Functional morphology of genitalia of four species of julidan millipedes (Diplopoda: Nemasomatidae; Julidae)

The functional anatomy of the genitalia of Nemasoma varicorne (Nemasomatidae), Brachyiulus lusitanus, Unciger foehdus and Cylindroiulus boleti (Julidae) was investigated by shock freezing of animals in copula followed by serial semithin sectioning of the engaged genitalia. The species show conspicuous differences in the functional mechanism of their genitalia. In M varicorne and B. lusitanus the vulvae remain within the vulval sac during copulation while in U.foetidus and C. boleti parts of the gonopods (promerite and mesomerite) form clasper-like structures that pull out the vulvae from the vulval sacs. With the exception of C. boleti all investigated species have a 'central funnel' on the vulva which leads into the receptaculum seminis. The sperm-transferring part of the male gonopods (solenomerite) is introduced into this funnel during copulation. In B. lusitanus and C. boleti a projection of the posterior gonopods (end-projection, brachite) fits into a slit anterior to the openings of the receptacula. The results are discussed with regard to sexual selection theory and a hypothesis is proposed that explains the evolutionary change of millipede genitalia by a combination of female choice and sperm competition phenomena.     

Female wing spreading as acceptance signal in theDrosophila virilis group of species

Females of manyDrosophila species spread apart their wings prior to copulation. In the present study we found female wing spreading to provoke male copulation attempts inDrosophila virilis-group species, helping the males to attempt copulation when the female is ready to mate. The males of most species, however, rarely responded to female wing spreading by copulation attempt without licking the female genitalia before and/or after female wing spreading bout. Blocking the female genitalia (D. virilis, D. novamexicana) reduces males' tendency to attempt copulation after female wing spreading. In these, and most other species of the group, female wing spreading seems to be an efficient signal only when combined with stimuli from female genitalia.     

The effect of variation in parameters of the male calling song of the katydid,Amblycorypha parvipennis (Orthoptera: Tettigoniidae), on female phonotaxis and phonoresponse

After being placed equidistant from playbacks of two computer-generated male calls, females of the katydidAmblycorypha parvipennis preferentially moved toward call phrases that were louder, longer, and leading (initiated without being overlapped by other call phrase endings). Because earlier tests with calling males had indicated that male mating success was related to these call parameters, we suggest that mating success is partly a result of female choice. Females also preferentially responded to the initial, rather than the latter, half of male phrases. Results of other tests suggested that females were responding to increased phonatome rate characteristic of the first half of the phrase. Males may compete to lead in order to prevent jamming of initial phrase information. Females also preferentially phonoresponded (ticked) in response to longer phrases. In earlier studies of male mating success and female phonotaxis using live males, male weight, sound level, and leading were intercorrelated; however, none of these parameters were correlated with phrase length. We suggest that females may respond to different call parameters under different environmental conditions.     

Vertical bars on male Xiphophorus multilineatus: a signal that deters rival males and attracts females

We examined the function of the vertical bar pattern on maleswordtails (Xiphophorus multilinneatus) as a signal in bothmale-male competition and female choice. This pattern had previouslybeen described as an aggressive signal because males intensifiedthe bars during male-male encounters in the laboratory. Ourfield observations supported this observation and also showedthat bars intensified when males courted females. The intensityof bars was correlated with access to females in the field.Within the size range of males that have bars, however, neitherbar number nor male size appeared to influence access to females.We used freeze-branding to remove the bars from males in thelaboratory so that we could control for characters correlatedwith bar intensity, and tested males and females separatelyso that we could separate the influence of these two componentsof sexual selection. We compared the responses of males andfemales to males that had their bars removed and control malesfreeze-branded between the bars. Test males responded more aggressivelyto males without bars as compared to control males. In addition,females showed a preference for control males over males thathad their bars removed. These results suggest that the barsmay function as a signal that deters rival males and attractsfemales.     

Isolation and culture of protoplasts from young sporophytes ofSalvinia natans aseptically obtained by co-culture of female and male gametophytes

Sporophytes were aseptically obtained by co-culture of female and male gametophytes derived from two types of spores (megaspores and microspores) of the heterosporous fernSalvinia natans All. Protoplasts isolated enzymatically from juvenile leaflets of sporophytes were cultured in a 1/10 Murashige and Skoog's medium containing 2.2 M naphthalene acetic acid, 2.2 M 6-benzyl-aminopurine, 0.35 M mannitol, and 0.05 M sucrose. Cell division took place within 6 days of culture, and cell-clusters composed of 9–10 cells were observed after 30 days of culture.Abbreviations BA 6-benzyl-aminopurine - MS Murashige and Skoog - NAA naphthaleneacetic acid     

Phenology and anatomy of the reproductive phase of Abies pinsapo Boiss. (Pinaceae)

Phenology and anatomy of the reproductive phase of Abies pinsapo were studied. Male cones and female cones were differentiated in the autumn, and the dormant microsporangia contained pollen mother cells (PMCs) in the premeiotic stage. The male cones broke dormancy at the end of February when the pollen mother cells began meiosis. Pollen grains were shed at the five-celled stage at the end of April-early May. The female cones broke dormancy in mid-April. Anthesis took place at the end of April. No micropylar-pollination droplet was observed. After pollination the female cones developed quickly. The most important loss of cones occurred during the pollination period. The number of archegonia varied from one to three but two was most common. Fertilization took place at the end of June. The embryos developed during the summer, and seeds were dispersed in autumn. The results are discussed in relation to other conifers.     

马蹄香大小孢子发生及雌雄配子体形成

马蹄香（Ｓａｒｕｍａｈｅｎｒｙｉ,Ｏｌｉｖ．）花药壁的发育属双子叶型。花粉母细胞减数分裂为同时型,四分体主要为四面体形,少数为左右对称式排列。腺质绒毡层,其细胞可排列为不规则的两层,双核或多核。到单细胞花粉阶段,绒毡层细胞内切向壁上出现许多乌氏体。成熟花粉为２细胞型,圆球状,具单萌发沟。雌蕊６心皮,上部彼此分离、下部联合。倒生胚珠,双珠被,厚球心。胚囊发育蓼型。成熟胚囊为七细胞结构,但两个助细胞退化较早。     

Biology ofPterolonche inspersa (Lep.: Pterolonchidae), a biological control agent forCentaurea diffusa andC. maculosa in the United States

The moth,Pterolonche inspersa (Staudinger) (Lepidoptera: Pterolonchidae), is widely distributed in southern Europe, north Africa, Turkey and the former Soviet Union. It occurs in both thick and scattered stands of knapweeds in disturbed sites, usually on sandy and/or stony soil. Larvae bore in the roots of diffuse and spotted knapweeds (Centaurea diffusa De Lamarck andC. maculosa De Lamarck). There is one generation per year in northern Greece, and larvae feed in the roots for about 11 months during the growing season (August–September, to the following July–August). In the laboratory garden, emergence took place between the second half of July and the end of August, with peak emergence during mid August. In the field, adults were observed from early to late July. Female moths oviposited on rosettes during the first ten days of July and continued through the end of July. Eggs were laid singly or in groups of five or six, firmly attached to the leaves of the host plant. In the laboratory, females mated within 24 hours of emergence and the preoviposition period lasted 2.6±0.8 days. The oviposition period lasted 7.4±2.2 days and the average number of eggs per female was 142.2±59.2. The incubation period was 12±4.7 days; the pupal stage lasted 14.7±2.4 days; and females lived 15.8±2.4 days, while males lived 10.7±1.4 days. First instar larvae failed to survive on economically important Compositae in the generaCynara L.,Helianthus L.,Zinnia L. andCalendula L. (Dunnet al., 1989).     

GENETIC CORRELATION BETWEEN A FEMALE MATING PREFERENCE AND THE PREFERRED MALE CHARACTER IN SEAWEED FLIES (COELOPA FRIGIDA)

The mating preferences of female seaweed flies Coelopa frigida were determined by observing their acceptance or rejection of males of known size. The inversion karyotype of both males and females was also determined. Females exhibited a preference to mate with large males, and evidence is presented that a genetic correlation exists between the female preference and the preferred trait. Females carrying the inversion karyotype associated with large male size showed a strong preference for large males; females carrying the inversion associated with small male size also exhibited a preference for large males, but it was significantly less strong. This finding suggests that a Fisherian process may be operating.