Chromosomal Polymorphism and Female Receptivity in a Natural Population of DROSOPHILA PERSIMILIS

In a natural population of Drosophila persimilis (McDonald Ranch, Napa Valley, California), KL and MD chromosomal arrangement frequencies undergo a seasonal cycle, with MD common in spring and KL common in summer. Samples collected from spring and summer provided isofemale strains established as homozygous KL and MD pairs (kinlines) with each pair derived from a single heterokaryotype wild progenitor. Haploid doses of chromosomes 2 and 4 were controlled by marker-cross derivations of kinlines. Percentage onset of female receptivity was measured from cultures at 25° and at 15°, using ten kinlines from spring and nine from summer collections, with fast-mating hybrid males as standard testers. Mating tests consisted of 20 tester males x 20 females of specific age, karyotype, and kinline observed for 30 min. At 25° females became receptive at 48 hr after eclosion: parental line (KL_i/KL_i and MD_i/MD_i) females were approximately equal at 55 to 60% receptive, while among hybrids, MD_i/MD_j homokaryotype females were significantly less receptive (68%) than all other outbred combinations (73 to 77%). At 15°, females became receptive at four days of age, with increases on the fifth and sixth days: both parental line and outbred MD/MD females were significantly more receptive (28% at four days and 62% at six days) than all heterokaryotype females (20 to 26% at four days and 55 to 59% at six days), which in turn were more receptive than KL/KL parental and outbred females (10% at four days and 40% at six days). Heterosis was expressed at 25°, but not at 15°. Thus, dominance for female receptivity was temperature dependent. Females polymorphic for these third chromosomal karyotypes possess differential temperature sensitivity for onset of receptivity and are likely to contribute in a significant way to the observed seasonal frequency cycle in the natural population from which they have been derived.     

Physiological factors in the courtship processing of Drosophila melanogaster

The sexual receptivity of young virgin Drosophila melanogaster females develops between 24 and 48 hr from eclosion. Measurement of this process suggests that percentage receptivity (reflecting ‘switch-on’) and courtship duration (reflecting ‘courtship processing’) may not be controlled by entirely different processes. A decline in courtship duration was found to accompany the swtich-on of receptivity, suggesting that the settings in the courtship processing system are under the control of the same developmental process.Once a female has become sexually mature her courtship processing system is set to require certain quantities of courtship before acceptance occurs. This setting is stable, at least while the female is still virgin, and is correlated with a fundamental variable in the reproductive biology of the female, her fecundity.     

Male aggression,limited female choice and the ontogeny of mating behaviour in the flesh fly Sarcophaga crassipalpis

Previous work has shown that male flesh flies (Sarcophaga crassipalpis Macquart) exhibit an ontogeny of behaviour from eclosion through sexual maturity that includes extensive changes in the expression of aggressive, non‐aggressive interactive and non‐interactive behaviours. To determine how the presence of a female flesh fly influences the manifestation of these behaviours, male flesh flies of different ages post‐eclosion are paired with same‐age females and their behaviours are monitored in a simple arena during a 50‐min observation period. All flies are socially isolated until pairing. Although the levels of expression of aggressive and non‐aggressive interactive behaviours are depressed relative to previous findings in male‐opponent pairs, the ontogeny of aggression still occurs as indicated by a significant increase, with age, in the agonistic behaviour ‘hold’. Similar to male‐opponent pairs and individual males, the performance by males of the non‐interactive behaviours ‘walking’ and ‘standing’ diminishes, whereas ‘upside‐down’ increases with age. By contrast, ‘grooming’ shows a significant age‐related decline. No courtship behaviours are observed in the males, although the aggressive behaviour ‘hold’ is a significant transition to mating. Females show no obvious courtship or rejection behaviours, although the significant increase in ‘upside‐down’ with age could possibly be a behavioural gateway to mating. The results of this study indicate that extensive age‐related changes encompassing the entire behavioural repertoire are intrinsic to male flesh flies and persist under a variety of different social contexts.     

Effect of social condition on behavioral development during early adult phase in <Emphasis Type="Italic">Drosophila prolongata</Emphasis>

Behavioral changes during early development provide useful insights into the internal mechanisms that generate complex behavior expressed by mature individuals. At the same time, social conditions during early adult phase can influence behavior in later stages of development even in holometabolous insects. In this study, age-dependent changes in courtship behavior and the effect of social conditions were examined in a fruit fly, Drosophila prolongata. Younger males showed lower mating activity and simpler courtship behavior. Mating activity reached a maximum level by 5 days after eclosion, whereas expression of complex courtship behavior was not yet fully developed at that time, suggesting that they are controlled by different mechanisms. When two males were maintained in the same vial, not only mating activity but also courtship complexity was reduced, demonstrating for the first time that preceding social experience, not current social conditions, influenced the complexity of male courtship. The effect of social experience was completely erased by 1 day of isolation, however, showing that social experience did not suppress or promote behavioral development itself. Rather, these results suggest that the observed effect of social experience was a plastic response of males that reduced investment in courtship effort by anticipating increased male–male competition.     

半闭弯尾姬蜂羽化、交配及产卵行为观察

在22℃,相对度60％～70％的实验室条件下,研究了半闭弯尾姬蜂Diadegma semiclausum的羽化、交配与产卵行为。结果表明：半闭弯尾姬蜂蜂蛹从开始羽化到羽化结束历经4d,羽化高峰期出现在羽化的第3d,羽化数量为25头,占全部羽化数量的58．82％;第3d中羽化高峰出现在8：00～13：00,羽化数量为16．5头,占全天羽化数量的66．00％。半闭弯尾姬蜂交配过程大致分为3个阶段：准备阶段、交配阶段、结束阶段;交配后开始产卵,产卵过程大致分为寄主寻找和确定、穿刺和产卵、产卵结束和梳理。     

大猿叶虫交配行为的观察

大猿叶虫Colaphellus bowringi Baly是十字花科上的重要害虫,一生能多次交配。本试验在25℃,光周期L∶D=12∶12条件下观察了大猿叶虫成虫连续7d的交配行为。结果表明:(1)每日平均交配(5.67±0.26)次,最高可达11次,不同日龄间的交配次数存在显著差异。(2)平均每日用于交配的时间为(238±10)min,占总时间的33.5%,最长可达493min,占总时间的68.5%,不同日龄间的交配时间有极显著差异。(3)交配持续时间最短8min,最长达289min,平均为(48±2)min;同一日内,随着交配次数增加,交配持续时间逐渐缩短;不同日龄间的交配持续时间存在显著差异。(4)相邻两次交配之间的间隔时间最短5min,最长300min,平均交配间隔(75±3)min;交配间隔时间随日龄的增加而明显延长。     

草地贪夜蛾生殖行为及其昼夜节律研究

草地贪夜蛾Spodoptera frugiperda是当前跨国迁飞性重大害虫,云南是其重要虫源地及其向内地迁移的重要通道。生殖行为是性选择和物种进化的重要基础,基于生殖行为的害虫监测和防治策略也有重要价值。本研究模拟自然条件下可能出现的择偶情况,采用永久配对和每日更换配偶两种处理,对草地贪夜蛾成虫一生(约10 d)的生殖行为和节律进行了连续观测。结果表明,该蛾在羽化当日(0日龄)即出现召唤和求偶行为但无交配发生,在1日龄开始出现交配行为并在2日龄开始产卵,从2日龄到6日龄期间一直保持了较高的生殖活动,之后开始下降。雄虫求偶与雌虫召唤在节律上有较高的同步性,交配高峰多出现在召唤和求偶高峰之后。每日更换配偶与永久配对相比,雌蛾表现出较高的求偶频率和持续时间,较高交配比率和频率。雌虫在遇到新配偶或与新配偶交配后,会延缓产卵或下调产卵速率。从性选择理论来看,这些行为策略将有助于雌虫获得物质或基因利益,值得进一步探究。交配次数、召唤时长与雌虫寿命之间相关性不显著,但前5 d产卵速率与雌虫寿命间存在显著负相关,即早期产卵量较高的雌虫寿命较短,符合早期繁殖-后期存活基因拮抗假说。     

Towards the identification and synthesis of the sex pheromone of the citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae)

The objective of this work was to characterize the sexual behavior of the citrus leafminer, Phyllocnistis citrella Stainton, as the foundation for the isolation, identification, and synthesis of the complete sex pheromone of this species. Mating occurred in a time window of 2h, starting 1h before the onset of photophase. The large majority of tested insects mated in the first two days after emergence, with no significant difference between mating at day 1 and day 2. A stereotypical courtship and copulation behavior were described for this species. When mating was successful, the copulation was recorded in average for 49.6 min. In Y-olfactometer tests conducted at the time of mating activity, males were strongly attracted to caged virgin females as well as to extracts from putative pheromone glands.     

MATING PROPENSITY AND COURTSHIP BEHAVIOR IN SERIALLY BOTTLENECKED LINES OF THE HOUSEFLY

The efficacy of bottlenecks to stimulate divergence in courtship behavior and consequent premating isolation was tested by serial founder-flush episodes of three sizes (one, four, or 16 pairs) on a population of houseflies established in the laboratory from a single field population. After the fifth founder-flush episode, intraline and interline crosses were performed to detect divergence in mating propensities and patterns of assortative mating. Videotapings of intraline courtships for the bottleneck lines and the control were evaluated for changes in courtship repertoire. All bottleneck lines showed significant divergence from the control in male and/or female mating propensity and in courtship behavior. Divergence from the control was bidirectional for both male and female mating propensities as well as for courtship element utilization. Out of 15 tests for assortative mating between bottleneck lines and between bottleneck lines and the control, only two cases of positive assortative mating and one case of negative assortative mating were detected. Because some bottleneck lines showed increased courtship element utilization and because decreased courtship utilization in some bottleneck lines was related to higher male mating success, the mechanisms behind the Kaneshiro model (which is based upon ancestral females discriminating against bottleneck males that had “lost” courtship elements) were not supported in general. A partitioning effect of the bottlenecks upon the intrinsic variation in the ancestral population for courtship pattern appeared to explain a large component of the directions of divergence from the control. Still, the pattern of divergence of some bottleneck lines apparently was not constrained by the intercorrelation structure of courtship behaviors detected in the control. Because previous studies showed that the bottleneck lines had rebounded from inbreeding depression to fitness levels of the control, this study documents nondebilitating differentiation in the courtship repertoire that can account for divergent mating propensities and premating isolation.     

Changes in exploration from courtship to the breeding state in red-rumped parrots (Psephotus haematonotus)

Animals explore their environment to gather information about feeding areas, resting places, or suitable territories for reproduction. During the annual cycle seasonal variation in exploration occurs at least in some species. In this study, exploratory behaviour of red-rumped parrots (Psephotus haematonotus) was investigated during part of the reproductive period including courtship and incubation. On 2 test days 14 pairs in either the courtship or the breeding state were confronted with three unknown objects in their familiar aviary for 6 h on each of 2 days. Test days were separated by a 2-day pause. Exploration by the males did not change from courtship to breeding, whereas in females latency to first contact increased, and duration of exploration and the number of objects touched decreased from courtship to breeding state. Considering the pair as a unit, the total duration of exploration was shorter in breeding pairs than in pairs during courtship. Changes in exploration from the first to the second day of object exposure occurred in both sexes. Males explored longer on the second day, females contacted the objects significantly later on the second day but showed no significant changes in duration of exploration. The changes in exploration might be due to changed cost/benefit considerations during courtship and breeding.     

Age at reproductive maturity and effect of age and time of day on sex attraction in the potato psyllid Bactericera cockerelli

Abstract The potato psyllid, Bactericera (= Paratrioza) cockerelli (?ulc) (Hemiptera: Triozidae), is a major pest of potato. Studies were conducted to determine the age at which both males and females reach reproductive maturity and the effect of age and time of day on sex attraction. Adult B. cockerelli reach reproductive maturity within 48 h post‐eclosion, with females being mature on the day of eclosion and males at 1 day post‐eclosion. Oviposition generally began 2 days after mating but was delayed when females mated within 2 days post‐eclosion. In laboratory olfactometer assays, the age of females used as odor sources and the age of males assayed to these odors did not affect sex attraction, with both younger (1–4‐day‐old) and older (8–10‐day‐old) males being attracted to females, regardless of female age (1–4‐day‐old or 8–10‐day‐old). Males assayed to live females at different times during the photophase (between 8:00 and 20:00 hours) were attracted to females between 11:00 and 17:00 hours, showing a temporal periodicity in sex attraction with B. cockerelli at least during the photophase.     

Age‐related activity patterns are moderated by diet in Queensland fruit flies Bactrocera tryoni

Life‐history parameters and the fitness of tephritid flies are closely linked to diet. Studies of locomotor behaviour can provide insights to these links, although little is known about how locomotor behaviour is influenced by diet. In the present study, video recordings of Queensland fruit flies Bactrocera tryoni Froggatt (Diptera: Tephritidae) (‘Q‐flies’) that are maintained individually in cages are used to determine how diet affects the activity patterns (flight, walking, grooming, inactivity) of males and females at ages ranging from 4 to 30 days. The frequency and total duration of activities over 10‐min trials are affected by diet, age and sex. Supplementation of diet with hydrolysed yeast results in a higher frequency and duration of flight in flies of all ages and both sexes. The effect of diet on other activities varies with age. Q‐flies fed sugar only increase walking frequency steadily from 4 to 30 days post‐eclosion, whereas flies fed sugar + yeast have higher walking frequencies at 4 and 10 days than flies fed sugar only, although they then exhibit a sharp decline at 30 days post‐eclosion. The frequency and duration of inactivity remain consistent in flies fed sugar + yeast, whereas flies fed sugar only exhibit a marked increase in inactivity from 4 to 30 days post‐eclosion. Compared with older flies, 4 day‐old Q‐flies fed sugar only spend considerably more time grooming. The potential of activity monitoring as a quality control test for flies that are mass‐reared for use in sterile insect technique programmes is discussed.     

Vibrational playbacks and microscopy to study the signalling behaviour and female physiology of Philaenus spumarius

The meadow spittlebug Philaenus spumarius, vector of the bacterium Xylella fastidiosa, relies on vibrational communication to accomplish mating: the female calls to establish a duet with a male. A deeper knowledge of the species’ reproductive biology and behaviour would provide useful information for developing control techniques based on principles of ‘biotremology’, which studies the vibrational behaviour of animals. Playback tests were conducted on single females and male–female pairs of P. spumarius from June to October 2018, and the features of the recorded calling signals were analysed using a wavelet decomposition. Dissections were performed on females to evaluate the relationship between calling activity and ovarioles development. From August onwards, females started to emit calling signals and to develop ovarioles. Female calling activity, duration of their chirps and their responsiveness to mating increased as the season progressed, and they were correlated with ovarioles’ development and presence of mature eggs. Hence, the ovarian maturation represents a key factor in association with the development of the sexual behaviour of P. spumarius females. Conversely, males produced advertisement signals soon after adult eclosion in May, but these signals were not involved in the pair formation process. Mating was achieved only when males produced courtship signals in response to female calling signals and established with them vibrational duets starting from August. Here, we provide new information regarding the P. spumarius’ ethology and hypothesize that potential mating disruption techniques should consider the insect physiology and be applied when both sexes are responsive to mating signals.     

星豹蛛求偶和交配行为

以星豹蛛(Pardosa astrigera)为研究对象,在室内对其求偶和交配行为进行了描述。雄蛛"俯卧撑"式动作(push-up)在求偶中具重要作用。交配初期,两侧触肢交替插入;随交配进行,单侧触肢连续插入3~5次后才换另一侧触肢插入,触肢每插入一次,基血囊膨大多次。完整交配一次雄蛛触肢器平均插入次数为29·625。交配前求偶时间、交配持续时间和有效交配时间分别平均为6min、32min25s和11min11s。星豹蛛雄蛛可进行多次交配,而雌蛛一般为单次交配。雌蛛交配状态(是否已经交配)影响其同类相食行为,已交配雌蛛对雄蛛同类相食率显著高于未交配雌蛛对雄蛛同类相食率。     

Maturation of the flight motor pattern without movement inManduca sexta

The development of the flight motor pattern was studied by recording acutely with fine wire electrodes inserted in the thoracic muscles of pharate moths of known age and by recording chronically for up to 8 days with implanted electrodes. Externally visible morphological characteristics by which the age of a pharateManduca sexta can be established were identified (Table 1). Bouts of activity lasting approximately 30 min to 2 h and alternating with inactive periods of similar duration were recorded as early as the ninth day after pupation and on all successive days until early on the day of eclosion, typically 19 days after pupation (Figs. 1,5). During the 3 days preceding the day of eclosion a rhythmic flight motor pattern was produced (Fig. 2). The rhythmic activity ceased 5^1/2–10^1/2 h before eclosion and only an occasional, large potential change was recorded from the thoracic muscles during this time (Fig. 3). During the 3 days of rhythmic activity the percent-age of time that the animal was active did not change (Fig. 4). The flight motor pattern matured, in that the cycle-time decreased and became less variable (Fig. 6). The approximate flight phase relationship between an elevator muscle and the dorsal longitudinal depressor muscle did not become less variable as the cycle-time improved. The flight motor pattern produced by pharate moths caused neither movement of the scutum nor an increase in thoracic temperature in marked contrast to the consequences of adult motor activity (Fig. 7). Intracellular recording from the dorsal longitudinal muscle of pharate moths 20–30 h before eclosion showed that, after repeated stimulation of the motor nerve at 2/s, only small junctional potentials were elicited (Fig. 8). A burst of 6 stimuli at 50/s elicited 2–5 active membrane responses and a contraction. These observations explain the absence of thoracic movement in immature animals producing the flight motor pattern and the presence of movement in immature animals stimulated to eclose. They also show that the neuromuscular junction matures rapidly during the day before eclosion.     

Analysis of the Territorial, Courtship and Coupling Behavior of the Hemipterophagous Butterfly, Spalgis epius (Westwood) (Lepidoptera: Lycaenidae)

In this study we examined the territorial, courtship and coupling behavior, mating interruptions and influence of sunlight on mating behavior in Spalgis epius (Westwood). We constructed an ethogram of territorial and courtship behavior, and catalogued the sequence of behavioral acts associated with mating behavior. Mating behavioral acts were divided into four repertoires i.e. pre-courtship, pre-coupling, coupling and post-coupling behaviors. Totally 22 behavioral acts were recorded from four repertoires. Tree canopy, canopy height and sunlight conditions are the important factors that influence copulation in S. epius. The courtship activity led to successful copulation in 71.9 % pairs. Incidence of different types of courtship and copula interruptions in S. epius was also recorded.     

Behavior of triatomines (Hemiptera: Reduviidae) vectors of Chagas' disease. II. Influence of feeding, lighting and time of day on the number of matings, mating speed and duration of copulation of Panstrongylus megistus (Burm, 1835) under laboratory conditions

To determine the influence of feeding, lighting and time of day on the copulating behavior of Panstrongylus megistus, 480 insect pairs were divided into four groups of 120 each and tested in the following respective situations: without food deprivation (F.D.), with five days of F.D., with ten days of F.D., and with 20 days of F.D. The tests were performed between 9:00 a.m. to 12:00 a.m. and 7:00 p.m. to 10:00 p.m., with light (700-1400 lux) and in the dark (1.4-2.8 lux) and behavior was recorded by the time sampling technique. Mating speed (MS) and duration of copulation (DC) were also calculated for each situation. The maximum frequency of copulation was observed after five days of F.D., at night, in the dark (n = 16), and the minimum was observed for recently-fed pairs, at night, with light (n = 4). Males approached females more often than females approached males. MS was lowest in pairs with twenty days of F.D., at night, with light (mean = 23.0 +/- 16.0 minutes), and highest in recently-fed pairs, during the day, with light (mean = 2.9 +/- 2.5 minutes). DC was shortest in recently-fed insects, during the day, in the dark (mean = 23.5 +/- 6.7 minutes), and longest in recently-fed animals, at night, in the dark (mean = 38.3 +/- 6.9 minutes).     

垂叶榕果内寄生瘿蚊的发生规律

在云南西双版纳热带地区,一种还未被描述属和种的瘿蚊寄生于垂叶榕果内的雌花子房里,并膨大形成虫瘿,靠取食花胚组织完成发育.通过2010年定时定点的系统观察和研究瘿蚊的发生规律,结果发现:该种瘿蚊在垂叶榕上发生频率较高,抽样的18批果有17批被瘿蚊寄生,其中有13批果的寄生比率超过了60％,部分甚至达到100％.瘿蚊寄生雌花的平均比率不超过6％,平均每个榕果内有瘿蚊1～40只不等.瘿蚊寄生不仅降低了垂叶榕的种子数,还致命性地影响着传粉榕小蜂的繁殖.在对瘿蚊的羽化、交配行为及其成虫的活动规律观察中,结果显示:寄生在一个榕果里瘿蚊需要5～7d才能羽化完,其羽化高峰期出现在第2～3天;一天内羽化的高峰出现在上午8:00-10:00及晚上20:00-0:00;而羽化后瘿蚊活动高峰期出现在上午8:00-11:00.雄蚊会帮助雌蚊离开榕果并优先获得交配权,雌蚊交配后飞离繁殖自身的榕树,去寻找适合产卵的榕果繁殖后代,雄蚊不离开羽化树,而死在繁殖自身的榕树附近.这些结果为深入研究瘿蚊的防治技术提供了科学依据.     

Diurnal locomotion activity of adult rice bug, <Emphasis Type="Italic">Leptocorisa chinensis</Emphasis> (Hemiptera: Alydidae), at different ages,measured by actograph and video camera

To elucidate the relationship between locomotion activity and reproductive status versus age after eclosion of the rice bug, Leptocorisa chinensis, locomotion activity and mating behavior were investigated by use of an actograph and video recording system. Locomotion activity of males and females 3, 7, 14, and 21 days after eclosion was recorded. High locomotion activity was observed in the scotophase. In both sexes, the activity pattern changed with age; that is, settling mode was observed in younger (3 and 7 days old) individuals and locomotion mode in older (14 and 21 days old) individuals. Locomotion activity in the scotophase in settling-mode individuals was lower than in locomotion-mode individuals, and they often stayed on rice panicles all day. On the other hand, the activity of locomotion-mode individuals was high throughout the scotophase. Most locomotion-mode males had mature gonads. Courtship and mating behavior occurred in the scotophase. The results indicate that L. chinensis adults spend a lot of time on food plants and their gonads develop during the young, teneral period. They subsequently change to the locomotive mode and move around, probably for reproductive activity.     

Mating speed and the interplay between female and male courtship responses inDrosophila melanogaster (Diptera: Drosophilidae)

The objective of this study was to compare measures of general activity and sexual behavior for various genotypes within a strain of Drosophila melanogaster, which had known differences in mating speed. Three inbred lines of D. melanogaster differed significantly in mating speed when tested in female-choice and in single-pair experiments. Analyses of locomotor activity and sexual activity of females and males revealed no significant differences between the inbred lines. An analysis of the interplay between female and male courtship behaviors enabled the examination of signal-response differences between the inbred lines. The inbred lines with intermediate and slow mean mating speed showed a decreased number of significant transitions between female and male behavioral responses. This decrease was more severe in the slow mating line. Further, the intermediate- and slow-mating females and males displayed courtship responses toward signals of the opposite sex that were different from those of the fastmating line. Models of the relationship between behavioral activity and mating speed in Drosophila are discussed and a different explanation for variation in mating speed among the three inbred lines is considered.