Types and numbers of sensilla on antennae and maxillary palps of small and large houseflies, Musca domestica (Diptera, Muscidae)

Abstract

Houseflies, Musca domestica, obtained from a high-larval-density culture were significantly (ca. 1.5 times) smaller than those from a low-larval-density culture. The same held true for their antennae and maxillary palps. Structure, number, and distribution of sensilla on antennae and palps of small and large flies were investigated using Scanning electron microscopy and Transmission electron microscopy. In each funiculus three pits were present, two (Type I) consisting of several compartments and one (Type II) of one compartment. Four types of olfactory sensilla were detected: trichoid sensilla on the funiculi, basiconic sensilla on funiculi and palps, grooved sensilla on funiculi and in pits Type I, and clavate sensilla on funiculi and in pits Type II. Type I pits also contained striated sensilla (presumably hygroreceptors). Mechanosensory bristles were present on scapes, pedicels, and palps. Noninnervated microtrichia were found on the palps and all antennal segments. The large houseflies possessed nearly twice as much sensilla as the small flies. So far, we did not observe differences in behavior between small and large flies. We assumed that small flies, being olfactory less equipped than large flies, may be able to compensate for this by, e.g., visual cues or by their olfactory sensilla being more sensitive than those of large flies. To be able to answer these questions careful studies have to be done on the behavioral responses of small and large flies to environmental stimuli. In addition, electrophysiological studies should be performed to reveal whether the responses of individual sensilla of flies reared under different conditions have been changed.

Morphological Characterization and Distribution of Sensilla on Maxillary Palpi of SixBactroceraFruit Flies (Diptera: Tephritidae)

“…cucurbitae, B. diaphora, B. dorsalis, B. minax, B. scutellata, and B. tau. The results in this study generally conform to those previously reported for other dipteran species (Sukontason et al 2003;Wasserman & Itagaki 2003;Spiegel et al 2005;Ngern-Klun et al 2007;Sukontason et al 2007;Chen & Fadamiro 2008;Smallegange et al 2008).…”

“…The MI are the most abundant on the maxillary palpi of both sexes of the 6 species. They were classified as non-innervated structures in some insect species (Fernandes et al 2002(Fernandes et al , 2004Sukontason et al 2007;Smallegange et al 2008). The microtrichia are most often described as mechanoreceptors associated with antennal structures (Hull & Cribb 1997;Siddiqui et al 2010), and specifically associated with dipteran antennae (Castrejon-Gomez & Rojas 2009; Arzuffi et al 2008;Chen & Fadamiro 2008;Fernandes et al 2002;Sukontason et al 2004Sukontason et al , 2007.…”

Ultrastructure of antennal and posterior abdominal sensilla in Chlorophorus caragana females

“…Female insects locate hosts by means of complicated behaviors in which sensilla play important sensing roles. For many insects, the antenna are important for olfaction, and sensilla distributed on the ovipositors are often used in oviposition behavior (Rice et al, 1973;Smallegange et al, 2008;Spänhoff et al, 2003a;Spiegel et al, 2005;Sukontason et al, 2007).…”

Ultrastructure of antennal sensory organs of horse nasal-myiasis fly, Rhinoestrus purpureus (Diptera: Oestridae)

“…Trichoid sensilla, as one of the basic type of antennal sensilla in many other flies (Ross 1992;Shanbhag et al 1995;Hunter and Adserballe 1996;Shanbhag et al 2000;Sukontason et al 2004Sukontason et al , 2007Smallegange et al 2008;Liu et al 2013;Zhang et al 2013a, b), are undiscovered in R. purpureus. In some hippoboscids (Hippobosca equina, Hippobosca longipennis, Melophagus ovinus) (Zhang et al 2015) and phorids (Megaselia scalaris) (Loew) (Sukontason et al 2005), trichoid sensilla are also absent.…”

“…As the crucial sensory organs involved in feeding, mating, and spawning (Fernandes et al 2005;Amer and Mehlhorn 2006;Smallegange et al 2008;Guha et al 2012;Wang et al 2012), antennal sensilla of flies have managed to evolve various features to enhance their sensitivity and adaptability to the ever-changing environment (Ross 1992;Sukontason et al 2004;Zhang et al 2012aZhang et al , b, 2013aWang et al 2014). Little is known about the antennal sensilla of adult R. purpureus.…”