Geographic variation of Africanized honey bees (Apis mellifera L.) in Brazil: Multivariate morphometrics and racial admixture

The correspondence between morphometric and isozymic geographic variation patterns of Africanized honey bees in Brazil was analyzed. Morphometric data consisted of mean vectors of 19 wing traits measured in 42 local populations distributed throughout the country. Isozymic data refer to allelic frequencies of malate dehydrogenase (MDH), and were obtained from Lobo and Krieger. The two data sets were analyzed through canonical trend surface, principal components and spatial autocorrelation analyses, and showed north-south dines, demonstrating that Africanized honey bees in southern and southeastern Brazil are more similar to European honey bees than those found in northern and northeastern regions. Also, the morphometric variation is within the limits established by the racial admixture model, considering the expected values of Africanized honey bee fore wing length (WL) in southern and northeastern regions of Brazil, estimated by combining average values of WL in the three main subspecies involved in the Africanization process (Apis mellifera scutellata, A. m. ligustica and A. m. mellifera) with racial admixture coefficients.

Enzymes present in the thoracic gland extracts from workers and males of Apis mellifera (Hymenoptera: Apidae)

This research deals with the analysis of the enzymes present in thoracic gland extracts from newly emerged, nurse workers, forager workers, newly emerged males, and mature males of A. mellifera L. (Hymenoptera, Apoidea, Apidae). The enzymes found in larger quantities in the thoracic gland occurred in all classes of workers and are digestive. Acid phosphatase and Naphtol-AS-BI-phosphohydrolase act in protein synthesis, leucine arylamidase hydrolyses proteins and a-glucosidase actuate in the nectar processing into honey. Naphtol-AS-BI-phosphohydrolase was found in larger quantities only in workers, this suggests action in protein synthesis by the thoracic gland, b-galactosidase is in larger amounts in the newly emerged bees (workers and males) this aids in the provision of other substances to be used as an energy source when glucose or sucrose are absent. Differences between enzymatic profiles from workers and males are usually related to their colony tasks, or related to their physiological necessities per individual in specific life stages.

Experimental control of the effect of extra doses of juvenile hormone on bee development: The case of the wax glands of Apis mellifera (Hymenoptera: Apidae)

Experiments on the effect of topical application of the synthetic juvenile hormone (JH-III) and of the solvent used to dissolve the hormone on the development of the wax glands of workers of Apis mellifera, were made. The results show that it was impossible to determine the effect of the juvenile hormone (JH) apart from its solvent (acetone), which also alters the developmental pattern of the gland. Most of the experiments reported in scientific literature do not consider the effect of the solvent, analyzing the results by only comparing the treatment with the hormone plus solvent to a control without any treatment. The data presented suggests that this kind of procedure compromises the evaluation of the real JH effect.

A method for rearing immature stages of Apis melifera outside the colony (Hymenoptera: Apidae)

The objective this work is to define an effective method for following the development of immatures of Apis mellifera from metamorphosis to the emergence of the adult, under conditions allowing the application of diverse treatments. The results showed the best method to be when broods with 5th instar larvae and prepupae were maintained in incubators with the temperature and humidity controlled at 34°C and 65 to 70% respectively.

Alterations induced by juvenile hormone in glandular cells of the Apis mellifera venom gland I - Application on the larvae (Hymenoptera: Apidae)

Histological analyses were made in order to evaluate the effects of the topic application of a synthetic juvenile hormone (JH-III Sigma) on the development of the venom glands in workers of Apis mellifera. Three experimental groups were used: the first received 1 μl of a dilution of the juvenile hormone in hexane (2μg/μl); the second group received 1 μl of hexane; and the third group, the control, did not receive any kind of treatment. The application was made on larvae at the beginning of the fifth instar and the glands were collected at different developmental stages. The results showed that the application of the diluted hormone, as well as the hexane alone, accelerated gland development in relation to the control group at all developmental stages studied. These data suggest that the juvenile hormone acts on the development of the venom gland; nevertheless, this action could be amplified by the effect of the solvent used in the present work, as well as in other studies concerning this matter.

Enzymatic activity of hypopharyngeal gland extracts from workers of Apis mellifera (Hymenoptera, Apidae, Apinae)

This research presents a comparative study of enzymatic activity of the hypopharyngeal gland extracts from workers of Apis mellifera in three physiologic stages: newly emerged, nurse and forager workers, with the objective of contributing to the comprehension of the gland function. In order to determinate the enzymes present in the extracts, the Api Zym kit (Bio Mérieux) was used to test the activity of 19 different enzymes. The enzymes found in larger amounts only in the hypopharyngeal glands from certain individuals were the following: in newly emerged workers, the N-acetyl-down double arrow sign-glucosaminidase that may be digesting the chitin of some food ingested by the bee; in forager workers, the acid phosphatase that is likely acting in authophagic processes, the a-glucosidase, in the processing of nectar into honey, and the down double arrow sign-glucosidases, in the pollen digestion.

Juvenile hormone promotes changes in the expression of hypopharyngeal gland proteins of worker Apis mellifera (Hymenoptera: Apidae)

The present investigation compares the protein electrophoreses profiles of the hypopharyngeal glands of 12 and 25 day old Apis mellifera workers, some of which were experimentally treated with an analogue of juvenile hormone in the moment of the emergence while others were not treated. According to the evaluation of the presented variations by four main bands, it is concluded that the analogue juvenile hormone changes the glandular genetic expression pattern, promoting the disappearance of two from the four main bands in 25 day old workers. The effect of this hormone is discussed as an hypopharyngeal maturation inductor, in synergetic action with the bee age acting early in the glandular cycle.

Mating influence in the ovary differentiation in adult queens of Apis mellifera L. (Hymenoptera, Apidae)

The present results show that in the ovarioles of a newly emerged (0 day) queen of A. mellifera only two regions may be distinguished: a proximal, short germarium and a very long distal, terminal filament. As the queen matures and gets ready for the nupcial flight, the germarium increases in lenght, advancing towered the distal end, as the terminal filament shortens. The ovarioles of queens ready to mate (6 to 8 days old) have, already one or two ovarian follicles, i.e. a very short proximal vitellarium, but a real vitellogenesis only starts after the fecundation. If the queen does not mate the ovarioles structure is disrupted (12-16 days old). In mated queen eggs the ovarioles present three differentiated regions, from the apice to the basis: a short terminal filament, a medium size germarium, and a very long basal vitellarium. As the eggs are laid, the emptied follicle collapses, degenerates and produces a corpus luteum.

Cell nucleus activity during post-embryonic development of Apis melliferaL. (Hymenoptera: Apidae). Intranuclear acid phosphatase

We report nuclear acid phosphatase activity in the somatic (intra-ovariolar and stromatic) and germ cells of differentiating honey bee worker ovaries, as well as in the midgut cells of metamorphosing bees. There was heterogeneity in the intensity and distribution of electron dense deposits of lead phosphate, indicative of acid phosphatase activity in the nuclei of these tissues, during different phases of post-embryonic bee development. This heterogeneity was interpreted as a variation of the nuclear functional state, related to the cell functions in these tissues.

Ovarian growth during larval development of queen and worker of Apis mellifera (Hymenoptera: Apidae): a morphometric and histological study.

The present work reports the differences between the ovarian grow in queen and worker larvae of A. mellifera, from the start of differential feeding. The observations made of the growth rates in larvae of both castes showed that the queen and worker larvae have the same rates of cephalic capsule growth from one instar to another but the weight gain is greater in queens. In the same way, the draw areas of ovaries of queens increase more and continuously, while from the 5th instar on the ovaries of workers decrease in size. The decrease is due to a loss of ovariole numbers that starts early in the worker larvae and increases in the 4th-5th instar. The ovarian shape in queens and workers became different in the last larval instars.

Susceptibility of Apis mellifera (Hymenoptera: Apidae) to pellitorine, an amide isolated from Piper tuberculatum (Piperaceae)

The acute toxicity of pellitorine, an amide isolated from Piper tuberculatum (Piperaceae) which is studied as a biopesticide in European corner borer, was evaluated on larvae and newly emerged adults of honeybee Apis mellifera by means of contact and ingestion bioassays. Workers in the larval and adult phase were separated in groups, which received pellitorine in different concentrations. The larvae were maintained in their own original cells, receiving feeding and normal care from the nurses. The adults were confined in wooden cages with screens, receiving artificial diet made up of sugar and water (1:1). The concentrations of 40, 200, 1 000, 5 000 and 25 000 ng a.i./individual were obtained diluting pellitorine in 98% ethanol. LD10 values of 39.14, 36.16 and 13.79 ng a.i./insect were determined for larvae, for adults by ingestion and adults by contact, respectively. The honeybee larvae were shown to be highly susceptible to the amide pellitorine.

Influence of the application of juvenile hormone on the haemolymph total proteins and electrophoretic pattern of worker larvae of Apis mellifera

The aim of the present work was to verify the influence of the juvenile hormone (JH) applied on worker larvae of Apis mellifera 2 to 5 days old over the haemolymph total protein and electrophoretic pattern. Each larvae received topical applications of 1 ml of a solution of JH in hexane (1 μg/ml) on their 2 nd, 3 rd 4 th and 5 th day after hatching and had the amount and electrophoretic pattern of proteins from the haemolymph analyzed during the remaining days of their life. As a control, haemolymph of larvae of the same age that did not receive any kind of treatment was analyzed. The results show that the application of JH on larvae 3 or more days old affect the amount and electrophoretic pattern of the proteins, with this effect lasting through the subsequent days.

Redescription and reevaluation of the generic status of Leptodactylus dantasi (Amphibia, Anura, Leptodactylidae) and description of its unusual advertisement call

Leptodactylus dantasi Bokermann is redescribed from adult specimens collected in Parque Nacional da Serra do Divisor, State of Acre, Brazil, near the border between the Brazilian state of Acre and Peru. We propose the inclusion of this species in the genus Hydrolaetare. A new diagnostic character observed for the genus is the presence of fringes of fingers, and fringes and webbing of toes, finely serrate; the serrate edge of the fringe and webbing can be keratinized in males, females, and subadults. Hydrolaetare dantasi (Bokermann) is characterized by robust body and limbs, a broad and depressed head, slightly shorter than wide, and long, pointed and basally webbed toes. Hydrolaetare dantasi differs from the only other species in this genus, Hydrolaetare schmidti (Cochran and Goin), mainly by having toes webbed basally (fully webbed in H. schmidti). The advertisement call of H. dantasi is composed of two components; an initial note produced by the impact of the vocal sac against the ground and a second note corresponding to a long whistle of ascending frequency. The initial note is a percussive sound and represents an unusual form of sound emission in anurans; the second note is a vocalization.

Ultrastructural and Cytochemical Aspects of Metamorphosis in the Midgut of Apis mellifera L. (Hymenoptera: Apidae: Apinae)

The midgut of Apis mellifera is remodeled during metamorphosis. The epithelium and, to a lesser extent, the muscular sheath degenerate between the end of the last larval instar and the onset of pupation (prepupa).The larval epithelium is shed to the midgut lumen and digested, while a new epithelium is reconstructed from larval regenerative cells. During pupation, some reorganization still occurs, mainly in brown-eyed pupae. In pharate adult, the midgut wall shows the characteristics of adult, although some cells have pycnotic nuclei. The localization of alkaline and acid phosphatases showed that these enzymes were not involved in the reabsorption of the midgut wall.

Eficiência de extratos de plantas medicinais e aromáticas em atrair a abelha africanizada (Apis mellifera L.) em cultura de abacateiro (Persea americana Mili.)

The objective of the experiment was to test attractive substances for Africanized honey bees, Apis mellifera L., in avocado, Persea americana Mill. Were pulverized extracts of lemon grass (Cympobogon citratus), ocimum (Ocimum sellowii), Lippia alba, orange leaves (Citrus sinensis), eucaliptus leaves (Eucalyptus sp), eugenol and linalol and the frequency of bees on flowers were evaluated. The frequency of honey bees did increase with the application of the extracts falsa melissa, eucaliptus leaves and orange leaves, used as attractants in Quintal variety. The products tested in Eppendorf tubes did not increased the frequency the bees in Quintal and Fortuna varieties.