Acoustic signaling,territoriality, and mating in whistling moths,Hecatesia thyridion (Agaristidae)

Males of the agaristid moth Hecatesia thyridiondefend small patches of coastal heathland in southwestern Australia in the late afternoon. As they fly back and forth low over their territories, they produce an acoustical signal. Neighboring males commonly fly toward each other; these interactions often result in aerial duels, with the eventual departure of one of the males. Playback experiments established that males were attracted to the sounds of other males. Females were observed to fly into territories and eventually mate with the signaling occupant. Marked males sometimes returned to the same spot on consecutive days. On any given day males occupied only a fraction of the sites that were acceptable territories. The mating system of H. thyridionappears to be a dispersed lek, with males acoustically advertising territories that are used for mating and not for feeding or oviposition.     

The mating system of a bee fly (Diptera: Bombyliidae). II. Factors affecting male territorial and mating success

Males of an undescribed bombyliidfly (Comptosia sp.)occupy traditional territories on a Southeast Queensland hilltop, to which females come solely for the purpose of mating. Territorial fights between males involve aerial collisions during which modified spines on the wing margins produce scars on the bodies of opponents. Territory owners and mating males are not different in size or age from the remainder of the male population. Although residency is related to fighting success, the strength of the effect is ambiguous. Consequently, our data do not appear to fit predictions from game theoretical models for fighting protocol. Hilltop males lacked the extensive population variation typically found in territorial species, and thus, the presumed advantages of traits such as large size may be suppressed. Hilltop males were larger than males at a nonhilltop, resource-based mating site and the possibility of alternative mating tactics is discussed.     

An Extreme Case of Interspecific Territoriality: Male Anthidium manicatum (Hymenoptera,Megachilidae) Wound and Kill Intruders

Anthidium manicatum males defend patches of flowering plants as mating territories and copulate with females that enter the territory to obtain nectar or pollen. Territorial males defend their territories not only against conspecific males but also against many other insect species that attempt to utilize the flowers inside the territory. In our study area, a territorial male defended its territory against conspecific males on average only twice per h but it attacked other species of insects on average 70 times per h. Territorial males distinguished between different species of intruders and attacked them unequally. During the hour following experimental removal of the territory holder the number of intruders of some insect species tripled but the number of intruders of those species that were rarely attacked remained approximately the same. A. manicatum males, but not females, bear long spines on the last two segments of the abdomen. Territorial males rammed intruding insects at high speed and shortly before the moment of impact they curved the abdomen forward to hit with the spines. Intruders could be seriously damaged or killed by these attacks. Abdominal spines of A. manicatum males may have evolved as weapons to increase the effectiveness of interspecific territoriality.     

Non-resource based territoriality in males of the butterflyXamia xami (Lepidoptera: Lycaenidae)

In the Pedregal de San Angel reserve, in Mexico City, males of the butterfly Xamia xamiperch in and defend areas with well-defined topographic limits. These areas lack concentrations of receptive females and of larvae and adult resources. One individual defends the same territory an average of 5 h/day, up to a maximum of 23 days. The same areas are used as territories by different males during the year. These areas share some characteristic features which are described. Evidence is presented in support of the hypothesis that the territories function as mating stations. A possible scenario for the evolution of this territorial mating system is advanced.     

Increased energy investment in testes following territory acquisition in a maternal mouthbrooding cichlid

Underwater observations conducted in Lake Tanganyika showed that males of a maternal mouthbrooding cichlid, Petrochromis fasciolatus, defended a mating territory for at least several months, but left at approximately noon every day. After the experimental removal of males from their territories, new owners occupied the vacated territories within several days. New owners exhibited higher body-condition factors and fat indices than the original owners. These results suggest that the new owners had not previously occupied a territory, considering the physical exhaustion of owners owing to the energy expenditure on territory maintenance and mating behaviors and a limited time for feeding. Original owners had heavier testes than new owners, despite similar body sizes. This disparity in testis weight suggests that energy investment in testes increases following territory acquisition. Among males that newly occupied a territory during the observation period, larger individuals occupied territories sooner, suggesting that large body size facilitates competition for territory. It is concluded that energy investment in testes is delayed for somatic growth until territory acquisition.     

Mating behavior and male mating success in wildAnastrepha Ludens (Diptera: Tephritidae) on a field-caged host tree

Mating behavior and factors affecting mating success of males were studied using wild Anastrepha ludens on a fieldcaged host tree. The most common courtship sequence had five components: (1) male calls from the underside of a leaf, (2) female arrives to the maleoccupied leaf, (3) male orients to female and stops calling, (4) one or both approach to a face-to-face position 1–3 cm apart, and (5) male mounts female after 1–2 s. Courtship behavior was almost identical to that of laboratoryculture flies observed previously under laboratory conditions. Most malefemale encounters occurred at a height of 1–2m, well inside the outer canopy of the tree. Differential mating success by males occurred. No male mated more than once per day, owing possibly to a very short sexual activity period. Factors favoring mating success of males were survival ability and tendency to join male aggregations and to fight other males. Thorax length and age (9–11 days difference) had no effects on male copulatory success. Overall win/loss percentage was not related to mating success because the males that were most successful at mating fought mostly among themselves, driving their win/loss percentage down. However, these successful males (at mating) won most of their fights against less successful males. Results confirmed a lek mating system: males aggregated, called, and defended territories; territories did not contain femalerequired resources; and females exercised mate choice, apparently through selection of sites within leks.     

Territory Availability at Different Spatial Scales does not Affect Fighting Investment in Males of the Lycaenid Butterfly Strymon mulucha

In territorial species, rivals investment in fights over territories may increase when the availability of suitable areas for defense is low. This should occur because low territory availability may increase the costs to maintain and acquire territories. Although such process occurs in small spatial scales (local scale), territory availability in larger scales (regional scale) may also affect fighting investment, as losers should incur additional dispersing costs to find new territories. In this study, we used males of the hilltopping butterfly Strymon mulucha to evaluate the hypothesis that males should invest more in territorial fights when the costs to find new territories are higher (both at local and at regional scale). We timed male–male contests for territories located in 12 hilltops and measured male density per territory in each hilltop (local scale). We also quantified the distance between hilltops containing suitable areas for territories (regional scale). Male–male contests lasted 21 s on average, and copulations did not occur during the observations. The duration of contests was unrelated to the male density per territory or to the distance among hilltops, indicating that the investment in fights was unaffected by the availability of territorial sites, independent of the spatial scale. As male–male contests in S. mulucha are longer than the mean contest duration in other butterfly species and mating is extremely rare, we suggest that the value of each territory may be high enough to favor males that always invest as much as possible in contests.     

Do Feeding Resources Induce the Adoption of Resource Defence Polygyny in a Lekking Butterfly?

Among polygynous species, males often compete for the possession of mating sites to increase their reproductive success. Weaker individuals frequently adopt alternative non‐territorial mate‐locating tactics, but the adoption of alternative territorial tactics may also occur. Although alternative tactics with territory defence are less common in arthropods, factors that drive its adoption may provide information to understand the organization of different territorial mating systems in the group. Here we investigate the adoption of resource‐based territoriality as an alternative to a non‐resource‐based one by males of the butterfly Paryphthimoides phronius. Male P. phronius commonly defend sunny clearings lacking feeding resources in the forest edge (non‐resource‐based territoriality). However, after experimentally offering fermenting fruit in previously undefended sites, we showed that males also adopt a resource defence tactic. Males in territories with fermenting fruits apparently feed on this resource when they are not defending the territory. However, males in sites without resources did not migrate to territories with resources when given the opportunity. To our knowledge, this is the first experimental investigation to show a non‐resource‐ and an alternative resource‐based mate‐locating tactic in a butterfly. We suggest that this behavioural flexibility may represent an important step to understand the ecological factors responsible for the organization and evolution of different territorial mating systems in insects.     

同种雄性竞争对手的存在对星豹蛛雄蛛求偶和交配行为的影响

越来越多的研究发现,雄性产生精子(精液)也需付出代价。雄性除了依据配偶质量和竞争对手的竞争强度适应性调整生殖投入外,雄性在求偶和交配行为上也相应产生适应性反应,求偶和交配行为具有可塑性。目前雄性求偶和交配行为可塑性研究主要集中于雌性多次交配的类群中,在雌性单次交配的类群中研究甚少。以雌蛛一生只交配一次而雄蛛可多次交配的星豹蛛为研究对象,比较:(1)前一雄性拖丝上信息物质对后续雄蛛求偶和交配行为的影响,(2)雌雄不同性比对雄蛛求偶和交配行为的影响。研究结果表明,星豹蛛前一雄蛛拖丝上的信息物质对后续雄蛛求偶潜伏期、求偶持续时间和交配持续时间都没有显著影响,但前一雄蛛拖丝上的信息物质对后续雄蛛求偶强度有显著抑制作用。同时,性比对星豹蛛雄蛛求偶和交配行为都没有显著影响。可见,星豹蛛雄蛛对同种雄性拖丝上的化学信息可产生求偶行为的适应性调整,而对性比不产生适应性反应。     

Influences on variation in territorial tenures of male white-faced dragonflies (Leucorrhinia intacta) (Odonata: Libellulidae)

Some individuals in species with extended periods of territorial occupancy may change territory locations within a single bout of territorial activity. Length of occupancy of mating territories among males in a local population of white-faced dragonflies (Leucorrhinia intacta) varied from more than 6 h to 15 min or less. Males with short tenures often established territories in several locations on the pond during a day. Several hypotheses have been proposed to explain shifting territorial sites rather than remaining in a single site during one bout of territoriality. We attempted to test the hypothesis that males shift to leave low-quality sites. Site quality may be affected by costs of defense in relation to intruder rate and the mating benefits of holding the territory. To test whether variation in these possible effects of benefits and costs of territoriality influenced tenure, we manipulated local quality of oviposition substrate and perch density. The quality of oviposition substrate, but not perch density, influenced both potential benefits and costs of territoriality. Female density was higher in areas with good substrate, but so were rates of males intruding into the territories, rates of chasing by territorial males, and local density of territorial males. More matings occurred in areas with good substrate, but among males with tenures of 15 min or more, mating success per male and tenure lengths did not differ statistically among treatments. Defense costs were low for all treatments and perhaps were not an important influence on tenure duration. Territorial males in this population probably adjusted local density to expected mating success by initial choice of site rather than by varying tenure length. Variation in tenure length at a site resulted, in part, from stochastic external factors, such as predation attempts.     

Host plant-based territoriality in the white peacock butterfly,Anartia jatrophae (Lepidoptera: Nymphalidae)

Mate locating behavior of Anartia jatrophaewas studied near Ochopee, Collier County, Florida. Males were individually marked, and focal animal samples were used to determine activity, residency, and interactions with other butterflies. We recaptured more than half of 53 marked males within the study area on subsequent days. Marked males restricted non-feeding activity to roughly circular areas typically less than 15 m in diameter. Males showed considerable site fidelity and chased both conspecifics and a variety of other insects. Typically, encountered individuals flew away, and the resident peacock male returned to perch near his previous perch. Encounters with conspecific males averaged 38 sec, three times longer than with other insects. Such site fidelity combined with aggressive interactions indicates territorial behavior. When male density more than doubled, site fidelity decreased, resident turnover increased, and areas that had not been defended at lower density were defended. Without exception, defended sites contained the larval host, Bacopa monnieri.In butterfly mating systems, defense of host plants appears to be much less common than defense of natural features such as landmarks.     

Effects of multiple matings on reproductive fitness of male and female Diaeretiella rapae

Mating frequency and the amount of sperm transferred during mating have important consequences on progeny sex ratio and fitness of haplodiploid insects. Production of female offspring may be limited by the availability of sperm for fertilizing eggs. This study examined multiple mating and its effect on fitness of the cabbage aphid parasitoid Diaeretiella rapae McIntosh (Hymenoptera: Aphidiidae). Female D. rapae mated once, whereas males mated with on average more than three females in a single day. The minimum time lag between two consecutive matings by a male was 3 min, and the maximum number of matings a male achieved in a day was eight. Sperm depletion occurred as a consequence of multiple mating in D. rapae. The number of daughters produced by females that mated with multiple‐mated males was negatively correlated with the number of matings achieved by these males. Similarly, the proportion of female progeny decreased in females that mated with males that had already mated three times. Although the proportion of female progeny resulting from multiple mating decreased, the decrease was quicker when the mating occurred on the same day than when the matings occurred once per day over several days. Mating success of males initially increased after the first mating, but then males became ‘exhausted’ in later matings; their mating success decreased with the number of prior matings. The fertility of females was affected by mating with multiple‐mated males. The study suggests that male mating history affects the fitness of male and female D. rapae.     

Overlapping territories ofPseudosimochromis curvifrons males and other herbivorous cichlid fishes in Lake Tanganyika

Males of the herbivorous cichlid fishPseudosimochromis curvifrons established mating territories 3–10 m in diameter, which included both spawning and feeding sites. Territorial males attacked conspecific males and also other species. Only conspecific males were chased out of the territories. Territorial males attacked other species at the spawning sites while courting or waiting for females and at other sites in their territories while patrolling and foraging. Attacks against herbivorous species were more frequent than against non-herbivores since herbivores were much more abundant. Territories of four abundant herbivorous cichlids largely overlapped the territories ofP. curvifrons males. Symbiotic relationships were not detected between the species. Instead, they were aggressive towards each other but coexisted by segregating feeding sites in the overlapping areas. The aggressive coexistence ofP. curvifrons males with other herbivores may have resulted from the energetic costs of defending their relatively large territories against all food competitors. Interspecific food-resource partitioning may also have facilitated the coexistence.     

Mating tactics and male wing dimorphism in the damselfly,Mnais pruinosa costalis selys (Odonata: Calopterygidae)

Males of the damselfly,Mnais pruinosa costalis, exhibit wing color dimorphism: one form has orange wings, and the other hyaline wings which resemble female wings. The former is usually territorial and the latter uses sneaky mate securing tactics. When orange-winged males failed to establish territory, they became floaters that day. Hyaline-winged males perched around their territories and often, formed in tandem without any apparent courtship behavior when they found females. Their copulation frequency was higher and copulation duration longer than those of territorial males. A few females oviposited without remating. Total oviposition duration of females with which a hyaline-winged male mated was more than 32 min per male on average in a day Females that copulated with hyaline-winged males often remated with orange-winged residents before oviposition. Total duration of oviposition bouts of females after mating with floaters was short (15 min), while that with territorial residents was long (66 min). As a result, total oviposition duration of females with which an orange-winged male mated was about 40 min in a day. The reproductive success of the hyaline-winged males may be similar to that of the orange-winged males.     

Laboratory evaluation of interspecific mating between Zeugodacus fruit flies and Bactrocera dorsalis

The increasing number of tephritid pest invasions worldwide highlights the importance of interspecific interactions among tephritid pests. The melon fly [Zeugodacus cucurbitae (Coquillett)], the pumpkin fruit fly [Zeugodacus tau (Walker)], and the oriental fruit fly [Bactrocera dorsalis (Hendel)] (all Diptera: Tephritidae) are neotropical fruit flies with overlapping distributions. Their interactions during mating hours have rarely been observed in nature due to their nocturnal behavior. Here, laboratory studies were conducted under no-choice and choice conditions to quantify interspecific mating. The interactions during mating hours resulted in interspecific mating, which reduced conspecific mating success and interrupted mating activity patterns. Successful interspecific mating pairs of Z. cucurbitae and Z. tau were recorded in no-choice and choice tests. Interspecific mating between male Z. cucurbitae and female Z. tau significantly reduced conspecific mating in Z. tau. Observations of the diel mating activity patterns showed that male Z. cucurbitae initiated calling behaviors earlier than Z. tau males, giving Z. cucurbitae more chances to court Z. tau. Though males of neither Zeugodacus species formed mating pairs with B. dorsalis, Zeugodacus males reduced conspecific mating in B. dorsalis in the choice trials. Thus, interspecific interactions among Z. cucurbitae, Z. tau, and B. dorsalis affected conspecific mating; interrupted conspecific mating activity patterns were recorded in all three species. This information could be used to improve management practices.     

The effects of male body size on territorial and mating success in the landmark-defending fly Hermetia comstocki (Stratiomyidae)

Abstract.

• 1 Males of Hermetia comstocki Williston compete for territorial control of certain agaves and yuccas. Winners copulate with females that visit these plants solely to acquire a mate.
• 2 Males vary in body weight by more than an order of magnitude and larger flies almost always defeat smaller ones in aerial contests for control of landmark territories.
• 3 The mean body size (as measured by wing-length) was significantly greater for males retaining residency at a site for at least one hour compared to males unable to do so. Likewise, males able to return to a perch site in the study area on more than one day were larger on average than males unable to do so.
• 4 Male preferences for landmark territories remained similar across years. Large males dominated the perch landmarks most likely to be occupied by males and most likely to be visited by females.
• 5 Despite the fighting and territorial advantages enjoyed by large males, the mean size of males found mating with females was not significantly larger than that of the general population.
• 6 The apparent failure of large males to secure a statistically significant mating advantage may be a statistical consequence of the small sample size of males observed mating. On the other hand, any mating advantage of large males may be reduced because (a) receptive females visit many different landmarks, (b) females mate with the first male they encounter at a landmark, regardless of his size, (c) there are usually many vacant landmarks available for smaller males, and (d) even popular territories are often open to small males, thanks to the low site-tenacity of territory owners.

     

Male Alpine Chamois Occupy Territories at Hotspots Before the Mating Season

Ungulate mating systems vary broadly both between and within species. Studies on mating systems in different habitats can provide clues to the ecological factors determining this diversity. Despite its abundance in the European Alps and its importance as a game species, surprisingly little is known about the mating system of Alpine chamois Rupicapra rupicapra rupicapra. We tested the hypothesis that adult males first defend mating territories in late spring, when females segregate from males and well before the Nov. rut. In the Gran Paradiso National Park (north‐western Italian Alps), adult males shared a winter range but occupied individual ranges in summer and early autumn. Males were more aggressive to each other in the summer than in the spring. A strong site fidelity from one year to the next was found for the summer and early autumn months. Those males that occupied the same territories both in the summer and during the rut (Nov.) appeared to be at hotspots, attractive to females during the rut because of reduced snow cover. Other males appeared to cluster around these hotspots during the rut. Territories that were first occupied during the summer were visited by more females than those that were not established until the rut began. Our results suggest that the mating system of this population of Alpine chamois consists of the early occupation of clustered mating territories. The early establishment of mating territories in areas frequented by females during the rut may lead to reproductive benefits for male chamois.     

Aggressiveness during monogamous pairing in the sleepy lizard, <Emphasis Type="Italic">Tiliqua rugosa</Emphasis>: a test of the mate guarding hypothesis

The Australian sleepy lizard, Tiliqua rugosa, maintains monogamous associations for an average of 6 weeks before mating each spring. One hypothesis to explain this prolonged partnership is that males are guarding their female partners from rival males. This hypothesis has three predictions, that males are more aggressive than females to conspecific males, that male aggression will increase as the time of mating gets closer, and that males will be more aggressive towards conspecific males when they are with their partner than when they are alone. We tested those predictions with indirect evidence of aggression, using counts of scale damage on randomly encountered lizards, and with direct observations of their responses to approaches by conspecific and heterospecific models. As predicted by the mate guarding hypothesis, males showed more evidence of aggression towards conspecifics than did females. However, in contrast to the hypothesis, males did not become more aggressive as the time of mating came closer, and males in pairs were less aggressive than males on their own. Mate guarding cannot be the only process that has led to the prolonged monogamous associations in this species. Parental care is also unknown in these lizards, and we suggest that monogamy may be maintained through some form of female coercion, allowing females to gain additional fitness from the enhanced vigilance that results from male proximity.     

Hilltopping in the Pipevine Swallowtail Butterfly (Battus philenor)

In central Arizona, receptive females of the pipevine swallowtail, Battus philenor, are widely scattered in time and space, and in this region the butterfly's mating system is one in which males patrol mountain peaks. Hilltopping males engage intruding males in ascending flights that appear to be ritualized aerial combat with individuals defending patrolling sites for relatively short periods on any given day. The day-to-day appearance of marked males is irregular, unlike the site fidelity shown by males of many other hilltopping insects. The distinctive pattern of male territoriality in B. philenor may be partly a response to very low male and female density in the observed population. Males at the hilltop chase, court, and attempt to copulate with virgin females released near them. Males assess the receptivity of females rapidly, and receptive females permit a lengthy copulation to occur after a courtship that lasts less than 30 s. During an initial copulation males pass a spermatophore that weighs about 6% of their body mass, with partners on following days receiving a smaller but still substantial donation.     

Piracy mating by large males in a monogamous substrate-breeding cichlid in Lake Tanganyika

Telmatochromis temporalis is a biparental substrate breeding cichlid that mates in size-assortative monogamy at the southern end of Lake Tanganyika. In this population, at least a few months before the rainy season, large males (90–110 mm TL) did not pair. However, they maintained large territories that were defended against conspecific large males and that contained several pairing small males (50–80 mm). Large males occasionally visited the nests of the small pairs in their territories, and selectively took over the nests by attacking the owner male. During the takeover, the large males courted the small females in the nests and might have ejaculated sperm. After the large males left the nests, the small owner males conducted paternal care at the nests. These behaviour patterns of large males are similar to piracy mating reported in other polygamous fish species. The piracy mating of large maleT. temporalis seems to be an alternative tactic when large females are not available.