This study evaluated the influence of age and adult nutritional status of Ceratitis capitata males on their ability to inhibit female remating. Their roles and that of copula duration on the amount of sperm transferred to female spermathecae were also analysed. After emergence, adults were kept in separate groups according to their diets (either high protein – 6.5 g of brewer’s yeast, or low protein – 3.5 g of brewer’s yeast) and their age at the time of use in experiments (4, 8, 12, 16 and 20 days old). The results demonstrated that: (i) male age was not a factor that influenced remating when females mated with well‐nourished males; however, the youngest males (4 days old) in the low‐protein group were less efficient in preventing female remating; (ii) 12‐ and 16‐day‐old males fed on a high‐protein diet transferred and produced more sperm than males of other groups; (iii) there was no correlation between copula duration and the amount of sperm transferred to the female; the longest copula durations were observed among low‐protein‐diet/20‐day‐old males. These results suggest that age and nutrition influence the ability of the males to inhibit female remating. The sterile insect technique is most effective when females do not remate after coupling with sterile males, and therefore, the capacity to inhibit female remating is an important characteristic of males released in the field.

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Most studies of the sexual behaviour of the Mediterranean fruit fly Ceratitis capitata Wiedemann 1824 (Tephritidae: Ceratitidini) have concentrated on determining which male characteristics influence their copulatory success and little is known about the female’s influence on this process. The present study investigated the influence of female size on the selection of different sized males. The experiments were undertaken using a colony maintained under laboratory conditions for 15 years with the frequent introduction of wild flies. Adults of different sizes (‘larger’ and ‘smaller’) were obtained by providing two groups of larvae with different concentrations of protein (7.0 g of yeast/100 ml of water = high protein content, 3.0 g of yeast/100 ml of water = low protein content). Mate choice tests were performed in a laboratory environment as well as in a field cage, with larger or smaller females being simultaneously exposed to larger and smaller males. The results indicated that in both the laboratory and field cage tests both larger and smaller females preferred mating with larger males. The data is discussed in terms of the possible advantages to the females associated with their choice of males with large body sizes.

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