In this study, rearing systems for, and the quality and demographic parameters of, a wild strain (WS) and two laboratory strains (LSs; one maintained on a torula yeast-casein diet and the other on a starter-gel diet) were determined for the American guava fruit fly Anastrepha striata (Schiner). No differences were observed between the LSs, but there were significant differences between the LSs and WSs. The LSs had the highest values for larval recovery, pupal weight, egg hatch, number of eggs/female per day, net reproductive rate and intrinsic rate of increase. Therefore, during a short oviposition period, the LSs had a high fecundity. There were no differences in pupation at 24 h and larval weight between the WS and LS. However, the values of parameters, adult emergence, female and male life expectancies, age at first oviposition, oviposition and post-oviposition periods and mean generation time were the highest in the WS.

Bactrocera invadens Drew, Tsuruta & White and Ceratitis fasciventris (Bezzi) are the major fruit fly pests of fruits and vegetables in Africa. The effects of two types of larval diet, liquid and solid (carrot based), on various quality control parameters (pupal recovery, pupal weight, adult emergence, flight ability, fecundity and fertility) of the two fruit fly species were investigated for five generations. The potential to replace two imported ingredients (yeast and wheat germ oil) with inexpensive and locally available alternatives was also explored. Most of the quality control parameters evaluated (pupal recovery, pupal weight, adult emergence and fecundity) for B. invadens reared on a liquid diet outperformed those reared on the carrot-based solid diet. In contrast, even though C. fasciventris was able to develop successfully on the liquid diet, three of the quality control parameters evaluated (pupal recovery, pupal weight and fecundity) were significantly lower over the generations when compared with those from insects reared on a solid diet. Except for flight ability, the parameters of B. invadens reared on the diets subsituted with the local yeast were of lower quality compared with those reared on the liquid diet containing the imported yeast. Corn (maize) and soybean oils were promising substitutes for wheat germ oil in the liquid larval diet of B. invadens without compromising any of the quality control parameters.

The objective of this study was to determine whether a generic diet could be developed for three species of Anastrepha: A. ludens, A. obliqua and A.serpentina. Laboratory and mass-rearing tests to assess the suitability of the A. ludens (Loew) (ALU) diet, normally used for rearing A. ludens, indicated that it was also suitable for rearing A. obliqua (Macquart) and A. serpentina (Wiedemann). Therefore, this diet appeared to be a suitable generic diet for the three species based on quality control parameters. In comparison with those observed when rearing larvae on the commonly used A. obliqua diet, the number of A. obliqua larvae recovered per g diet increased from 4.2 to 5.1, larval weight increased from 17 to 18.2 mg, pupation after 24 h from 89.3 to 96.9%, adult emergence from 91.5 to 93.7% and flight ability (% of fliers) from 86.1 to 90.4% when reared on the ALU diet. Usually, A. serpentina larvae are reared on the A. serpentina diet, but when reared on the ALU diet, larval recovery increased from 61.8 to 69.8%, number of larvae recovered per g diet from 3.7 to 4.4, larval weight from 21.7 to 23.8 mg and flight ability from 64.6 to 70.2%. These results show that the nutritional requirements of the three Anastrepha species are similar. The use of a generic diet for rearing the three species requires only one line to prepare the diet, reducing time and labour costs.

Fatty-acid and energy content of Maja brachydactyla eggs at different developmental stages (recently spawned, half-developed and ready to hatch) were analysed in order to understand what is being consumed and produced during the embryonic development. Egg volume increased during development (34%, 0.187 to 0.285 mm3, N = 270) and was negatively correlated with egg energy and fatty-acid content (r = −0.80 and r = −0.46, respectively), which decreased through embryogenesis. The most consumed fatty acids were the PUFA (21.2 μg · mg dw−1), followed by the SFA (18.8 μg · mg dw−1) and MUFA (14.9 μg · mg dw−1). Palmitic (16:0), oleic (18:1n-9) and eicosapentaenoic (EPA, 20:5n-3) acids were preferentially consumed (13.14, 9.21 and 8.67 μg · mg dw−1, respectively). The fatty acid composition found in M. brachydactyla eggs reflected the habitat and omnivorous and detritivorous scanvenger diet of the adults, although the consumption of algae was more important than previously thought, at least in the area where these adults were captured. Pre-hatching eggs have a high PUFA content (64.5 μg · mg dw−1 or 46.3% of the egg fatty-acid content). We conclude that larvae of this species might need a diet rich in PUFA, particularly EPA and DHA, for successful development. From the culture perspective, live preys commonly used in aquaculture will likely require to be enriched with DHA.

The influence of larval diet, body weight at imago, size of blood-meal and age on the fecundity of Culex quinquefasciatus was investigated. The mean weights of mosquitoes at adult emergence varied significantly with larval diet. Larvae reared on liver diet grew into heavier adults, and produced more eggs than those reared on milk. The volume of blood engorged by the female mosquitoes apparently remains constant during each gonotrophic cycle. However, the number of eggs produced is a function of both the blood-meal size and age of the mosquitoes. These results were discussed in relation to the need for full knowledge of the reproductive potential of this species of filaria vectors.