Effect of the juvenile hormone on the development of the mandibular gland in workers' pupae of Apis mellifera L. (Hymenoptera, Apidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chemical communication in Apis mellifera: Temporal modulation of alarm behaviors

The effect of pheromones and their chemical analogues in honeybee alarm behaviors was studied in observation boxes. Defensive behaviors, as follows: a) attraction to scent source, b) elevation of wings in 'V', c) abdomen elevation, d) abdomen elevation and pumping and e) first leg pair elevation had been temporarily registered when the following compounds were presented: isoamyl alcohol, octyl alcohol, benzyl alcohol, n-butyl acetate, n-octyl acetate, isopentyl acetate, benzyl acetate and 2-heptanone. The results were as follows: 1. the bees elicited some characteristic behaviors when chemical alarm messages were presented, 2. agression (stinging) was not completed with any compound tested, probably because there was not a target (visual stimulus), 3. in all situations the attraction to scent source was low, 4. all the behaviors were elicited in a temporarily different way, 5. the compounds that elicited stronger responses and a greater number of the investigated behaviors were: isopentyl acetate, 2-heptanone, octyl acetate and n-octyl alcohol. In all situations, the first behavior response (and the most intense one) was the elevation and pumping the abdomen. This suggests that the chemical message was promptly recognized and then transmitted to each worker. So, the results obtained in the present work, suggest that chemical alarm messages may be recognized by different mechanisms of neural integration.

Comparative study of the cuticular hydrocarbon composition of Melipona bicolor Lepeletier, 1836 (Hymenoptera, Meliponini) workers and queens

In social insects, cuticular hydrocarbons are involved in species, kin, caste and nestmate recognition. Gas chromatography and mass spectrometry were used to compare the cuticular hydrocarbon composition of workers, males and queens of Melipona bicolor. The cuticular hydrocarbon composition of this species was found to consist mainly of C23, C25:1, C25, C27:1, C27, C29:1 and C29, which are already present in imagoes that have not yet abandoned the brood cell. This composition varied quantitatively and qualitatively between and within the castes and sexes. The newly emerged workers and young queens (virgins) had similar cuticular hydrocarbon profiles, which were different from those of the males. When the females start executing their tasks in the colony, the cuticular hydrocarbon profile differences appear. The workers have less variety, while the queens conserve or increase the number of cuticular hydrocarbon compounds. The queens have more abdominal tegumentary glands than the workers, which apparently are the source of the new cuticular compounds.

Trail-Pheromone Specificity of Two Sympatric Termites (Rhinotermitidae) from Southeastern Brazil

Studies on pheromone specificity are of ecological interest in termite biology where different species share the same habitat. In this work we evaluated the role of the trail pheromones as a mechanism for the isolation of sympatric populations of Coptotermes gestroi and Heterotermes tenuis (Rhinotermitidae) in Brazil. Based on our results, we conclude that trail pheromones are potentially capable of separating sympatric colonies of these species. Furthermore, the trail-pheromone specificity found in these species could be explained by quantitative differences of the common component of the trail pheromone. However, secondary components on the trail pheromone may neutralize the quantitative differences of a common component. Activity bioassays showed that synthetic (Z,Z,E) 3,6,8-dodecatrien-1-ol may act as the common component of the trail pheromone of these species. Further studies should focus on the chemical identification of the trails laid by the termites.

Histochemistry and protein profile of the mandibular glands of workers of the ant Atta sexdens rubropilosa (Hymenoptera: Formicidae)

Insect mandibular glands are always associated to the mandibles; they are part of the salivary glandular system. The mandibular glands are composed by a reservoir associated to the secretory cells, with each secretory cell connected to the reservoir by means of individual canaliculi. These glands play an important role in the production of pheromones, which are compounds involved in defense, communication, and reproduction of the colony. Mandibular glands of soldiers and major and minor workers of the ant Atta sexdens rubropilosa were processed for different histochemical tests, total protein content, and protein electrophoretic profile determination. The histochemical tests detected the presence of lipids, DNA/RNA, polysaccharides, and proteins at different regions of the gland. The protein electrophoretic profiles showed that the total protein content as well as the number of peptides of each caste follow a progressive order in relation to the size of the individual. Thus, we suggest that the production of secretion is directly linked to the task that the individual performs in the colony.

The hypopharyngeal gland of leaf-cutting ants (Atta sexdens rubropilosa) (Hymenoptera: Formicidae)

The social behavior of ants is controlled by means of dynamic interactions between the environment and the individuals, mainly through pheromones. Among the exocrine glands is the hypopharyngeal gland (HG), located laterally over the pharyngeal plate. The present work aimed to describe and compare the HG in the different castes of the leaf-cutting ant Atta sexdens rubropilosa Forel 1908. The HG of different castes showed similar morphology varying only in relation to the secretory cell number. The secretory intracellular reservoir presented positive reaction to Xylidine Ponceau and P.A.S, indicating the presence of protein and polysaccharides in the secretion. Therefore, we suggest that the function of this gland would be the production of digestive enzymes and/or some sort of mucus, which, together with the secretions produced by the salivary glands of the thorax, would be related to the production of saliva.

Reproductive behavior of Eidmanacris corumbatai garcia (Orthoptera: Phalangopsidae)

Adult males of Eidmanacris corumbatai Garcia have reduced tegmina without stridulatory apparatus. For this reason, they developed other means of intra-specific communication. During courtship, the males use a combination of foreleg drumming and waving of the antennae, in addition to chemical signaling through pheromones. The females become receptive to copulation when the males expose their metanotal gland. This gland, located on the male metanotum, is also a source of substances on which females feed before receiving the spermatophore. During copulation, the female destroys the apex of the metanotal gland to gain access to the secretion released by this structure.

Dynamics of foraging and recruitment behavior in the Asian subterranean termite Coptotermes gestroi (Rhinotermitidae)

The present study investigated the trail-following behavior of the subterranean termite Coptotermes gestroi (Wasmann Rhinotermitidae) under laboratory conditions. The results showed that workers were the first to initiate the exploration to the food source. When food was discovered they returned to the nest laying a trail for recruiting nestmates to the food source. In this situation, workers always traveled significantly faster when returning from the arenas. Both workers and soldiers were recruited to the food source; however, the soldier/worker proportion was higher during the first phase of the recruitment. When no food was available, the number of recruited nestmates and the speed on their way back to the nest were significantly lower. The results also showed that scout foragers always laid trail pheromones when entering into unknown territories, and that chemical signals found in the food could induce workers of C. gestroi to increase their travel speed. Copyright © 2012 Alberto Arab et al.

Blood Cues Induce Antipredator Behavior in Nile Tilapia Conspecifics

In this study, we show that the fish Nile tilapia displays an antipredator response to chemical cues present in the blood of conspecifics. This is the first report of alarm response induced by blood-borne chemical cues in fish. There is a body of evidence showing that chemical cues from epidermal 'club' cells elicit an alarm reaction in fish. However, the chemical cues of these 'club' cells are restricted to certain species of fish. Thus, as a parsimonious explanation, we assume that an alarm response to blood cues is a generalized response among animals because it occurs in mammals, birds and protostomian animals. Moreover, our results suggest that researchers must use caution when studying chemically induced alarm reactions because it is difficult to separate club cell cues from traces of blood. © 2013 Barreto et al.

Biologia comportamental de Synoeca surinama: enxameio e interações socias (Vespidae, Polistinae: Epiponini)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise comparativa da expressão protéica em glândulas pós-faríngeas de saúva-limão, Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae) submetidas à suplementação lipídica

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Relação entre o corpo gorduroso e a vitelogênese em fêmeas de Melipona quadrifasciata anthidioides Lep

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Imunocastração e ractopamina na dieta de suínos: implicações na qualidade de carne fresca e melhorada por injeção (enhancement)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Changes in chemical profile of cephalic salivary glands of Scaptotrigona postica (Hymenoptera, Meliponini) workers are phase-related

Most advanced eusocial bees recruit their nestmates to food resources. Recently, studies in Meliponini species showed that the cephalic salivary (labial) glands (CSGs) are responsible for the production of scent-trail pheromones. Studies on CSGs have shown changes in glandular cell morphology since the worker emerges from brood combs (newly emerged) till forager phase, which may be correlated to changes in the composition of secretion produced. However, no study has been made till now regarding to the composition of CSGs secretion of Scaptotrigona postica and the chemical changes that occur in this secretion according to the worker's life phase or tasks performed. In this study, the chemical profile of CSG secretion in S. postica workers was studied. Glands were taken from specimens newly emerged (NE), working in the brood combs area (CA) and forager (FO) and were analyzed by gas chromatography-mass spectrometry. The results showed that glandular secretion consists of oxygenated compounds of middle volatility (acids, alcohols, aldehydes, ketones, esters and ether), and their quantity varies among the different phases of life, increasing as the individual undergoes from intra- to extra-colonial activities. The NE phase contained the smallest variety and quantity of compounds. Due to the variability of compounds, the CA workers were separated into 3 groups according to the chemical constitution of their secretion. Forager workers showed the largest quantity and variety of chemical compounds. The major compounds in forager gland secretion are 7-hexadecen-1-yl acetate and 5-tetradecen-1-yl acetate. Statistical analysis indicates that the chemical composition of glandular secretion is task-related.

Exometaboloma do tegumento da vespa social Polybia paulista por análises GC-MS: bases moleculares do reconhecimento de tipos parentais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)