Seasonal Weight Fluctuations In Wild Queensland Fruit Fly Bactrocera Tryoni (Froggatt) (Diptera: Tephritidae) May Be A Survival Mechanism

We wanted to evaluate if the body weight of wild adult Queensland fruit fly Bactrocera tryoni changed in response to season or months to confirm results reported in the mass rearing facility. Also, this will provide insights into survival mechanisms in wild flies. We analysed 34,924 flies from the Sydney surveillance array and measured dry and fresh weight across time (months and seasons). We used results from sterile fly production to extrapolate survival traits based on adult fly weights. We found the heaviest flies were collected in late winter (August) and early spring (September and October) and heavier weights are indicative of higher eclosion and flight ability. On the other hand, lighter flies were collected in May, June and July, followed by the other autumn months. We suspect this is associated with longevity and winter survival. We conclude that fly weights vary according to months and seasons and these variations may confer different survival traits for each season.