The harmful effects of chemical-based termiticides and the increased incidence of termite resistance have resulted in the need for safer and more effective termiticides.Therefore,the screening of antitermiticidal acti...The harmful effects of chemical-based termiticides and the increased incidence of termite resistance have resulted in the need for safer and more effective termiticides.Therefore,the screening of antitermiticidal activity of naturally-occurring products could possibly hamper an alternative means in termite control strategies.The aims of this study were to determine the toxicity and repellency of L.leucocephala,A.paniculata,Az.indica and P.niruri crude extracts against two subterranean termites,G.sulphureus and C.gestroi.Bioassays were conducted by applying varying concentrations of the plant extracts(10,000 ppm,5000 ppm and 500 ppm)on both termite species under laboratory conditions.All extracts exhibited a significant antitermiticidal activity in time-and concentration-dependent manners after 14 days of exposure.The highest mortality of G.sulpureus and C.gestroi were noted in all methanolic extracts of P.niruri,L.leucocephala,A.paniculata,Az.indica at 10,000 ppm.High repellent activity was also noted in the choice bioassay when both termites were treated with all methanolic extracts at 10,000 ppm.展开更多
Coptotermes gestroi and Heterotermes tenuis have been described as important urban pests in Brazil. The establishment of control technologies using baits that consider the social behavior of termites requires a better...Coptotermes gestroi and Heterotermes tenuis have been described as important urban pests in Brazil. The establishment of control technologies using baits that consider the social behavior of termites requires a better knowledge of their foraging behavior. Thus, this study analyzed the feeding behavior of these species with three different forms of food placement： food on the surface of a substrate and food either partially or completely buried in the substrate. Experimental arenas were composed of a central chamber connected to three food chambers. Each central chamber contained 550 foragers of C. gestroi or 517 foragers of 11. tenuis. Blocks of Pinus elliottii were placed in the different food chambers. After 28 days, the consumption of each wood block and the percentage of foraging individuals recruited for food chambers were verified in relation to the total survival rate obtained for each one of the 20 replicates. Results showed that completely buried food was most consumed for H. tenuis and presented a higher recruitment rate of workers and soldiers for both species. Although the consumption had non-significant differences for C. gestroi, these termites exhibited a tendency to prefer completely buried food. In these conditions, it can be concluded that the forms of food placement used in the present research influenced the recruitment of individuals for both species. Data also suggests that when the foraging subterranean termites find food resources in the tunneling substrate, they tend to concentrate their efforts on it, a behavior regime that reduces exposure to external environment.展开更多
文摘The harmful effects of chemical-based termiticides and the increased incidence of termite resistance have resulted in the need for safer and more effective termiticides.Therefore,the screening of antitermiticidal activity of naturally-occurring products could possibly hamper an alternative means in termite control strategies.The aims of this study were to determine the toxicity and repellency of L.leucocephala,A.paniculata,Az.indica and P.niruri crude extracts against two subterranean termites,G.sulphureus and C.gestroi.Bioassays were conducted by applying varying concentrations of the plant extracts(10,000 ppm,5000 ppm and 500 ppm)on both termite species under laboratory conditions.All extracts exhibited a significant antitermiticidal activity in time-and concentration-dependent manners after 14 days of exposure.The highest mortality of G.sulpureus and C.gestroi were noted in all methanolic extracts of P.niruri,L.leucocephala,A.paniculata,Az.indica at 10,000 ppm.High repellent activity was also noted in the choice bioassay when both termites were treated with all methanolic extracts at 10,000 ppm.
文摘Coptotermes gestroi and Heterotermes tenuis have been described as important urban pests in Brazil. The establishment of control technologies using baits that consider the social behavior of termites requires a better knowledge of their foraging behavior. Thus, this study analyzed the feeding behavior of these species with three different forms of food placement： food on the surface of a substrate and food either partially or completely buried in the substrate. Experimental arenas were composed of a central chamber connected to three food chambers. Each central chamber contained 550 foragers of C. gestroi or 517 foragers of 11. tenuis. Blocks of Pinus elliottii were placed in the different food chambers. After 28 days, the consumption of each wood block and the percentage of foraging individuals recruited for food chambers were verified in relation to the total survival rate obtained for each one of the 20 replicates. Results showed that completely buried food was most consumed for H. tenuis and presented a higher recruitment rate of workers and soldiers for both species. Although the consumption had non-significant differences for C. gestroi, these termites exhibited a tendency to prefer completely buried food. In these conditions, it can be concluded that the forms of food placement used in the present research influenced the recruitment of individuals for both species. Data also suggests that when the foraging subterranean termites find food resources in the tunneling substrate, they tend to concentrate their efforts on it, a behavior regime that reduces exposure to external environment.
