Abstract
Diaphorina citri Kuwayama is the most economically important citrus pest which is the primary vector of Candidatus Liberibacter spp. causing citrus greening (huanglongbing, HLB) disease. To better understand the developmental and structural changes of antennae and antennal sensilla in D. citri nymphs, we investigated the antennal morphology, structure and sensilla distribution of the five nymphal stages of D. citri using scanning electron microscopy. The antennae of the five different nymphal stages of D. citri were filiform in shape, which consisted of two segments in the first-, second- and third-instar nymphs; three segments in the fourth- and fifth-instar nymphs. The length of their antennae was significantly increased with the increase of the nymphal instar, as well as the total number of antennal sensilla. Ten morphological sensilla types were recorded altogether. They were the long terminal hair (TH1), short terminal hair (TH2), sensilla trichoidea (ST), cavity sensillum 1 (CvS1), cavity sensillum 2 (CvS2), sensilla basiconica 1-3 (SB1-3), sensilla campaniform (SCA) and partitioned sensory organ (PSO). Also, the distribution of antennal sensilla in each nymphal stage of D. citri was asymmetrical. The SBs only occurred on the antennae of the third-, fourth- and fifth-instar nymphs. Only one CvS2 was found in the third- and fifth-instar nymphs, and one SCA in the fourth- and fifth-instar nymphs, respectively. The possible roles of the nymphal antennal sensilla in D. citri were discussed. The results could contribute to a better understanding of the development of the sensory system, and facilitate future studies on the antennal functions in D. citri nymphs.
Highlights
The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is the most economically important citrus pest because it is the primary vector of Candidatus Liberibacter spp. causing citrus greening disease, the most serious citrus disease worldwide [1,2]
The antennae of D. citri nymphs were observed when individuals were fixed in a ventral position and looking at the region located between the compound eyes
The antennae of the first, second- and third-instar nymphal stages of D. citri were composed of two segments (Fig 1A, 1B and 1C), whereas the fourth- and fifth-instar nymphal antennae consisted of three parts: two basal segments and the flagellum with poorly defined subsegments (Fig 1D and 1E)
Summary
The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is the most economically important citrus pest because it is the primary vector of Candidatus Liberibacter spp. causing citrus greening (huanglongbing, HLB) disease, the most serious citrus disease worldwide [1,2]. Diaphorina citri apparently originated in southern Asia, but has spread to other world citrus-producing areas [2]. More than 50 species of the family Rutaceae have been recorded as hosts of D. citri [3]. Nymphs and adults suck phloem sap from the foliage. Antennal sensilla ultrastructure of various nymphal stages of Diaphorina citri
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
