Scanning electron microscopy of sensilla on the labial and maxillary palps of adult Callidiellum villosulum Fairmaire (Coleoptera: Cerambycidae)

Abstract

This study used scanning electron microscopy (SEM) to observe the morphology and sensilla of the labial and maxillary palps of adult Callidiellum villosulum Fairmaire between sexes. Combining behavioral activities may provide an effective control target for this pest. In this study, the results showed that there were three segments on the labial palps and four segments on the maxillary palps. The length and width of each segment of the labial and maxillary palps were significantly larger in females than in males. Four types of sensilla were found on the labial and maxillary palps of both sexes of adult C. villosulum: sensilla basiconica (SB I, II, III, and IV), sensilla chaetica (SCh I and II), sensilla placodea (SP), and sensilla campaniformia (SCa). SB IV, SCa, and Sh II were significantly more developed on female labial and maxillary palps than on males', which may be related to their oviposition behavior. By contrast, SB I was more significantly developed on males than on females, which may be related to their mating selection. At the same time, for both sexes, the numbers of Sh I and Sh II on the maxillary palps were significantly higher on labial palps. Maxillary palps could be inferred to potentially play a more important role than the labial palps in the activities of adult C. villosulum. Results will help us further understand the host selection and egg‐laying behavior of adult C. villosulum. Such an understanding shall greatly promote the information‐based design of pest control methods.

Morphological comparison of the sensilla on the maxillary and labial palps between male and female adults of Moechotypa diphysis (Coleoptera: Cerambycidae)

“…As the feeding organ of insects, mouthparts are always considered to be the most important sensing organ to locate host, identify mate, and help the insects to select food (Bernays & Chapman, 2001; Chapman, 2003; Schoonhoven & Loon, 2002). The realization of these specific functions of mouthparts depends on the morphology and distribution of receptors, which can help to improve the specific behavior of insects that is related to the gustatory perception (Labandeira, 1997; Merivee et al, 1999; Ren et al, 2014; Wu et al, 2021).…”

“…The maxillary and labial palps are the main components of the insect mouthparts. They are usually used to contact chemosensory signals and are densely covered with the gustatory sensilla (Hall et al, 2019), which are responsible for receiving a variety of stimuli (Hu et al, 2020; Lu et al, 2011; Shi et al, 2021; Wu et al, 2021). The ultrastructural features of the maxillary and labial palps have been observed by the application of scanning electron microscope (SEM), such as largidae, fruit fly, and plant hopper (Coronado‐Gonzalez et al, 2008; Garzo et al, 2012; Hao et al, 2016; Wang et al, 2020).…”

“…For example, when the longhorn beetle females try to choose the oviposition site, they usually use the maxillary and labial palps to interact with the bark and the sap to determine whether the plant is suitable for laying egg (Zhang et al, 2018). However, as far as we know, the detailed descriptions about the sensilla on the maxillary and labial palps are only limited in a few species such as Callidiellum villosulum (Wu et al, 2021) and Xylotrechus grayii (Chen et al, 2018). Expanding the study about the sensilla on the maxillary and labial palps of longhorn beetles will help to reveal the complex sensing mechanism of Cerambycidae (Ren et al, 2014).…”

“…of insects that is related to the gustatory perception (Labandeira, 1997;Merivee et al, 1999;Ren et al, 2014;Wu et al, 2021).…”

“…The maxillary and labial palps are the main components of the insect mouthparts. They are usually used to contact chemosensory signals and are densely covered with the gustatory sensilla (Hall et al, 2019), which are responsible for receiving a variety of stimuli (Hu et al, 2020;Lu et al, 2011;Shi et al, 2021;Wu et al, 2021).…”