Characterization of development, behavior and neuromuscular physiology in the phorid fly, Megaselia scalaris

Abstract

The Phoridae is known as 'scuttle flies' because they walk in rapid bursts of movement with short pauses between. In this study, larval locomotive behavior and development was characterized in the phorid, Megaselia scalaris. Comparison was made with the well-characterized fruit fly model, Drosophila melanogaster. Developmentally, the rate of maturation was consistently slower for Megaselia than Drosophila. This disparity was exaggerated at lower temperatures, particularly during larval development. In addition to slower growth, movements in Megaselia were also slower, as evidenced by reduced rates of larval body wall contractions and mouth hook movements. Megaselia larvae also displayed a unique behavior of swallowing air when exposed to a small pool of liquid. This permitted floating upon immersion and, therefore, might prevent drowning in the natural environment. The anatomical and physiological properties of a neuromuscular junction in the phorid larvae were also examined. The innervation of the motor nerve terminals on the ventral abdominal muscle (m6) is innervated by Type Ib and Is axons, similar to Drosophila. As in Drosophila, the Is terminals produce larger excitatory postsynaptic potentials (EPSPs) than the Ib. The amplitudes of the EPSPs in M. scalaris were reduced compared to those of D. melanogaster, but unlike D. melanogaster the EPSPs showed marked facilitation when stimulated with a 20 Hz train. We conclude that there may be differences in synaptic structure of the nerve terminals that could account for the different electrophysiological behaviors. ᮊ

Laboratory Identification of Arthropod Ectoparasites

“…Patients will often present larvae collected from their toilets and bath tubs with the concern that they were shed in their stool or urine. These flies are usually saprophagous (111)(112)(113)(114)(115), and there is no true evidence of them causing pathology in the human host. The most common fly larvae seen in these scenarios are drain flies (Psychodidae) and rat-tailed maggots (Syrphidae).…”

A Laboratory-Based Study for First Documented Case of Urinary Myiasis Caused by Larvae of Megaselia scalaris (Diptera: Phoridae) in Saudi Arabia

“…Megaselia scalaris is a small hump-backed fly with characteristic rapid jerky movements on surfaces, hence the common name is the scuttle fly [3,6]. The females are highly attracted by strong odors and lay their eggs on deferent decomposing materials including feces, flesh, vegetables, and fruits.…”

“…The fifth larva was crushed and examined microscopically as a wet mount with saline, and then certain parts were transferred onto another slide, allowed to air dry, fixed with methanol, and finally stained with 10% (v / v) Giemsa stain. Identification of larvae and adult flies was done according to keys described by previous workers [2][3][4][5].…”

“…3). According to the description in previous workers, the larvae were assumed as the first and second-instar larvae of M. scalaris [2][3][4][5].…”

Actions of MDMA at glutamatergic neuromuscular junctions

“…Selective stimulation to the axons that give rise to the Ib and the Is terminals was produced by altering the stimulus intensity and duration while monitoring the EPSP amplitudes in m6. Since the EPSP amplitudes are reflective of the type of terminal responding this measure was used (Harrison and Cooper, 2003;Kurdyak et al, 1994). The physiological solution, HL3, is the same as previously described .…”