Age-dependent changes in calling effort in the bell cricket <Emphasis Type="Italic">Meloimorpha japonica</Emphasis>

We investigated how male age and body weight influence male mating effort in the bell cricket Meloimorpha japonica. We adopted a longitudinal approach to study resource allocation to male mating effort (calling duration during 24 h) in the bell cricket. Calling durations and body weight of each male were measured at 7–8 days (young age), 14–15 days (middle age), and 22–25 days (old age) after the final molt. Calling duration increased between young and middle age. During the period between middle and old age, the amount of change in the calling duration was positively correlated with the body weight. The results suggested that older (i.e., low residual reproductive value) and better quality males invested more resources in mating effort.     

Calling behavior of the female german cockroach,Blattella germanica (Dictyoptera: Blattellidae)

Virgin German cockroach females, Blattella germanica(L.), were observed, for the first time, to exhibit a characteristic calling behavior during which females emit a volatile sex pheromone. Under a photoperiod of 12L12D, the percentage of 7-day-old virgin females that exhibited this behavior peaked before the end of the scotophase in a similar pattern to the diel periodicity of mating. A clear relationship was evident between calling and stages of sexual receptivity during successive gonotrophic cycles. Females initiated calling 5–6 days after the imaginal molt, when their basal oocytes were 1.6 mm long. If not mated, females continued to exhibit bouts of calling during the next 3–4 days until 24 h before ovulation. Calling was completely suppressed by mating as well as the presence of an egg case in the genital atrium in both virgin and mated gravid females. We suggest that calling and the emission of a volatile sex pheromone serve to attract males from a distance as well as to potentiate responses to contact sex pheromone in aggregations.     

Age-dependent pattern of calling behavior in <Emphasis Type="Italic">Atheloca subrufella</Emphasis> (Hulst) (Lepidoptera: Phycitidae)

Changes in the signaling effort of virgin females are known to occur until their first mating. Young females tend to increase the calling effort (number and time duration of bouts) as they age. In this context, the calling behavior of virgin females of Atheloca subrufella, an important pest of coconut palms (Cocos nucifera), was studied under laboratory conditions. Thirty four virgin females were observed during 16 scotophases (25 ± 2 °C, 75 ± 5 % RH and 10 h scotophase), until they stopped calling in the following photophase. The calling position, pattern and frequency were evaluated. Females of A. subrufella showed only one calling position, and calling peaked between the second and fifth scotophases. Most females did not start calling immediately after emergence. Neither the individual duration of calling nor the number of calling bouts changed over time. However, the time that calling started was earlier in older females, probably to avoid competition with younger females and increase the probability of mating. These data support the hypothesis that there is an age-dependent pattern of pheromone emission in virgin females of A. subrufella.     

Mate-location flight of the red-necked longicorn beetle, <Emphasis Type="Italic">Aromia bungii</Emphasis> (Coleoptera: Cerambycidae): an invasive pest lethal to Rosaceae trees

The red-necked longicorn beetle, Aromia bungii (Faldermann) (Coleoptera: Cerambycidae), which has recently invaded Japan, is a serious pest species. The larvae kill cherry and orchard Rosaceae trees, such as peach, plum, and apricot. To clarify their features for mate location, male and female flight behaviors were observed in wind tunnels with caged males and females as lures. In a small wind tunnel (50 cm in diameter, 2 m in length), both sexes showed takeoff behavior according to increasing airflow. The rate of female takeoff against the male lure, a live male in a wire-netting cage, tended to be higher than for other combinations. In a large wind tunnel (ca. 1.6 m in diameter, 4 m in length), both sexes ascended and showed momentary hovering and astatic flight. When male lure cages were placed windward in the wind tunnel, females showed “upwind flight,” while males did not. It is assumed that females were induced to fly upwind by a factor derived from live males, likely to be an airborne pheromone component.     

Toward the Identification of the Sex Pheromone of Diatraea indigenella Dyar & Heinrich (Lepidoptera: Crambidae): Calling Behavior and Chemical Structure of a Major Component

Behavioral patterns and pheromone titer in females of the steam borer Diatraea indigenella Dyar & Heinrich were assessed for 7 days during scotophase under a 13:11 L:D photoperiod. Calling was observed from the first scotophase for most of the females. The highest percentage of calling females was recorded 6 h after the onset of scotophase. Calling bouts and length of calling were affected by age, decreasing dramatically after the sixth scotophase. By coupling chemical and electrophysiological techniques (GC–EAD, GC–MS) and olfactometer bioassays (Z,E)-9,11-hexadecadienal was identified as the main sex pheromonal component in the extracts of female glands. The concentration varied from 2.53 to 13.7 ng gland^?1 with a peak at the 6th hour of scotophase. In addition, two unidentified secondary active components were detected at very low concentrations. Behavioral assays showed that 86% of the male moths were more attracted to the gland extracts than to hexane (control), and 77% of the male moths were more attracted to the gland extract than to the synthetic major component (Z,E)-9,11-hexadecadienal. However, 68% of males preferred the synthetic major component over hexane. The identification of the major sex pheromonal component represents an important step toward the complete elucidation of the composition of the sex pheromone of D. indigenella in order to develop monitoring tools.     

Nocturnal Calling Behavior in Mantids

Females of Mantis religiosa and Empusa pennata were video taped for several 24 h periods to determine if they showed behaviors associated with pheromone release. In the photophase the abdomen of both species was motionless and rested in continuous contact with the wings. However, at the beginning of the scotophase the females bent the abdomen ventrally so that the space between the abdomen and the wings increased significantly with respect to the daytime posture. Calling behavior (abdominal bending) was maintained throughout the 8 h scotophase and ended abruptly at lights on. Females of M. religiosa did not start calling until they were 30 days of age. Calling disappeared in mated females, but it reappeared two weeks later. Males stayed motionless in response to the odors emitted by other males or by noncalling females, but walked when a calling female was placed in the air flow. These observations suggest that female mantids bend their abdomens at night to release a sex pheromone. The adaptive function of nocturnal sex pheromone release in sexually cannibalistic species that rely strongly on visual cues for mating is discussed.     

Mate choice and sexual conflict in <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> (Rotifera)

Male mate choice in Brachionus plicatilis is based on information from coronal receptors and contact chemoreception of a glycoprotein signal on the body surface of females. Male mating behavior is modulated by mating signal quality and strength, which determines male mating persistence and circling intensity. We probe the sensory abilities of males by better resolving their discrimination of female age. Males preferentially initiate mating with young females, but not too young. Males circle 0.2 h old females just hatched from resting eggs only about 1/2 as frequently as 12 h old females. Males are even more discriminating of females with whom they copulate, preferring 3 h old females significantly more than 0.2 h or 6 h old females. In contrast, males cannot distinguish between virgin females and those who have already copulated. Similarly, males circled and copulated with females hatching from resting eggs with equal frequency as those hatching from amictic eggs. The counterpoint to male mate choice is female resistance to mating. When males contact females, the females respond with one of four behaviors: no response, acceleration, foot flipping, or coronal retraction. In 65% of male–female encounters, there was no initial response by females. However, when males began circling females, females accelerated 11.1 times more often than when males were absent. The second type of evasive female behavior was foot-flipping, which tends to knock off males attempting to circle the female. In the presence of circling males, females performed foot-flipping behavior three times more often than in the absence of males. Coronal retraction, where they stop swimming and withdraw their corona, was observed less frequently than acceleration or foot-flipping, and there was no difference in the presence or absence of males. These data are interpreted in the context of sexual conflict, where the behaviors that optimize male and female fitness differ. Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont & R. Rico-Martínez Advances in Rotifer Research     

Encounter with heavier females changes courtship and fighting efforts of male field crickets Gryllus bimaculatus (Orthoptera: Gryllidae)

The effects of mating experience on male mating behavior are mediated by four factors: mating cost, such as resource depletion, perception of mating opportunities, self-perception of attractiveness, and female quality. For example, encountering females might increase male expectations of prospective mating opportunities, while copulation increases self-perception of attractiveness in males. To determine the relative importance of these factors, the effect of mating on the two components of reproductive effort (courtship and fighting effort) in Gryllus bimaculatus was examined. Calling activity before and after encountering females was measured, and copulation success was recorded. Subsequently, the intensity and outcome of male–male fighting behavior was recorded. Female encounter increased calling activity irrespective of copulation, thereby indicating that the perception of mating opportunities is important factor for the males. Changes in courtship effort of males were larger and fighting success was lower when they were previously paired with relatively heavier females. These results indicate that male reproductive effort is also affected by quality of previous mating partners.

     

Effects of exposure to pheromone and insecticide constituents of an attracticide formulation on reproductive behavior of oriental fruit moth (Lepidoptera: Tortricidae)

The effect of exposure to both the pheromone and insecticide constituents of an attracticide formulation on subsequent pheromonal response of male oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), was tested in several wind tunnel bioassays. Male response to the attracticide formulation was significantly reduced in all behavioral categories, including source contact 1 h after sublethal exposure (both by voluntary contact in the wind tunnel and forced application in the laboratory) to the attracticide formulation containing inert ingredients, pheromone, and insecticide. Sublethal exposure to the attracticide formulation in the laboratory (forced application) 24 h before the bioassay resulted in a significantly lower proportion of males subsequently responding to attracticide droplets in the wind tunnel. However, voluntary contact of male moths with the toxic formulation in the wind tunnel had no effect on subsequent response 24 h later. Exposure of males to different constituents of the attracticide formulation demonstrated that both pheromone and insecticide exerted effects on subsequent male pheromonal response. Exposure to the formulation containing the inert ingredients plus the pheromone (no insecticide) significantly reduced male behavioral responses to an attracticide droplet in the wind tunnel 1 h but not 24 h after exposure, compared with males treated with inert ingredients alone. Response to attracticide droplets was further reduced by exposure to the entire attracticide formulation containing inert ingredients, pheromone and insecticide at both 1 and 24 h postexposure. Similarly, males exposed to inert ingredients plus pheromone were less likely to orient to female-produced plumes 1 h but not 24 h after exposure than males treated with inert ingredients alone. Response to female-produced plumes was further reduced at 1 h but not at 24 h after exposure to the entire attracticide formulation. Mating success of males was significantly reduced by exposure to the entire attracticide formulation but not to the formulation without insecticide when placed with females 1 and 24 h postexposure. These findings suggest that sublethal poisoning of males exposed to the attracticide formulation will enhance the effectiveness of this formulation under field conditions.     

旋花蛾性信息素成分的鉴定

提取和鉴定了杂草田旋花Convolvulus arvensis的天敌旋花蛾Tyta luctuosa的性信息素主要成分,并应用风洞实验对雄蛾进行了测试。结果表明,腺体提取物和雌蛾求偶时所释放的主要性信息素成分均为2种化合物：顺-9-十四碳烯醛（Z9-14∶Ald）和顺-11-十六碳烯醛（Z11-16∶Ald）。腺体提取物中2种化合物的总量在个体间差异很大（22～167 ng）,但二者的比率相对稳定（Z9-14∶Ald/Z11-16∶Ald=0.3±0.15）。雌蛾所释放的性信息素量及比率在个体间也存在差异。每只雌蛾求偶时平均每小时释放94 ng Z9-14∶Ald和45 ng Z11-16∶Ald,平均比率为2.2。风洞实验结果显示,48%的雄蛾可被合成的性信息素混合物（0.4 μg Z9-14∶Ald, 2 μg Z11-16∶Ald）引诱完成逆风飞行并最终触及刺激源,而2种对照组（以求偶期雌蛾或性信息素腺体提取物为刺激源）的引诱率则分别为62%和44%。     

Effects of methoxyfenozide-treated surfaces on the attractiveness and responsiveness of adult codling moth (Lepidoptera: Tortricidae)

The attractiveness and responsiveness of adult codling moth, Cydia pomonella (L.), exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide was investigated in wind tunnel and orientation tube assays. When males were exposed to either water- or surfactant-treated surfaces for 48 h, and regardless of what treatment surfaces the females had been exposed to, the mean percent recaptures of such treated males in the wind tunnel assay were sometimes significantly greater than the recaptures of males that had been exposed to methoxyfenozide. Similarly, in the orientation tube assay, males exposed to methoxyfenozide-treated surfaces almost always had significantly lower mean levels of individuals exhibiting sexual excitability and the mean distances traveled upwind, regardless of female exposures. The two assays demonstrated that male codling moths exposed to methoxyfenozide-treated surfaces were not as responsive to calling females (treated and nontreated) as were the nontreated males. Conversely, females exposed to methoxyfenozide-treated surfaces were just as attractive to nontreated males as were nontreated females. It appears that a male's ability to respond to a calling female is more negatively affected by the ecdysone agonist than a female's ability to call and attract males.     

Mating tactics in the sub-Antarctic deep-sea squid <Emphasis Type="Italic">Onykia ingens</Emphasis> (Cephalopoda: Onychoteuthidae)

The behavior of polar deep-sea nekton is very poorly known. To obtain insight into mating behavior of the abundant and ecologically important sub-Antarctic deep-sea squid Onykia ingens, our goals were to (1) quantify spermatophore production; (2) determine the preferred location for spermatangia deposition; (3) investigate whether male and female O. ingens mate with multiple mates; and (4) discuss the location of implanted spermatangia in light of mating behavior and egg fertilization. Toward this end, we examined male and female O. ingens specimens from Falkland Island and New Zealand waters. Male O. ingens store up to 198 spermatophores (mean 103 ± 61; n = 12) in their reproductive system, which are produced over a period of considerable somatic growth (200–400 mm ML), and which may have a considerable size range. Males insert their long extendible terminal organ in the mantle cavity of the female, potentially through the funnel, to deposit spermatophores in one or more of four regions on the female’s body. Most implanted spermatangia (52.5 %) were found in the funnel region, but many were also found inside the mantle cavity closer to the oviducts. Males with longer terminal organs therefore may be able to position closer to the oviducts where fertilization chances are higher than for spermatangia located in the funnel region. The number of implanted spermatangia per individual female (4–60, mean 29 ± 20; n = 24), the multiregional spermatangia deposition, and the different outer appearance of spermatangia, suggested that females have multiple mating events. Since males produce more spermatophores (up to 200) than the number of spermatangia in one region (<60), it is likely that males too mate with more than one female. We show how quantitative assessment of reproductive characteristics can provide insight into the reproductive behavior of deep-sea species for which in situ observations are currently lacking.     

Effects of male age on the mating behavior of both sexes in the sorghum plant bug, Stenotus rubrovittatus (Hemiptera: Miridae)

In the sorghum plant bug Stenotus rubrovittatus (Matsumura) (Hemiptera: Miridae), mating behavior consists of male courtship and female mating receptivity. Previous studies have found that female age is correlated with ovary development and that mature females with developed ovaries are more receptive to male courtship. Thus, we examined whether male age affects the mating behavior of both sexes and male accessory gland development. Unmated males 0–9 days after emergence and 3-day-old virgin females receptive to male courtship were studied. Immediately after emergence, only 20 % of the males courted females (n = 25). At 3 days old, 68 % of the males courted females (n = 25), the most active age. In contrast, more than 75 % of the courted females were receptive to the male courtship regardless of male age. These results indicate that only male courtship behavior is affected by male age, although it is not enhanced in proportion to male age. Male accessory glands developed with male age. However, no clear relationship was detected between male courtship behavior and accessory gland development. In S. rubrovittatus, it is difficult to explain male courtship behavior solely from male age and accessory gland development.     

Effect of Larvae Treated with Mixed Biopesticide Bacillus thuringiensis - Abamectin on Sex Pheromone Communication System in Cotton Bollworm,Helicoverpa armigera

Third instar larvae of the cotton bollworm (Helicoverpa armigera) were reared with artificial diet containing a Bacillus thuringiensis - abamectin (BtA) biopesticide mixture that resulted in 20% mortality (LD₂₀). The adult male survivors from larvae treated with BtA exhibited a higher percentage of “orientation” than control males but lower percentages of “approaching” and “landing” in wind tunnel bioassays. Adult female survivors from larvae treated with BtA produced higher sex pheromone titers and displayed a lower calling percentage than control females. The ratio of Z-11-hexadecenal (Z11–16:Ald) and Z-9-hexadecenal (Z9–16:Ald) in BtA-treated females changed and coefficients of variation (CV) of Z11–16:Ald and Z9–16:Ald were expanded compared to control females. The peak circadian calling time of BtA-treated females occurred later than that of control females. In mating choice experiment, both control males and BtA-treated males preferred to mate with control females and a portion of the Bt-A treated males did not mate whereas all control males did. Our Data support that treatment of larvae with BtA had an effect on the sex pheromone communication system in surviving H.armigera moths that may contribute to assortative mating.     

the effect of pair formation on diel calling patterns in two cricket species,Gryllus veletis andGryllodes sigillatus (Orthoptera: Gryllidae)

After pair formation, male crickets should reduce calling to minimize the risks to males of attracting predators and/or rivals. We tested this hypothesis in two cricket species, one in which males exhibit a high mating propensity (Gryllus veletis)and another in which the mating propensity of males is constrained by the manufacture of elaborate, bipartite spermatophores (Gryllodes sigillatus).Calling durations of male G. veletisdeclined precipitously after the introduction of females but remained unchanged in G. sigillatus.We attribute the asymmetric effect of female proximity on male calling to differences in the mating propensity of males of the two species. Male G. veletisabstain from further calling in favor of repeated matings with the same female. Male G. sigillatusprobably lack the opportunity to mate repeatedly with the same female and, thus, resume calling shortly after mating to increase their probability of attracting additional mates.     

Investigations of Mechanisms of Pheromone Communication Disruption of Choristoneura rosaceana (Harris) in a Wind Tunnel

Although atmospheric treatment with synthetic pheromone is used commercially to control several lepidopteran pests, little is known about how mate-finding behavior is altered by this procedure. Mechanisms of disruption of the mate-finding behavior of Choristoneura rosaceana (Lepidoptera: Tortricidae) were examined in wind tunnel bioassays. Male moths were exposed to synthetic sex pheromone or pheromone components prior to or during upwind flight to a calling virgin female. The proportion of males successfully contacting a calling female was reduced only when the synthetic pheromone treatment was presented simultaneously. A synthetic source of the attractive four-component pheromone placed upwind of a calling female was more effective than a less attractive two-component blend in achieving disorientation. Habituation of the central nervous system does not appear to be a significant factor in disruption of mate-finding behavior of male C. rosaceana, as exposure to pheromone prior to the bioassay did not alter the proportion of males that achieved subsequent upwind flight. Disruption of mate-finding behavior of C. rosaceana in a wind tunnel is probably the result of a combination of mechanisms including adaptation of antennal receptors, camouflage of the female-produced plume, and false-trail following which contributed to the additive disruption effect observed with the most attractive four-component pheromone.     

Emergence, Mating, and Postmating Behaviors of the Oriental Beetle (Coleoptera: Scarabaeidae)

In a previous field-trapping study of the oriental beetle, Exomala orientalis (Waterhouse), by using synthetic sex pheromone on golf course fairways, numerous males were observed and trapped during the hours of peak mating activity. However, very few beetles were observed in the same areas when synthetic pheromone was absent. To investigate the hypothesis that mating in nature occurs cryptically within vegetation at the soil surface, laboratory studies on female emergence and pheromone release, male emergence and mate-locating, and female and male mating behaviors were conducted. Mate acquisition and copulation occurred on the soil surface near the female emergence site, with both sexes engaging in pheromone-mediated behaviors after having emerged from the soil. A highly stereotyped female pheromone release, or calling, behavior was observed, consisting of insertion of the female's head into the soil and elevation of the tip of her abdomen into the air. Bioassays conducted in a wind tunnel that simulated a turf fairway environment showed that walking and flying were both important in the upwind response of males to females. Mating and copulation occurred without an obvious complex courtship, but observations of postmating behaviors suggested that mate guarding occurs.     

Reproductive behaviour of the South American fruit fly Anastrepha fraterculus (Diptera: Tephritidae): laboratory and field studies

Abstract. The mate choice, courtship and oviposition behaviour of laboratory-reared and field-collected Anastrepha fraterculus (Wied.) were compared. In laboratory cultures in Southampton the duration of male calling activity in small leks increased gradually from 1-2h at 5 days old to up to 7 h at 10 days. This finding correlates with previous reports on the time at which male salivary glands, which are believed to produce sex pheromone, are fully developed. Wild flies which emerged from infested fruits in Brazil began to oviposit on the day they mated, whereas in laboratory flies oviposition began 1 day following the first mating. Both types of fly usually defended their position on a particular fruit throughout the day, and re-mated with either virgin or mated males. There was no significant difference in mating duration. Females did not copulate before the mean age (±SE) of 16.8±0.9 days. For both types of flies mating initiation occurred in the first 2h of photophase, with virgin females choosing mainly mated males. The average number of matings in the laboratory was three for females and four for males, and the interval between matings in females was significantly increased after the second mating. It is suggested that the tendency of virgin females to mate with mated males will lead to increased fitness, as males are on average 48 days old at their second mating. The potential life span of around 200 days for both sexes would allow adults to bridge the gap between seasonally available fruits in warm-temperate and sub-tropical South America.     

Factors influencing the release of volatiles in Anastrepha obliqua males (Diptera: Tephritidae)

During sexual signaling, males of Anastrepha obliqua (Macquart) form leks and attract females by producing sounds and releasing volatile compounds. The objective of this study was to investigate the influence time of time of day, age, irradiation, mating status, and the presence of host fruit on the release of volatile components by laboratory-reared A. obliqua males. A. obliqua males released four compounds identified by gas chromatography coupled with mass spectrometry (GC-MS) as (E,E)-alpha-farnesene, (Z,E)-alpha-farnesene, (Z)-3-nonenol, and a farnesene isomer during calling behavior. Although males released volatiles during the entire day, the amount of volatiles was higher in the early morning and afternoon hours. Males began to emit volatiles when they were 6 d old, but only the amount of (Z)-3-nonenol was affected by age. Irradiation of flies with gamma rays from a (60)Co source at a dose rate of 0.8 Gy significantly reduced the amount of volatiles released during calling behavior. The amount of volatiles was lower in recently mated males than virgin males. However, there were no significant differences between virgin males and males 24 h after mating. The presence of host fruit did not affect the amount of volatiles compared with the control.     

褛裳夜蛾的交配行为及雄蛾对性腺提取物的反应节律

详细观察了褛裳夜蛾成虫的交配行为,利用风洞、触角电位技术研究了雄蛾对性腺提取物的反应节律,通过林间诱蛾试验进行了验证,旨在为褛裳夜蛾性信息素的精确提取及性信息素组份分离、鉴定提供依据。研究结果表明:成虫的求偶、交配行为均发生在暗期,有一定的节律性:雌蛾在羽化3d以后开始求偶,1周左右表现最为强烈,3-4日龄雌蛾在暗期4-6h开始求偶,最大求偶率在暗期6-8h;5-9日龄在进入暗期就开始求偶,最大求偶率出现在暗期4-6h。风洞试验表明,3-7日龄的雄蛾对性腺提取物均有明显的性行为反应,5日龄雄蛾在暗期4-6h对性腺提取物的反应最为强烈。3-6日龄的成虫在暗期4-6h开始交配,而7-8日龄的成虫于暗期2-4h开始交配,6日龄的成虫交配率最高,交配高峰在暗期4-8h。雄蛾对性腺提取物的触角电位反应也有一定的节律性:雄蛾对4日龄雌蛾性腺提取物开始有电生理反应,对6-7日龄暗期5h性腺提取物反应最为强烈。林间诱蛾试验测定了性腺提取物的引诱活性,7日龄雌蛾性腺提取物林间诱蛾量最高,引诱高峰在暗期4-6h,该结果也验证了褛裳夜蛾雄蛾对性腺提取物的反应节律。