Female preference for male courtship flashes in Photinus ignitus fireflies

In Photinus fireflies, males produce spontaneous bioluminescentcourtship flashes. Females preferentially respond to particularmale flashes with flashes of their own. This study exploredvariation in female flash responsiveness as a function of maleflash duration, female condition, lantern size, and lanterndistance, as well as the relationship between male characteristicsand spermatophore mass in Photinus ignitus fireflies. We determinedfemale preference by scoring female flash response to simulatedmale flashes and determined variation in overall female flashresponsiveness for laboratory-mated, laboratory-fed, and controlP. ignitus females. Flash duration, lantern size, and body masswere recorded for field-collected males. Males were then matedto determine spermatophore mass. Females exhibited greater preferencefor artificial flashes representing the upper range of conspecificmale flash duration and lantern size as well as flashes producedat a closer distance. Both laboratory-mated and laboratory-fedP. ignitus females showed lower overall responsiveness acrossall flash durations relative to control females that did notmate or feed in the laboratory. Male flash duration predicteda significant proportion of the variation in spermatophore massfor early-season males. These results suggest that female Photinusignitus may prefer long flashes in order to obtain the directbenefit of larger spermatophores and may adjust their overallflash responsiveness as the relative importance of this benefitvarieswith changing female condition.     

Abdomen Posture and Flash Gesture Direction in a Female Synchronic Firefly <Emphasis Type="Italic">Photinus carolinus</Emphasis> (Green) (Coleoptera: Lampyridae)

North American Photinus fireflies use bioluminescent flashes to communicate an individual’s species and sex, and to attract potential mates. A female firefly responds to a male firefly’s courtship flash with her own species-specific flash. We used a photic stimulator to produce male-like species-specific P. carolinus LED courtship flashes. These evoked species-specific response flashes from a female. The female’s flashes were preceded by a flash gesture comprising a sequence of abdominal postural adjustments (pitch, roll, and yaw). These gestures changed her lantern’s orientation which, at rest, was downward towards the substrate. Our results demonstrate that these gestures mediate a lateralization of the female’s response flashes towards the direction of the stimulating LED. That is, she directs her response to the left of midline when stimuli are presented from her left, and similarly, she directs her response to the right of midline when stimuli are presented from her right. The directional aspect of the flash gesture adds a new perspective to the complexity of the behaviors associated with flash communication in fireflies. Lateralization of the flash gesture suggests that the female’s visual system processes information about the location of male’s flashes as well as their temporal pattern.     

Flash communication between the sexes of the firefly, Photuris lucicrescens

ABSTRACT. The courtship signal of the male firefly, Photuris lucicrescens Barber (Coleoptera, Lampyridae), is a brilliant crescendo flash which grows in intensity, reaches a peak and abruptly terminates. It was found to be triggered by a long neural burst from the brain. Males and females produce weak, twinkling flashes which induce male crescendo flashes. Female responses were triggered by a slowly rising intensity, and female response latency is therefore variable. Male and female P.lucicrescens fireflies produce two different types of flashes and both these flashes play an integral part in their courtship communication.     

Flash signals, nuptial gifts and female preference in photinus fireflies

The evolution of male courtship signals such as the bioluminescentflashes of fireflies may be shaped, at least in part, by femalepreference for particular characteristics of the male signal.These female preferences for male courtship signals may ariseas a result of the benefits of choosing males with particulartraits. One possible benefit of mate choice occurs if femalescan use male courtship signals as an honest indicator of malenutritional contributions at mating, nuptial gifts. This paperreviews female preference for male flash characteristics inPhotinus fireflies (Coleoptera: Lampyridae), and the potentialfor females to use male flash characteristics to predict nuptialgift quality. In Photinus firefly species with single pulseflashes females preferentially respond to flashes of greaterintensity and duration. Male Photinus provide a nuptial giftto females at mating in the form of a spermatophore and flashduration serves as a good predictor of spermatophore mass formales collected early in the season. However, Photinus firefliesdo not feed as adults, so spermatophore mass decreases withsubsequent matings. In response, nutrient-limited females maystop preferentially responding to longer duration flashes, increasingtheir overall responsiveness later in the mating season as theyforage for spermatophores. Therefore, the evolution of malecourtship signals in Photinus fireflies is the product not onlyof female preference for male flash characteristics, but alsothe costs and benefits of female choice that shape these preferences.     

Allometry and proximate mechanisms of sexual selection in photinus fireflies, and some other beetles

Ever since Darwin identified it as the force responsible forthe evolution of exaggerated male characters, sexual selectionhas been the focus of research aimed at understanding the mostbizarre and intriguing morphologies and behaviors in Nature.Two congeneric species in the firefly genus Photinus, P. pyralisand P. macdermotti, afford a unique opportunity to examine theinteraction between sexual and countervailing natural selectionthat act to shape the evolution of mating behavior and bodysize in closely related species with very different courtshipstrategies. Photinus pyralis males emit very bright flashesduring their extended patrolling flights and form ‘loveknots’ of competing suitors, while P. macdermotti males,whose courtships seldom exceed two competing males, produceweaker flashes during a shorter patrolling period. Possibly as a consequence of their scramble competition andlong flights, not only is there an extremely wide range of bodysizes in P. pyralis males, but they also exhibit wing allometricslopes greater than one, and lantern allometries less than one.In contrast, P. macdermotti males do not have allometric slopessignificantly different from one. Small males, when tested inan artificial scramble situation move faster than large males,an advantage in the intense competition that ensues once a femaleis located. Females answer several males in alternation andfail to respond to all male flashes, with the evident consequencethat love knots frequently develop around such fickle females.Allometric relationships in two non-luminescent beetle specieswith non-visual courtship protocols are compared. Visual, sexuallyselected characters showed positive allometric slopes, whilenon-visual characters showed isometry or negative slopes. Datapresented here support the existence of distinct patterns inmodality-specific sexual selection.     

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.     

Attraction of the sexes inFormica lugubris Zett (Hymenoptera: Formicidae)

Summary Sexuals ofFormica lugubris fly to mating places, where females attract males by using a sex pheromone. Females collected on the nest surface before departing on a mating flight are much less attractive than those collected on the mating place after the mating flight, suggesting that the mating flight triggers the release of the sex pheromone. Olfactory cues are essential for males to locate females while they patrol. Males probably use visual cues to locate females once they have alighted nearby them. Males are also attracted by aggregations of other males on the ground, probably because one or several females are likely to be close to male aggregations.     

Flash Precision at the Start of Synchrony in Photuris frontalis

Synchronous flashing occurs in certain species of SoutheastAsian and North American fireflies. Most Southeast Asian synchronyinvolves stationary congregating fireflies, but North Americansynchrony occurs in flying fireflies that do not congregate.Southeast Asian synchrony is usually continuous, but North Americansynchrony is interrupted. Photuris frontalis, the only memberof the North American genus Photuris to synchronize, shows anintermittent synchrony. This involves synchronization and repeatedre-synchronizations while in flight. The precision that occursat the start of synchrony was studied in Ph. frontalis usingcaged fireflies and photometry. Barrier experiments (using twofireflies) or flash entrainment experiments (using one LED andone firefly) were performed to measure the temporal precisionof the first entrained flash. In both cases, the first entrainedflash was close to unison synchrony (phase = 1.0) and showedlittle variability. The behavioral implications of the abilityto synchronize with the first entrained flash are not known,but it might facilitate male-male interactions during brief,transient encounters such as maintaining distance between closelyflying males in search of females.     

Male courtship signals and female signal assessment in Photinus greeni fireflies

The evolutionary dynamic of courtship signaling systems is drivenby the interaction between male trait distributions and femalepreferences. This interaction is complex because females maychoose mates based on multiple components of male signals, andfemale preference functions may vary depending on mate availability,female reproductive state, and environmental conditions. InPhotinus fireflies (Coleoptera: Lampyridae), flying males emitbioluminescent flash signals to locate sedentary females, whichreply selectively to attractive male flash signals with theirown response flash. In this study, we first examined temporalvariation in the paired-pulse flash patterns produced by Photinusgreeni males in the field and found significant among-male variation(70% of total variation) in interpulse intervals (IPIs). Therewas no significant relationship between male IPI and spermatophoresize, suggesting that P. greeni male courtship signals do notprovide females with reliable indicators of male material resources.In laboratory playback experiments, we presented P. greeni femaleswith simulated flash signals to assess how IPI and pulse durationindependently affected the likelihood of female flash response.We also examined the effects of female body mass and time duringthe mating season on female preference functions, hypothesizingthat females would be less discriminating when they were heavier(more fecund) and when mate availability declined. We foundthat P. greeni females discriminated among signals within theirspecies' range based primarily on flash pattern IPI. Neitherthe time during the mating season nor female weight alteredfemale preference functions for IPI, although season did influencefemale response to pulse duration. These results reveal thatP. greeni females discriminate among conspecific males basedprimarily on male IPIs, the same signal character previouslyshown to be important for firefly species recognition. Fieldplayback experiments indicated that female responsiveness peakednear the average IPI given by males at different ambient temperatures,suggesting that fireflies exhibit temperature coupling similarto that seen in many acoustically signaling animals.     

Intercolony variation in foraging flight characteristics of black‐headed gulls Chroicocephalus ridibundus during the incubation period

Using GPS loggers, we examined the influence of colony, sex, and bird identity on foraging flight characteristics of black‐headed gulls Chroicocephalus ridibundus during the incubation period. We studied tracks of 36 individuals breeding in one urban and two rural colonies in Poland. Birds from both rural colonies performed the furthest flights (mean max distance 8–12 km, up to 27 km) foraging mainly in agricultural areas. Gulls from the urban colony performed shorter flights (mean 5 km, up to 17 km) visiting mainly urbanized areas and water bodies. We found that females performed longer flights and their flight parameters were less repeatable compared to males. Males from both rural colonies visited water bodies more frequently than females. In all colonies, males (but not females) used habitats unproportionally to their availability in the vicinity. Relatively low interindividual and relatively high intraindividual overlap in home ranges indicated considerable foraging site fidelity. Individuals specialized in the use of a particular type of habitat performed shorter foraging flights compared to individuals using diverse habitats during their foraging flights. Our results indicate diverse foraging strategies of black‐headed gulls, including generalists that explore various habitats and specialists characterized by high foraging site and habitat fidelity.     

Diurnal and seasonal changes in the mate-locating behavior of the satyrine butterfly <Emphasis Type="Italic">Lethe diana</Emphasis>

The time schedule of mate-locating behavior in the male satyrine butterfly Lethe diana was studied. Males displayed territorial behavior only in the afternoon, but it was not known whether they attempted to locate mates in the morning. In order for males of most butterfly species to mate with a virgin female, it would be most effective to initiate mate-locating behavior in the morning, when synchronous eclosions occur. Males of L.diana flew patrols in the morning and displayed territorial behavior in the afternoon. The cost of territorial behavior is probably less than that of patrolling, as territorial flights are shorter than those when patrolling. The temporal switching of mate-locating behavior is theoretically favored, since the reproductive value of females decreases later in the day, when males perform the less costly mate-locating behavior. Thus, the diurnal switching of male mate-locating behavior may be an adaptive strategy in response to the rapid decline in the reproductive value of females over the course of a day.     

Is the firefly flash regulated by calcium?

The very different courtship flashes of Photuris versicolorand Photuris lucicrescens males mirror the pattern of neuralimpulses produced by their brain. Their lanterns luminescencevery differently, however, in response to direct, electricalstimulation. Whereas P. lucicrescens lanterns glow in responseto high frequency, continuous electrical stimulation, thoseof P. versicolor produce only rapid, triple-pulsed flashlettesthat resemble, but are not identical to, their courtship flashes.In addition, the exposed lantern tissue of P. versicolor males,when immersed in firefly saline high in potassium and calciumions, scintillates with hundreds of photocytes flashing in randomfashion. P. lucicrescens male lanterns, so treated, only glow.Tests of P. versicolor lanterns with salines of different compositionsuggest that calcium ions are essential in producing this intense,long lasting scintillation response and are therefore possiblyimplicated in the final stages of flash control in this species.     

Role of interflash intervals in a firefly courtship (Photinus macdermotti)

The flash code of Photinus macdermotti fireflies has been measured over a temperature range of 16 to 25°C. The code changes in characteristics fashion during different phases of firefly courtship. Males produce rhythmic patrolling flashes while flying, and when answered, shift to courtship flash pairs of significantly shorter interval. Females will answer some consecutive patrolling flashes and normally respond after the second flash of each male courtship pair. A possible behavioural role for the shifting of male patrolling and courtship flash intervals and for the female's response patterns is proposed.     

Environmental and physiological factors influencing phototactic flight of Bemisia tabaci

Abstract. Experiments were conducted in a glasshouse and in the laboratory to determine the environmental and physiological parameters that affect flight behaviour of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). The number of whiteflies taking off and exhibiting a positive response to sky light in the glasshouse was greatest from 08.30 to 10.00 hours. During peak flight activity less than 5% of the population engaged in phototactic orientation. Temperature was the best single predictor for the phototactic response, accounting for 75% of the variability in whitefly ascent. Sex ratios were determined for individuals remaining on poinsettia, Euphorbia pulcherrima (Willd.), and for individuals that exhibited phototactic orientation; both groups deviated from an expected 1:1 ratio. Males were more prevalent on the plants (1:0.76), whereas females were much more prevalent (1:3.02) among the whiteflies responding to sky light. A higher percentage of the females displaying a phototactic response contained eggs when compared to females remaining on poinsettia (87 v 65%). The two groups of females did not differ significantly in their weights, but males that remained on the plants were heavier than males that responded to sky light. Mark–recapture studies and experiments where phototactic individuals were removed from the population established that the response was short-lived. Whiteflies exhibiting a phototactic response in the glasshouse were more likely to exhibit long-duration, phototactic flights in a vertical flight chamber when compared to individuals that remained on poinsettia (80.7 ± 6.7 v 36.0 ± 5.8% phototactic response; 7.0 ±3.2 v 0.7±0.2min flights). There was also less deviation in flight across the horizontal plane among the individuals that exhibited a positive response to sky light in the glasshouse in comparison to individuals that remained on their host. However, initial rates of climb were not significantly different between the two groups of whiteflies.     

Oxygen Evolution from Algae Illuminated by Short and Long Flashes of Light

The oxygen produced by illuminating Ankistrodesmus braunii withsingle light flashes has been determined using the Hersch galvanicoxygen cell. Measurements were made with the cells suspendedin alkaline solution equilibrated with nitrogen containing oxygenat a partial pressure of 10^–4 mm. Hg.

1. A single light flash, if very brief (less than 5 millisec.)results in no measurable oxygen production; a longer flash (35millisec.) gave a yield of approximately 1 mole O₂/800 moleschlorophyll.
2. A pair of flashes suitably spaced gave a greateryield thanthe sum of the yields when given individually, althoughonewas so brief that by itself it produced no measurable oxygen.The yield of a long flash preceded by a short flash was twiceas great as that of the long flash given alone; when the flashorder was reversed the combined yield was smaller but stillgreater than for the long flash alone.
3. The combined yieldof a pair of flashes varies with the intervalseparating theflashes, rapidly rising to a maximum and thendecaying moreslowly. With a long and short flash the optimalinterval was0.7 sec. but some enhancement of yield was observedwhen theflashes were separated by as long as 10 or 15 sec.
4. When theflashes were superimposed on background illuminationthe yieldswere increased and were measurable even for the shortflashes.Measured with background illumination the optimal yieldfora pair of short flashes was obtained with flashes separatedby about 0.05 sec.

     

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.     

Spontaneous flash communication of females in an Asian firefly

Fireflies are well known for the use of bioluminescence for sexual communication. In species using flash signals for pair formation, species and sexual identity are conferred by flash timing parameters such as flash duration, flash interval, flash number, and response delay. In dialog fireflies in North America, the male is the advertiser and the female is the responder. In these species, the male flash signal parameter varies depending on species, but the female flash signal parameter is limited only to response delay. However, in fireflies other than dialog fireflies, sexual flash communication is not well studied. Although many female-advertisement-like fireflies are reported, we have no confirmed case of sexual communication in a female-advertisement species. Here, we report the sexual flash communication of an Asian firefly, Luciola (Hotaria) parvula, in which the female flashes spontaneously. By using an electronic firefly, we confirm experimentally that males are specifically attracted to flashes with a female-specific flash duration. This is the first experimental report of sexual communication of a female advertiser in firefly communication. In this species, females call males usually with spontaneous flashes unlike dialog fireflies.     

Behavioral ecology of Japanese paper wasps,Polistes spp. III. Decision making byP. chinensis antennalis foundresses at the departure from nests

Analysis of the behavior of foundresses of a Japanese paper wasp,Polistes chinensis antennalis Pérez, was made to clarify the patterns of decision making. It was found that: (1) Foundresses postponed the next activity off the nest after being attacked by a foundress from another colony. (2) After a spiral flight, the frequency of subsequent spiral flights and patrol flights around the nest increased. (3) Following successful flesh collection, the frequency of flesh collection increased. (4) Following successful flesh collection, the time spent for a single trip of flesh collection increased. It was concluded thatP. chinensis antennalis foundresses solve their dilemma between the need of nest defence and resource gathering by decision making based on intraspecific attacks and the intake of the most difficult resource to obtain.     

Photic Inhibition of Brain Stimulated Firefly Flashes

A study of the effects of photic stimulation on the abilityto induce flash luminescence in the female Photuris fireflyby electrical brain stimulation was made. Pulses of light deliveredto the eye of the firefly aie not only able to inhibit spontaneousflashing but also reduce the ability of electrical biain stimulito induce firefly flashes. Inhibition by photic pulses is mosteffective when the pulses are delivered approximately 300–400msec prior to brain stimulation. Only flashes of biain stimulus—flashonset latency greater than 120 msec can be inhibited in thisfashion, while driven flashes of 90 msec were immune from theinhibitory effect. It is suggested that the inhibilory effectsof photic stimulation provide some physiological explaintionof the male-female response latency found in the courting fireflies.     

The behavioral responses of a nocturnal burrowing marsupial (Lasiorhinus latifrons) to drone flight

The use of drones in wildlife research and management is increasing. Recent evidence has demonstrated the impact of drones on animal behavior, but the response of nocturnal animals to drone flight remains unknown. Utilizing a lightweight commercial drone, the behavioral response of southern hairy‐nosed wombats (Lasiorhinus latifrons) to drone flights was observed at Kooloola Station, Swan Reach, South Australia. All wombats flown over during both day and night flights responded behaviorally to the presence of drones. The response differed based on time of day. The most common night‐time behavior elicited by drone flight was retreat, compared to stationary alertness behavior observed for daytime drone flights. The behavioral response of the wombats increased as flight altitude decreased. The marked difference of behavior between day and night indicates that this has implications for studies using drones. The behavior observed during flights was altered due to the presence of the drone, and therefore, shrewd study design is important (i.e., acclimation period to drone flight). Considering the sensory adaptations of the target species and how this may impact its behavioral response when flying at night is essential.