The dentition of the Indian Knoll skeletal population: odontometrics and cusp number.

Data on the permanent dentition of 153 individuals from the well known Indian Knoll skeletal population are presented. Mesiodistal and buccolingual measurements were taken with a Helios dial caliper. Cusp number of maxillary and mandibular molars are recorded. The Indian Knoll dentition is larger than many modern groups but smaller than Australoid or Mesolithic groups. With the exception of maxillary 12, males have larger teeth than females in both dimensions. The lower canine is the most dimorphic tooth. Through rank order correlation, an association was shown between the sexual dimorphism of the mesiodistal and buccolingual dimensions. Compared to modern groups, the Indian Knoll population displays a moderate degree of sexual dimorphism in tooth size. In general, the coefficients of variation were greater for the more distal teeth within morphological classes. Amounts of size variability did not differ significantly between the sexes; moreover, rank order correlations indicated that patterns of variability in both dimensions were similar for males and females. The predominant cusp number pattern for upper molars is 4-3-3 and for lowers 5-5(4)-5. No sex differences were shown for cusp occurrence or bilateral asymmetry in cusp number.     

Metric and morphological variability in the dentition of Colobine monkeys

A morphological study was performed using 97 Colobus polykomos and 41 Nasalis larvatus. The premolars and molars of these two taxa of leaf-eating monkeys were similar in that they possessed deeply grooved and highly pointed cusps. Of 7 dental traits investigated, 4 were significantly different between the 2 forms. Indeed, with 2 of these, the position of the lingual cusp on PM₄ and the number of cusps on PM³ displayed highly contrasting structures.Metric analysis was conducted using 47 C. polykomos and 37 N. larvatus specimens. Mesiodistal and buccolingual measurements were taken on the upper canine and all postcanine teeth. Sexual dimorphism was detected in most maxillary dental measurements and all mandibular estimates of both species. In all cases, males exceeded females in tooth diameter. Testing between species by sex revealed that C. polykomos was significantly larger in several canine and premolar dimensions while N. larvatus had significantly larger molar dimensions. An additional 73 measurements were selected to represent occluding dental structures and a morphological integration analysis was conducted. Results of this analysis indicated that C. polykomos possessed a C¹-PM₃ complex which was more highly intercorrelated whereas the broad lophed N. larvatus molars constituted a more highly correlated functional unit.It was suggested that the above differences between these two groups of leaf-eating monkeys probably resulted from inbreeding, isolation and drift.     

Sexual size dimorphism,growth, and maturity of the fluvial eight-barbel loach in the Kako River,Japan

The maturation and growth pattern of the fluvial eight-barbel loach Lefua sp. (Japanese name: nagare-hotoke-dojo), an endangered species, was investigated using an individual identification-recapture method from 1995 to 1998 in an upper reach of a headwater tributary of the Kako River, Hyogo Prefecture, Japan. Based on observations of the gonads through the abdominal skin, the loach was estimated to breed mostly from May to July. All the males matured by age 1⁺, and all the females matured by age 2⁺. Gamete release in all individuals of both males and females was predicted from recaptured loaches during each breeding season. The standard length of mature females was significantly larger than that of males, showing sexual size dimorphism (SSD). The maximum sizes recorded were 75.4 mm SL for females and 61.2 mm SL for males. Both males and females of immature specimens grew mainly from May to November, including the breeding season, with no significant differences in growth rates between them. After sexual maturity, both males and females grew mainly from July to October (or November), after the breeding season, and the females exhibited higher growth rates than males. Therefore, SSD of the species seems to be attributable to the different growth rates after maturity. The longevity of the loach was estimated to exceed ten years based on individual growth patterns of various sizes during the survey period. It is likely that the loach has an iteroparous life history, breeding every year, and moderate growth rates after maturity.     

Geography of sexual dimorphism in the tooth size of the red fox Vulpes vulpes (Mammalia, Carnivora)

Geographic variation in sexual dimorphism of tooth size was assessed for the red fox Vulpes vulpes (Linnaeus, 1758) across the whole northern range of the species. Twenty-one measurements of tooth size and skull length were taken from 2849 specimens (1577 males and 1272 females) originating from 12 Nearctic and 25 Palearctic localities. The index of sexual dimorphism was calculated as a quotient of the mean measure of certain characters in males by the respective mean in females ( M _m/ M _f). In the whole range, the males were larger than females and mean dimorphism index of tooth size ranged from 1.01 to 1.06. On average, the tooth measurements in males were 3.6% larger than in females. The highest dimorphism was observed in the canines. Dimorphism of tooth size was higher in the Palearctic than Nearctic. Statistically significant differences between regions were found for lengths of C¹, C₁ and M₁. In the Palearctic, higher values of the dimorphism indices were observed particularly in the southern parts of the Eurasian range of the red fox and in Great Britain. For a few metrical traits, sexual dimorphism indices presented significant relations to some geo-climatic variables. The geographic pattern of size dimorphism in the red fox seems to be shaped by sexual selection, intraspecific and interspecific competition and population density.     

Factors affecting daily ranges of red deer<Emphasis Type="Italic">Cervus elaphus</Emphasis> in Białowieża Primeval Forest,Poland

Daily ranges of 19 (6 males, 13 females) adult red deerCervus elaphus Linnaeus, 1758 were studied using 24-h tracking sessions in Białowieża Primeval Forest (BPF), Poland, from 2001 to 2004. Overall, size of mean (± SE) daily ranges was larger for males (1.22 ± 0.10 km²) than females (1.00 ± 0.09 km²), although the difference was not significant. Similarly, mean daily ranges were 6–46% larger for males than females in each season, although there were no statistical differences in mean daily ranges among seasons for each sex. Abiotic factors, especially temperature, significantly affected daily ranges of females, but not males, suggesting sexual differences in response to weather variables. On a daily basis, males used 3% of their annual home range, whereas females used 12% of their annual home range, indicating females used their annual home ranges more intensely than males. Consecutive daily ranges overlapped little for each sex. Daily ranges of red deer in BPF were considerably larger than previously reported in Europe, suggesting factors unique to BPF also influenced size of daily ranges.     

Static intraspecific allometry of jaws and teeth in Cercopithecus aethiops

Adult static intraspecific allometry of jaw size and tooth area was evaluated in a sample of 100 Cercopithecus aethiops crania (50 male, 50 female). Tooth areas were calculated from mesiodistal and buccolingual measurements of all the teeth in both arcades and were scaled to four viscero-cranial measurements: bimaxillary breadth, maxillo-alveolar length, mandibular length and bigonial width. Allometric coefficients calculated for jaw dimensions alone indicate tighter viscerocranial integration in females than in males. A finding of note was that half of the variation in maxillo-alveolar length may be accounted for by variation in mandibular length: females are isometric, males negatively allometric.
A similar degree of allometric mosaicism was found when maxillary incisor size was scaled to maxillary length and width. In females, the relationship was negatively allometric, whilst incisor size in males was found to be unrelated to either. Negative allometry characterized the relationship of canine base area to jaw length in both sexes, with males additionally being positively allometric to mandibular width.
The scaling of postcanine tooth areas to jaw length was characterized by a dichotomous pattern: males showed significant mandibular integration whilst females showed only significant maxillary integration. Compensatory tooth size interaction between maxillary canine base area and the summed incisor and postcanine areas was suggested by the significant negative allometric relation between them.     

Anomalous development and differential DNA replication in the X-Chromosome of a Drosophila hybrid

Male hybrids of the cross D. azteca x D. athabasca are larger (hybrid giant males) than their parents, whereas hybrid females are of the same size as the parental species. Microspectrophotometric measurements have shown that the larval polytene salivary gland chromosomes of hybrid giant males undergo one more endoreplication than those of their sisters or parents. Replication patterns of the larval salivary gland chromosomes were compared after pulse labeling with ³H-thymidine and autoradiography. In females of either species as well as of hybrids X-chromosomes and autosomes are equally labeled, i.e. all chromosome arms replicate synchronously. In males, however, often fewer sites are labeled on the X-chromosome than on the autosomes. In addition, in a significant number of nuclei from D. athabasca males and also from hybrid giant males the converse can also be observed: i.e. more sites are labeled on the X-chromosome than on the autosomes. The modified labeling patterns are interpreted as an indication of a time-shift in the replication of hemizygous X-chromosomes in males, in relation to the autosomes.     

Spatial and temporal distribution of Antarctic fur seals (Arctocephalus gazella) on the breeding grounds at Bird Island,South Georgia

Summary The number of Antarctic fur seals (Arctocephalus gazella) in the area of the Scotia Sea has been increasing. Observation of their distribution on the breeding grounds are important to help design and interpret censuses. These seals are highly polygynous. In the study area at Bird Island, South Georgia, females give birth and are mated in densely packed colonies located along the shore close to the tideline. Males establish territories in this area, but are also found further inland. This study examined the density-dependent processes regulating the instantaneous size of the male breeding population; the distribution of males in relation to space and the number of females available to be mated and the effect of gregarious behaviour of females on male dispersion. Males were only territorial on the beaches in the areas where most females gave birth and subsequently had their post-partum oestrus. There was an apparent lower (19–20 m²) and upper (40 m²) limit to territory size. Males were excluded from the beach areas when the average density on the beaches was greater than 5 males per 200 m². An asymptotic density of 10–11 males per 200 m² was reached on the beaches and 4–5 males per 200 m² elsewhere. These two asymptotic densities may represent the upper and lower limits of density for a territorial system of dispersion. A model of the temporal changes in female numbers suggested that the total number of females occupying an area of beach during the mating period was approximately twice the number at the peak of the season. There was no indication that males compensated for low female density by increasing territory size. Females and pups became more dispersed after the end of the mating period. It is suggested that one function of gregariousness in females is as a mechanism for mate selection. This study also has implications for methods used to measure population size.     

Population and reproductive biology of the fiddler crab Uca thayeri Rathbun, 1900 (Crustacea: Ocypodidae) in a tropical mangrove from Northeast Brazil

Population and reproductive biology of Uca thayeri Rathbun, 1900 were studied for the first time in a tropical mangrove. Absolute density, sex ratio, population structure, handedness, breeding season and fecundity were investigated. Seven transects were delimited in a mangrove area of the Pacoti River, Northeast of Brazil (3° 43′ 02″ S/38° 32′ 35″ W). On each transect, ten 0.25 m² squares were sampled on a monthly basis during low tide periods from September 2003 to August 2004. A total of 483 crabs were obtained, of which 250 were males, 219 non-ovigerous females, and 14 ovigerous females. The U. thayeri population presented bi-modal size frequency distribution, with males and non-ovigerous females not differing significantly size-wise. Ovigerous females were larger than males and non-ovigerous females. The overall sex ratio (1:1.07) did not differ significantly from the expected 1:1 proportion. The major cheliped was the right one in 50% of the males. The observed density was of 8.5 individuals/m², with the specimens being found mostly in shaded areas. Ovigerous females were found in 5 months of the year, coinciding with the rainy season, suggesting that the population of U. thayeri presents seasonal reproductive events. Juvenile crabs were more abundant during the dry period, while larger crabs were found mainly during the rainy period. The fecundity of the studied population was much smaller than that of subtropical populations of this species. The regression analysis shows that the number of eggs increases linearly with the increase of carapace width.     

The longitudinal development of running economy in males and females aged between 13 and 27 years: The Amsterdam Growth and Health Study

The purpose of this study was to describe the longitudinal development of running economy [defined as the oxygen uptake (V˙O₂) at a submaximal running speed] in males and females from teenage to young adult age using data from the Amsterdam Growth and Health Study. Submaximal V˙O₂ (in ml · kg⁻¹· min⁻¹) was measured in 84 males and 98 females while they ran on a treadmill at a constant speed of 8 km · h⁻¹ for 6 min at three different treadmill slopes (0%, 2.5% and 5%). This test was carried out six times, on the same subjects at the ages of 13, 14, 15, 16, 21, and 27 years. The longitudinal development of running economy in males and females was analysed using a two-way analysis of variance for repeated measurements. At all three slopes, a significant decrease in V˙O₂ with increasing age was found for both males and females, implying a significant increase in running economy for both sexes. Males showed significantly higher V˙O₂ values than females at all ages measured and for all three slopes, suggesting that females have a significantly higher running economy than males. In order to make a better comparison of the V˙O₂ of individuals of different sizes, allometric models were used; power function ratios were constructed in which body mass was expressed to an exponential power. Following this analysis the difference in submaximal V˙O₂ and running economy between males and females appeared even larger. Accepted: 20 February 1997     

Genetic analysis of the mating system and opportunity for sexual selection in northern water snakes (Nerodia sipedon)

We used data collected over 3 years at two study sites to quantifythe rates and consequences of multiple paternity and to determinethe opportunity for selection on male and female northern watersnakes (Nerodia sipedon). We sampled litters from 45 femalesthat gave birth to 811 offspring. Using eight microsatelliteDNA loci (probability of exclusion of nonparental males >0.99), we assigned paternity to 93% of neonates from one studypopulation and 69% of neonates from the other population. Observationsof participation in mating aggregations predicted individual reproductive success poorly for two reasons. First, males regularlycourted nonreproductive females. Second, more than half ofall sexually mature males obtained no reproductive successeach year, despite the fact that many of them participatedin mating aggregations. The number of sires per litter ranged from one to five, with 58% of all litters sired by more thanone male. Multiple paternity increased with female size, apparentlyboth because bigger females mated with more males and becausethe larger litters of big females provide paternity opportunitiesto more males. Multiple paternity was also more prevalent inyears with shorter mating seasons. We detected no advantage to multiple paternity in reducing either the number of unfertilizedovules or stillborn young. Despite the majority of males siringno young each year, some males fathered young with as manyas three different females in one year. Male reproductive successincreased by more than 10 offspring for each additional mate,whereas female success increased by fewer than 2 offspring foreach additional mate. The opportunity for sexual selectionwas more than five times higher in males than females.     

The differences among Jewish communities—Maternal and paternal contributions

The haplotypes of Y chromosome (paternally inherited) and mtDNA (maternally inherited) were analyzed in representatives of six Jewish communities (Ashkenazic, North African, Near Eastern, Yemenite, Minor Asian/Balkanian, and Ethiopian). For both elements, the Ethiopian community has a mixture of typically African and typically Caucasian haplotypes and is significantly different from all others. The other communities, whose haplotypes are mostly Caucasian, are more closely related; significant differences that were found among some of them possibly indicate the effects of admixture with neighboring communities of non-Jews. The different contribution of the Y chromosome and mtDNA haplotypes to the significant differences among the communities can be explained by unequal involvement of males and females in the different admixtures. In all communities, except the Ethiopians, the level of diversity () for Y chromosome haplotypes is higher than that for mtDNA haplotypes, suggesting that in each community the people who become parents include more males than females. An opposite proportion (more females than males) is found among the Ethiopians. Correspondence to: U. Ritte     

On the Spinicaudata (Branchiopoda) from Lake Cuitzeo,Michoacán,México: First report of a clam shrimp fishery

Cuitzeo is the second largest lake in México (ca. 425 km²). Indigenous people collect clam shrimp (locally known as `conchilla') and sell them dry as pets' food; the income is important for the local economy. To our knowledge, this is the first report of a clam shrimp fishery. Two conchilla species co-occur: Eocyzicus digueti (Richard) and Leptestheria compleximanus (Packard). They were restricted to the saline, soda-alkaline, and temporally astatic W and NW portions of the lake. E. digueti constituted 70% of the total clam shrimp abundance, and L. compleximanus the remainder. Populations were dominated by juveniles, followed by females and males, with sex ratios (male:female) of 1:1.2 to 1:1.4. E. digueti was larger (3–11 mm) than L. compleximanus (3–8.5 mm), and males were larger than females in both species. There were highly significant correlations between carapace size and the number of growth lines and carapace size and the number of eggs. Although previously reported from México, both species are new records for Lake Cuitzeo and for Michoacán state.     

Species and sexual differences in antennal lobe architecture and glomerular organization in two parasitoids with different degree of host specificity, Microplitis croceipes and Cotesia marginiventris

The endoparasitic wasps (Hymenoptera: Braconidae), Microplitis croceipes (specialist) and Cotesia marginiventris (generalist), are parasitoids of lepidopteran larvae and differ in their degree of host specificity. Recent studies have reported key differences between the two species in the abundance of antennal olfactory sensilla and their response to host-related volatiles. Here, we have compared antennal lobe architecture and glomerular organization in the two parasitoid species by using a combination of axonal tract tracing techniques and confocal microscopy. In M. croceipes, the medial half of the antennal lobe is larger with a greater number of glomeruli compared with the lateral half, whereas in C. marginiventris, the lateral half is larger than the median half. The volume of the antennal lobe is approximately 2.5 times greater in M. croceipes than in C. marginiventris. However, the number of glomeruli per antennal lobe is only slightly higher in M. croceipes (females: 219–222; males: 220–224) than in C. marginiventris (females: 192–194; males: 193–196). A comparison of males and females within each species demonstrated a striking sexual difference in terms of an enlarged glomerulus (macroglomerulus or MG) at the entrance of the antennal nerve and of a complex of 3–4 MG (CMG) in the posterior region of the antennal lobe of males of both species. Being specific to males, both the MG and CMG might be involved in the detection of female-related odor.     

Inter- and intra-specific differences in the number of larval instars in British populations of 24 species of stoneflies (Plecoptera)

1. Ontogenetic changes during the life cycle of aquatic insects are important not only in life‐history studies but also in evaluating food‐web structure. They require information on the growth and number of larval instars but such information is lacking for many species, including Plecoptera. Therefore, the chief objectives of the present study were to determine inter‐ and intra‐specific differences in the number of larval instars in British populations of 24 species of stoneflies, to test Dyar’s hypothesis that growth followed a geometric progression, and to synthesise this information with previously published values for four British species. 2. Larvae were reared at constant temperatures in the laboratory from eggs from 63 populations (one to six populations per species). First instars from each population were divided into three batches and each batch was reared at one of three constant temperatures. For each species, the rearing temperature and source population had no significant effect on the mean size of each larval instar. 3. The relationship between the geometric mean length of each instar and instar number was well described by an exponential equation (P < 0.001, r² > 0.9 for all species), thus supporting Dyar’s hypothesis. Only one species, Brachyptera risi, had the same number of instars for males and females (12–13). For the other 15 herbivorous species and the four smaller carnivorous ones, the number of instars was higher for females than males (range 11–16 for males, 12–17 for females). The larger size of the females was due to their additional instars, not a sex difference in growth rates. In contrast, there was a clear growth separation of the sexes after the 9th or 10th instar for the four largest carnivores. The number of larval instars was highest for these four species (range 16–19 for males, 18–23 for females), and females were much larger than males. 4. A multiple regression equation with data from the present and previous studies (n = 27) showed that variability in the mean length of the first instar and the maximum number of larval instars for each species accounted for 88% and 91% of the variability in the mean length of the final instar for males and females, respectively. 5. Values for Plecoptera in other countries were in general agreement with those in the present study, especially in the same families. Two old, but widely quoted, high values are doubtful. The present study and four previous ones provide a sound basis for ontogenetic studies on 28 species of Plecoptera and their role in aquatic ecosystems.     

Spermiogenesis of inversion heterozygotes in backcross hybrids between Drosophila buzzatii and D. serido

Interspecific F1 hybrid females of D. serido and D. buzzatii are fertile, but hybrid males are sterile. By successive backcrossing of hybrid females to D. buzzatii males it is possible to diminish the genomic contribution of D. serido to the hybrid karyotype. Finally, only selected chromosome sections of D. serido known as inversions restricted to this species were individually left in the otherwise D. buzzatii karyotype, namely: 2 C2b-F4a (j⁹m⁹n⁹), 2 B2c-F4a (j⁹k⁹), 3 C5a-G1b (k²), 4 E2a-G2f (m) and 5 C5d-F2h (w). The present paper deals with the influence of these chromosome sections on sperm differentiation. Any of them produces hybrid male sterility in heterozygous condition. We analyzed spermiogenesis using the DNA specific fluorescence dye BAO in hybrid males which were heterozygous either for only one inversion, as in chromosomes 3, 4 and 5, or for a series of inversions on the same chromosome, as in chromosome 2. The abnormalities recorded included abnormal formation of the cysts, lower than normal number of cysts, abnormal number of nuclei per cyst, incomplete elongation of the cyst, incomplete elongation of the nuclei, displacement of the nuclei from the head region of the cyst and lack of individualization. In no case was there any contents in the seminal vesicle. The section from chromosome 2 of D. serido had the most drastic effect; the disruption produced by the chromosome section corresponding to inversion 3 k² was only a little more severe than that due to 5 w, and both may be distinguished only quantitatively; inversion 4 m produced the slightest deviation from normal spermiogenesis. The larger the serido section introduced in the hybrid, the more severe were the abnormalities it produced. An interpretation in terms of a balance genic theory on the functioning of the genetic system is given.This is paper No. VII in the series The evolutionary history of Drosophila buzzatii.     

Non-random Mating in the Dance Fly Empis borealis: The Importance of Male Choice

In the dance-fly Empis borealis (Diptera, Empididae), females form swarms to which males, carrying a nuptial gift, come for mating. We examined whether males or females were choosy and/or competed for mates. First, measurements of the size relationships between copulating males and females, nuptial gifts and the swarming females from different swarms were assessed. Second, male visiting time in differently sized female swarms was recorded. Larger (wing-length) females participated disproportionately in copulations in each swarm, but not for the population at large. Female mating status (virgin/non-virgin) or proximity to oviposition (egg size) did not influence the likelihood of copulation. No assortative mating pattern was found: male size and size of nuptial gift did not correlate with size of the mating female. The time spent by males in swarms increased with the number of females present and it took longer when males left a swarm without copulation than when doing so. Male visiting time per female was negatively correlated with number of females in swarms. Males more often left smaller than larger swarms without mating. We conclude that E. borealis males discriminate among females but find no evidence for male competition or for female choice. It is still a question to what degree females compete for males.     

Relative contribution of caries and periodontal disease in adult tooth loss among patients reporting to the Institute of Dental Sciences,Belgaum, India

Objectives: To examine the reasons for tooth loss in an adult population. Methods: Patients who reported to the department of prosthodontics in Institute of Dental Sciences, Belgaum, located in the north‐western part of the state of Karnataka, in the southern region of India over a period of 2 months, with at least one missing tooth (excluding third molars) constituted the sample size. There were a total of 365 patients (185 females and 180 males) within the age group of 16–84 years (mean age 51.06 ± 16.47 years) who fulfilled this criterion. Socio‐demographic profile was recorded along with a clinical examination for assessing the number and pattern of tooth loss. The reasons for tooth loss were recorded according to the history reported by the patient. Results: In the present study of 365 patients, 58.9% of the patients were completely edentulous, 41% were partially dentate, of which 20.8% had lost their teeth from caries, 11% from periodontal disease and 9.3% from a combination of reasons. More females had lost their teeth because of dental caries whereas more males had lost their teeth because of periodontal disease, this being statistically significant. (χ² = 16.53, p = 0.001). Highly significant results were obtained for age and reasons for tooth loss. (χ² = 150.39, p < 0.001). Irrespective of the socio‐economic status, dental caries was the most common cause for tooth loss in partially dentate patients though it was not statistically significant (χ² = 13.62, p = 0.325). Mandibular first molars were the teeth most frequently lost due to dental caries. The maxillary left central incisor was most frequently lost due to periodontal disease, followed by the maxillary right central incisor. Conclusions: Since both dental caries and periodontal disease contributed to tooth loss at different ages, risk indicators need to be identified.     

Mating behaviour and mating success in woodfrogs Rana sylvatica

Mating behaviour of woodfrogs was investigated in a woodland pond in southeastern Michigan. Males became sexually mature one year before females and outnumbered females by 5.6 to 1 at the breeding site. Males employed searching behaviour to obtain mates. Yearly male mating success varied from 0 to 2 matings, and larger males had a greater probability of mating than smaller males. The mating season lasted less than 10 days. Most egg masses were deposited in 1 m² of a 256-m² pond. Experimental introduction of egg masses to the breeding site indicated that presence of eggs was sufficient to stimulate egg deposition. The influence of selection for synchronous sexual receptivity in females, communal egg deposition, and delayed female sexual maturation on male mating behaviour and variation in male mating success is discussed.     

Reproductive interference between Aedes albopictus and Aedes flavopictus at a place of their origin

Aedes (Stegomyia) albopictus and Aedes (Stegomyia) flavopictus are related species that have overlapping distributions from southern to central Japan. To understand how they interact, we studied reproductive interference between them, particularly focusing on the body size difference between the mating pair. Here, we examined the effects of conspecific, heterospecific and double mating (i.e. heterospecific mating followed by conspecific mating) on copulation duration, egg production and hatchability of eggs using mosquitoes that varied in body size. Females mated only with heterospecific males produced few viable eggs, indicating that post‐mating isolation is almost complete. When mated with heterospecific males before conspecific mating, the production of viable eggs was lower than when mated only with conspecific males, revealing the occurrence of reproductive interference. The degree of reproductive interference was larger in Ae. flavopictus than in Ae. albopictus when the female size was small but did not differ between them when the female size was large. Aedes albopictus females appear to be able to distinguish Ae. flavopictus males from conspecific males and larger females are more successful in the rejection of heterospecific males. On the other hand, Ae. flavopictus were not able to discriminate between conspecific and heterospecific males.