In this paper social relationships (as defined by Hinde) between age/sex classes of kangaroos, wallabies and rat-kangaroos are reviewed and characterized by frequencies, direction and, where possible, intensity of behavioural interactions, by their patterning in sequences and by distance regulation. Male social organization in the wild for larger non-solitary species is organized in an age/size-related hierarchy. Frequent interactions among equal-sized males stabilize this hierarchy and large males by their simple presence deter younger ones from courting.

Depending on social organization in the wild, the presence of one or more males, sometimes males from different age classes, is desirable from the animal welfare standpoint.

The structure of breeding groups can be greatly improved in terms of welfare and breeding optimization, when a diversity of social relationships are as close to natural conditions as possible.

The short-lived polygamous moth Grapholita molesta (Busck) is an important fruit pest worldwide. Trapping males by synthetic female sex pheromones is not an effective reproductive control strategy. It is important to improve this technology by understanding the mating system of G. molesta. This study investigated mating opportunities and fertile egg production by altering the operational sex ratio, mating age, and male mating history in repeated single mating and multiple mating in the two sexes. Our results showed that the mating and reproductive parameters of virgin males were affected by the number and age of virgin females. Males preferred a female number ≤three-fifths of the male number or ≤2-day-old females, while they discriminated against a female number ≥three times of the male number or ≥5-day-old females. On the other hand, the mating and reproductive parameters of virgin females were affected by repeated single mating and especially multiple mating under different male mating histories. Females preferred once-mated males and discriminated against virgin males. These results indicated that mating systems including more and older virgin females for virgin males and different virgin males for virgin females may be suitable for suppressing G. molesta populations. Hence, these results revealed that preventing mating of virgin adults by synthetic female sex pheromones should be most effective in controlling G. molesta.

Knowledge on the reproductive biology of target insect pest is essential for the effective implementation of pheromone-based pest management tactics. In mealybugs, the second largest family of scale insects, the existence of female multiple mating was recently suggested. In this study, we aimed at testing how general is this behavior in mealybugs, by investigating polygyny and polyandry in two cosmopolitan pest mealybugs, Planococcus citri and Pseudococcus calceolariae. Males of these species were able to mate an average of 11.9 and 13.3 females, respectively, during their lifespan. The number of fertilized females per male decreased with male age/mating history for both mealybugs. We found no differences in female fecundity and fertility, when fertilized by males with different mating history. When we used male age as a proxy of mating history, we observed a significant negative effect on female fecundity. The females of both species remained receptive after first copula and eventually mated multiple times. The percentage of remated females of P. citri decreased linearly with time since first copula, with some maintaining receptivity up to 24 h. Males showed no preference between virgin and mated females, in static-air olfactometer tests. We found no benefit of female multiple mating in relation to fecundity. In biparental mealybugs, the mating system of males is possibly scramble competition polygyny; and that of females is possibly polyandry, with female receptivity restricted to a relatively short period. We discuss the practical implications of the results for pest management.

The importance of various factors influencing the evolution of herbicide resistance in weeds is critically examined using population genetic models. The factors include gene mutation, initial frequency of resistance alleles, inheritance, weed fitness in the presence and absence of herbicide, mating system, and gene flow. Where weed infestations are heavy, the probability of selecting for resistance can be high even when the rate of mutation is low. Subsequent to the occurrence of a resistant mutant, repeated treatments with herbicides having the same mode of action can lead to the rapid evolution of a predominantly resistant population. At a given herbicide selection intensity, the initial frequency of resistance alleles determines the number of generations required to reach a specific frequency of resistant plants. The initial frequency of resistance alleles has a greater influence on the evolutionary process when herbicides impose weak selection, as opposed to very strong selection. Under selection, dominant resistance alleles increase in frequency more rapidly than recessive alleles in random mating or highly outcrossing weed populations. In highly self-fertilizing species, dominant and recessive resistance alleles increase in frequency at approximately the same rate. Gene flow through pollen or seed movement from resistant weed populations can provide a source of resistance alleles in previously susceptible populations. Because rates of gene flow are generally higher than rates of mutation, the time required to reach a high level of resistance in such situations is greatly reduced. Contrary to common misconception, gene flow from a susceptible population to a population undergoing resistance evolution is unlikely to slow the evolutionary process significantly. Accurate measurements of many factors that influence resistance evolution are difficult, if not impossible, to obtain experimentally. Thus, the use of models to predict times to resistance in specific situations is markedly limited. However, with appropriate assumptions, they can be invaluable in assessing the relative effectiveness of various management practices to avoid, or delay, the occurrence of herbicide resistance in weed populations.

The genetic variation at 12 isozyme loci was investigated in the three species (Xanthium italicum, X. strumarium, and X. orientale) forming a X. strumarium complex in Italy. Very little variation was found within species at the loci studied in contrast to the considerable interspecies genetic differentiation at several loci. The gene differentiation between species was ranged from 61 to 91%. The observed genetic structure of the X. strumarium complex was consistent with that found for predominantly autogamous species. The values of maximum outcrossing rates estimated in original sampling sites and in a field test ranged from 8 to 17%, confirming previous observations that Xanthium species are predominantly self-pollinated. Gene duplications were evident in the three Xanthium species because of their likely polyploid origin. The percentage of duplicate loci exhibiting “fixed heterozygosity” was 25, 25, and 16% in X. italicum, X. strumarium, and X. orientale, respectively. Data presented supported that both mating system and ploidy level were fundamental features in adaptation process of investigated Xanthium species. Some evidence suggested that polyploidization occurred before speciation of X. italicum, X. strumarium, and X. orientale. As a consequence, a common ancestral progenitor could be postulated for the three species. During geographical adaptation, the three species fixed alternative alleles in some loci, and the process was favored by the predominantly autogamous mating system. On the contrary, fixed heterozygosity in duplicated loci allowed maintenance of a sufficient level of gene diversity in the three Xanthium species to ensure wide adaptability in different microhabitats (i.e., abandoned land, roadsides, and field crops) and to avoid the negative effect of inbreeding depression.

This study tested for social monogamy in Alpheus brasileiro Anker, 2012. We also analysed egg production in this species. Sampling was conducted bimonthly from March 2013 to January 2014, and specimens were collected manually in the intertidal estuarine zone of Cananéia, São Paulo, Brazil. A total of 186 specimens (92 males and 94 females) were captured, and ~46% of them were found living in heterosexual pairs. The carapace length (CL mm) of paired males and females was positively correlated. We analysed 35 females carrying eggs underneath the abdomen: 28 of these females had eggs in stage I of development, four had eggs in stage II, and three had eggs in stage III. The average (±SD) mean fecundity for females carrying early (stage I) eggs was 149 (±93) eggs. Egg volume differed significantly among developmental stages, with a 35.4% increase in egg volume between stages I and III. The egg volume and size (CL) of females correlated positively. A positive correlation between the number of eggs and carapace length was found, with a proportional increase in the number of eggs according to the size of females. Our results suggest that the studied population of A. brasileiro is socially monogamous and provide the first insights into egg production in this species.

Knowledge of processes responsible for seed dormancy can improve our understanding of the evolutionary dynamics of reproductive systems. We examined the influence of the breeding system on primary seed dormancy in Hypericum elodes, an Atlantic–European softwater pools specialist plant that exhibits a mixed mating strategy (the ability to both self- and cross-pollinate) to set seeds. Seeds were obtained through hand pollination treatments performed in a natural population during three consecutive years. Primary dormancy of seeds recovered from each pollination treatment was measured by analysing the seed germination response at dispersal and after various periods of cold stratification. While all collected seeds exhibited physiological dormancy, the degree of primary dormancy was associated with the pollination treatments. Weak and rapid loss of primary dormancy characterized seeds recovered from self-pollinated flowers, while stronger dormancy was found in seeds obtained from cross-pollination. The association between pollination treatments and primary dormancy indicated that the mating system should be considered as a source of variation for dormancy degree, proportional to self- and cross-pollinations (selfing rate) within populations of this species. These results suggest that by shedding seeds with various degrees of dormancy, plants may distribute their offspring across time by means of polymorphism in germination response. We conclude that seed germination alone is not an appropriate fitness measure for inbreeding depression estimates, unless dormancy is removed.

In this paper we describe acoustically the wing-fanning behaviour showed by the male of the braconid Psyttalia concolor towards females and other conspecific males. Psyttalia concolor is a synovigenic koinobiont larval–pupal endoparasitoid of many Tephritidae, used in olive crops to control the olive fruit fly, Bactrocera oleae. In this braconid male wing fanning produces a courtship song characterised by sequences of homogenous pulses with harmonic structure and a fundamental frequency of about 180 Hz. Song parameters can vary according to the behavioural context. Statistically significant differences, both in terms of pulse frequency and duration, characterise fanning towards females in comparison with male–male approaches. Moreover, the pulse duration is associated with the fanning song displayed before a successful courtship. Our observations allowed us to define the airborne component of the sound and to definitely confirm the exclusive role of the wings in signal production within sexual communication in P. concolor.

Austinixa aidae inhabits burrows of the ghost shrimp Callichirus major at Perequê-açu beach, Ubatuba, Brazil. We described the host-use pattern and sexual dimorphism of A. aidae to test for monogamy given the generality of this mating system in the subfamily Pinnothereliinae (family Pinnotheridae) to which A. aidae belongs. Against expectations, A. aidae lives as solitary individuals within burrows more frequently than expected by chance alone. Additional observations suggested that A. aidae exhibits a polygynandrous mating system with males moving among burrows in search of receptive females. First, only 21% of the burrows harboured heterosexual pairs of crabs and the body size of paired crabs was poorly correlated. This suggests pair instability and frequent shifts among burrows by male and/or female crabs, as reported before for other symbiotic crustaceans in which the body size of paired crabs is poorly correlated. Second, males paired with females that were sexually receptive (without embryos) or that have been receptive recently (carrying early embryos) were found more frequently than expected by chance alone. The above agrees with that reported for species in which sexual pairing does not last long. Third, sexual dimorphism in terms of claw size and coloration was evident. Claws were larger in males than in females, a condition that argues in favour of male–male competition in A. aidae. In addition, the body coloration of males was more similar to the sand grains of the beach than that of females. This sex-specific coloration suggests that males are ‘better adapted' than females to roam on the surface of the beach in search of burrows because their coloration should diminish the risk of detection by predators. Experiments are needed to reveal the details of the polygynandrous mating system herein inferred for A. aidae and to understand those conditions favouring particular reproductive strategies in symbiotic decapod crustaceans.

Tephroseris longifolia subsp. moravica (Asteraceae) is an endangered narrow endemic taxon recently recorded from nine sites in Slovakia and the Czech Republic. We provide the first consistent information on its reproductive biology – mating system, seed output, germination, seedling emergence and survival. Based on results from isolation, hybridization and emasculation experiments on different subspecies, T. longifolia s.l. should be treated as an allogamous taxon without apomictic reproduction. Five populations of T. l. moravica were studied in detail for seed output and germination characteristics. The output of well-developed seeds per flowering shoot was estimated to be 592 (1125 seeds per flowering plant). A granivorous butterfly, Phycitodes albatella (family Pyralidae), was identified as a pest, reducing seed output by 18–28%. Germination (reaching 30–62% after dry storage for 4 months) rapidly decreased with storage in room conditions. Deep freeze storage increased germination, although not significantly. Seeds obtained from natural populations had higher germination percentages and germinated faster than seeds from cultivated plants. Seedling emergence in situ was very low (0.9–2.06% of the sown seeds) without significant differences among sites.

Many local breeds of farm animals have small populations and, consequently, are highly endangered. The correct genetic management of such populations is crucial for their survival. Managing an animal population involves two steps: first, the individuals who will be permitted to leave descendants are to be chosen and the number offspring they will be permitted to produce has to be determined; second, the mating scheme has to be identified. Strategies dealing with the first step are directed towards the maximisation of effective population size and, therefore, act jointly on the reduction in the loss of genetic variation and in the increase of inbreeding. In this paper, the most relevant methods are summarised, including the so-called ‘Optimum Contribution’ methodology (contributions are proportional to the coancestry of each individual with the rest), which has been shown to be the best. Typically, this method is applied to pedigree information, but molecular marker data can be used to complete or replace the genealogy. When the population is subjected to explicit selection on any trait, the above methodology can be used by balancing the response to selection and the increase in coancestry/inbreeding. Different mating strategies also exist. Some of the mating schemes try to reduce the level of inbreeding in the short term by preventing mating between relatives. Others involve regular (circular) schemes that imply higher levels of inbreeding within populations in the short term, but demonstrate better performance in the long term. In addition, other tools such as cryopreservation and reproductive techniques aid in the management of small populations. In the future, genomic marker panels may replace the pedigree information in measuring the coancestry. The paper also includes the results of several experiments and field studies on the effectiveness and on the consequences of the use of the different strategies.

Selfing has been considered the most common mode of reproduction in Echinococcus flatworms. However, population genetic studies on the asexual larval stage involving nuclear co-dominant markers have not always revealed significant heterozygote deficiencies – the expected outcome of a regularly and highly inbred population. In this study, we analysed the genetic structure of Echinococcus granulosus sensu lato populations from Southern Brazil during their adult (sexual) stage using 1 mitochondrial and 1 nuclear marker (cox 1 and mdh, respectively). We show that parasite genetic differentiation is largest among definitive hosts (domestic dogs) from different farms, suggesting that transmission is mostly maintained within a farm. Moreover, we show that heterozygote deficiencies are not significant, and we suggest that outbreeding is the most common mode of reproduction of the parasite in that region.

Behavioural sex-role reversal occurs when males and females exchange their standard roles in territorial defence or parental care. One circumstance under which sex-role reversal may occur is when males are a limiting resource, so that females have to compete for access to mates. Here we report on male rarity and male and female behaviour of species within the damselfly genus Nesobasis, endemic to Fiji. Earlier reports suggested that, in some members of this genus, males were seldom observed and that females of these species were consequentially territorial, a phenomenon described as ‘sex-role reversal’. Quantitative estimation of the ratio of adult males to females at 15 localities in 13 Nesobasis species (1489 individuals) indicated that males were extremely rare in some species, yet common in others. This interspecific variability in male rarity cannot be explained by elevation or habitat. Formal observations of three species with abundant males revealed that males of these species were highly territorial: they physically challenged intruders while remaining within a confined area. By contrast, in three species where males were consistently rare or absent, females were not territorial: instead, they moved widely and were primarily engaged in oviposition. While we do not know the underlying reason for the unusual rarity of males at oviposition sites in some species, it is clear that this rarity has not provided sufficient selection pressure to generate genuine sex-role reversal.

Grasspea (Lathyrus sativus L.) is an annual, herbaceous, drought-resistant legume and staple crop in Asian and African countries. Little is known about the nature and the amount of genetic diversity present in existing grasspea seed collections, yet this information is pivotal for future breeding programmes, such as those striving to reduce high neurotoxin levels present in seeds. Here we report on the level of genetic diversity within a world-wide collection of L. sativus, determined by isozymatic analysis. Although grasspea is generally considered a predominantly self-pollinating species, we found that the population genetic structure of these accessions showed a considerable outcrossing rate of 36%. The identification of a mixed mating system in L. sativus has significant implications for collecting and multiplying genetic resources for conservation and for future breeding purposes. In addition, we determined the genetic closeness of grasspea accessions from different geographical regions around the world. While we noticed an allelic richness in this species that was conserved across the regions, we did not find any evidence of high genetic identity between accessions, even when originating from the same geographical location. Instead, we found that greater genetic variability existed at the intra-regional level than at the inter-regional level.

The soldier crab Mictyris brevidactylus breeds in winter. Large females spawned over a few days in early winter after most had decalcified their vulvar opercula. Some females spawned in their first winter, less than 1 year after settlement. The crabs probably copulate during a few days before spawning while the vulvar opercula are decalcified. During the daytime low tide in the breeding season, large males emerged and fed on the sediment surface. Females, on the other hand, made a sand roof above themselves using sand pellets from which they had sorted out food particles, and they fed while hiding under it. After the males had ceased their surface activities, they entered the sand tunnel made by the female. The roof was connected with a hollow shaft, which had been made when the crab had ascended to the surface. Before the habitat was submerged, the shaft was plugged from within with sand to form an air chamber, which suggests that the male and female descend together in the air chamber and copulate there. It is possible that the crab uses the sand roof as a visible signal to attract mates.

Spacing patterns of individuals within an island population of the Central American spiny rat Proechimys semispinosus were studied by radio-tracking eight adults for 2 months during the rainy season and eight adults for 1 month during the dry season in central Panama. All trees ≥10 cm diameter at breast height on the island were mapped, tagged, identified to species, and inventoried monthly to determine fruit production. Diurnal telemetry was conducted to locate daytime resting burrows. Burrow habitat was quantified by measuring nine variables at each burrow site. Individuals had larger home ranges and greater home-range overlap during the rainy season, and males had marginally larger home ranges than females. No evidence was found of attraction, avoidance or exclusive use of space by adult spiny rats. Thirty-six located burrows had nine instances of co-occupancy. Burrows were located close to water and had little herbaceous cover. The presence of broadly overlapping home ranges, larger home ranges of males vs females, greater numbers of burrows of females in home ranges of males vs those of females, and larger home ranges of sexually active males suggest that P. semispinosus had a promiscuous mating system within this population.

The Lower Risk/near threatened giant babax Babax waddelli is endemic to southern Tibet. The babaxes, living in groups of 3–8 individuals year-round, favoured edge habitats in forest regions where the group encounter rate during the breeding period was 0.35 groups h−1 and population density 0.04 birds ha−1, and in scrub regions they depended on the patches covered with higher bushes in which the group encounter rate and population density were 0.32 groups h−1 and 0.03 birds ha−1 respectively. The global population of the babaxes was estimated to be 120,000 birds. Reproductive and behavioural data were collected from scrub environments in a valley. Egg laying occurred between early May and early June, and clutch size ranged from 2 to 4 eggs, 2.9 on average. Incubation and fledging lasted 16–18 days respectively. Nesting success, measured as the proportion of clutches from which at least one young survives to fledging, was 75%. Some of the babax's nests were cooperatively attended by group members and the others only by both parents. The most preferable nesting areas were in dense bushes more than 1.8 m in height (mainly Rosa sericea, Berberis hemleyana, Cotoneaster divaricatus, Sibiraca angustata and Salix sclerophylla). Such strong dependence on high bushes leaves babaxes more susceptible to vegetation degradation. As a result, the increasing clearance of scrub habitats for firewood is a major current threat to the birds around the mid-Yalong Zangbo River, a region with the densest human population and most rapidly developing economy in Tibet. Their naturally low population density and strongly social grouping behaviour present extra risk factors that have to be taken into account. The importance of vegetation protection for long-term survival of this endemic species is highlighted.

The mating system displayed by a species or population is a complex result of interactions among many factors, including social organization and resource distribution. Lekking is rare among mammals, and despite decades of research and theoretical debate, there is still little agreement concerning the socio-ecological conditions that give rise to this mating system. This study documents a lek-like mating system in a population of white-nosed coatis Nasua narica: the first such system observed in a carnivore species. Male coatis in Tikal National Park, Guatemala, aggregated around mobile bands of females during the mating season. The males displayed from the forest canopy above the bands, and females ascended to a male's perch when they were ready to mate. Males did not provide resources or parental care. Thus, the mating system, which differed from classic lekking only in the lack of an arena, can be best described as mobile lekking. Male coatis apparently resort to self-advertisement when the large size and large home ranges of female groups make defence of females or resources impractical.