CR Biologies

Wilson R. Lourenço

Andrea Rossi

The cave population of Chaerilus Simon, 1877 from Palawan, Philippines, and description of a new species (Scorpiones: Chaerilidae)

Jean-François Bach

Causality in medicine

Hira Saleem

Qurat ul Ain Kokab

Yasir Rehman

Arsenic respiration and detoxification by purple non-sulphur bacteria under anaerobic conditions

Nicolas Bacaër

Sur la taille finale des épidémies dans un environnement périodique

Faïza Masmoudi-Allouche

Walid Kriaa

Noureddine Drira

Staminodes evolution and in vitro development innovation in date palm (Phoenix dactylifera L.)

Catherine Golstein

Pascal Boireau

Jean-Christophe Pagès

on behalf of the Scientific Committee of the High Council for Biotechnology in France

Insects: Friends, foes, and models/Insectes : amis, ennemis et modèles / C. R. Biologies 342 (2020) 247–278 269
Session V. Vector insects and transmission
of diseases
21
Do we have to get rid of
mosquitoes to eliminate
malaria?
Markus Gildenhardt , Elena Levashina ∗
Vector Biology Unit, Max Planck Institute for Infection Biology,
Berlin, Germany
∗ Corresponding author.
E-mail address: levashina@mpiib-berlin.mpg.de
(E. Levashina)
Malaria is a local disease with global impact. The fitness of
vector-borne Plasmodium parasites, the causative agents of
malaria, is closely linked to the ecology and evolution of its
mosquito vector. Ongoing adaptive radiation and introgression
diversify mosquito populations in Africa. However, whether
the genetic structure of vector populations impacts malaria
transmission remains unknown.
We discuss below new approaches that gauge the contribution
of mosquito species to Plasmodium abundance in nature, with a
particular focus on time-series analyses in the context of popu-
lation genetics and epidemiology [1]. Our data highlighted the
importance of focusing vector control strategies on mosquito
species that drive malaria dynamics.
Using time-series collections and the econometric approach
Granger causality, we demonstrated that the abundance of
Plasmodium-infected mosquitoes in a field site in Mali was
driven by only one of the two sympatric vectors (Fig. 1). This
mosquito species carried a susceptible allele of the known
antiparasitic gene TEP1 [2,3], and until now it was resistant to
colonization efforts and, therefore, is not the target of current
gene drive applications.
Extending such studies to other key components of vecto-
rial capacity and epidemiological and parasitological surveys
should ultimately identify patterns, tipping points, and gen-
eral laws that describe dynamics, emergence, and resurgence
of mosquito-borne diseases.
Fig. 1 Granger causality.
Disclosure of interest The authors declare that they have no
competing interest.
References
[1] M. Gildenhard, E.K. Rono, A. Diarra, et al., Mosquito
microevolution drives Plasmodium falciparum dynamics,
Nat. Microbiol. 4 (6) (2018) 941–947.
[2] S. Blandin, S.-H. Shiao, L.F. Moita, C.J. Janse, A.P. Waters, F.C.
Kafatos, et al., Complement-like protein TEP1 is a determi-
nant of vectorial capacity in the malaria vector Anopheles
gambiae, Cell 116 (2004) 661–670.
[3] S.A. Blandin, R. Wang-Sattler, M. Lamacchia, J. Gagneur, G.
Lycett, Y. Ning, et al., Dissecting the genetic basis of resis-
tance to malaria parasites in Anopheles gambiae, Science 326
(2009) 147–150.
https://doi.org/10.1016/j.crvi.2019.09.022
22
Human activities and climate
change in the emergence of
vector-borne diseases
Anna-Bella Failloux
Arboviruses and Insect Vectors Laboratory, Department of
Virology, Institut Pasteur, Paris, France
E-mail address: anna-bella.failloux@pasteur.fr
Because of human population expansion and activities,
arthropod-borne viruses (arboviruses) have increased in
importance during these last decades. Arboviruses are main-
tained by alternate replication in both vertebrate hosts and
arthropod vectors. Successful transmission relies on a complex
life cycle in the vector, which starts when a competent arthro-
pod ingests an infectious blood meal from a viremic vertebrate
host. Following an extrinsic incubation time during which the
virus replicates in the vector midgut, followed by systemic viral
dissemination to the salivary glands, the vector can transmit
the virus to a new naïve host. Whereas they typically cause self-
limiting, acute infections in their vertebrate hosts, arboviruses
establish persistent infections in their vectors.
Arboviruses are typically maintained within an enzootic cycle
between wild animals and vectors. As human populations
encroach on regions where these diseases are endemic,
spillover transmission to humans and domestic animals can
lead to large-scale disease outbreaks affecting millions of peo-
ple. Dengue, chikungunya, Zika, and yellow fever mainly use
humans as amplification hosts. Extensive urbanization com-
bined with increased commerce and travel give rise to the
mosquitoes Aedes aegypti and Aedes albopictus, both highly
adapted to the human environment. The high densities of these
human-biting mosquitoes that proliferate in highly populated
cities made the bed to explosive outbreaks of arboviral dis-
eases. As insects are ectothermic organisms, climate change
may affect the geographical distribution of vectors, with con-
sequences on the transmission of arboviruses.
Yellow fever (YF) is a good example of an emerging arbovirus,
as it illustrates three main steps in the emergence: (i) introduc-
tion of a new pathogen in a new environment causing urban
outbreaks, (ii) spillback of this pathogen into the wild initiating
an enzootic cycle, and (iii) the spillover of this pathogen from
an enzootic cycle to initiate an urban cycle (Fig. 1).
YF (YFV, Flavivirus, Flaviviridae) is a disease endemic to tropical
regions of Africa and South America. There are seven lineages:
five in Africa and two in America. Each year, 200,000 cases and
30,000 deaths were reported. In 2016, YFV emerged in Angola
and imported cases were detected outside Africa, posing the
threat of emergence of this virus outside Africa and Americas
(Amraoui et al. Euro Surveill 2016).
YFV was introduced into the New World during the slave trade,
causing devastating outbreaks in several American countries,
including cities like New York City and Boston. Once Carlos
Finlay and Walter Reed had demonstrated that the YFV was
transmitted by a mosquito, Ae. aegypti, eradication campaigns
of the vector were initiated, leading to the control of YF.
In Brazil, Ae. aegypti was eradicated in 1954. YF disappeared
from cities and only persisted in a sylvatic cycle where YFV
circulated between zoophilic mosquitoes (Hemagogus and
Sabethes) and non-human primates. Using experimental infec-
tions, we showed that the zoophilic mosquitoes (Hemagogus
leucocelaenus and Sabethes albiprivus) were able to transmit
YFV at very high rates (Couto-Lima et al. Sci Rep 2017). With
the relaxation of control measures in Brazil, Ae. aegypti was
reintroduced in 1967 and Ae. albopictus in 1986. We showed
that Ae. aegypti and Ae. albopictus were highly susceptible to
YFV. We also demonstrated that using a protocol of experi-
270 Insects: Friends, foes, and models/Insectes : amis, ennemis et modèles / C. R. Biologies 342 (2020) 247–278
mental selection, we were able to select a YFV well adapted to
a transmission by Ae. albopictus (Amraoui et al. Sci Rep 2018).
This result should alert about the potential of YFV to initiate an
urban cycle in Brazil, like in the past.
Fig. 1 The three main steps in the emergence of an arbovirus.
Disclosure of interest The author declares that she has no
competing interest.
https://doi.org/10.1016/j.crvi.2019.09.023
23
Benefits and limitations of
emerging techniques for
mosquito vector control
Catherine Golstein ∗,1, Pascal Boireau1,2,
Jean-Christophe Pagès1,3,
on behalf of the Scientific Committee of the High Council for
Biotechnology in France
1 Haut Conseil des biotechnologies (HCB, High Council for
Biotechnology), Paris, France
2 Anses, Maisons-Alfort, France
3 François Rabelais University, Tours, France
∗ Corresponding author.
E-mail address:
catherine.golstein@hautconseildesbiotechnologies.fr
(C. Golstein)
In response to a broad governmental referral, the French High
Council for Biotechnology has published an opinion on the use
of genetically modified (GM) mosquitoes for vector control [1].
Emerging techniques of vector control were developed to over-
come (i) the lack of therapies, preventive treatments and
vaccines for most mosquito-borne diseases, and (ii) the limi-
tations of existing vector control techniques (the situation is
particularly critical regarding insecticides: in France, essen-
tially only one insecticide is used against adult mosquitoes
(deltamethrin), and its efficacy decreases due to resistance evo-
lution in mosquito populations).
To date, only one GM mosquito-based technique has been
developed to an operational level, Oxitec’s RIDL technique,
which seeks to reduce a mosquito population by repeated mass
releases of sterilising transgenic males [2]. Two other tech-
niques under development rely on CRISPR-based gene drive,
seeking to spread a genetic trait in a wild population, either to
eliminate the population by spreading sterility [3] or to make
the target mosquitoes incapable of transmitting pathogens [4].
To identify the specific benefits and limitations of the different
GM mosquito-based techniques, a cross-analysis of different
vector control techniques was conducted with respect to possi-
ble objectives, efficacy and sustainability, technical constraints
and risks to health and the environment. Consideration was
given to both existing techniques (chemical, biological, phys-
ical, and environmental) and emerging techniques based on
release of mosquitoes, whether GM (RIDL and the different
gene drive techniques) or non-GM–irradiated (standard sterile
insect technique (SIT)) or carrying Wolbachia1 (incompatible
insect technique (IIT) and spread of pathogen interference (PI)
technique).
As specified by the referral, we considered the mosquito-borne
diseases and vector species present across France, including
overseas territories. The French territories being dispersed
across the world, the most notable mosquito-borne diseases
worldwide were considered, namely dengue, chikungunya,
Zika, yellow fever, West Nile fever, for the viral diseases, and
malaria and lymphatic filariasis for the parasitic diseases. We
focused on the corresponding local vector species: mainly
Aedes aegypti and Aedes albopictus, and species of Anopheles
and Culex.
These vector species have very distinct features, not only
in distribution and vector competence, but also in bio-
ecology (reproduction modes, potential for survival, host
preferences, peaks and sites of aggressiveness, invasive
potential. . .). The vector systems themselves (the triad
mosquito/pathogen/vertebrate host), as well as the diversity of
situations encountered across the territories add another layer
of complexity. This overall complexity must be understood and
taken into account in order to design the most appropriate
vector control strategy.
Cross-analysis of the different vector control techniques has
been conducted in great detail and has made it possible to
identify specific features and relative benefits and limitations
of each of these techniques. Detailed results are developed in
HCB’s opinion (HCB, 2017).
At a more general level, we found:
– no divide between GM and non-GM techniques or between
emerging and existing techniques (Fig. 1);
– shared characteristics within different sets of techniques,
i.e. (i) techniques based on release of mosquitoes, (ii) pop-
ulation reduction techniques2 vs. population modification
techniques3, (iii) self-limiting techniques4 vs self-sustaining
techniques5;
– complementarity of the techniques.
Lastly, we found that the benefits and limitations of these vec-
tor control techniques cannot be treated in a generic manner,
but will depend on the target vector species, the intended
objective, and the broader context (epidemiological, environ-
mental and socio-economic context, including available human
and financial resources).
Key highlights for each of these broad conclusion points are
developed below.
Fig. 1 Possible objectives and sustainability potential of exist-
ing and emerging vector control techniques (Insects Grand
Conference Talk, C. Golstein and P. Boireau, 14 March 2019).
Most exist. tech.: Most existing vector control techniques,
including use of chemical insecticides; SIT: standard Sterile
Insect Technique (mostly based on irradiated mosquitoes);
RIDL: Release of Insects carrying a Dominant Lethal (GM-
mosquito based technique); IIT: Wolbachia-mediated Incom-
patible Insect Technique; GD: Gene Drive techniques, for
population elimination or modification (GM-mosquito based
techniques in this report); Wb-PI: Wolbachia-mediated spread
of pathogen interference; wMel Pop and wMel: two different
strains of Wolbachia.


Benefits and limitations of emerging techniques for mosquito vector control

CV3 - Editorial Board/English

Maha Medjerab

Mohamed Abdelali

Ali Khalkhal

Nesrine Semiane

Soumia Hammadi

Aicha Mallek

Zineb Bellahrache

Hadjer Agoun

Yasmina Dahmani

Adrenal cortex disorders in a new model of obesity, Gerbillus gerbillus, exposed to a high carbohydrate diet

Reema Rani

Rajender Singh

Neelam R. Yadav

Evaluating stripe rust resistance in Indian wheat genotypes and breeding lines using molecular markers

Érik Orsenna

250 Insects: Friends, foes, and models/Insectes : amis, ennemis et modèles / C. R. Biologies 342 (2020) 247–278
All Dutch painters.
One easy case of naturalistic aphid lie in the paintings of Maria
Sibylla Meriam, a painter and entomologist of the seventieth
century who has painted aphids in numerous works, and both
entitled some of her paintings with the word, and depicted the
whole aphid ecosystem including all trophic levels in the global
picture (Rode akelei met bladwesp en bladluis, 1684).
One important item in our quest is the topos of the female
aphid (and eventually superfemale aphid). It probably did not
start with Charles Bonnet, but at least has fully expanded
after him. This talented Swiss student of Réaumur discovered,
described, and demonstrated parthenogenesis in what could be
called one of the first modern scientific papers in biology, its
Traité d’entomologie (1745). This signed a series of quasi-quotes
all over the following centuries, exemplifying the importance
of this reproductive trait in biology, as well as the impor-
tance of aphids as a model for this trait: this started by a
pejorative citation of Eugène Delacroix in a letter to a friend
in 1830 (“What a pity that such brilliant mind and man has
lost his time and eyes for understanding the venial sin of such
hideous animals”), followed by a real tribute to parthenogen-
esis in the masterpiece of Simone de Beauvoir, Le deuxième
sexe (Volume 1, Chapter 1, “The data of Biology”). One may
also quote in this very context the interesting parallel, made
by the contemporary art blog Quadrivia, between partheno-
genesis and the codified representation of “Sainte Anne
trinitaire” in the European religious sculpture of the late Mid-
dle Ages (https://quadriv.wordpress.com/2011/06/10/jesus-
aphids-and-parthenogenesis/). The sculptural code of Ste
Anne consisted in a triptychal representation of Virgin Mary,
her mother Anne, and child Jesus in a strange charac-
ter proportionality of adult (Anne), child-adult (Mary) and
child-child (Jesus). This invasion of the female-only char-
acter over the Holy Trinity was increasingly popular in
central Europe from the fortieth to the sixtieth century
(https://fr.wikipedia.org/wiki/Sainte Anne trinitaire), and was
only stopped by a specific canonical law codifying the Marial
cult, or hyperdulia, within the Council of Trento (1542–1563).
Although no aphid is represented in such topoi, of course,
the parallel between parthenogenesis and viviparity, somehow
unique to aphids, and the mystery of immaculate conception
ought to be underlined.
Already exemplified by Eugene Delacroix, cited above, the
recurrent and frequent topos of the evil aphid has been used
many times in French literature. Victor Hugo listed the vile
aphid among a list of biological fearsome fellows (Les Contem-
plations, T3 L6 26, p. 467 as appears in the Frantext database).
However, the complimentary figure of the humble aphid is
also present in post-ninetieth-century occurrences, typically
shown in Maurice Carême’s poem entitled Le Puceron.
Coming to modern art, the appearance of aphids tends
to explode, and I will only quote two examples. One
is what could be called the surrealistic oulipian aphid by
Boris Vian (Fig. 2), the other being the situationist aphid
of the musical theme of the Polish artist Duy Gebord in
the well-named Mildew album (https://duygebord.bandcamp.
com/album/mildew). The former merits a short outline, as it
is emblematic of the mosaic Carollian style of Boris Vian (Les
Fourmis, Fig. 2A). The prose starts as a very standard description
of a explicitly boring subject, to fall out into the final black-
hole of Oulipian fantasy (which translates as “The rearing of the
Tyrolian ‘gnatlet’or the milking of woolly aphids”). The induced
image explicitly (again) looks as Fig. 2A, driving the reader in a
universe of gentle and poetic madness typical of Vian’s prose.
It should be noted that the French mouchetis tyrolien (trans-
lated as Tyrolian gnatlet) does not refer, as it seems through
subtle juxtaposition, to an insect: instead it refers to an indus-
trial painting technique, also typical of the universe of engineer
Boris Vian, who started as fonctionnaire of the French normal-
ization agency AFNOR (as did Albert Einstein with the Swiss
patent agency). . .
We hope that our short survey of a hitherto boring subject has
driven the reader on the wild side of the history of arts and
sciences, and that the final references will allow him to escape
even more, at night, from its truly exciting daytime highways
Fig. 2 The milking of woolly aphids, as cited by Boris Vian
in Les Fourmis (Gallimard, La Pléiade) and reported on the left,
with a possible representation on the right: Le Génie des alpages,
F’Murr, Casterman.
of insect science. This compendium and conference is part of
an ongoing project, involving the aphid BAPOA community for
data collection, and partially published by Encyclopaphid [6].
The full corpus contains more than 100 entries and the present
outline is thus only the hidden part of the iceberg, to be fully
published soon.
This conference is quoted in the CNRS repository HAL as:
https://hal.archives-ouvertes.fr/hal-02069668.
Disclosure of interest The authors declare that they have no
conflict of interest.
References
[1] B. Morris, Insects and human life, Berg, Oxford, New York,
2004 [317 p.].
[2] P.G. Bahn, R.K. Butlin, in: J. Clottes (dir.), L’art des objets
au Paléolithique, colloque international. Foix, Le Mas-d’Azil,
Foix, 16–21 novembre 1987 sous la dir. de Jean Clottes, Min-
istère de la culture de la communication, Paris, 1987, pp.
247–253.
[3] C.L. Hogue, Annu. Rev. Entomol. 32 (1987) 181–199.
[4] M. Dicke, Am. Entomol. 46 (2000) 228–237.
[5] D. Arasse, Le détail, in: Pour une histoire rapprochée de la
peinture, Flammarion, Paris, 2009 [1 vol. (380 p.)].
[6] Y. Rahbé, E. Keller-Rahbé, S. Orlandi, P. Senges, C.-
A Dedryver, Aphids in art, a borderless outline. An
anniversary section of Encyclopaphid (GBR edition), in:
J.-C. Simon, M. Hullé, E. Turpeau (Eds.), Encyclopaphid,
INRA, Rennes, 2018 [https://www6.inra.fr/encyclopedie-
pucerons eng/].
https://doi.org/10.1016/j.crvi.2019.09.004
4
The shining world of beetles
Michel Mitov
Centre d’élaboration de matériaux et d’études structurales,
CEMES, CNRS, Toulouse, France
Twisted liquid-crystalline organizations are ubiquitous in liv-
ing matter [1,2]. Many insects own a tessellated carapace with
bumps, pits, indentations, stripes or spots (Fig. 1). These geo-
metric variation often exhibit iridescent colors, which are the
consequence of a complex twist of chitin macromolecules. Such
optical information with vivid structural colors might be of
paramount importance in the life and the evolution of most
day-living insects. Many biological functions are yet debated.
They are related to conspecific or intra-species communication,
thermoregulation, camouflage, survival or navigation [1,3].
For example, the cuticle of the scarab beetle Chrysina glo-
riosa exhibits two bands (Fig. 2). The green band serves as a
wavelength-selective (green) diffuser due to the set of polygons
Insects: Friends, foes, and models/Insectes : amis, ennemis et modèles / C. R. Biologies 342 (2020) 247–278 251
Fig. 1 A set of insects with a variety of patterns and irides-
cent colors issued from the State Museum of Natural History in
Karlsruhe, Germany (image by H. Zell).
Fig. 2 Chrysina gloriosa, from a macroscopic view to micro-
textures as observed in the green and silver bands.
arranged on a curved surface and, at the mesoscopic scale, it
behaves as an array of wavelength-selective micromirrors [4].
The silver stripe plays the role of a flat metallic reflector oper-
ating over the visible spectrum and into the infrared spectrum
[4]. The orientation of the helicoidal structure varies in green
stripes (Fig. 3), whereas it is fixed in silver stripes.
The outermost part of insect cuticles is very often covered with
wax, which restricts water loss, prevents desiccation, may lend
superhydrophobic and self-cleaning properties to the cuticle,
and serves for chemical communication in many species. While
cuticular waxes are considered isotropic, the wax layer of the
cuticle of C. gloriosa exhibits an intriguing nanoscale laminate
texture, as revealed by electron microscopy of the transverse
sections [5].
Micro-textured cuticles of scarabs may inspire researchers
and engineers to make their replicas as optical materials.
Potential applications are in the field of wavelength-specific
light modulators in routing technologies, broadband reflec-
tors for energy savings, coatings for cryptography purposes
(wavelength-dependent and polarization-dependent micro-
and nanoscale patterns), camouflage (suits with a broad reflec-
tion in the IR spectrum identical to the one of the background)
or thermoregulation for buildings.
Disclosure of interest The author declares that he has no com-
peting interest.
Fig. 3 Transverse view of the cuticle of Chrysina gloriosa in
a green band as seen by transmission electron microscopy. A
typical fingerprint texture is displayed in the chitin network of
the cuticle. The distance between two lines of equal contrast
is related to the pitch of the twisted structure. The helical axis
is perpendicular to the lines. Concave nested arcs are visible
below each polygonal cell. Hypothetical functions are reported:
chemical information (wax layer), optical communication in
the visible and near-infrared spectra, infrared thermoregula-
tion.
References
[1] M. Mitov, Cholesteric liquid crystals in living matter, Soft.
Matter 13 (2017) 4176–4209.
[2] Article in CNRS News at: https://news.cnrs.fr/articles/
natures-liquid-crystals.
[3] M. Mitov, I.C. Khoo (Eds.), Multifunctional reflectors in the
carapace of scarab beetles, Liquid Crystals XXII, SPIE Proc.,
2018 [10735, 10735B].
[4] G. Agez, C. Bayon, M. Mitov, Multiwavelength micromir-
rors in the cuticle of scarab beetle Chrysina gloriosa, Acta
Biomater. 48 (2017) 357–367.
[5] M. Mitov, V. Soldan, S. Balor, Observation of an anisotropic
texture inside the wax layer of insect cuticle, Arthropod
Struct. Dev. 47 (2018) 622–626.
https://doi.org/10.1016/j.crvi.2019.09.005
5
Géopolitique du moustique
Érik Orsenna
Académie française, 23, quai de Conti, 75006 Paris, France
E-mail address: nomade222@orange.fr
Pour l’économiste que je suis, doublé d’un romancier passionné
par les ménages à trois et les meurtres, aucun animal n’est plus
intéressant que le moustique, vieux de 250 millions d’années
et riche d’environ quatre mille espèces.
D’abord, même s’il ne peut voler loin, on le retrouve partout,
d’un bout à l’autre de la planète. Il incarne donc la mondiali-
sation et l’unité de la santé: one health, une bonne santé des
humains n’est possible que si se portent aussi bien les animaux
et les végétaux.


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The cave population of <i>Chaerilus</i> Simon, 1877 from Palawan, Philippines, and description of a new species (Scorpiones: Chaerilidae)

Causality in medicine

Arsenic respiration and detoxification by purple non-sulphur bacteria under anaerobic conditions

Sur la taille finale des épidémies dans un environnement périodique

Staminodes evolution and in vitro development innovation in date palm (<i>Phoenix dactylifera</i> L.)

Benefits and limitations of emerging techniques for mosquito vector control

CV3 - Editorial Board/English

Adrenal cortex disorders in a new model of obesity, <i>Gerbillus gerbillus</i>, exposed to a high carbohydrate diet

Evaluating stripe rust resistance in Indian wheat genotypes and breeding lines using molecular markers

Géopolitique du moustique

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