The intermediate sperm type and genitalia of <Emphasis Type="Italic">Zorotypus shannoni</Emphasis> Gurney: evidence supporting infraordinal lineages in Zoraptera (Insecta)

The sperm ultrastructure and the male and female genital apparatus of Zorotypus shannoni were examined and documented in detail, mainly using transmission electron microscopy micrographs. The findings suggest an evolutionary trend shared with Z. hubbardi and Z. impolitus. The three species are characterized by enlarged mitochondrial derivatives and related modifications. Giant sperm are probably a synapomorphy of Z. hubbardi and Z. impolitus, whereas an intermediate condition of this feature is found in Z. shannoni. The monophyletic origin of Z. caudelli, Z. magnicaudelli, Z. huxleyi and Z. weidneri is suggested by characteristically modified axonemes. The presence of extra-acrosomal material is also an unusual feature for Zoraptera, but this condition also occurs in the majority of polyneopteran groups. The long and convoluted female spermathecal duct with secretory and duct-forming cells is a constant feature in Zoraptera. The enlarged seminal receptacle suggests an evolutionary link between the male genital structures and the sperm size on one hand, and the size of the female spermatheca on the other. The small and otherwise uniform group Zoraptera exhibits a remarkable variation of sperm types and genital structures, suggesting the impact of different types of selection. It is likely that cryptic female choice plays a major role in shaping the genital apparatus.     

Operational Sex Ratio and Alternative Reproductive Behaviours in Chinese Bushcricket, Gampsocleis gratiosa

The effects of operational sex ratio (OSR) on male mating tactics in the Chinese bushcricket Gampsocleis gratiosa were investigated in male‐ and female‐biased environments. We measured fresh and dry spermatophore contents and copulation duration, and counted sperm numbers of each copulation. The fresh weight of spermatophore and spermatophylax was positively correlated with male body weight. The males in a strongly male‐biased environment produced significantly heavier fresh ampulla and more sperm per ejaculation, which were likely tactics for successful matings under the competition of rivals. The spermatophore might function as a structure to protect the fertilization potential of the ejaculate from rival males.     

Patterns of Sperm Transfer Behavior in a Pholcid Spider with Two Distinct Copulatory Phases

Sexual selection is the responsible force for the evolution and maintenance of genital diversity and function. This is the case for example, of genital movements performed by males during mating and copulation duration. Spiders perform ritualized copulations whereby males carry out different types of movements using their pedipalps with varying duration. The function and duration of these pedipalp movements is unclear. In the pholcid spider, Holocnemus pluchei males that copulate with virgin females perform two copulatory phases: phase I in which the pedipalps move and phase II in which pedipalps remain motionless. Using H. pluchei as a study species, our study aims were: 1) to assess if sperm transfer occurs when pedipalps move or are still and quantify the number of sperm in male bulbs and in the female uterus externus after copulation; and, 2) to determine if amount of sperm transferred to females is associated with duration of each copulatory phase. Two experimental groups (i. e. complete copulation and interrupted copulation) were established in which the amount of sperm remaining in the male bulbs and the amount of sperm stored by females were determined. Our results show that sperm transfer occurs during phase I, that males transfer almost all sperm from their bulbs while the females store only 20% of that male amount. There was no relation between the amount of sperm transferred or stored and the duration of the copulatory phases. These results support the hypothesis that while both phases may serve a copulatory courtship, only phase I (when pedipalps move) serves for sperm transfer.     

Strategic Investment in Sperm Removal Behaviour in a Bushcricket

Multiple mating by females is widespread and generates sperm competition among the ejaculates of rival males over fertilization. One way in which males can avoid or reduce sperm competition is by displacing or removing previous males’ sperm from female sperm stores. An apparent example of this occurs in the bushcricket Metaplastes ornatus. Males perform a specialised sperm removal behaviour (SRB), using their highly-derived subgenital plate, with which they remove sperm from the female’s spermatheca during the early phases of mating before transferring a spermatophore of their own. Here we investigated whether males strategically invest in SRB according to the amount of previously stored sperm present in females. Each male was tested twice, once with a female containing sperm (‘filled’ condition) and once with a female from whom most previously deposited sperm had recently been removed by another male (‘emptied’ condition). For comparison, a separate group of males was paired with virgin females. Males did not discriminate between non-virgin females in the ‘emptied’ or ‘filled’ conditions in terms of their investment in SRB, suggesting they may not able to perceive the amount of sperm present in the female’s spermatheca. By contrast, male investment in SRB was significantly reduced in pairings with virgin females, indicating that males are sensitive to some aspect of a female’s mating status. Our results thus suggest that males modulate SRB in response to female-mediated cues, possibly chemical cues left by previous males, which would not be present on virgin but would be on non-virgin females.     

Mating Behavior and Basic Biology of <Emphasis Type="Italic">Haywardina cuculi</Emphasis><Emphasis Type="Bold">(</Emphasis>Diptera: Tephritidae), a Poorly Known Species Exhibiting High Variability in Copulation Duration

The natural history and mating behavior of a species of tephritid fruit fly in the poorly studied genus Haywardina are described for the first time. Haywardina cuculi Hendel larvae were recovered over four field seasons from infested fruit of Vassobia breviflora (Sendtn.) Hunz, which constitutes a new host plant record for this species. Recovered pupae emerged as adults over 183 days on average, suggesting that most individuals became dormant. Adult flies engaged in sexual activity as soon as two days after emergence, were highly promiscuous, and displayed large variability in copulation duration. As for most tephritid species in the subtribe Carpomyini, H. cuculi exhibited a resource defense mating system. Fly activity peaked around noon. Copulation could last from 9 min to 17 h, with most copulations beginning in the afternoon and lasting until the following day. We discuss the potential significance of copulation duration variability in light of mate guarding and sperm competition hypothesis and outline future research to understand the evolution of life history and these behavioral strategies.     

A review of the <Emphasis Type="Italic">Chrysolina lineella</Emphasis> species-group of the subgenus <Emphasis Type="Italic">Anopachys</Emphasis> Motschulsky, 1860, genus <Emphasis Type="Italic">Chrysolina</Emphasis> Motschulsky, 1860 (Coleoptera,Chrysomelidae, Chrysomelinae)

The Chrysolina lineella species-group of the subgenus Anopachys Motschulsky, 1860 is revised. Chrysolina watanabei Takizawa, 1970 is revalidated from the synonymy with Ch. lineigera (Jacobson, 1901). Ch. sundukovi Mikhailov, 2006 is a new junior synonym of Ch. watanabei. Special attention is paid to the infraspecific variability of the male and female genitalia. The structure of the aedeagal flagellum and the spermatheca are used as diagnostic characters. A key to species is included. Ch. watanabei is for the first time recorded from the Asian continent (Primorskii Territory of Russia and Northeastern China).     

The Elaborate Postural Display of Courting <Emphasis Type="Italic">Drosophila persimilis</Emphasis> Flies Produces Substrate-Borne Vibratory Signals

Sexual selection has led to the evolution of extraordinary and elaborate male courtship behaviors across taxa, including mammals and birds, as well as some species of flies. Drosophila persimilis flies perform complex courtship behaviors found in most Drosophila species, which consist of visual, air-borne, gustatory and olfactory cues. In addition, Drosophila persimilis courting males also perform an elaborate postural display that is not found in most other Drosophila species. This postural display includes an upwards contortion of their abdomen, specialized movements of the head and forelegs, raising both wings into a “wing-posture” and, most remarkably, the males proffer the female a regurgitated droplet. Here, we use high-resolution imaging, laser vibrometry and air-borne acoustic recordings to analyse this postural display to ask which signals may promote copulation. Surprisingly, we find that no air-borne signals are generated during the display. We show, however, that the abdomen tremulates to generate substrate-borne vibratory signals, which correlate with the female’s immobility before she feeds onto the droplet and accepts copulation.     

Stridulation and Courtship Behaviour of Four Endemic Pill-Millipedes, <Emphasis Type="Italic">Arthrosphaera</Emphasis> spp. (Sphaerotheriida: Arthrosphaeridae) of the Western Ghats of India

Mating behaviour of four species of pill-millipedes under genus Arthrosphaera Pocock (Arthrosphaera dalyi Pocock and Arthrosphaera disticta Pocock, Arthrosphaera fumosa Pocock and Arthrosphaera magna Attems) endemic to the Western Ghats of Southern India was analyzed in mesocosms. Stridulation is a classical communication signal in males as well as females for mate selection. Conglobation (or volvation) is a mechanism of defence to protect from disturbance or avoid predation. If male touches female or vice versa they conglobate. To avoid disparity among individuals of the same species, volvating pill-millipedes evolved stridulation behaviour for communication. The male broadcasts appropriate signal to female through stridulation to advertise its interest in mating. The females test the male’s fitness by conglobation and suitable male uncoils the partner through stridulation signals. Male with its pygidium successfully uncoils the female and attains suitable orientation for courtship. Male pairs with female ventro–ventro contact in opposite direction to deposit sperm into the vulva of female. The duration of mating varies from species to species and usually a lapse from 3 to 30 min. Vibration generated by stridulation is species-specific and its perception mechanism in pill-millipedes is yet to be clearly understood. Present study emphasized the structure of stridulatory organs, mechanism of stridulation and pattern of mating behaviour in four species of pill-millipedes.     

Effect of gut bacteria on fitness of the Chinese citrus fly, <Emphasis Type="Italic">Bactrocera minax</Emphasis> (Diptera: Tephritidae)

A likely symbiotic association between tephritid fruit flies and gut bacteria has been recognized since the beginning of the last century. However, direct evidence for a link between gut bacteria and fruit fly fitness is still limited or absent for many species. Similar to other tephritids, the gut of Bactrocera minax (Enderlein) (Diptera: Tephritidae) is known to contain bacteria throughout the life stage, but what, if any, impact these bacteria have on B. minax fitness is entirely unknown. In order to elucidate the effects of bacteria on the fitness of B. minax, resident bacteria were isolated from the adult gut using culture-dependent techniques. Adult fly diets were subsequently supplemented with three bacterial isolates (Klebsiella pneumonia, Citrobacter braakii and Pantoea dispersa), or bacteria were removed from flies by antibiotics treatment: untreated adults provided a control. Adult fitness parameters (male and female longevity, female fecundity, male copulation number) were measured for the two treatments and one control group. Results were complex depending on the fitness parameter measured and the bacterial species. Compared to the controls, antibiotic treated B. minax had significantly decreased fecundity, but male and female longevity was increased. When flies were fed diets supplemented with any of the three bacterial isolates, female fecundity was significantly enhanced. However, only Citrobacter braakii significantly increased male mating frequency than control males. The results show that gut bacteria directly influence fitness of B. minax, but impacts are dependent on the bacterial species and the fitness parameters measured.     

The first record of <Emphasis Type="Italic">Pronotalia</Emphasis> Gradwell, 1957 (Hymenoptera,Eulophidae) Wasps from Georgia

Four species of Pronotalia Gradwell (Hymenoptera, Eulophidae: Tetrastichinae) are recorded from the Lagodekhi Reserve (Georgia). Formerly, only P. carlinarum (Szelényi et Erdös) was known from Transcaucasia (Armenia) (Kostjukov, 1978). Pronotalia fiorii (Domenichini), P. orobanchiae Graham, and P. trypetae Gradwell are recorded for Georgia and Transcaucasia for the first time. In addition to these species, only 4 species are known from Europe and Anatolia: P. erzurumica Doganlar, P. hungarica (Erdös), P. inflata Graham, and P. tortumensis Doganlar; thus, 50% of Pronotalia species from Europe and Anatolia occur in the Lagodekhi Reserve.     

Courtship in Two Morphotypes of the <Emphasis Type="Italic">Anastrepha fraterculus</Emphasis> (Diptera: Tephritidae) Cryptic Species Complex and their Implications for Understanding Mate Recognition

Ritualized courtship behaviors are used to recognize potential mates and behavioral patterns are inevitably different among populations that demonstrate reproductive incompatibility. We characterized and compared the courtship behaviors of two morphotypes of the cryptic species complex Anastrepha fraterculus: Brazil-1 morphotype and Brazil-3 morphotype. Courtship behaviors were filmed to analyze the behavioral sequences of these two morphotypes during homotypic crossings. The behavioral units Alignment (AL) and Abdominal movements (AB and AB-call) were newly recognized in the courtship ethogram of Anastrepha fraterculus males. The two morphotypes show distinct behavioral sequences leading up to copulation. Some behaviors were repeated frequently during the courtship process, while others were more restricted to the final moments of courtship. The three behavioral units that contributed most to copulation success were Contact, Alignment, and Arrowhead 1 in the Brazil-1 morphotype and Alignment, Arrowhead 1, and Fanning in the Brazil-3 morphotype. Some behavioral routines differed across the two morphotypes. Significant differences were also noted between the frequencies of the behavioral units displayed during courtship in the two morphotypes. The relationships between the pre-zygotic incompatibilities of the Brazil-1 and Brazil-3 morphotypes and the differences between the courtship behaviors of their males are discussed. Our results indicate that behavioral isolation is involved in the process of pre-zygotic reproductive isolation of Brazil-1 and Brazil-3 morphotypes.     

Intra-specific variation of sperm length in the malaria vector <Emphasis Type="Italic">Anopheles gambiae</Emphasis>: males with shorter sperm have higher reproductive success

Background

Intra-specific variation in sperm length influences male reproductive success in several species of insects. In males of the malaria vector Anopheles gambiae, sperm length is highly variable but the significance of this variation is unknown. Understanding what determines the reproductive success of male mosquitoes is critical for controlling malaria, and in particular for replacing natural populations with transgenic, malaria-resistant mosquitoes.

Methods

A laboratory population of A. gambiae males was tested for intra-specific variation in sperm length. A full-sib quantitative genetic design was used to test for a genetic component of sperm length in A. gambiae males and estimate its heritability. This study also tested for a relationship between sperm length and male reproductive success in A. gambiae. Male reproductive success was measured as the proportions of inseminated and ovipositing females.

Results

There was intra-specific variation of sperm length in A. gambiae. There was no significant genetic variation in sperm length and its heritability was low (h² = 0.18) compared to other insects. Sperm length was correlated with male body size (measured as wing length). Males with short sperm had significantly higher reproductive success than males with long sperm and this was independent of body size.

Conclusion

This is the first study to demonstrate intra-specific variation in sperm length in A. gambiae and that males with short sperm have higher reproductive success. That sperm length influences female oviposition is important for any strategy considering the release of transgenic males.

     

Reproductive Biology of <Emphasis Type="Italic">Leptocybe invasa</Emphasis> Fisher &amp; La Salle (Hymenoptera: Eulophidae)

Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae) is an invasive pest in Eucalyptus plantations around the world. The successful colonization of L. invasa is possibly related to its reproductive biology. The objective of this study was to examine the reproductive biology of L. invasa. In Guangxi Province, the sex ratio (proportion of female, 0.99) of L. invasa was female-dominant throughout the year based on natural and artificial infestation. This result was similar to the ratios observed for other geographic populations in China, including those in Fujian (0.99), Guangdong (0.98), Hainan (0.95), Jiangxi (0.96), and Sichuan (0.99). The offspring sex ratio favored females. A large number of females emerged from the galls produced by females, with few males found. Galls on the petioles and midribs of Eucalyptus plants could be caused by newly emerged females with mature eggs. The lengths of the ovariole, spermatheca, common oviduct, and reproductive glands did not differ among L. invasa females, but their lateral oviducts showed differences from 0 to 42 h after emergence, indicating that this insect is proovigenic. These results could explain why L. invasa populations can rapidly increase in invaded areas.     

Culturable symbionts associated with the reproductive and digestive tissues of the Neotropical brown stinkbug <Emphasis Type="Italic">Euschistus heros</Emphasis>

Symbionts are widely distributed in eukaryotes, and potentially affect the physiology, ecology and evolution of their host. Most insects harbour free-living bacteria in their haemocoel and gut lumen, intracellular-living bacteria in a range of tissues or bacteria in host-derived specialized cells. Stinkbugs, as do many arthropods, harbour extracellular bacteria in the gut that may affect the fitness of their host. This study identified the culturable symbionts associated with the ovaries, spermatheca, seminal vesicle and posterior midgut region (V4) of males and females of Euschistus heros (F.) (Hemiptera: Pentatomidae). Several culture media were used to isolate the bacteria associated with these structures. The selected colonies (morphotypes) were cultured in liquid medium, subjected to genomic DNA extraction, 16S rRNA gene amplification, and restriction fragment length polymorphism (RFLP) analyses. Morphotypes with distinct RFLP patterns were purified and sequenced, and the sequences obtained were used for putative identification and phylogenetic analysis. Comparison of the sequences with those available in the EzTaxon-e database and the use of a matrix of paired distances grouped the isolates in phylotypes belonging to the Phylum Proteobacteria. Proteobacteria was represented by γ-Proteobacteria phylotypes belonging to Enterobacteriaceae, while Firmicutes had Bacilli phylotypes distributed in Enterococcaceae and Staphylococcaceae. Some of the phylotypes identified were associated exclusively with single structures, such as ovaries, spermatheca and the V4 midgut region of males and females. All culturable bacteria associated with the seminal vesicle were also associated with other tissues.     

Spermatozoa production in male <Emphasis Type="Italic">Varroa destructor</Emphasis> and its impact on reproduction in worker brood of <Emphasis Type="Italic">Apis mellifera</Emphasis>

Reproduction in Varroa destructor exclusively takes place within the sealed honey bee brood cell and is, therefore, limited by the duration of the postcapping period. Oogenesis, ontogenetic development and mating must be optimized to ensure the production of as many mated daughter mites as possible. One adult male mite has to mate with up to five sister mites and transfer 30–40 spermatozoa to each female. We analyzed the production and transfer of male spermatozoa during a reproductive cycle by counting all spermatozoa in the genital tracts of the male and daughter mites in 80 worker brood cells at defined times after cell capping. We could show that spermatozoa production in male mites is an ongoing process throughout their adult lifetime starting after the adult molt. The spermatozoa are transferred to the females in an early non-capacitated stage and require further maturation within the female’s genital tract. Our study points out that a Varroa male has at any time in the brood cell enough spermatozoa to inseminate all daughter mites but does not waste energy in producing a big surplus. In total one male produced, on average, 125 spermatozoa during a reproductive cycle in worker brood which is sufficient for successful matings with at least three daughter mites. Spermiogenesis in Varroa males represents therefore a further adaptation to the limited time available for reproduction.     

Social Relationships between Males and Females in Rock Lizard (<Emphasis Type="Italic">Darevskia brauneri</Emphasis>, Lacertidae). 2. Searching for an Area of Stable Residence,Criteria for Choice of Social Partner,and Factors of Friendly Integration of Dyads

Long-termed intersexual friendly relationships between males and females of the Brauner’s lizard are characterized by high levels of spatial association and high frequency of affiliative behavior between partners (see report 1). In present article we consider changes in the frequency of affiliative behavior in males (Am) and females (Af) after the first appearance of female on the male’s territory and conditions for the transition of lizard to stable residency (SR). Generally, Am becomes stable during the first days of initial period and does not change later. This fact suggests that in most instances male’s choice criteria are some peculiarities of the female’s exterior. In the initial period, Af is always low, however, gradually rises to the level of Am if Am is high. The main condition of female’s SR is high Am of the owner of the territory where female establishes her comfort areas. Hence, social partner choice in female is based on male’s behavior, and high Am triggers the formation of friendly interrelations. Significant correlation between social and sexual interrelations is absent. As can be judged by female’s reactions to male’s sexual behavior, his sexual activity is rather a factor of social disintegration. Structure of costs for social partner search is different in males and females, and these differences well harmonize with differences in gender strategies of partner choice. The social strategies are well interpreted in terms of the optimal foraging theory.     

A Sperm Spawn-Inducing Pheromone in the Silver Lip Pearl Oyster (<Emphasis Type="Italic">Pinctada maxima</Emphasis>)

Pheromones are considered to play an important role in broadcast spawning in aquatic animals, facilitating synchronous release of gametes. In oysters, the sperm has been implicated as a carrier for the spawn-inducing pheromone (SIP). In hatchery conditions, male pearl oysters (Pinctata maxima) can be stimulated to spawn through a variety of approaches (e.g. rapid temperature change), while females can only be induced to spawn through exposure to conspecific sperm, thus limiting development of targeted pairing, required for genetic research and management. The capacity for commercial production and improvement of genetic lines of pearl oysters could be greatly improved with access to a SIP. In this study, we prepared and sequenced crude and semi-purified P. maxima sperm extracts that were used in bioassays to localise the female SIP. We report that the P. maxima SIP is proteinaceous and extrinsically associated with the sperm membrane. Bioactivity from pooled RP-HPLC fractions, but not individual fractions, suggests that the SIP is multi-component. We conclude that crude sperm preparations, as described in this study, can be used as a sperm-free inducer of female P. maxima spawning, which enables for a more efficient approach to genetic breeding.     

New species of the tenebrionid genus <Emphasis Type="Italic">Menimus</Emphasis> sharp, 1876 (Coleoptera,Tenebrionidae) from southern Palaearctic

Three new species of the genus Menimus are described from Yunnan Province, China. Over 70 species of Menimus are distributed in the tropical and subtropical zones from India to Oceania and New Zealand. A new subgenus, Sinomenimus subgen. n., is erected with the type species M. kabaki sp. n. characterized by the absence of eyes and by the presence of the spermatheca and sharp depression at the posterior margin of the thoracic metasternite. The following new synonymy is established: Menimus Sharp, 1876 = Neomenimus Kaszab, 1939, syn. n., with the following new combinations resulting: Menimus clavatus (Kaszab, 1939) = Neomenimus clavatus Kaszab, 1939, comb, n.; Menimus biroi (Kaszab, 1939) = Neomenimus biroi Kaszab, 1939, comb, n.; Menimus setosus (Kaszab, 1939) = Neomenimus setosus Kaszab, 1939, comb, n.; Menimus brevissimus (Kaszab, 1939) = Neomenimus brevissimus Kaszab, 1939, comb. n.