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1.
Localization of quantitative trait loci for diapause and other photoperiodically regulated life history traits important in adaptation to seasonally varying environments
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Venera I. Tyukmaeva Paris Veltsos Jon Slate Emma Gregson Hannele Kauranen Maaria Kankare Michael G. Ritchie Roger K. Butlin Anneli Hoikkala 《Molecular ecology》2015,24(11):2809-2819
Seasonally changing environments at high latitudes present great challenges for the reproduction and survival of insects, and photoperiodic cues play an important role in helping them to synchronize their life cycle with prevalent and forthcoming conditions. We have mapped quantitative trait loci (QTL) responsible for the photoperiodic regulation of four life history traits, female reproductive diapause, cold tolerance, egg‐to‐eclosion development time and juvenile body weight in Drosophila montana strains from different latitudes in Canada and Finland. The F2 progeny of the cross was reared under a single photoperiod (LD cycle 16:8), which the flies from the Canadian population interpret as early summer and the flies from the Finnish population as late summer. The analysis revealed a unique QTL for diapause induction on the X chromosome and several QTL for this and the other measured traits on the 4th chromosome. Flies’ cold tolerance, egg‐to‐eclosion development time and juvenile body weight had several QTL also on the 2nd, 3rd and 5th chromosome, some of the peaks overlapping with each other. These results suggest that while the downstream output of females’ photoperiodic diapause response is partly under a different genetic control from that of the other traits in the given day length, all traits also share some QTL, possibly involving genes with pleiotropic effects and/or multiple tightly linked genes. Nonoverlapping QTL detected for some of the traits also suggest that the traits are potentially capable of independent evolution, even though this may be restricted by epistatic interactions and/or correlations and trade‐offs between the traits. 相似文献
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3.
H. X. Lin T. Yamamoto T. Sasaki M. Yano 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(7):1021-1028
To characterize quantitative trait loci (QTLs), we used marker-assisted selection (MAS) to develop three nearly isogenic lines
(NILs) differing only for the presence of a single, specific QTL (QTL-NILs) –Hd1, Hd2, and Hd3 – for heading date in rice. The three lines contained the chromosomal region of the target QTL from donor variety Kasalath(indica) in the genetic background of var. Nipponbare (japonica). To analyze epistatic interactions in pairs of these QTLs, we also used MAS to develop four combined QTL-NILs with 2 of
the 3 QTLs or with all 3. Different daylength treatment testing of the QTL-NILs revealed that the three QTLs control photoperiod
sensitivity. Genetic analysis of F2 populations derived from crosses between the three QTL-NILs with a single QTL using molecular markers revealed the existence
of epistatic interactions between Hd1 and Hd2, and Hd2 and Hd3. These interactions were also confirmed by the analysis of combined QTL-NILs under different daylength conditions. The existence
of an epistatic interaction between Hd1 and Hd3 was also clarified. Based on these results, we suggest that the Kasalath allele of Hd3 does not affect photoperiod sensitivity by itself but that it is involved in enhancement of the expression of the Nipponbare
alleles of Hd1 and Hd2.
Received: 22 October 1999 / Accepted: 21 March 2000 相似文献
4.
The objective of this study was to dissect the genetic control of days to flowering (DTF) and photoperiod sensitivity (PS)
into the various components including the main-effect quantitative trait loci (QTLs), epistatic QTLs and QTL-by-environment
interactions (QEs). Doubled haploid (DH) lines were produced from an F1 between two spring Brassica napus cultivars Hyola 401 and Q2. DTF of the DH lines and parents were investigated in two locations, one location with a short
and the other with a long photoperiod regime over two years. PS was calculated by the delay in DTF under long day as compared
to that under short day. A genetic linkage map was constructed that comprised 248 marker loci including SSR, SRAP, and AFLP
markers. Further QTL analysis resolved the genetic components of flowering time and PS into the main-effect QTLs, epistatic
QTLs, and QEs. A total of 7 main-effect QTLs and 11 digenic interactions involving 21 loci located on 13 out of the 19 linkage
groups were detected for the two traits. Three main-effect QTLs and four pairs of epistatic QTLs were involved in QEs conferring
DTF. One QTL on linkage group (LG) 18 was revealed to simultaneously affect DTF and PS and explain for the highest percentage
of the phenotypic variation. The implications of the results for B. napus breeding have been discussed.
The text was submitted by the authors in English. 相似文献
5.
Alfonso Cuesta-Marcos Ernesto Igartua Francisco J. Ciudad Primitiva Codesal Joanne R. Russell José L. Molina-Cano Marian Moralejo Peter Szűcs María Pilar Gracia José M. Lasa Ana M. Casas 《Molecular breeding : new strategies in plant improvement》2008,21(4):455-471
Heading date is a key trait for the adaptation of barley to Mediterranean environments. We studied the genetic control of
flowering time under Northern Spanish (Mediterranean) conditions using a new population derived from the spring/winter cross
Beka/Mogador. A set of 120 doubled haploid lines was evaluated in the field, and under controlled temperature and photoperiod
conditions. Genotyping was carried out with 215 markers (RFLP, STS, RAPD, AFLP, SSR), including markers for vernalization
candidate genes, HvBM5 (Vrn-H1), HvZCCT (Vrn-H2), and HvT SNP22 (Ppd-H1). Four major QTL, and the interactions between them, accounted for most of the variation in both field (71–92%) and greenhouse
trials (55–86%). These were coincident with the location of the major genes for response to vernalization and short photoperiod
(Ppd-H2 on chromosome 1H). A major QTL, near the centromere of chromosome 2H was the most important under autumn sowing conditions.
Although it is detected under all conditions, its action seems not independent from environmental cues. An epistatic interaction
involving the two vernalization genes was detected when the plants were grown without vernalization and under long photoperiod.
The simultaneous presence of the winter Mogador allele at the two loci produced a marked delay in heading date, beyond a mere
additive effect. This interaction, combined with the effect of the gene responsive to short photoperiod, Ppd-H2, was found responsible of the phenomenon known as short-day vernalization, present in some of the lines of the population.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
Living in seasonally changing environments requires adaptation to seasonal cycles. Many insects use the change in day length as a reliable cue for upcoming winter and respond to shortened photoperiod through diapause. In this study, we report the clinal variation in photoperiodic diapause induction in populations of the parasitoid wasp Nasonia vitripennis collected along a latitudinal gradient in Europe. In this species, diapause occurs in the larval stage and is maternally induced. Adult Nasonia females were exposed to different photoperiodic cycles and lifetime production of diapausing offspring was scored. Females switched to the production of diapausing offspring after exposure to a threshold number of photoperiodic cycles. A latitudinal cline was found in the proportion of diapausing offspring, the switch point for diapause induction measured as the maternal age at which the female starts to produce diapausing larvae, and the critical photoperiod for diapause induction. Populations at northern latitudes show an earlier switch point, higher proportions of diapausing individuals and longer critical photoperiods. Since the photoperiodic response was measured under the same laboratory conditions, the observed differences between populations most likely reflect genetic differences in sensitivity to photoperiodic cues, resulting from local adaptation to environmental cycles. The observed variability in diapause response combined with the availability of genomic tools for N. vitripennis represent a good opportunity to further investigate the genetic basis of this adaptive trait. 相似文献
7.
Timing of diapause termination has an important influence on individual reproductive success, but relatively little research
has explored how individuals differ in their response to diapause termination cues. We tested individual variation in the
timing of post-diapause activity in Polistes dominulus paper wasps. Wasps were overwintered in a temperature-controlled chamber. In the spring, ambient temperature was gradually
increased and the time each foundress became active was recorded. Timing of post-diapause activity was most strongly associated
with the facial patterns that function as a conventional signal of quality. Foundresses with facial patterns indicating high
quality became active at lower temperatures than individuals with facial patterns indicating low quality. Early diapause termination
is associated with dominance, so the relationship between diapause termination and facial patterns provides a mechanism linking
facial patterns with dominance. Body weight and mating status did not influence timing of post-diapause activity. Juvenile
hormone (JH) titer at the time of diapause termination was also measured in a subset of foundresses. There was no JH titer
threshold for diapause termination. Instead, our results suggest that individuals may have different threshold responses to
JH, as individuals that became active at a lower temperature had lower JH titers than individuals that became active at a
higher temperature. Overall, there is substantial individual variation in response to diapause termination cues and the variation
is likely to have important impacts on the fitness of nest-founding females. 相似文献
8.
M. Reza Mehrnejad & Michael J.W. Copland 《Entomologia Experimentalis et Applicata》2005,116(2):109-114
The processes involved in the induction and termination of diapause in the parasitoid Psyllaephagus pistaciae Ferrière (Hymenoptera: Encyrtidae) were investigated under controlled laboratory conditions. Results indicated that the parasitoid P. pistaciae is able to overwinter successfully as a pupa within the mummified psyllid host Agonoscena pistaciae Burckhardt and Lauterer (Homoptera: Psylloidea), and the parasitoid clearly responded to a short photoperiod by entering diapause. The incidence of diapause increased significantly with decreasing temperature, indicating the existence of an interaction between low temperature and short‐day photoperiod that resulted in a 100% diapause. However, low temperature alone partly stimulated P. pistaciae to enter diapause. The incidence of diapause was likely to be independent from psyllid nymphal instar and the condition of its mother. This investigation showed that the termination of diapause in the overwintering parasitoid pupae and the duration of diapause completion or adult emergence is photoperiod independent, but dependent on temperature. However, chilling treatment was found to be unnecessary for diapause termination in P. pistaciae, although it decreased the duration of diapause maturation. The positive responses of parasitoids to environmental factors appears to act as a basic strategy to induce diapause in the parasitoid P. pistaciae against extreme climatic conditions. 相似文献
9.
Within organisms, groups of traits with different functions are frequently modular, such that variation among modules is independent and variation within modules is tightly integrated, or correlated. Here, we investigated patterns of trait integration and modularity in Brassica rapa in response to three simulated seasonal temperature/photoperiod conditions. The goals of this research were to use trait correlations to understand patterns of trait integration and modularity within and among floral, vegetative and phenological traits of B. rapa in each of three treatments, to examine the QTL architecture underlying patterns of trait integration and modularity, and to quantify how variation in temperature and photoperiod affects the correlation structure and QTL architecture of traits. All floral organs of B. rapa were strongly correlated, and contrary to expectations, floral and vegetative traits were also correlated. Extensive QTL co-localization suggests that covariation of these traits is likely due to pleiotropy, although physically linked loci that independently affect individual traits cannot be ruled out. Across treatments, the structure of genotypic and QTL correlations was generally conserved. Any observed variation in genetic architecture arose from genotype × environment interactions (GEIs) and attendant QTL × E in response to temperature but not photoperiod. 相似文献
10.
D2‐like dopamine receptors mediate regulation of pupal diapause in Chinese oak silkmoth Antheraea pernyi
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Qiushi Wang Ikumi Hanatani Makio Takeda Katsutaka Oishi Katsuhiko Sakamoto 《Entomological Science》2015,18(2):193-198
The present study investigated the pharmacological properties of dopamine receptors that functioned in the termination of pupal diapause in the Chinese oak silkmoth, Antheraea pernyi (Lepidoptera: Saturniidae). Dopamine receptors are classified according to their structure and function into two subfamilies as D1‐ and D2‐like receptors. D1‐like receptors activate, whereas D2‐like receptors inhibit, adenylate cyclase. We examined the effects of agonists and antagonists selective for D1‐ and D2‐like receptors on the diapause state. As A. pernyi is a long‐day species, pupal diapause is maintained during short days and can be terminated by exposure to a long‐day photoperiod. The D2‐like receptor‐selective agonist quinpirole delayed the timing of adult emergence under long days, and the D2‐receptor‐selective antagonist sulpiride terminated pupal diapause even under a short‐day photoperiod. The D1‐like receptor‐selective agonist and antagonist, SKF‐38393 and SCH‐23390, respectively, caused no significant effects on diapause pupae. These results suggest that not D1‐ but D2‐like receptors mediated diapause regulation in A. pernyi. This dopamine pathway appeared to block the termination of pupal diapause. Furthermore, the actions of the cAMP analog 8‐CPT‐cAMP and dopamine receptor antagonists upon diapause pupae were similar, which supports the notion that D2‐like receptors involved in diapause of this insect prevent adenylate cyclase from producing cAMP like vertebrate D2‐like receptors. Taken together, our findings suggest that dopamine blocked diapause termination through D2‐like receptors that inhibited adenylate cyclase in A. pernyi. During short days under which diapause was maintained in pupae, the dopaminergic mechanism might be stimulated to suppress cAMP levels in cells regulating diapause. 相似文献
11.
The paper reviews the data on diapause and related phenomena in stink bugs (Heteroptera: Pentatomidae). Using stink bugs as
examples, the consecutive stages of the complex dynamic process of diapause (such as diapause preparation, induction, initiation,
maintenance, termination, post-diapause quiescence, and resumption of direct development) are described and discussed. Out
of 43 pentatomid species studied in relation to diapause in the Temperate Zone up to date, the majority (38 species) overwinter
as adults, two species—as eggs, and another two species—as nymphs. Pentatoma rufipes is believed to be able to overwinter at different stages of its life cycle. Less than 5 % of pentatomid species are probably
able to overwinter twice. Only five species have obligate diapause, others have the facultative one. Day-length and temperature
are the main diapause inducing factors in the majority of species. The role of food in the control of seasonal development
is essential in the pentatomid species feeding on plant seeds. In different species, different stages are sensitive to day-length.
Some pentatomids retain sensitivity to photoperiod even after diapause, others lose it and become photo-refractory (temporarily
or permanently). In Pentatomidae, such seasonal adaptations as photoperiodic control of nymphal growth rates, seasonal body
colour change, migrations, and summer diapause (aestivation) are widely represented, whereas wing and/or wing muscle polymorphism
has not been reported yet. In the subfamily Podopinae, induction of facultative reproductive winter diapause is under the
control of photoperiod and temperature. All species feed on seeds and their seasonal development to a great extent reflects
availability of food. However, the same food preferences and pattern of seasonal development are also characteristic to many
species from the subfamily Pentatominae. All species of the subfamily Asopinae are predators. Among them, Picromerus bidens and Apateticus cynicus have obligate embryonic winter diapause, which is rear among true bugs. At the same time, A. cynicus and Podisus maculiventris belong to the same tribe but have different types of diapause: obligate embryonic diapause in A. cynicus and facultative adult diapause in P. maculiventris. Other Asopinae species studied up to date have facultative adult diapause controlled by photoperiod and temperature with
probably only one exception: in Andrallus spinidens, adult diapause is controlled by temperature, and photoperiod plays only a secondary role. Thus, in spite of the similar
habits and feeding types among Asopinae, the species of this subfamily have different types of diapause and the latter is
controlled by different factors. In the subfamily Pentatominae, most species overwinter as adults and induction of their diapause
is controlled by the long-day type photoperiodic response, in spite of the differences in their feeding preferences (within
phytophagy). However, there are some exceptions in this subfamily, too: Palomena prasina, P. angulosa and Menida scotti have obligate diapause, which conditions univoltinism in these pentatomids. In M. scotti, only females have obligate adult diapause, whereas males remain physiologically active through the whole winter, this pattern
being unusual for Heteroptera. The univoltine seasonal cycle of this species with summer diapause (aestivation) and apparent
migrations is similar to that of shield bugs (Scutelleridae). According to the analysis of seasonal development, the evolution
of seasonal adaptations in Pentatomidae does not directly reflect their phylogeny. However, individual genera, small tribes
or even subfamilies have similar complexes of seasonal adaptations. At the same time, Pentatominae is a large and apparently
collected taxon, but most of species in this subfamily have the same facultative adult diapause. 相似文献
12.
Whether alien insects that are introduced into temperate regions adapt to seasonally changing environmental conditions is an important question in evolutionary biology. If rapid evolution has occurred in a non‐native environment, a latitudinal cline in critical photoperiod for diapause induction (i.e., the photoperiod at which half of the individuals enter diapause) and in life cycle synchronization with host plant phenology should be evident among locations. The alien bruchid Acanthoscelides pallidipennis (Motschulsky) (Coleoptera: Bruchidae) is native to North America and introduced into Japan with the host plant Amorpha fruticosa L. (Fabaceae) in the late 1940s. To examine whether seasonal adaptation has occurred in A. pallidipennis, we conducted a laboratory experiment and phenological observations using three latitudinally different populations. We bred F1 eggs at 22 °C and five photoperiodic regimens – L:D = 10:14, 13:11, 14:10, 15:9, or 16:8 hours – and examined whether diapause was induced. The estimated critical photoperiod for diapause induction was longest in the most northern population and shortest in the most southern population. Life cycle was found to be synchronized with host phenology in each location. Also voltinism varied geographically, from univoltine in the northern population to bivoltine in the southern populations. These results showed that A. pallidipennis rapidly adapted to seasonal environmental conditions in Japan after its introduction. 相似文献
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14.
Abstract. Eight strains of the spider mite Tetranychus urticae, originating from different localities in western and central Europe, with latitudes ranging from 40.5 to 60oN, displayed marked differences in the period of chilling at 4oC required for diapause termination under a diapause-maintaining short-day photoperiodic regime at 19oC, to which the mites were transferred after the cold period. The higher the latitude from which the strains originated the longer was the period of chilling required for diapause termination, suggesting the presence of a gradient in diapause intensity, diapause being deeper the more northern the origin of the strains. Two strains originating from higher altitudes appeared to have a much deeper diapause than expected from their latitudinal origin. In addition, these two mountain strains showed mutual differences in diapause intensity, notwithstanding the fact that they originated from similar latitudes and altitudes; local climatic conditions probably act as strong selective forces with regard to diapause depth. All strains appeared to be sensitive to photoperiod during the period of diapause development. Diapause was quickly completed by a long-day photoperiod (LD 17:7 h), but was maintained by a short-day photoperiod (LD 10:14h). However, even under the latter regime sensitivity to photoperiod gradually diminished and eventually disappeared, thus leading to ‘spontaneous’ termination of diapause. The length of the period of diapause development, as measured by the sensitivity to photoperiod of diapausing mites, varied between strains; it was shorter in the southern strains and longer in the northern strains. The results indicate great variation in diapause intensity between strains, which is probably genetically determined and may have adaptive significance for this widespread species. When young females which had just entered diapause were kept for ever longer periods of time under the diapause inducing short-day regime at which they had been reared, before being transferred to the cold room, the duration of the period of chilling required for diapause termination was found to decrease proportionally in all three strains tested. These results suggest that intensification of diapause does not occur in T. urticae; diapause intensity seems to be highest at the beginning of diapause and to diminish gradually during diapause development. 相似文献
15.
RAMI KFIR 《The Annals of applied biology》1993,123(1):1-7
The effect of temperature, photoperiod, artificial diet and water on the termination of diapause by larvae of the stem borer, Chilo partellus (Lepidoptera: Pyralidae), was studied in the laboratory. Termination of diapause as indicated by pupation was affected mainly by a combination of high temperature and a long day photoperiod. Total darkness did not prevent termination of diapause and pupation occurred also in larvae which were never exposed to water. Long days accelerated pupation, but, under 16 h daylength, termination of diapause was faster than under constant illumination. Provision of artificial diet had no effect or slowed down pupation but water decreased the time to pupation. Under 28°C, 16 h daylength and availability of water, C. partellus diapausing larvae terminated diapause and pupated in about 9 days. 相似文献
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17.
Effect of photoperiod on the development and diapause of the green lacewing Chrysopa pallens (Neuroptera: Chrysopidae) 总被引:1,自引:0,他引:1
To investigate the physiology of Chrysopa pallens, the effect of photoperiod on diapause and development was examined in a Japanese population (33.4°N). The response stage for diapause of C. pallens was considered to be the prepupal stage. The critical photoperiod for diapause induction at 20.0°C was between 13 h light : 11 h dark (LD 13:11) and LD 14:10. The larval developmental period was affected by photoperiod: larvae in diapause took longer to complete their development. This difference of larval developmental period in relation to photoperiod was considered to be an adjustment of larval diapause timing. 相似文献
18.
Sean F. Ryan Patti Valella Gabrielle Thivierge Matthew L. Aardema J. Mark Scriber 《Insect Science》2018,25(2):328-336
A key adaptation in insects for dealing with variable environmental conditions is the ability to diapause. The tiger swallowtail butterflies, Papilio glaucus and P. canadensis are ideal species to explore the genetic causes and population genetic consequences of diapause because divergence in this trait is believed to be a salient factor in maintaining a hybrid zone between these species. Yet little is known about the factors that influence diapause induction in this system. Here we explored how spatial (latitudinal), environmental (temperature) and genetic (hybridization) factors affect diapause induction in this system. Specifically, a series of growth chamber experiments using wild caught individuals from across the eastern United States were performed to: (1) evaluate how critical photoperiod varies with latitude, (2) isolate the stage in which induction occurs, (3) test whether changes in temperature affected rates of diapause induction, and (4) explore how the incidence of diapause is affected in hybrid offspring. We find that induction occurs in the larval stage, is not sensitive to a relatively broad range of temperatures, appears to have a complex genetic basis (i.e., is not simply a dominant trait following a Mendelian inheritance pattern) and that the critical photoperiod increases by 0.4 h with each increasing degree in latitude. This work deepens our understanding of how spatial, environmental and genetic variation influences a key seasonal adaptation (diapause induction) in a well‐developed ecological model system and will make possible future studies that explore how climatic variation affects the population dynamics and genetics of this system. 相似文献
19.
Epistatic interaction is an important genetic basis of grain yield and its components in maize 总被引:4,自引:0,他引:4
X. Q. Ma J. H. Tang W. T. Teng J. B. Yan Y. J. Meng J. S. Li 《Molecular breeding : new strategies in plant improvement》2007,20(1):41-51
A population of 294 recombinant inbred lines (RIL) derived from Yuyu22, an elite maize hybrid extending broadly in China,
has been constructed to investigate the genetic basis of grain yield, and associated yield components in maize. The main-effect
quantitative trait loci (QTL), digenic epistatic interactions, and their interactions with the environment for grain yield
and its three components were identified by using the mixed linear model approach. Thirty-two main-effect QTL and forty-four
pairs of digenic epistatic interactions were detected for the four measured traits in four environments. Our results suggest
that both additive effects and epistasis (additive × additive) effects are important genetic bases of grain yield and its
components in the RIL population. Only 30.4% of main-effect QTL for ear length were involved in epistatic interactions. This
implies that many loci in epistatic interactions may not have significant effects for traits alone but may affect trait expression
by epistatic interaction with the other loci. 相似文献
20.
《Chronobiology international》2013,30(2):102-113
Environmental cues, mostly photoperiod and temperature, mediated by effects on the neuroendocrine system, control reproductive diapause in female insects. Arrest of oocyte development characterizes female reproductive diapause, which has two major adaptive functions: It improves chances of survival during unfavorable season(s), and/or it confines oviposition to that period of the year that is optimal for survival of the eggs and progeny. Although reproductive diapause is less well studied in male insects, there may be no sex-dependent differences in regard to the first of these functions. The second one, however, is not valid for the male; instead, selection pressure directs the male's reproductive strategy toward maximum chances of fertilization of the female's eggs with minimum waste of energy. Therefore, in species with female reproductive diapause, the males may or may not exhibit diapause, but if they do, their diapause must be adapted to that existing in conspecific females. Male reproductive diapause is defined as a reversible state of inability of the male to inseminate receptive females. In relation to reproductive diapause, there are several patterns of coadaptations between male reproductive strategy and timing of female receptivity, (a) In some insects, the females are receptive in the early part of their diapause; mating occurs during this period and there is no diapause in the male. The male dies shortly after copulation and the female stores the sperms to fertilize the eggs that develop after termination of the female's diapause, (b) In some species, as in the grasshopper Anacridium aegyptium, females are receptive during diapause; though oocyte development is arrested, copulation occurs and the stored sperms fertilize the eggs when the female's diapause ends. Males were claimed to have no diapause, but recent studies have revealed the presence of a reproductive diapause in a proportion of the males. This and other cases show that female receptivity during reproductive diapause may or may not be accompanied by male reproductive diapause. If there is a reproductive diapause in the male, it is controlled by the same endocrine mechanism, the corpora allata (CA), as in the females, (c) In many species females are refractory during their diapause. In these cases, males exhibit reproductive diapause, which may be light, as in the beetle Oulema melanopus, or well established, as in certain grasshoppers, butterflies, and beetles. In the latter cases, male diapause is controlled by similar environmental cues (photoperiod, temperature) and by the same intrinsic mechanism (neuroendocrine system, especially CA) as female diapause. Nevertheless, male diapause is less intense; the environmental cues leading to its termination are less complex and/or less extreme, so male diapause terminates before that of the females. Presumably, male diapause is under two antagonistic selection pressures: A male should not waste energy by courting dia-pausing refractory females, but he should be ready to copulate as soon as the females become receptive, otherwise he may lose in the competition between males for females. Some further strategies, which do not seem to fit the above patterns, are also outlined. 相似文献