Effect of High and Low Concentrations of Sugar Solutions Fed to Adult Male, Phormia regina (Diptera: Calliphoridae), on ‘Bubbling’ Behavior

Abstract

‘Bubbling’ behavior, or the regurgitation of liquid from the crop through droplet formation on the proboscis, has been observed in many nonblood feeding dipterans. One factor that has been identified as a cause for ‘bubbling’ is the concentration of the solution flies ingest. The hypothesis presented in this paper states that male flies ingesting more dilute solutions will exhibit more bubbling behavior than those that ingest a less dilute solution. Concentrations tested were a high concentration of 80% sucrose solution and a low concentration of 20% sucrose solution. Males only were tested to avoid any confounding effect of the females need for energy sources for reproduction. Male flies that ingested the 80% sugar solution showed 45% of the flies tested bubbling, which was significantly different from the flies that ingested 20% solution, which had only 5% of the flies bubbling. No significant weight loss or percentage of weight loss was observed between bubbling and nonbubbling flies for either sugar solution concentration. Results comparing a high and low concentration of sucrose do not support the theory of elimination of excess water loss to concentrate dilute solutions or the “dilute solution hypothesis”. Other factors, not identified previously, that could contribute to bubbling, are changes in osmolality, utilization of blood sugar (i.e., trehalose), and the regulation of the proventricular valve.

Droplet bubbling evaporatively cools a blowfly

“…Indeed, behaviours sharing resemblance to bubbling have been associated to evaporative cooling in bumblebees 25 , hawk moths 26 , sawfly larvae 27 , and mosquitoes 28 . The thermoregulatory function of bubbling in Diptera, although suggested in the past 18 , was almost entirely discredited later on in favour of a more widely accepted role in food-processing 17 , 19 , 20 , 29 . Our study, however, provides strong evidence for the fact that bubbling does indeed play a relevant role in T b regulation.…”

Nectar concentrating behavior by bees (Hymenoptera: Anthophila)

“…This behavior -generally referred to as "bubbling"shares many similarities with nectar concentrating in bees, including the regurgitation of a droplet of fluid and the repeated extrusion and retraction of the mouthparts (Thomas 1991;Hendrichs et al 1992;Stoffolano et al 2008). Experimental and observational evidence generally supports the hypothesis that this behavior is performed to eliminate excess water rather than to aid in thermoregulation (Hendrichs et al 1992, Robynne de Wet 2007, Stoffolano et al 2008, but see Larson and Stoffolano 2011).…”

DNA barcoding and the differentiation between North American and West European Phormia regina (Diptera, Calliphoridae, Chrysomyinae)

“…Hence, the strong mtDNA divergence between N American and W European Phormia regina requires a sound comparison of the ecology of populations from both continents, especially since Phormia regina is a key species in the study of the physiology and neurology of insect feeding (e.g. Haselton et al 2009 , Larson and Stoffolano 2011 , Ishida et al 2012 ). Moreover, if locally diverged populations differ in their developmental biology, then this may affect the estimate of PMImin.…”