O. von Helversen

Sulphur-containing "perfumes" attract flower-visiting bats.

Abstract We tested the attractiveness of individual scent compounds of bat-pollinated flowers to their pollinators, small flower-visiting bats of the genus Glossophaga (Phyllostomidae). Twenty compounds belonging to four different chemical substance classes were tested, both in the laboratory and in the field. In the laboratory, the bats (Glossophaga soricina) approached odour sources spontaneously and without preceding experience. Without ever receiving any reward they preferred the scent of a sulphur-containing compound, dimethyl disulphide, to several other odour components emitted by bat-pollinated flowers, and to scentless controls. In the field, at La Selva station in the tropical lowland rain forest of Costa Rica, G. commissarisi were attracted by two sulphur-containing compounds, dimethyl disulphide and 2,4-dithiapentane, to visit artificial flowers filled with sugar water. Thus, in nectarivorous bats the sense of smell obviously plays an important role in searching for and localising food sources, and even single components of the scent bouquets of bat-pollinated flowers are attractive. The preference for sulphur-containing odours seems to be innate.

Storage and display of odour by male Saccopteryx bilineata (Chiroptera, Emballonuridae)

Abstract Males of the sac-winged bat, Saccopteryx bilineata, actively fill their propatagial sacs with secretions from the genital region, the gular gland, urine and saliva. From our observations and those of Starck we deduce that propatagial sacs in S. bilineata do not have a glandular function, but are instead organs for the storage and display of odours. In addition to the already known “salting” and hovering behaviour of male S. bilineata, we describe in detail how odour is fanned to roosting individuals during the complex, stereotypic hovering displays. S. bilineata males also coat the fur of their backs with saliva using the wing tip and might scent-mark territory boundaries. “Yawning” may represent a visual as well as an olfactory cue. Odour seems to play an important role in the social communication of S. bilineata and in other emballonurids, as revealed by the broad distribution of wing sacs in this family. S. bilineata males display odour during energetically costly hovering flights in front of females. We demonstrate that the number of hovering displays increases with harem size. The mating effort of S. bilineata males comprises a multimodal signalling behaviour. Although males defend harem territories in which females gather, females seem to be able to choose the father of their progeny freely among the males of a colony. This may have led to the evolution of the complex mating displays by male S. bilineata.

Acoustic pattern recognition and orientation in orthopteran insects: parallel or serial processing?

In grasshoppers the acoustic information for pattern recognition and directional analysis is processed via parallel channels and not serially. This can be concluded from the following results established by behavioural experiments:1.For pattern recognition the inputs from both sides are added internally. This implies that directional information is lost on this channel and must be processed in parallel.2.The location of a female song can be influenced by introducing short clicks from both sides, forcing the grasshopper to turn to the louder resp. leading side. Also, when given a choice between two patterns of different efficiency, the grasshoppers turned towards the side with the stronger directional cues and not to the side with the more efficient pattern.3.The parallel processing of acoustic information in grasshoppers corresponds to the evolution of acoustic communication in Acridids, as song evolved only when the ability of hearing and localization was already present. This is in contrast to crickets where the close evolutionary coupling of singing and hearing in the context of mate finding possibly favoured a serial processing of song recognition and localization.

Conflicting molecular phylogenies of European long-eared bats (Plecotus) can be explained by cryptic diversity

Conflicting phylogenetic signals of two data sets that analyse different portions of the same molecule are unexpected and require an explanation. In the present paper we test whether (i) differential evolution of two mitochondrial genes or (ii) cryptic diversity can better explain conflicting results of two recently published molecular phylogenies on the same set of species of long-eared bats (genus Plecotus). We sequenced 1714bp of three mitochondrial regions (16S, ND1, and D-loop) of 35 Plecotus populations from 10 European countries. A likelihood ratio test revealed congruent phylogenetic signals of the three data partitions. Our phylogenetic analyses demonstrated that the existence of a previously undetected Plecotus lineage caused the incongruities of previous studies. This lineage is differentiated on the species level and lives in sympatry with its sister lineage, Plecotus auritus, in Switzerland and Northern Italy. A molecular clock indicates that all European Plecotus species are of mid or late Pliocene origin. Plecotus indet. was previously described as an intergrade between P. auritus and Plecotus austriacus since it shares morphological characters with both. It is currently known from elevations above 800 m a.s.l. in the Alps, the Dinarian Alps and the Pindos mountains in Greece. Since we could demonstrate that incongruities of two molecular analyses simply arose from the mis-identification of one lineage, we conclude that molecular phylogenetic analyses do not free systematists from a thorough inclusion of morphological and ecological data.

Karyotype comparison and phylogenetic relationships of Pipistrellus-like bats (Vespertilionidae; Chiroptera; Mammalia)

Detailed karyotype descriptions of 20 Pipistrellus-like bat species belonging to the family Vespertilionidae are presented. For the first time, chromosomal complements of four species, i.e. Pipistrellus stenopterus (2n=32), P. javanicus (2n=34), Hypsugo eisentrauti (2n=42) and H. crassulus (2n=30) are reported. A Pipistrellus kuhlii-like species from Madagascar represents a separate species distinguished from the European Pipistrellus kuhlii (2n=44) by a diploid chromosome number of 42. Banded karyotypes are presented for the first time for Scotozous dormeri, Hypsugo capensis, Hesperoptenus blanfordi, Tylonycteris pachypus and robustula. Chromosomal evolution in the family Vespertilionidae is characterized by the conservation of entire chromosomal arms and reductions in diploid chromosome number via Robertsonian fusions. Less frequently, centric fissions, para- and pericentric inversions and centromere shifts were found to have occurred. In several cases a certain type of chromosomal change predominates in a karyotype. Examples of this are the acquisition of interstitial heterochromatic bands in Tylonycteris robustula, and centric shifts in P. javanicus, H. eisentrauti and Hesp. Blanfordi. The species examined here belong to three tribes, i.e. Pipistrellini, Vespertilionini and Eptesicini, which are distinguished by chromosomal characteristics. According to our results, the species Pipistrellus (Neoromicia) capensis belongs to the Vespertilionini and not to the Pipistrellini. We therefore propose to elevate the subgenus Neoromicia to generic rank.

Song pattern recognition and an auditory time window in the female bushcricket Ancistrura nigrovittata (Orthoptera: Phaneropteridae)

Mate finding in the phaneropterid bushcricket Ancistrura nigrovittata is achieved by a duet, where the female replies with a short sound to the male song. In experiments with artificial song models we analysed the parameters necessary for eliciting a female response. A verse of the male song consists of a group of 5–9 syllabes which after an interval of about 400 ms is followed by a final syllable. The female response was shown to depend on two processes: (i) recognition of the syllable group as belonging to a conspecific male and (ii) perception of the final syllable as a trigger. Critical parameters for the recognition process are the duration of syllables and syllable pauses, as well as the number of syllables in a group. However, even with an optimal syllable group, the response probability still depends on the interval between the syllable group and the final syllable. The female only responds when the final syllable of the male song occurs within a 250 ms long time window begining approximately 250 ms after the end of the males syllable group. Her reply consists of a single tick, which follows the males final syllable with a latency of only 25 ms.

The unusual inheritance pattern of the courtship songs in closely related grasshopper species of the Chorthippus albomarginatus‐group (Orthoptera: Gomphocerinae)

Sibling species of the Chorthippus albomarginatus‐group are exceptional among all European grasshopper species because they have an extremely elaborate courtship behaviour. Here, we present a genetic analysis of the courtship song differences between two closely related grasshopper species Ch. albomarginatus and Ch. oschei. Measurements of seven courtship song characters and one parameter of courtship visual display were compared among parentals, F1 and F2 hybrids, and backcrosses. Variation in one morphological character, the number of stridulatory pegs, was studied as well. The distributions of song phenotypes were more consistent with a type‐III genetic architecture, which involves complementary or duplicate pairs of loci. We suggest that this type of architecture may provide the novel elements of the hybrid songs, even more complex than the parental ones, which may offer a new starting point for sexual selection. One parameter of the visual display appeared to be controlled by a single locus, but differences in other characters of visual display could be explained by a more complex inheritance pattern. Inheritance of the peg number differences was consistent with a simple polygenic additive model. Sex linkage and/or maternal effects were not detected for any trait. We found a disproportionate influence of the Ch. albomarginatus parent on most hybrid song characteristics and the visual display, and this may support a previously suggested idea that Ch. albomarginatus is an ancestral form and Ch. oschei is a derived species.

A re-examination of the taxonomy of the Chorthippus albomarginatus group in Europe on the basis of song and morphology (Orthoptera: Acrididae).

A study of European sibling species of the Chorthippus albomarginatus group shows that the males could be well distinguished on the basis of the number and density of the stridulatory pegs. We recorded and analysed the calling and courtship songs of the males, as well as the stridulatory movements of the hind legs. Analysis of the stridulatory leg movements allowed us to reveal more differences between both the courtship songs and the calling songs of the European species of this group. On the basis of the morphology, calling and courtship song analysis, we describe a new species, Ch. ferdinandi sp. n., from Greece (Peloponnesus) and a new subspecies, Ch. oschei pusztaensis ssp. n., from the Balkans, Hungary, Moldova and Ukraine. Ch. bruttius Fontana & La Greca, 1999 is classified as a subspecies of Ch. karelini. We describe the phylogenetic relations between the European species of the Ch. albomarginatus group based on the courtship song complexity and courtship visual display.