Ultrastructure of the antennal sensilla of aphids

Abstract

An electron microscopical study of aphid antennal sensilla has revealed two types of trichoid sensilla. Type I, innervated by a single neuron is mechanoreceptive; type II, innervated by three to five neurons is both mechanoreceptive and chemoreceptive with possibly a third function. Johnston's organ in the pedicel comprises a peripheral ring of scolopidia inserted into the joint with the flagellum; two non-peripheral groups of scolopidia lie in the lumen with attachment points in the wall of the third segment. The fine structure of a campaniform sensillum on the pedicel is described together with two homologous and previously unknown sense organs at the joint between the fifth and sixth antennal segments. An unusually placed scolopidium in the lumen of the sixth segment has also been found. The function of this scolopidium is unknown but Johnston's organ, the campaniform sensillum and joint receptors are suggested to act as antennal proprioceptors.

Recent advances in insect olfaction, specifically regarding the morphology and sensory physiology of antennal sensilla of the female sphinx moth Manduca sexta

“…Similar aporous sensilla were characterized as bimodal thermo-hygrosensilla by Yokohari (1981Yokohari ( , 1983 and Altner et al (1978Altner et al ( , 1981. Aporous coeloconic sensilla have also been described in several insects, such as aphids (Bromley et al, 1979), grasshoppers (Altner et al, 1981;Ameismeier, 1985), walking sticks (Altner et al, 1978), and mosquitoes (Boo and McIver, 1975;McIver and Siemicki, 1979).…”

Bridging the gap between chewing and sucking in the hemipteroid insects: <br />new insights from Cretaceous amber

“…Lienhard 1998). Furthermore, annulated flagellomeres are also observed in Thysanoptera (Mound & Masumoto 2009) and Hemiptera (Bromley et al 1980;Akimoto 1983) and this feature cannot be regarded as an autapomorphy of the Psocodea but as highly homoplastic or as belonging to the paraneopteran ground plan. The placement of Archipsyllidae in the Psocodea clade ) is therefore unjustified.…”

Mechanosensitive and Olfactory Sensilla of Insects

“…Resistance to mechanical stress and water loss, compatibility with flight aerodynamics, as well as structural limitations imposed by the need for grooming, may suppress the formation of odor sieves and also change the form and distribution of sensilla (see Kaissling, 1971, for examples). Thus, the cuticular hair may even be totally transformed into pore plates more or less flush with the antennal surface as in Hymenoptera (for references see Stepper et al, 1983;Schmidt and Kuhbandner, 1983), Homoptera (for references see Lewis and Marshall, 1970;Bromley et al, 1979), or lamellicorn beetles. In the latter group, Meinecke (1975) studied the inventory of olfactory sensilla of 42 species and found an impressive variety of cuticular structures showing morphological transitions in parallel with the presumed evolutionary lineage.…”