Evolutionary steps in the reproductive biology of Annonaceae

Flowers of Annonaceae are characterized by fleshy petals, many stamens with hard connective shields and numerous carpels with sessile stigmas often covered by sticky secretions. The petals of many representatives during anthesis form a closed pollination chamber. Protogynous dichogamy with strong scent emissions especially during the pistillate stage is a character of nearly all species. Scent emissions can be enhanced by thermogenesis. The prevailing reproductive system in the family seems to be self-compatibility. The basal genus Anaxagorea besides exhibiting several ancestral morphological characters has also many characters which reappear in other genera. Strong fruit-like scents consisting of fruit-esters and alcohols mainly attract small fruit-beetles (genus Colopterus, Nitidulidae) as pollinators, as well as several other beetles (Curculionidae, Chrysomelidae) and fruit-flies (Drosophilidae), which themselves gnaw on the thick petals or their larvae are petal or ovule predators. The flowers and the thick petals are thus a floral brood substrate for the visitors and the thick petals of Anaxagorea have to be interpreted as an antipredator structure. Another function of the closed thick petals is the production of heat by accumulated starch, which enhances scent emission and provides a warm shelter for the attracted beetles. Insight into floral characters and floral ecology of Anaxagorea, the sister group of the rest of the Annonaceae, is particularly important for understanding functional evolution and diversification of the family as a whole. As beetle pollination (cantharophily) is plesiomorphic in Anaxagorea and in Annonaceae, characters associated with beetle pollination appear imprinted in members of the whole family. Pollination by beetles (cantharophily) is the predominant mode of the majority of species worldwide. Examples are given of diurnal representatives (e.g., Guatteria, Duguetia, Annona) which function on the basis of fruit-imitating flowers attracting mainly fruit-inhabiting nitidulid beetles, as well as nocturnal species (e.g., large-flowered Annona and Duguetia species), which additionally to most of the diurnal species exhibit strong flower warming and provide very thick petal tissues for the voracious dynastid scarab beetles (Dynastinae, Scarabaeidae). Further examples will show that a few Annonaceae have adapted in their pollination also to thrips, flies, cockroaches and even bees. Although this non-beetle pollinated species have adapted in flower structure and scent compounds to their respective insects, they still retain some of the specialized cantharophilous characters of their ancestors.

Semioquímicos de moscas das frutas do gênero Anastrepha

Volatile compounds involved in the chemical communication of fruit flies have been studied for some years; however, their complete elucidation has not yet been reported. Tephritids, which belong to the Anastrepha genus, exhibit inter- and intraspecific changes regarding the chemical composition of their sex pheromones, as well as an evident relationship with the volatiles produced by their hosts. This paper reports advances in the elucidation of the chemical communication of Anastrepha species that involve sex pheromones, cuticular hydrocarbons, and the interaction between the fruit host volatiles and compounds released by the male flies.

Spatial distribution of canine Visceral Leishmaniasis in Ilha Solteira, São Paulo, Brazil

Visceral Leishmaniasis (VL) is caused by protozoan of genus Leishmania and transmitted by sand flies of genus Lutzomyia, which has been adapted to the peridomicile environment where dogs are their mainly food source, increasing the risk for human cases. In this study, techniques of geoprocessing and spatial statistics were utilized as a contribution to understanding the epidemiological dynamics of VL in the urban area of Ilha Solteira, SP.

Sugarcane stems as larval habitat for the stable fly (Stomoxys calcitrans) in sugarcane plantations

Outbreaks of stable fly, Stomoxys calcitrans, cause losses for livestock producers located near sugarcane mills in Brazil, especially in southern Mato Grosso do Sul. The sugarcane mills are often pointed by local farmers as the primary source of these outbreaks; some mills also joined the farmers in combating the flies. Brazilian beef cattle production has great economic importance in similar level to bio-fuel production as ethanol. In this context, the wide-ranging knowledge on the biology and ecology of the stable fly, including larval habitats and their reproduction sites is extremely important for further development of control programs. This paper aims to report the occurrence and development of S. calcitrans larvae inside sugarcane stems in three municipalities of Mato Grosso do Sul. The sugarcane stems give protection against bad weather conditions and insecticide application. In this way, for sustainable sugarcane growth specific research concerning this situation should be conducted.

Fly pollination and pollinator sharing in two synchronopatric species: Cordia multispicata (Boraginaceae) and Borreria alata (Rubiaceae)

The floral biology of Cordia multispicata (Boraginaceae) and Borreria alata (Rubiaceae) was studied in natural populations in a fragment of the Atlantic forest in Pernambuco, northeastern Brazil. Both species flower during almost the whole year. Cordia multispicata is a shrubby species with white, distylous and tubular flowers. Borreria alata is a herbaceous species. Its flowers are whitish, tubular and have a polymorphism in relation to the size of their style. Floral anthesis in both species begins at 6:00 a.m. Sugar concentration in the nectar was about 16% in C. multispicata and 30% in B. alata. Nine species of flies, mainly of the genus Palpada (Syrphidae), were observed visiting flowers of the two species. Seven of them were observed visiting and pollinating flowers of both C. multispicata and B. alata. Two species visited only flowers of C. multispicata, whereas no fly was exclusive to B. alata flowers. Both species have similar flower morphology, flowering time, habitats in the forest and establish populations very close to each other. These facts can favour the pollinators’ sharing and increase pollinator attraction.

Floral resources used by insects in a grassland community in Southern Brazil

The goal of the present study was to identify plant species used as food source, the floral resources utilized, and the insects that visit flowers in a grassland community in southern Brazil. The study was carried out in an area of one hectare, located in a grassland formation in the Parque Estadual de Itapuã, State of Rio Grande do Sul, Brazil. The flowering pattern was seasonal, and richness and abundance of insects was higher during the period of high resource availability. Flowers of 106 species of angiosperms (73 genera and 34 families) were used as source of floral resources for 219 species (2,767 specimens) of insects. A total of 91.5% of plant species were visited by bees, 53.8% by flies, 34.9% by wasps, 22.6% by butterflies, and 12.3% by beetles. Nectar was the main resource consumed by the visitors (41.1%). Asteraceae was the richest (38 spp.) and most visited family, with 63.1% of the species and 49.5% of all specimens of recorded insects. Bees were the most representative insects (33.2% spp., 65% indiv.), followed by flies (26.9% spp., 16.5% indiv.), wasps, butterflies and beetles. 40 plant species were considered important resources for the floral visitors' community, due to high number of, both, species and individuals recorded in their flowers. The family Asteraceae as a species set was the main floral resource used by insect visitors through the year and has great importance for the maintenance of populations of many species of bees, flies, wasps and butterflies in the studied area.

One-winged Drosophila subobscura: a phenotype with an obscure genetic basis

A line of one-winged Drosophila subobscura was studied. The absent wing is substituted by a bulky structure with macro and microchaetes, showing a thoracic appearance. Genetic crosses showed that there is no way to select for the trait by simple crossing. The number of one-winged flies in the various generations was always low. In one case a wingless fly was also obtained. The trait presents an unknown genetic pattern.

Egg size, yolk mass extrusion and hatching behavior in two cryptic speciesof Anastrepha fraterculus (Wiedemann) (Diptera, Tephritidae)

Variations in egg length were observed for two populations of cryptic species of Anastrepha fraterculus (Wiedemann). The eggs of type I flies were smaller than those of type II individuals. For both types, in regard to yolk mass extrusion, four classes of embryos were detected. Class 1: embryos that extrude masses at both extremities; class 2: embryos in which extrusion occurs only at the anterior pole; class 3: embryos that eliminate mass only at the posterior pole, and class 4: embryos that do not extrude any mass. Embryo class frequencies were similar for populations belonging to the same type, but different between types. Individual females may produce eggs from different embryo classes, but for any given female the pattern remains constant during a long period of oviposition. Variation in size of the extruded masses was similar for both populations. Individual females produced embryos with a small range of mass diameters, and different females produced masses of different mean size. However, individual mass size remained constant during oviposition. The results suggest the existence of genetic components involved in the control of this unusual process. Larvae of both types presented, just before eclosion, similar unusual behaviors: they ingest the anterior extruded mass, rotate 180°, absorb the posterior mass and eclose near the posterior pole. Data show that cryptic A. fraterculus type I and type II differs in regard to egg size as well as to the phenomenon of yolk mass extrusion

Evaluation of techniques for C and ASG banding of the mitotic chromosomes of Anastrepha species (Diptera, Tephritidae)

Methods previously described by Canovai et al. (Caryologia 47: 241-247, 1994) which produced C and ASG bands in mitotic chromosomes of Ceratitis capitata were applied to the chromosomes of several Anastrepha species. Metaphase plate yield was substantially increased by use of imaginal disks together with cerebral ganglia. The C-bands were quite prominent allowing the resolution of tiny blocks of heterochromatin. The ASG method produced G-like banded chromosomes, which permitted recognition of each individual chromosome. These simple techniques do not require special equipment and may be valuable for karyotype variability studies in fruit flies and other Diptera

Overexpression of kermit/dGIPC is associated with lethality in Drosophila melanogaster

Insertional mutagenesis is an important tool for functional genomics in Drosophila melanogaster. The insertion site in the KG00562 mutant fly line has been mapped to the CG8709 (herein named DmLpin) locus and to the 3’ of kermit (also called dGIPC). This mutant line presents a high lethality rate resulting from a gain of function. To obtain some insight into the biological role of the mutated locus, we have characterized the mutation and its relation to the high mortality of the KG00562 fly line. In this mutant, we did not detect one of the DmLpin transcripts, namely DmLpinK, but we did detect an unusual 2.3-kb mRNA (LpinK-w). Further investigation revealed that the LpinK-w transcript results from an aberrant splicing between the untranslated first exon of DmLpinK and the mini-white marker gene. Lack of DmLpinK or LpinK-w expression does not contribute to lethality, since heterozygous KG00562/Def7860 animals presented lethality rates comparable to those of the wild type. In contrast, the overexpression of kermit was associated with lethality of the KG00562 fly line. Significantly higher levels of kermit were detected in the Malpighian tubules of KG00562/+ flies that presented higher lethality rates than wild-type or KG00562/Def7860 animals, in which the lethality was rescued. In agreement with a recently reported study, our data support the hypothesis that misexpression of kermit/dGIPC could interfere with Drosophila development, with further investigations being needed in this direction.