthly and yearly patterns, we showed that pupal weight and egg hatch are consistently negatively related and that percentage male and emergence rates are consistently negatively related. These results suggest that these correlation pairs measure similar quality information and hence one QC variable from each pair could be dropped. Flight ability was not strongly correlated with any of the QC variables, suggesting that this QC variable remains a useful QC metric. Finally, the longevity under nutritional stress QC appears to be fairly insensitive to QCs and we suggest that it should be replaced by the standard mortality under stress test.

The sterile insect technique has been routinely used to eradicate fruit fly Bactrocera tryoni (Froggatt) incursions. This study considers whether fly quality in a mass-rearing facility can be improved by reducing irradiation doses, without sacrificing reproductive sterility. Pupae were exposed to one of five target irradiation dose ranges: 0, 40-45, 50-55, 60-65, and 70-75 Gy. Pupae were then assessed using routine quality control measures: flight ability, sex ratio, longevity under nutritional stress, emergence, and reproductive sterility. Irradiation did not have a significant effect on flight ability or sex ratio tests. Longevity under nutritional stress was significantly increased at 70-75 Gy, but no other doses differed from 0 Gy. Emergence was slightly reduced in the 50-55, 60-65, and 70-75 Gy treatments, but 40-45 Gy treatments did not differ from 0 Gy, though confounding temporal factors complicate interpretation. Reproductive sterility remained acceptable (> 99.5%) for all doses--40-45 Gy (99.78%), 50-55 Gy (100%), 60-65 Gy (100%), and 70-75 Gy (99.99%). We recommend that B. tryoni used in sterile insect technique releases be irradiated at a target dose of 50-55 Gy, providing improved quality and undiminished sterility in comparison with the current 70-75 Gy standard while also providing a substantial buffer against risk of under dosing.

An experiment to determine the efficacy of sprays containing polysaccharides (0.025-0.2 g/L water) and/or petroleum spray oil (1.25-10 mL/L water) for control of citrus leafminer, Phyllocnistis citrella, unequivocally demonstrated that oil sprays suppress the number of mines/leaf. Oil concentrations 2 2 . 5 mL/L of water were effective, but the polysaccharides had no effect. We recommend sprays containing 2.5-5 mL oil/L. of water. The results are discussed in relation to their perceived importance in citrus integrated pest management programs and historical recommendations for the use of oils to control the pest.

Behavioural responses of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), females to fruit dipped in water and fruit dipped in 0.5% (vol/vol) aqueous emulsions of a mineral oil were determined and analysed. The mineral oil was an nC20–22 distillation fraction of the base oil used to produce an nC23 horticultural mineral oil. Females caged with oil‐treated fruit had significantly longer prelanding intervals than females caged with water‐dipped fruit. The latter was attacked immediately or shortly after being caged with flies whereas some oil‐dipped fruit was not attacked within 180 min. The percentage of landings that led to oviposition on water‐ and oil‐treated fruit were 58 and 13%, respectively, and the percentages ovipositing after probing were 74 and 25%, respectively. Likewise, average times spent probing were 7 vs. 31 s whereas average times spent ovipositing were 321 vs. 223 s. Females spent less than half as much time on oil‐treated fruit than on water‐treated fruit. Transition probabilities of rejection, when applied to the behaviour sequence indicated that oil‐treated fruits are about nine times less likely to be infested with B. tryoni.