Comparing longevity of Pseudacteon species of different sizes: effect of sugar feeding

Abstract

Sugar feeding is known to enhance lifespan in many parasitoid species. Several species of phorid flies in the genus Pseudacteon (Diptera: Phoridae) have been introduced in the Southern U.S.A. for the biological control of imported fire ants of Solenopsis species (Hymenoptera: Formicidae). Pseudacteon species are short‐lived flies and little is known about their nutritional ecology. Results from previous studies in our laboratory show that one of the introduced species, Pseudacteon tricuspis Borgmeier, is capable of feeding on sugar sources with a significant increase in lifespan. However, in Pseudacteon phorid flies, the degree to which sugar feeding can enhance the lifespan of other species is not clear, nor is it known whether there is a relationship between body size and longevity. In the present study, the effect of sugar feeding on the survival of three phorid fly species of different body sizes, Pseudacteon cultellatus Borgmeier, Pseudacteon curvatus Borgmeier and Pseudacteon obtusus Borgmeier, is investigated. For all three species, flies continuously provided with 40% or 20% sucrose solution live longer than individuals provided water only or 40% sucrose solution only on the first day of adult life. However, the degree to which sugar feeding enhanced longevity varies by species and is highest for P. obtusus. The data also indicate that longevity in Pseudacteon phorid flies is related to body size: the largest species (P. obtusus) lives significantly longer than the smaller species (P. cultellatus and P. curvatus). These results suggest that adults of all three Pseudacteon species are capable of feeding on sucrose solution and that sugar feeding can enhance their longevity. The significance of these results is discussed in relation to the field performance of Pseudacteon phorid flies as biological control agents of imported fire ants.

Pseudacteon Phorid Flies: Host Specificity and Impacts on Solenopsis Fire Ants

“…The adult flies live only a few days in the laboratory, but their life span in nature is unknown (67,94). However, sugar feeding can considerably enhance the life span of adult phorid flies for approximately 4-15 days in the laboratory (1,23,31). Under field conditions, phorid flies may encounter and feed on nectar and/or honeydew sources, as they are capable of utilizing cotton aphid honeydew with an approximately 1-day increase in adult longevity (20,30,53).…”

Biology of Pseudacteon Decapitating Flies (Diptera: Phoridae) That Parasitize Ants of the Solenopsis saevissima Complex (Hymenoptera: Formicidae) in South America

“…As completely starved flies rarely live beyond one day, provision of water increases longevity by two days in the laboratory [24]. Sugar feeding can further increase the longevity considerably depending on rearing temperature and fly activity [24][25][26]. The ability to digest monosaccharide sugars (fructose, glucose) and disaccharide sugars (sucrose, trehalose) may explain significant but modest increase in longevity of P. tricuspis feeding on cotton aphid honeydew [27,28]; therefore, phorid flies can be expected to feed on nectar and/or honeydew sources in field.…”

Effects of Food Source Availability, Host Egg:Parasitoid Ratios, and Host Exposure Times on the Developmental Biology of Megacopta cribraria Egg Parasitoids

“…Several studies have shown that the presence of adult food sources maximizes the reproductive success of parasitoids by influencing emergence, female: male ratio, and longevity [ 9 , 10 , 11 , 12 ]. A carbohydrate-rich diet in animals can lead to a rise in glucose content in the follicular fluid, which increases the number and size of ovarian follicles [ 13 ].…”