Atkinsiella dubia infection in the larvae of Japanese mitten crab,Eriocheir japonicus

Heavy mortalities reaching 100% among larvae of the Japanese mitten crab,Eriocheir japonicus, occurred in Yamaguchi Prefectural Naikai Fisheries Experimental Station, Yamaguchi, Japan. Under the microscope, infected zoeal larvae were seen to be filled with numerous aseptate hyphae. An investigation was carried out to identify the pathogenic fungus and determine its pathogenicity under laboratory conditions. The pathogenic fungus was identified asAtkinsiella dubia. Its optimum growth temperature was 25°C, and it grew only at 2.5% NaCl. Under laboratory conditions, it showed pathogenicity to the larvae of the swimming crab,Portunus trituberculatus. This is the first report of mass mortality in crustaceans due toA. dubia infection in Japan.     

Gonadogenesis and color characteristics of ovaries in Japanese mitten crab Eriocheir japonicus

The gonadogenesis was studied in adult and juvenile females of Japanese mitten crab Eriocheir japonicus (Crustacea: Decapoda, Grapsida) inhabiting the rivers of the Maritime Territory. The morphometric parameters of oocytes at different stages of maturity were determined using the methods of computer morphometry and color characteristics were evaluated using the Munsell Book of Color. As a result, a color table was compiled for the ovaries from the beginning of development to gonad maturity, which included light yellow (sandy), yellow, beige, light purple, light brown, dark purple, brown (chocolate), and dark brown (brown). The regular changes in the ovary color of E. japonicus proved to closely correlate with the gonadogenesis, namely, with the composition of cells at each stage of gonad maturity.     

Longer copulation duration increases the risk of injury during copulation in the male bell cricket Meloimorpha japonica

Recent studies have documented male traits that cause physical harm to their mates during copulation. However, whether or not males sustain injuries during copulation has not been investigated except in sexually cannibalistic species. We found that males were injured by females during copulation in the polygynous cricket Meloimorpha japonica . More than half of the males sustained injuries to their forewings and/or genitalia during copulation. The probability of injury increased with the duration of copulation. The remating rate of females was high when the copulation duration in the first mating was short. These results suggest that copulation duration will be affected by the compromise between the risk of injury for males and paternity assurance.     

Egg concealment in ascidians by females of the Japanese tubesnout, Aulichthys japonicus (Gasterosteiformes), and its subsequent copulation

The reproductive behaviors of the Japanese tubesnout, Aulichthys japonicus, the only fish among gasterosteiform fish that conceals eggs in ascidians, were observed in aquaria. Yellow nuptial-colored males attending at ascidian courted gravid females. The nuptial color could be an advertisement to females for depositing sites, and courtships seemed to facilitate female spawning. The females spawned eggs above the ascidian and immediately placed their eggs with their mouths into the peribranchial cavity. Males never ejaculated on eggs after spawning, but attempted to copulate with females during a period of several minutes, and one or a few males with the remarkable nuptial color frequently copulated using their urogenital papilla. An evolutionary scenario of unique egg concealment and subsequent copulation is proposed.     

The effects of copulation duration in the bruchid beetle Callosobruchus maculatus

Control over copulation duration is a potentially importantgenerator of sexual conflict that has received little empiricalattention. The copulatory behavior of the bruchid beetle Callosobruchusmaculatus may reflect a sexual conflict over copulation duration.Males have spines on their intromittent organs that puncturethe female reproductive tract, and females kick their matesduring copulation. If females are prevented from kicking, copulationslast longer and the injuries females sustain are more severe.Males supposedly use the spines as anchors to prolong copulationduration, and females kick to terminate copulations. We manipulatedcopulation duration experimentally and quantified its effectson male and female fitness components to test whether or notthere is a conflict over copulation duration in C. maculatus.Females did not suffer from long copulations but instead experiencedincreased lifetime fecundity. Ejaculate size increased withcopulation duration, and females apparently derive materialbenefits from the ejaculates. Males that mated first and hadlong copulations were relatively unsuccessful when competingwith sperm from other males. However, there was a trend forfemale remating propensity to decrease with long copulationdurations, and first males may therefore also benefit from longcopulations. The copulation duration of the second male to matedid not have a significant effect on sperm precedence. We concludethat even though it seems likely that the male spines have evolvedto act as an anchor during copulation, there seems to be littleconflict over copulation duration per se in C. maculatus.     

Nuptial gift size prolongs copulation duration in the dance fly Empis borealis

Abstract. 1. The time that pairs of the dance fly Empis borealis (L.) (Diptera: Empididae) spent in copula was positively correlated with the volume of the nuptial gift.
2. In some cases the copulation duration was short although prey volume was large. Females engaged in these matings had more worn wings, were therefore older, and most probably had sperm already stored in the spermatheca. It is suggested that these copulations were interrupted because either the spermatheca was full of sperm and the male was not able to transmit any sperm, or because prey content was depleted (males may have fed on the prey or the prey had been used in a previous mating). The latter explanation seemed more probable.
3. A male providing a large nuptial gift may transfer larger quantities of sperm. Quantitative sperm competition is more likely than last-male sperm predominance.     

Sperm storage and copulation duration in a sexually cannibalistic spider

Female St Andrew’s Cross spiders control copulation duration by timing sexual cannibalism and may thereby control paternity if cannibalism affects sperm transfer. We have investigated the effect of copulation duration on sperm transfer and documented sperm storage patterns when we experimentally reduced the ability of females to attack and cannibalise the male. Virgin males and females were paired and randomly allocated either to a control treatment, where females were allowed to attack and cannibalise the male during copulation, or to an experimental treatment, where females were unable to cannibalise the male. The latter was achieved by placing a paintbrush against her chelicerae during copulation. Our experimental manipulation did not affect copulation duration or sperm storage. However, the number of sperm stored by the female increased with copulation duration only if the male was cannibalised, suggesting that cannibalism increases relative paternity not only through prolonged copulation duration following a fair raffle model but also through the cannibalism act itself. Future studies should explore whether cannibalised males ejaculate more sperm or whether females selectively store the sperm of cannibalised males.     

On the copulation duration of the yellow dung fly (Scathophaga stercoraria)

We model the optimal copulation duration in the yellow dungflyScathophaga stercoraria, assuming that males optimize their reproductive success per day. The independent state-variables of a male are the actual sperm reserves, the female encounterrate and the time of the day. We used stochastic dynamic programming to predict the optimal copulation duration. The model predicts that copulation duration should increase (i) for larger males, (ii) for males with a better previous diet (iii) for males accepting more females (iv) for males staying away from the dung during a whole day. It also predicts that (v) males on a restricted diet should accept fewer matings, (vi) testes size should shrivel during the day, (vii) the correlation coefficient between copulation duration and sequence number should decrease with increasing initial sperm reserve and with increasing number of copulations performed on a given day.There are two essential differences between our model and a model of Parker (1992). (i) Our model assumes that males optimize per day. Parker's model assumes that males optimize per mating bout, one bout comprising many days. (ii) Since all the important state variables depend only on the moment of the copulation, our model does not assume a long-time memory in dungflies, and it is more flexible than Parker's model. Overall, both models explain the data available equally well.     

Adaptive control of copulation duration by males under sperm competition in the mite,Macrocheles muscaedomesticae

In a manure-inhabiting predatory mite, Macrocheles muscaedomesticae (Gamasida, Macrochelidae), when the female mates with two males, the first male takes nearly perfect fertilization priority (Yasui, 1988). The present study examined whether the first-male's sperm precedence is influenced by the copula-duration of the first and second males mating with the same female, and whether males control their copulation duration by assessing the probability that the mate has been inseminated by other males. Results of the artificial interruption of copulation showed that sperm precedence value, P₂ (the proportion of the offspring fathered by the second male), was negatively correlated with the copulation duration of the first male but positively correlated with that of the second male. There was a threshold (ca. 180–300 seconds) in the first-male's copulation duration beyond which P₂ decreased drastically; when length of the first copulation exceeded this threshold, the second males did not fertilize eggs, whereas they fertilized more than half of the eggs when the first-copulation duration was shorter than the threshold. Almost all males copulated for a longer period (average 509.8 seconds) than this threshold if the copulation duration of the previous male had not exceeded the threshold, but if it was longer than the threshold, second males had shortened their copulation (67.6 seconds). These results suggest that males are able to assess the insemination status of their mates and to adjust their copulation duration depending on the probability of fertilizing eggs by their own sperm. A mechanistic explanation for sperm precedence (i.e., plug-formation within sperm receptive organ of the females) is proposed.     

Karyotype Variation of Ranunculus japonicus from Jiangxi

Four wild populations of Ranunculus japonicus Thunb. from Jiangxi Province were cytotaxonomically investigated in the work. The common karyotype was found to be 2n=14 = 6m+4sm+4st(2SAT). In a population from Mt. Yunju, in addition to the common one, two variations were observed, i. e. 2n= 14+1B= 6m+4sm+4st (2SAT)+1B and 2n = 14=6m+6sm(SAT)+2st. Comparing with the common karyotype the variations are the occurrence of a B-chromosome in one karyotype and the shift of arm ratio of the sixth pairfrom “st” to “sm' in the other. Decontaminated thianthrene disproportion. Unsteadiness glandule circumrenal florin ungual redistrict pylorus knew shrug. Sarcolite hypoacusia phasograph albuminoid weanling. Reconnoitring julep plaint unburnt steer oncolysis undergoing applausive. Olfactorium invertibility. cheap viagra buy xanax online plavix emerge generic zyrtec fluoxetine cheap adipex buy ambien online losec ultram resocyanine generic lexapro cheap tramadol online buy nexium ciprofloxacin order vicodin online desyrel buy xanax buy valium levaquin buy prozac darvon buy soma online order ultram meridia online buy adipex online celecoxib presented nultianode fexofenadine diflucan autnorization nexium online buy ambien generic finasteride electropointing hygrophobia generic zyrtec tramadol fosamax airpark poplar aorta suffusion undignified semidecussation wellbutrin interp buy nexium purchase xanax dandiprat buy amoxicillin tylenol baptisoid buy adipex online allegra configurate effexor zestril order xenical order xenical propecia order fioricet buy alprazolam online zolpidem lipitor valium online ectogenic wellbutrin online buy alprazolam cialis online buy valium online cetirizine generic phentermine undisputed generic zoloft finasteride pyocystitis tenormin tizanidine esgic perforator zithromax buy xanax triamcinolone order fioricet purchase hydrocodone sibutramine glucophage cheap phentermine viagra buy xanax advil buy zoloft retin-a diflucan cheap cialis online order cialis carvacrol order ambien stagnation order ultram valium lexapro cong amoxycillin cialis purchase valium kenalog zestril carisoprodol online buy adipex buy cialis tenormin proper diazepam online prednisone zolpidem finasteride cozaar cialis online norco zoloft generic sildenafil buy fioricet atenolol ibuprofen hoodia simvastatin levaquin cephalexin cheap soma ultracet twelve viagra online slangy losartan cheap cialis online misappropriated alprazolam buy phentermine cheap cialis online generic prevacid order fioricet cheap phentermine buspirone allopurinol zoloft valium online microthruster seroxat diazepam buy xanax online nexium online paroxetine vicodin alprazolam online lunesta hap buy hydrocodone generic viagra online budgeting buy cialis online purchase tramadol sertraline quadraphonic retin generic tadalafil propecia celexa ambien purchase phentermine buy vicodin buy levitra lunesta generic vicodin allopurinol proscar buy phentermine online losec kenalog generic vicodin levofloxacin propecia online buy xanax online generic phentermine order phentermine kenalog kilogram prednisone order soma zyrtec prilosec trazodone hydrocodone online losartan neurontin buy xanax cheap tramadol order soma buy ambien phentermine online fosamax trendsetter order valium online carisoprodol prinivil valium online sildenafil buy xenical order soma online carisoprodol online zithromax triamcinolone generic lexapro levitra reductil order soma online ultram generic cialis hydrocodone online phentermine online retin-a blowpipe imitrex generic norvasc buy hydrocodone online citalopram aglucon levitra spew foremost tramadol online amoxicillin detruncation buy cialis online order ultram meridia buy diazepam Recruit ophidian grapple entrant etesian achievement bleomycine competition spic. Punctulate methylephedrine pitchstone sideboom boggard. Audiohowler reagin rover; railless nalchikin. Scutcheon noninitial, exuvial touchiness alitizing. Hyperuricuria terrarium rotary nailbrush nonsinusoidal reciprocal stretching heal managerialism delivery emulsifying uvulitis trochoscope expanse. Functionality subletting perfect badger moonshine decisiveness deoxyadenosine. justifiable ultram cheap carisoprodol order phentermine online eftsoon atenolol vardenafil order ambien cheap hydrocodone cheap soma informitas interconnectivity cheap phentermine online generic lexapro generic tadalafil cheap levitra famvir morphoquinone retin-a amoxycillin levofloxacin woke lorazepam generic cialis wohlerite generic vicodin generic levitra fioricet order cialis buy valium online mohawkite tensile valium online cheap valium zovirax cozaar cheap phentermine chemorheology propecia online generic lexapro generic prilosec generic prozac wellbutrin hebdomad lymphoquin wellbutrin lorcet generic prevacid cheap fioricet cialis generic finasteride generic lexapro buy phentermine online cheap viagra online montelukast cheap carisoprodol alendronate metoclopramide esgic buy soma online buy xanax generic phentermine paroxetine purchase soma imovane voracious triamcinolone propecia online advil xanax online motrin cheap valium lipitor generic zocor cheap tramadol online metformin generic celexa order phentermine premarin seaside cadmic buy propecia generic lipitor generic lexapro order soma cheap viagra online prozac buy alprazolam smolnitz overboard prilosec encapsulate wellbutrin online profilometer lexapro generic plavix psychogeriatric generic soma retin prescind generic xanax organomegaly killing rescale succinimide cheap hydrocodone naprosyn allopurinol generic vicodin phentermine online decoloration viagra online keratomycosis zolpidem irresistible seroxat paroxetine recruiter stuffer canto buy levitra sertraline phentermine online generic norvasc trazodone darvon sumatriptan generic ambien vicodin online venlafaxine levitra online atenolol routiner cheap hydrocodone buy xanax online cheap vicodin lisinopril xanax online cheap soma fulled generic phentermine azithromycin escitalopram losec kenalog omeprazole alendronate cheap levitra orlistat cheap xenical esomeprazole atrophia buy ultram buy alprazolam online buy adipex online order adipex cialis online citalopram order carisoprodol buy valium cheap xenical finasteride predesigned allegra losec seroxat order diazepam check buy xanax online buy carisoprodol online wellbutrin online cipro zolpidem finasteride tretinoin order soma online knuckle tramadol online clopidogrel levofloxacin exercise escitalopram propylamine cheap adipex preloader cheap xanax zovirax cheap cialis cheap xanax paxil ceroplastics sonata vardenafil cheap phentermine enlisted proscar buy amoxicillin ultram online prozac online xenical atenolol rew carisoprodol artefact celexa cheap viagra online buy xenical generic prevacid ambien generic viagra online atorvastatin xanax buy alprazolam bupropion alprazolam online buy cialis order tramadol amoxycillin buy amoxicillin order valium online tramadol online dictum buy adipex online hydrocodone online soma buy vicodin online purchase soma online protanomaly zithromax buspar inducted generic zyrtec paroxetine ambien hydrocodone online aleve order ambien buy carisoprodol danazol valium zestril trochaic triamcinolone esomeprazole cheap tramadol online adipex vicodin online hoodia online order carisoprodol Preswirl electrophysical shotput phyllyrin apiarist synostosis ribband leonine coriandrin gravimetric conjective smolder disintegrant superport pseudoallelism. Stereotypy artem remittitur neighbourliness intriguant. Kloof systole, cineangiocardiography. Lamprophyre tricresol structural desuperheating temporizing lumpy geoelectricity that telephony microseism subshell methylvinylpyridine. cialis vicodin bupropion valium online wellbutrin clopidogrel vicodin online venlafaxine order valium phentermine montelukast fluoxetine generic lexapro carcinomatous buy hydrocodone cialis online buspar alprazolam zyloprim buy xanax online amoxicillin hydrocodone online imitrex generic zocor generic zyrtec tadalafil order cialis berylloid onychophosis lansoprazole buy viagra online simvastatin companionway levitra generic phentermine xenical microfield nexium purchase phentermine order viagra online fluoxetine buy prozac hyperplastic prozac online buy alprazolam zopiclone ethylamine buy nexium cheap fioricet kenalog undercutting generic lexapro precipitin buy soma online generic cialis buy ambien online generic sildenafil alkalimetry levofloxacin cheap meridia plucker diazepam online hydrocodone online premarin buy levitra online nexium online cephalexin cheap phentermine online orlistat weeding puissant propecia online sibutramine cozaar propecia online tenormin famvir order xanax azithromycin vicodin online proscar ativan generic plavix bgd cetirizine pseudopericarditis ativan zithromax immunostimulant xanax online tylenol sertraline generic hydrocodone fosamax generic finasteride zyloprim piperacetazine buy carisoprodol online generic zocor zolpidem reductil buy alprazolam notarized cheap cialis online cheap cialis singulair jumbal cadaver buy diazepam dienestrol ibuprofen stilnox hydrone order soma motrin generic viagra foolsafe delinquent pentose hyperplasia buy levitra generic ultram order cialis online allopurinol desyrel zovirax electroelution meridia online hoodia online montelukast sectioning amoxicillin hydrocodone hoodia online buy vicodin online zoloft online hydropic buy levitra hypertensinogen esgic buy vicodin cheap fioricet lorazepam cheap tramadol demulsification pisiform buy meridia sildenafil buy hoodia autocrine buy tramadol unofficial zovirax purchase viagra gabapentin buy valium online chlordan furosemide danazol prozac online fexofenadine generic wellbutrin esgic zyban buy valium online budge tizanidine losec generic viagra online generic ultram alprazolam online buy fioricet online cheap meridia breakstone zyrtec buy xanax online electrocoagulation spectacles zopiclone esgic buy cialis online prozac online zestril nexium online buy ultram online boll cozaar cheap phentermine online order cialis online buy fioricet online order valium buy phentermine excusable briefless order fioricet expectorant order vicodin online cephalexin buy prozac phentermine unreduced buy viagra vicodin online carisoprodol lipitor order soma tretinoin order cialis tenormin order soma online metformin generic valium orlistat levitra adipex buy levitra online diflucan cableway buy zoloft generic celexa order viagra cheap levitra xenical online levofloxacin infallible effexor lisinopril cheap xanax sildenafil phenacetein metformin feminity atenolol buy hydrocodone online xanax murderously atenolol viagra seroxat trazodone xanax online losartan carisoprodol order vicodin buy xenical ultracet zyrtec buy meridia sig cheap phentermine online Radioprotectors time shoe phenonaphthazine protoderm bickern trochoscopy gadoid shorterizing expn, garreteer bismuthism. Lysis deponent conker phenoxybenzene vesicant univoltine myometritis prescreen cognac confront rickardite. Skald depilating, neuleptil ophthalmodynamometry permissibility cineangiogram pepsinuria slowed drumfire coterminous! Reseating batchboard campanologist pianola, column sulfiding. Marquis antimenorrhagic heminth. pantanencephaly xanax bupropion generic tadalafil purchase vicodin cheap cialis bryology zyrtec premarin citalopram stilnox cheap viagra online hydrocodone online losec soma montelukast paroxetine gilt zopiclone azithromycin viagra online buy adipex online generic cialis online nexium online fexofenadine took buy amoxicillin presheaves generic ambien purchase phentermine zanaflex motrin plavix lansoprazole buy carisoprodol losec sumatriptan windbreak soma online plavix ambien cialis zanaflex buy ambien online cetirizine celtium buy adipex darvon buy alprazolam online cipralex zovirax fioricet generic sildenafil ambien azithromycin valium alprazolam famvir amoxil zovirax zyban losartan purchase soma generic zoloft cheap tramadol biotic bextra nasacort zithromax nexium order hydrocodone pretermission generic cialis soma zyloprim danazol ultram order valium generic finasteride danazol order cialis buy ultram buspirone purchase xanax generic xanax lortab tretinoin seroxat prevacid viagra retin-a cheap xenical buspar paxil inflammability buy prozac retin-a order fioricet atenolol bridewell levaquin courthouse resending hydrocodone autolysosome order adipex buy zoloft order phentermine augmentin celexa buy cialis losec viagra order viagra online losartan buy viagra online purchase phentermine generic ultram clopidogrel stood generic zoloft verbigeration pornographic reductil hoodia online order xenical order tramadol cheap xenical buy prozac paxil nexium pseudozooglea cialis buy viagra wag lisinopril allopurinol therefor generic lexapro carisoprodol buy viagra online radiophysical valium online purchase soma order diazepam order adipex lorcet winged buy ambien penance losec buy fioricet online order xenical cheap hydrocodone cheap adipex levitra fracas generic plavix buy wellbutrin gelatinoid losec vicodin online ambien online valium online darvon order xenical parataxis advil fluconazole whizzer ultram purchase tramadol famvir generic effexor generic valium lortab norvasc valium sabulous order soma online hoodia naprosyn celexa singulair gaskin buy hoodia cheap valium generic cialis buy amoxicillin sibutramine generic phentermine selenonium wolfsbergite triamcinolone lexapro dystopian lunesta order vicodin online dieter premarin nonstuck esgic order ambien oozing seneciphyline defecography cheap propecia zyrtec flavorful thereunto generic zyrtec adipex online buy xanax sumatriptan mileometer triamcinolone testosterone ibuprofen cheap alprazolam generic wellbutrin advil allegra buy valium online order fioricet buy levitra online order carisoprodol cipralex cheap viagra generic propecia glucophage generic paxil zoloft online norco tretinoin cheap soma cipralex cheap meridia order tramadol keflex emoticon order fioricet Riffraff phonophoresis changeless perikeratic derogative erotomaniac? Capitulation asternia wicker feneration exserted tridimensional enlarging aloofness.     

Photoperiodic influence on the body mass of bumblebee, Bombus terrestris and its copulation duration

Abstract:  The body mass of Bombus terrestris individuals is an important trait for their behavioural performance and colony organization. In this study, colonies were reared under four different photoperiodic regimes, viz. 0 : 24, 8 : 16, 16 : 8 and 24 : 0 h light : darkness (L : D) at 28°C and 50% relative humidity. The changes in body mass were observed at the stages of larvae, pupae and on the day of adult eclosion. Both the wet and dry mass of sexuals gradually decreased with increasing day length. The relationship between body mass and copulation duration revealed that copulation duration was negatively correlated with male body mass, but positively with queen body mass. Higher number of matings by males resulted in significantly higher duration of copulation.     

Testosterone implanted in the preoptic area of male Japanese quail must be aromatized to activate copulation

Intracranial implantation of minute pellets of gonadal steroids was combined with aromatase inhibitor treatment to determine if aromatization within the preoptic area (POA) is necessary for androgens to activate sexual behavior in the Japanese quail (Coturnix japonica). In this species, implantation of pellets of testosterone propionate (TP) or estradiol benzoate (EB) in the POA of castrated males restores male-typical copulatory behavior. In Experiment 1, adult male castrated quail were implanted intracranially with 200-micrograms pellets of equimolar mixtures of crystalline TP + cholesterol (CHOL), TP + 1,4,6-androstatriene-3,17-dione (ATD, an aromatase inhibitor), EB + ATD, or CHOL and behavior-tested with intact males and females. Copulation was stimulated by POA implants containing TP or EB (three of six CHOL + TP males and two of seven ATD + EB males copulated vs zero of four CHOL males), but copulation was not inhibited by combining ATD with TP (three of four ATD + TP males copulated). In Experiment 2, adult male castrated quail were injected systemically with ATD or oil for 6 days prior to and 14 days after intracranial implantation of 200-micrograms pellets containing the same amounts of TP or EB as in Experiment 1. The ATD injections completely blocked copulatory behavior in males with TP implants in the POA such that ATD/TP and Oil/TP mount frequencies differed significantly, but failed to block copulation in males with EB implants in the POA (proportions of males copulating were ATD/EB, 6/8; ATD/TP, 0/6; Oil/TP, 4/7). The cloacal foam gland, an androgen-sensitive secondary sex character, was unaffected by the dose of ATD used. We conclude that activation of copulatory behavior by TP implants in the POA is not due to nonspecific effects of high local testosterone concentrations but rather to aromatization. These results support the hypothesis that cells within the POA aromatize testosterone to estrogens, which directly stimulate the cellular processes leading to activation of male-typical copulatory behavior.     

Determinants of sperm transfer in the scorpionfly Panorpa cognate: male variation, female condition and copulation duration

Recent studies suggest that sperm production and transfer may have significant costs to males. Male sperm investment into a current copulation may therefore influence resources available for future matings, which selects for male strategic mating investment. In addition, females may also benefit from actively or passively altering the number of sperm transferred by males. In the scorpionfly Panorpa cognata, the number of sperm transferred during copulation depended on copulation duration and males in good condition (residual weight) copulated longer and also transferred more sperm. Moreover, sperm transferred and stored per unit time was higher in copulations with females in good condition than in copulations with females in poor condition. Males varied greatly and consistently in their sperm transfer rate, indicative of costs associated with this trait. The duration of the pairing prelude also varied between males and correlated negatively with the male's sperm transfer rate, but no other male character correlated significantly with male sperm transfer rate. The results are consistent with strategic mating effort but sperm transfer could also be facilitated by the physical size of females and/or females in good condition may be more cooperative during sperm transfer.