7 research outputs found
Electroantennographic responses of Heterotermes tenuis (Isoptera: Rhinotermitidae) to synthetic (3Z,6Z,8E)-Dodecatrien-1-ol
Review and update on the biology of coptotermes havilandi (Isoptera, Rhinotermitidae)
The introduction of Coptotermes havilandi in Brazil and some aspects of its biology are reviewed. We also describe an aerial principal nest collected from the 15th floor of a high-rise building and its subsidiary nest collected from the 14th floor of the same building. The population of the principal nest consisted of one imaginal physogastric queen, one imaginal king, 20 nymphoid neotenics (14 females and 6 males), 188 nymphs, many workers, presoldiers, soldiers and larvae. The population of the subsidiary nest consisted of 32 nymphoid neotenics (all females), alates, 2 preneotenics, some larvae and nymphs, many workers, presoldiers and soldiers. These neotenics were larger than those found in the principal nest. No eggs were found in either nest. A morphometric analysis of the nymphs and nymphoids was carried out and the morphology of the neotenics and of the imaginai reproductives is described
Electroantennographic responses of Heterotermes tenuis (Isoptera: Rhinotermitidae) to synthetic (3Z,6Z,8E)-Dodecatrien-1-ol
The subterranean termite Heterotermes tenuis (Isoptera: Rhinotermitidae) is a pest of great importance for the Brazilian economy as it causes serious damages in commercial reforestations of Eucalyptus spp. and sugarcane cultures. (3Z,6Z,8E)-Dodecatrien-1-ol has been identified as a pheromone of some species of subterranean termites. The objective of this research was to synthesize (3Z,6Z,8E)-dodecatrien-1-ol and determine by electroantennographic (EAG) bioassays the selectivity and sensitivity of H. tenius antennae to its whole worker extract and to the synthetic triene alcohol
Electroantennographic responses of Heterotermes tenuis (Isoptera: Rhinotermitidae) to synthetic (3Z,6Z,8E)-Dodecatrien-1-ol
The subterranean termite Heterotermes tenuis (Isoptera: Rhinotermitidae) is a pest of great importance for the Brazilian economy as it causes serious damages in commercial reforestations of Eucalyptus spp. and sugarcane cultures. (3Z,6Z,8E)-Dodecatrien-1-ol has been identified as a pheromone of some species of subterranean termites. The objective of this research was to synthesize (3Z,6Z,8E)-dodecatrien-1-ol and determine by electroantennographic (EAG) bioassays the selectivity and sensitivity of H. tenius antennae to its whole worker extract and to the synthetic triene alcohol
Cuticular Hydrocarbons of Heterotermes tenuis (Isoptera: Rhinotermitidae): Analyses and Electrophysiological Studies
Termites have become an important pest of Eucalyptus and Pinus reforestations, sugarcane and other cultures. An alternative for the control of this pest would be the use of attractive traps that take in account the social behavior of these insects. Diverse factors are important for the insects in the localization of the habitat and the choice of the food and specific odors can facilitate this. Studies referring to Heterotermes tenuis (Isoptera: Rhinotermitidae) are scarce. The objective of this work was to analyze the tergal cuticular extract of H. tenuis and determine the selectivity and sensitivity of its antennae to the components of this extract by electroantennography (EAG). The composition of the cuticular extract was determined by GC-MS analysis. The hydrocarbons found were restricted to linear alkanes, being most abundant C24 to C27 that comprises ca. 65% of the total. Olefins were not detected. EAG and behavioral test responses to the cuticular hydrocarbons were greater and significantly different from the control and the high selectivity of the antennae to the extract indicates its potential as chemical messenger. Cuticular hydrocarbons mixture is species-specific and can be used to identify a given taxon without the diagnostic castes, soldiers or imagoes. Difference in the composition appears to relate with the type of habitat of specie
Identification, cloning, expression and functional characterization of an astacin-like metalloprotease toxin from Loxosceles intermedia (brown spider) venom
Injuries caused by brown spiders (Loxosceles genus) are associated with dermonecrotic lesions with gravitational spreading and systemic manifestations. The venom has a complex composition containing many different toxins, of which metalloproteases have been described in many different species of this genus. These toxins may degrade extracellular matrix constituents acting as a spreading factor. By using a cDNA library from an Loxosceles intermedia venom gland, we cloned and expressed a 900 bp cDNA, which encoded a signal peptide and a propeptide, which corresponded to a 30 kDa metalloprotease, now named LALP (Loxosceles astacin-like protease). Recombinant LALP was refolded and used to produce a polyclonal antiserum, which showed cross-reactivity with a 29 kDa native venom protein. CD analysis provided evidence that the recombinant LALP toxin was folded correctly, was still in a native conformation and had not aggregated. LALP addition to endothelial cell cultures resulted in de-adhesion of the cells, and also in the degradation of fibronectin and fibrinogen (this could be inhibited by the presence of the bivalent chelator 1,10-phenanthroline) and of gelatin in vitro. Sequence comparison (nucleotide and deduced amino acid), phylogenetic analysis and analysis of the functional recombinant toxin revealed that LALP is related in both structure and function to the astacin family of metalloproteases. This suggests that an astacin-like toxin is present in a animal venom secretion and indicates that recombinant LALP will be a useful tool for future structural and functional studies on venom and the astacin family