Antennal morphology and sensillum distribution of female cotton leaf worm Spodoptera littoralis (Lepidoptera: Noctuidae)

Abstract

Female cotton leaf worm Spodoptera littoralis (Biosduval) is highly dependent on its antennal sensory structures for host location for feeding or oviposition. The external structure, number, and distribution of the antennal sensilla of female S. littoralis were examined with light and scanning electron microscopy. The antenna of adult female is filiform, composed of a scape, a pedicel and a flagellum. The flagellum has 65-80 segments densely packed with sensilla distributed on the ventral surface and lateral edges of the flagellum except the dorsal surface which is packed with scales. Eight types of sensilla; trichodea, basiconica, auricillica, coeloconica, uniporous peg, chaetica, styloconica, and squamiformia were detected. Total number of antennal sensilla varied among different antennal portions. Proximal segments showed significantly more short trichoid and basiconic sensilla than distal ones, while distal segments have the longest sensilla chaetica. Last antennal segment carries the higher number of sensilla chaetica than other segments and ends with an apical crown which has 1-3 branches, each is endowed with 4-6 apical aporous sensilla styloconica. The possible function of the antennal sensilla is discussed in relation to their morphology. ª 2015 The Egyptian German Society for Zoology. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Insight Into the Ultrastructure of Antennal Sensilla ofMythimna separata(Lepidoptera: Noctuidae)

“…S. chaetica were found distributed around each antennal segment of M. separat a except the last segment which had a higher number of s. chaetica, and the similar distribution of this sensilla have been reported in Pseudaletia unipuncta ( Flower and Helson 1974 ), Helicoverpa armigera ( Diongue et al. 2013 ), and Spodoptera littoralis ( Seada 2015 ). S. chaetica were in general recognized as mechnoreceptors ( Keil and Steinbrecht 1984 ), while as uniporous (terminal pore) sensilla, it also have been suggested to have contact/chemoreceptor functions ( Seada 2015 ).…”

“…2013 ), and Spodoptera littoralis ( Seada 2015 ). S. chaetica were in general recognized as mechnoreceptors ( Keil and Steinbrecht 1984 ), while as uniporous (terminal pore) sensilla, it also have been suggested to have contact/chemoreceptor functions ( Seada 2015 ). And the characteristic that s. chaetica were significantly higher and wider than other sensilla suggests that this sensilla might have a protection role for other sensilla except as mechnoreceptors or contact/chemoreceptors.…”

Age influences the olfactory profiles of the migratory oriental armyworm mythimna separate at the molecular level

“…However, 14 gustatory receptor genes were identified in M. separate antennae, indicating that the antennae might be an important taste organ for M. separata . As shown in a former study, sensilla chaetica were distributed around each antennal segment of M. separata [14], which was with a terminal pore and with a shape that was higher and wider than that of other sensilla and have been suggested to have contact/chemoreceptor functions [49]. Sugar as the supplementary nutrient is essential for egg-ripening [8] and as the energy supplement influences the duration of migration [9].…”

Morphological Characterization of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae: Heliothinae)

“…Most noctuids have filiform antenna that are similar in general structure. These structures have several kinds of sensory setae, which can capture information on temperature, humidity, olfactory, and sexual pheromones (Jefferson et al 1970;Hardwick 1970;Castrejón-Gómez et al 1999;Seada 2015). No morphological differences were found between male and female antennae, an aspect also observed by Diongue et al (2013) in their study of types and functions of sensory setae of antennomeres.…”