Evidence of Wing Shape Sexual Dimorphism in Aedes (Stegomyia) albopictus in Mallorca, Spain

The Asian tiger mosquito Aedes albopictus (Skuse, 1894) is a highly invasive species widely distributed on the Spanish Mediterranean coast and the Balearic archipelago. Most studies involving this species in Spain have been focused on surveillance and control methods. However, micro-evolutionary studies for Ae. albopictus in Spain have been traditionally neglected. Morphological diversity could be the result of long-term evolutionary diversification in responses to selective pressures such as temperature, precipitation, food availability, predation, or competition that may influence flight activity, host-seeking, and blood-feeding behavior. Wing geometric morphometric have been used not only to study micro- and macro-evolution in mosquitoes but also in studies of population structuring and sexual dimorphism. Therefore, the main goal of this study was to investigate the wing shape patterns of Ae. albopictus populations to unveil sexual dimorphism that could provide information about their ecology and behavior. Mosquito eggs were collected using oviposition traps at the main campus of the University of the Balearic Islands (Palma de Mallorca, Spain) and reared under laboratory conditions. In order to study wing shape variation patterns in Ae. albopictus males and females, the left wing of each adult mosquito was removed and analyzed based on 18 landmarks. Our results indicated strong levels of sexual dimorphism between Ae. albopictus males and females. Furthermore, according to the cross-validated reclassification test, males were correctly distinguished from females with an accuracy of 84% and females from males 75%. We observed a significant sexual dimorphism in the wing shape patterns of Ae. albopictus when considering different seasonal patterns (spring vs. autumn). Our results suggested that selective pressures may affect males differently to females. Host-seeking, blood-feeding, and oviposition behavior of females may act as a major driver for wing shape sexual dimorphism. These results should be considered for the development of more effective and targeted mosquito control strategies.

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Spinosyns Delivered in Sugar Meals to Aedes aegypti and Aedes albopictus (Diptera: Culicidae): Acute Toxicity and Subacute Effects on Survival, Fecundity, and Fertility

Journal of Medical Entomology ◽

10.1093/jme/tjab220 ◽

2022 ◽

Author(s):

Abdullah A Alomar ◽

Barry W Alto ◽

Edward D Walker

Keyword(s):

Acute Toxicity ◽

Aedes Aegypti ◽

Aedes Albopictus ◽

Nutritive Value ◽

Mosquito Control ◽

Environmental Safety ◽

Adult Mosquito ◽

Hatch Rate ◽

Median Lethal Concentrations ◽

Males And Females

Abstract Sugar is an essential source of nutrition for adult mosquitoes to acquire energy. Toxic sugar bait (TSB) provides a promising method for mosquito control by incorporating toxins into artificial sources of sugar (i.e., toxic baits) presented to wild populations. Spinosyns comprise a family of bacterial secondary metabolites with a unique mode of action against the insect nervous system, an appealing environmental safety profile, and potential for incorporation into sugar baits. This research evaluated acute and subacute effects of spinosad (spinosyns A and D) and spinetoram (spinosyns J and L) in sugar meals on survival, fecundity, and fertility of Aedes aegypti and Aedes albopictus. Acute toxicity of spinosyns doubled from 24 to 48 h of assessment, revealing a relatively slow and cumulative action of the formulated spinosyns. Median lethal concentrations at 48 h were lower for spinetoram than for spinosad, lower for Ae. albopictus than Ae. aegypti, and lower for males than females. When exposed to subacute LC50 concentrations of spinosad and spinetoram for 24 h, survival of males and females of both species was diminished compared with controls, fecundity of females was increased, but fertility as measured by hatch rate of eggs was decreased. The formulations may have increased the nutritive value of the sugar meals thereby boosting fecundity, while toxifying embryos, reducing fertility. The inclusion of subacute effects of spinosyns allows assessment of the broader consequences of TSB for adult mosquito control.

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Sexual dimorphism in skeletal shape in voles (Arvicolinae): disparate selection on male bodies and female heads

Journal of Mammalogy ◽

10.1093/jmammal/gyaa076 ◽

2020 ◽

Vol 101 (4) ◽

pp. 951-957

Author(s):

Jeremy S Morris ◽

Nala Rogers ◽

Alan R Rogers ◽

David R Carrier

Keyword(s):

Sexual Dimorphism ◽

Food Processing ◽

Processing Efficiency ◽

Selective Pressures ◽

Skeletal Size ◽

Quality Diet ◽

Males And Females ◽

Selection For ◽

Functional Indices ◽

Caloric Requirements

Abstract Sexual dimorphism evolves as a response to different selective pressures on males and females. In mammals, sexual selection on traits that improve a male’s ability to compete for access to mates is a common cause of sexual dimorphism. In addition to body mass, adaptations in specific components of the musculoskeletal system that increase strength, stability, and agility, may improve male fighting performance. Here we test the hypotheses that males, when compared to females, are more specialized for physical competition in their skeletal anatomy and that the degree of this sexual dimorphism increases with the intensity of male–male competition. In three species of voles (Cricetidae: Arvicolinae: Microtus), we found partial support for these hypotheses. Male-biased sexual dimorphism in a set of functional indices associated with improved fighting performance was identified in the postcranial anatomy. This dimorphism was greatest in the polygynous Microtus californicus, absent in the monogamous M. ochrogaster, and intermediate in the promiscuous or socially flexible M. oeconomus. However, in the skull, we found results opposite to our predictions. Females had larger skulls relative to overall skeletal size than did males. This may be associated with selection for increased food processing efficiency, which should be highly important because of the compounding effects of increased caloric requirements during gestation and lactation, and the generally low-quality diet of voles. In addition, larger heads in females may be associated with selection for greater digging ability or for defending offspring. These results suggest disparate selective pressures on the postcranial skeletons and skulls of male and female voles.

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Using the modern morphometric approach to determine sexual dimorphism of three medically important flies (Order: Diptera) in Thailand

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200542 ◽

2019 ◽

Vol 20 (5) ◽

Cited By ~ 1

Author(s):

TANAWAT CHAIPHONGPACHARA ◽

SEDTHAPONG LAOJUN

Keyword(s):

Sexual Dimorphism ◽

Sex Differentiation ◽

Common Factor ◽

Wing Shape ◽

Procrustes Analysis ◽

Size Analysis ◽

Wing Size ◽

Geometric Morphometric ◽

Generalized Procrustes Analysis ◽

Males And Females

Abstract. Chaiphongpachara T, Laojun S. 2019. Using the modern morphometric approach to determine sexual dimorphism of three medically important flies (Order: Diptera) in Thailand. Biodiversitas 20: 1482-1486. This study assessed landmark-based geometric morphometric (GM) approach to determine sexual dimorphism of three medically important flies in Thailand, Chrysomya megacephala (Fabricius), Musca domestica (Linnaeus) and Boettcherisca nathani (Lopes). In the wing size analysis, the centroid size (CS) was computed to estimate the wing size. During wing shape analysis, shape variables were analyzed from principal components of partial warp scores calculated after generalized procrustes analysis of coordinates. Non-parametric permutation-based tests (1000 cycles) were used (after Bonferroni correction) at p < 0.05 for statistical comparisons of sizes and shapes between males and females in each fly species. The results of this study, analysis of wing size for sexual dimorphism based on wing CS did not find statistical differences in flies of any type (p > 0.05). However, not the size, the shape of the wings is a common factor used in identification of sexual dimorphism. The wing shape in all species was different between male and female sexes. These results have shown that the GM approach was effective in identifying the sexual dimorphism of C. megacephala, M. domestica and B. nathani, which is one way to help with sex differentiation in cases of incomplete specimens that cannot be classified by morphological methods.

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Evolution of Drosophila buzzatii wings: Modular genetic organization, sex-biased integrative selection and intralocus sexual conflict

10.1101/2021.06.16.448721 ◽

2021 ◽

Author(s):

Patricia Paola Iglesias ◽

Fabio Andrade Machado ◽

S Llanes ◽

E Hasson ◽

E M Soto

Keyword(s):

Sexual Dimorphism ◽

Common Garden ◽

Wing Shape ◽

Population Divergence ◽

Isofemale Line ◽

Main Function ◽

Intralocus Sexual Conflict ◽

Selective Pressures ◽

Drosophila Buzzatii ◽

Line Design

The Drosophila wing is a structure shared by males and females with the main function of flight. However, in males, wings are also used to produce songs, or visual displays during courtship. Thus, observed changes in wing phenotype depend on the interaction between sex-specific selective pressures and the genetic and ontogenetic restrictions imposed by a common genetic architecture. Here, we investigate these issues by studying how the wing has evolved in twelve populations of Drosophila buzzatii raised in common-garden conditions and using an isofemale line design. The between-population divergence shows that sexual dimorphism is greater when sex evolves in different directions. Multivariate Qst-Fst analyses confirm that male wing shape is the target for multiple selective pressures, leading males' wings to diverge more than females' wings. While the wing blade and the wing base appear to be valid modules at the genetic (G matrix) and among-population (D matrix) levels, the reconstruction of between-population adaptive landscapes (Ω matrix) shows selection as an integrative force. Also, cross-sex covariances reduced the predicted response to selection in the direction of the extant sexual dimorphism, suggesting that selection had to be intensified in order to circumvent the limitations imposed by G. However, such intensity of selection was not able to break the modularity pattern of the wing. The results obtained here show that the evolution of D. buzzatii wing shape is the product of a complex interplay between ontogenetic constraints and conflicting sexual and natural selections.

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Growth and Sexual Dimorphism in the Dibbler, Parantechinus apicalis (Marsupialia, Dasyuridae)

Australian Mammalogy ◽

10.1071/am00239 ◽

1999 ◽

Vol 21 (2) ◽

pp. 239

Author(s):

H. Mills ◽

Z. German R ◽

C. Lambert ◽

P. Bradley M

Keyword(s):

Sexual Dimorphism ◽

Mating Systems ◽

Growth Patterns ◽

Sexually Dimorphic ◽

Breeding Strategies ◽

Wild Animals ◽

Selective Pressures ◽

Morphological Studies ◽

In Captivity ◽

Males And Females

Sexual dimorphism in animals has been recognised as being associated with particular breeding strategies or mating systems since Darwin's Origin of Species. Frequently, in polygamous situations, females express a variety of attributes to attract males, and males compete with each other for access to females. This produces different selective pressures in each sex, which in tum produces differing morphologies (Leigh 1995). Thus, the emphasis of morphological studies of sexual differences tends to focus on adults and not the growth patterns that generate those differences. Growth patterns in marsupials have been shown to be variable between species (Gemmell and Hendrikz 1993). Previous studies of dasyurid species in captivity concluded that the onset of dimorphism occurs prior to or during weaning (Whitford, Fanning and White 1982; Williams and Williams 1982), but wild animals are not sexually dimorphic until after weaning (Soderquist 1995). These studies have generally examined the growth rates of males and females and the timing of the onset of sexual dimorphism, but little attention has been focussed on how the differences between the sexes are generated.

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Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

Science Vision ◽

10.33493/scivis.17.01.05 ◽

2017 ◽

Vol 17 (1) ◽

pp. 25-32

Author(s):

Jacinta Lalchhanhimi ◽

Lalremsanga H.T.

Keyword(s):

Sexual Dimorphism ◽

Breeding Season ◽

Sound Production ◽

Reproductive Function ◽

Breeding Biology ◽

Tree Frog ◽

University Campus ◽

Morphometric Measurements ◽

Advertisement Calls ◽

Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

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Sexual Dimorphism among the Kathmandu University Students Assessed by Anthropometric Studies

International Journal of Contemporary Research and Review ◽

10.15520/ijcrr/2018/9/05/508 ◽

2018 ◽

Vol 9 (05) ◽

pp. 20469-20472

Author(s):

Shakya R ◽

Bhattacharya SC ◽

Shrestha R

Keyword(s):

Young Adults ◽

Sexual Dimorphism ◽

Young Adult ◽

University Students ◽

Plastic Surgery ◽

Age Group ◽

Adult Age ◽

Clinically Normal ◽

Crime Detection ◽

Males And Females

Objectives: To observe the sexual dimorphism among the young adult age group ranging from 18-21 years, of Kathmandu University students by measuring craniofacial circumference and canthal distances. Rationale of the study: These data could be useful for establishing the craniofacial standards and adds an implementation on plastic surgery, crime detection as well as in the industrial field. Method: 300 clinically normal students of Kathmandu University aged between 18-21 years were examined for the study. Fronto-occipital circumference, outer and inner canthal distances were measured. All the parameters were compared between males and females. Result: The cranial circumference as well as the inner and outer canthal distance in males was found to be significantly higher as compared to the females. Conclusion: The results concluded that sexual dimorphism remarkably exists in young adults of Kathmandu University students.

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Sexual dimorphism in the long-term stability (10 years) of skeletal Class III treatment

Progress in Orthodontics ◽

10.1186/s40510-021-00360-w ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Natalia Tejedor ◽

Conchita Martín ◽

José Antonio Alarcón ◽

María Dolores Oteo-Calatayud ◽

Juan Carlos Palma-Fernández

Keyword(s):

Sexual Dimorphism ◽

Class Iii ◽

Class Iii Malocclusion ◽

Skeletal Class ◽

Term Stability ◽

Long Term Stability ◽

Fixed Appliances ◽

Males And Females ◽

Class Iii Treatment

Abstract Background Class III malocclusion is associated with high sexual dimorphism, especially in individuals older than 13 years of age, with significant differences in growth between males and females during the pubertal and postpubertal stages, and in adulthood. The aim of this research was to examine differences between males and females in long-term stability (10 years) of treatment for skeletal Class III malocclusion. Methods Thirty patients (15 males and 15 females) with skeletal Class III malocclusion, who had been treated with rapid maxillary expansion (RME) combined with face mask protraction followed by fixed appliances, were selected sequentially. Thirty patients (15 males and 15 females) with skeletal Class I and mesofacial patterns treated only with fixed appliances for dental problems served as the control group. Differences between groups and sexes were evaluated using lateral cephalograms taken at the start of treatment (T0), immediately after the end of treatment (T1), and after 10 years (T2). The long-term treatment success rate was calculated. Results Ten years after Class III treatment, overjet and overbite relapse occurred similarly in females (− 0.68 ± 0.7 mm; − 0.38 ± 0.75 mm, respectively) and males (− 1.09 ± 1.47 mm; − 0.64 ± 0.9 mm, respectively); the ANB angle and Wits appraisal became significantly more negative in males (− 1.37 ± 1.06°; − 2.7 ± 2.53 mm) than in females (− 0.18 ± 1.26°; − 0.46 ± 1.94 mm). The success rate was 73.3% in males and 80% in females. Conclusions Significant differences in the long-term stability of Class III treatment outcomes have been found between males and females, with a larger skeletal Class III relapse and lower long-term success rates in males.

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Efficacy of Petiveria Alliacea (Linneaus) leaf and root bark powder in the control of filariasis vector Culex Quinquefasciatus

The Journal of Basic and Applied Zoology ◽

10.1186/s41936-020-00199-3 ◽

2021 ◽

Vol 82 (1) ◽

Author(s):

Michael Olarewaju Akintan ◽

Joseph Onaolapo Akinneye ◽

Oluwatosin Betty Ilelakinwa

Keyword(s):

Synergistic Effect ◽

Culex Quinquefasciatus ◽

Mosquito Control ◽

Exposure Period ◽

Botanical Insecticides ◽

Adult Mosquito ◽

Root Bark ◽

Plant Powders ◽

Petiveria Alliacea ◽

Feeding Activities

Abstract Background Mosquitoes are vectors of parasitic diseases such as malaria, lymphatic filariasis, yellow fever, and dengue fever among others. They are well known as public enemies for their noise nuisance, biting annoyance, sleeplessness, allergic reactions, and diseases transmission during the biting and feeding activities. This then necessitate the search for insecticides of plant origin which are bio-degradable, non-toxic, and readily available for man use. Result This study, evaluated the fumigant efficacy of the powder of P. alliacea to control the adult stage of Culex mosquito. Powder of Petiveria alliacea were administered at different dose of (1 g, 2 g, 3 g, 4 g, and 5 g), respectively. Result obtained shows the fumigant effect of the powder were effective with percentage mortality of 18.33–60.00% for the leaf powder and 23.30–71.60% for the root powder within 2 h post-treatment period (P < 0.05). The synergistic effect of the leaf and root powder was also investigated. The lethal dosage (LD50) of the leaf, root, and synergistic effect of leaf and root bark powder required to kill 50% of the adult Culex quinquefasciatus was 3.76 g, 2.86 g, and 2.63 g, respectively. However, 25.06 g, 15.25 g, and 12.94 g of the leaf, root, and leaf and root powder were required to kill 90% (LD90) after a 2-h exposure period. Conclusion These finding suggested P. alliacea powder could be a good source of insecticide which may be used for the production of biopesticides. The present findings have important implications in the practical control of adult mosquito by using botanical insecticides. These plant powders are easy to prepare, inexpensive, and safe for use in mosquito control.

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Modulation of odour-guided behaviour in mosquitoes

Cell and Tissue Research ◽

10.1007/s00441-020-03368-6 ◽

2021 ◽

Vol 383 (1) ◽

pp. 195-206

Author(s):

Sharon R. Hill ◽

Rickard Ignell

Keyword(s):

Functional Genomics ◽

Life Stage ◽

Blood Feeding ◽

Model Systems ◽

Extrinsic Factors ◽

Intrinsic Factors ◽

Host Seeking ◽

Enhancing Resources ◽

Maturation Age ◽

Behavioural Repertoire

AbstractMosquitoes are emerging as model systems with which to study innate behaviours through neuroethology and functional genomics. Decades of work on these disease vectors have provided a solid behavioural framework describing the distinct repertoire of predominantly odour-mediated behaviours of female mosquitoes, and their dependence on life stage (intrinsic factors) and environmental cues (extrinsic factors). The purpose of this review is to provide an overview of how intrinsic factors, including adult maturation, age, nutritional status, and infection, affect the attraction to plants and feeding on plant fluids, host seeking, blood feeding, supplemental feeding behaviours, pre-oviposition behaviour, and oviposition in female mosquitoes. With the technological advancements in the recent two decades, we have gained a better understanding of which volatile organic compounds are used by mosquitoes to recognise and discriminate among various fitness-enhancing resources, and characterised their neural and molecular correlates. In this review, we present the state of the art of the peripheral olfactory system as described by the neural physiology, functional genomics, and genetics underlying the demonstrated changes in the behavioural repertoire in female mosquitoes. The review is meant as a summary introduction to the current conceptual thinking in the field.

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