Terpene-lnduced Morphological Changes to Exoskeleton of Formosan Subterranean Termites (Isoptera: Rhinotermitidae): Toxic Effects of cis-nerol

2003 ◽  
Vol 38 (2) ◽  
pp. 225-233
Author(s):  
Betty C. R. Zhu ◽  
Gregg Henderson ◽  
Huixin Fei ◽  
Xiao Ying ◽  
Roger A. Laine

The terpenoid, cis-nerol was found to be highly toxic to the Formosan subterranean termite, Coptotermes formosanus Shiraki. Morphological abnormalities were observed in the exoskeleton including the spiracles and trichoid sensilla using scanning electron microscopy after exposure of termites to cis-nerol for 2 h. Proteins were found in a water-soluble fraction collected from the whole termite body exposed to cis-nerol for 60 min. It appears that terpenoids cause damage to cell membranes resulting in a significant loss of proteins.

Holzforschung ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 569-574 ◽  
Author(s):  
Wakako Ohmura ◽  
Shuichi Doi ◽  
Masakazu Aoyama ◽  
Seiji Ohara

Summary The attraction of steamed Japanese larch (Larix leptolepis (Sieb. et Zucc.) Gord.) heartwood to the subterranean termite, Coptotermes formosanus Shiraki was investigated. Hot-water extracts of the steamed and the non-steamed larch woods were sequentially extracted with n-hexane, diethyl ether, and ethyl acetate. Furthermore, the residual water-soluble fraction of the steamed wood was fractionated by column chromatography using an Amberlite XAD-2 resin. Feeding-preference and feeding-deterrence of the termite were assessed in the two-choice feeding tests using paper discs permeated with each fraction. The diethyl ether extracts of the non-steamed larch wood showed the feeding-deterrence activity. Taxifolin, the main component of these extracts, was found to be the major feeding-deterrence constituent. In the case of the steamed larch wood, taxifolin was not detected in any fractions, and the residual water-soluble fraction showed the feeding-preference activity. Furthermore, it was found that the feeding-preference constituents were contained in the coloring substances adsorbed by the Amberlite XAD-2 resin. From these results, the degradation of taxifolin and the formation of coloring substances during the steam treatment were to be considered as important factors of the attraction of steamed larch wood to the termite.


1988 ◽  
Vol 23 (3) ◽  
pp. 235-239 ◽  
Author(s):  
Nan-Yao Su ◽  
Rudolf H. Scheffrahn ◽  
Paul Ban

Workers of the Formosan subterranean termite, Coptotermes formosanus Shiraki, and the eastern subterranean termite, Reticulitermes flavipes (Kollar) were force-fed a dye marker, Sudan Red 7B, and confined with different proportions of unmarked termites. No significant mortality due to the dye was detected for up to 8 weeks after the treatment in either species. The marked/unmarked proportion did not affect the retention of the dye or mortality. Workers of C. formosanus retained visible dye for 6 weeks, while significant numbers (10–50%) of marked R. flavipes lost the dye within two weeks. Sudan Red 7B is suitable for estimating population size of C. formosanus with the multiple-marking method where the mark-recapture period extends to 6 weeks. The dye is not an adequate marker for R. flavipes when the mark-recapture period is ≥ 2 weeks.


Insects ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 37
Author(s):  
Franklin Quarcoo ◽  
Xing Hu ◽  
Arthur Appel

Behavioral symptoms and mortality associated with intoxication with insecticides fipronil and indoxacarb were determined in field-collected eastern subterranean termites, Reticulitermes flavipes (Kollar), and Formosan subterranean termites, Coptotermes formosanus Shiraki. Behaviors and mortality were evaluated at three temperatures (16, 22, and 28 °C) and three concentrations of fipronil (0.5, 1, and 5 ppm) and indoxacarb (50, 75, and 100 ppm). LT50 (median lethal time to kill 50% of the termites) values declined with increasing concentrations and temperatures for both fipronil-exposed eastern and Formosan subterranean termites, whereas these values were not always the highest at 16 °C for indoxacarb-treated termites. The greatest change (reduction) in LT50 values occurred for both species between 16 and 22 °C at the lowest concentration of each insecticide. Intoxication and moribundity were the most frequently observed behaviors for fipronil-exposed termites, whereas intoxication, ataxia, and moribundity were observed for most concentration and temperature combinations for indoxacarb-exposed termites. The inherent toxicity of fipronil was higher than that of indoxacarb. The higher presence and duration of intoxication behaviors may positively affect the performance of indoxacarb against subterranean termite colonies.


2014 ◽  
Vol 91 (5) ◽  
pp. 473-481 ◽  
Author(s):  
Guiai Jiao ◽  
Xiangjin Wei ◽  
Gaoneng Shao ◽  
Lihong Xie ◽  
Zhonghua Sheng ◽  
...  

1957 ◽  
Vol 35 (4) ◽  
pp. 241-250 ◽  
Author(s):  
W. G. Martin ◽  
J. E. Vandegaer ◽  
W. H. Cook

Livetin, the major water-soluble protein of hen egg yolk, was found to contain three major components having mobilities of −6.3, −3.8, and −2.1 cm.2 sec.−1 volt−1 at pH 8, µ 0.1, and these have been designated α-, β-, and γ-livetin respectively. The α- and β-livetins were separated and purified electrophoretically after removal of γ-livetin by precipitation from 37% saturated ammonium sulphate or 20% isopropanol. The α-, β-, and mixed livetins resembled pseudoglobulins in solubility but γ-livetin was unstable and this loss of solubility has, so far, prevented its characterization. Molecular weights determined by light scattering, osmotic pressure, and Archibald sedimentation procedure yielded respectively: 8.7, 7.8, and 6.7 × 104 for α-livetin, and 4.8, 5.0, and4.5 × 104 for β-livetin. Under suitable conditions of sedimentation and electrophoresis, egg yolk has been shown to contain three components having the same behavior as the three livetins of the water-soluble fraction.


Sign in / Sign up

Export Citation Format

Share Document