Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Jan 21;27(3):713.
doi: 10.3390/molecules27030713.

The Bright Side of the Tiger: Autofluorescence Patterns in Aedes albopictus (Diptera, Culicidae) Male and Female Mosquitoes

Anna C Croce  1   2 , Francesca Scolari  1   2
Affiliations

The Bright Side of the Tiger: Autofluorescence Patterns in Aedes albopictus (Diptera, Culicidae) Male and Female Mosquitoes

Anna C Croce et al. Molecules. .

Abstract

Light-based events in insects deserve increasing attention for various reasons. Besides their roles in inter- and intra-specific visual communication, with biological, ecological and taxonomical implications, optical properties are also promising tools for the monitoring of insect pests and disease vectors. Among these is the Asian tiger mosquito, Aedes albopictus, a global arbovirus vector. Here we have focused on the autofluorescence characterization of Ae. albopictus adults using a combined imaging and spectrofluorometric approach. Imaging has evidenced that autofluorescence rises from specific body compartments, such as the head appendages, and the abdominal and leg scales. Spectrofluorometry has demonstrated that emission consists of a main band in the 410-600 nm region. The changes in the maximum peak position, between 430 nm and 500 nm, and in the spectral width, dependent on the target structure, indicate the presence, at variable degrees, of different fluorophores, likely resilin, chitin and melanins. The aim of this work has been to provide initial evidence on the so far largely unexplored autofluorescence of Ae. albopictus, to furnish new perspectives for the set-up of species- and sex-specific investigation of biological functions as well as of strategies for in-flight direct detection and surveillance of mosquito vectors.

Keywords: antennae; chitin; imaging; maxillary palps; melanin; resilin; scales; sexual dimorphism; spectrofluorometry.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Head structures in Ae. albopictus adult females. (A) Bright field light view of the dorsal female head showing proboscis (pr), maxillary palps (mp) and antennae (a) departing from the head capsule (hc). (B) Fluorescent light view of the dorsal female head. Labella (la). (C) Fluorescent light view of the maxillary palps (mp). Bright field (D) and fluorescent (E) light view of the labella. Bars: 250 μm (A,B); 60 μm (C); 30 μm (D,E).
Figure 2
Figure 2
Head structures in Ae. albopictus adult males. (A) Bright field light view of the dorsal male head showing proboscis (pr), maxillary palps (mp) and antennae (a) departing from the head capsule (hc). (B) Fluorescent light view of the dorsal male head. Labella (la). (C) Fluorescent light view of the distal portion of a maxillary palp. Bright field (D) and fluorescent (E) light view of the terminus of a maxillary palp. Bright field (F) and fluorescent (G) light view of the labella. Bars: 360 μm (A,B); 90 μm (C); 25 μm (D,E); 40 μm (F,G).
Figure 3
Figure 3
Ae. albopictus adult female antenna. Bright field light view of the antenna, with inserts showing the AF in the flagellomer joints and in the sensilla. Sensilla chaetica (SCh); sensilla trichoidea (STr); short grooved peg (Gp) sensilla. Bar: 100 μm.
Figure 4
Figure 4
Ae. albopictus adult male antenna. Bright field light view of the antenna with inserts showing the AF in flagellomers 1 to 11 and in the sensilla, especially those located on the terminal flagellomer. Sensilla chaetica (SCh) arising from their sockets; sensilla trichoidea (STr). Bar: 100 μm.
Figure 5
Figure 5
Abdominal scales in adult Ae. albopictus females. (A) Bright field and (B) AF view of dorsal abdominal segments. (C) Enlarged view of the dorsal abdominal scales indicated by the dashed box in (B). (D) Bright field and (E) AF view of a portion of the ventral sternites with scales. Ventral (V) and dorsal (Do) sides. Scale bars: 110 μm (A,B); 20 μm (C–E).
Figure 6
Figure 6
Abdominal scales in adult Ae. albopictus males. (A) Bright field and (B) AF view of dorsal abdominal segments. (C) Bright field and (D) AF lateral view of dorsal abdominal segments. (E) Bright field and (F) AF view of a portion of the ventral sternites with scales. (G) Bright field and (H) AF enlarged view of ventral abdominal scales. Ventral (V) and dorsal (Do) sides. Scale bars: 50 μm (A–D); 60 μm (E,F); 30 μm (G,H).
Figure 7
Figure 7
Hindleg tarsal scales in adult Ae. albopictus females. (A) Bright field and (B) AF view of a hindleg tarsus (T). (C) Bright field and (D) AF view of the third, fourth and fifth basal bands. (E) Bright field and (F) AF enlarged view of the fifth tarsomere. Scale bars: 400 μm (A,B); 300 μm (C,D); 80 μm (E,F).
Figure 8
Figure 8
Hindleg tarsal scales in adult Ae. albopictus males. (A) Bright field and (B) AF view of a hindleg tarsus (T). (C) AF view of the fluorescent scales of tarsomere 1. (D) AF view of the fluorescent scales of tarsomere 3. (E) Enlarged view of tarsomere 5. Scale bars: 400 μm (A,B); 60 μm (C,D); 30 μm (E).
Figure 9
Figure 9
Typical examples of the AF spectra recorded from labella (A), maxillary palps (B), antennal elements (C), abdominal scales (D,E) and hindleg tarsi (F) of Ae. albopictus adult females and males. Spectra are normalized to the maximum peak intensity (100%) to better compare emission profiles. Spectra from females or males, or from selected structures, are identified by colors, as reported in the inlet legend on the right.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Udenfriend S. In: Fluorescence Assay in Biology and Medicine. 1st ed. Horecker B., Kaplan N.O., Marmur J., Scheraga H.A., editors. Vol. 2. Academic Press; New York, NY, USA: London, UK: 1969. pp. 195–404.
    1. Croce A.C. Light and autofluorescence, multitasking features in living organisms. Photochem. 2021;1:67–125. doi: 10.3390/photochem1020007. - DOI
    1. Lagorio M.G., Cordon G.B., Iriel A. Reviewing the relevance of fluorescence in biological systems. Photochem. Photobiol. Sci. 2015;14:1538–1559. doi: 10.1039/C5PP00122F. - DOI - PubMed
    1. Marshall J., Johnsen S. Fluorescence as a means of colour signal enhancement. Philos. Trans. R. Soc. B Biol. Sci. 2017;372 doi: 10.1098/rstb.2016.0335. - DOI - PMC - PubMed
    1. Abels J.P., Ludescher R.D. Native fluorescence from juvenile stages of common food storage insects. J. Agric. Food Chem. 2003;51:544–549. doi: 10.1021/jf020775m. - DOI - PubMed

Substances

LinkOut - more resources