Behavioural and electrophysiological responses of the coconut pest, Rhynchophorus ferrugineus (Coleoptera: Curculionidae) to host, nonhost and alternate host plant volatiles

Abstract

Steam bark distillates of the typica and aurancica varieties of Cocos nucifera (host plant) Ternlinulia catappa (Kottamba) and Albizzia urnara Boiv. (Albizzia) (nonhost plants) and Areca catechu L. (Puwak) and Areca concmna Thw. Enum. (Lentheti) (alternate hosts) were subjected to electrophysiological and behavioural assays to compare the attractiveness to the coconut pest, Rhynchophorus ferrugineus F. (Coleoptera: Curculionidae). In the electroantennogram (EAG) assay, the steam distillates of C. nucifera form aurancica elicited the highest response of 79.1% (relative to standard) and the form typica (young bark) 55.6% to the antenna ofR. ferrugineus both values being significantly different (p<0.05, ANOVA, Scheffe's test) from those of the nonhosts T. catappa and A. amara (10.9% and 5.9% respectively). EAGs of old bark (51.4%) steam distillate of C. nucifera form typica did not differ significantly from that of the young bark distillates (55.6%). The two alternate hosts, A. catechu and A. concinna showed moderate EAG activities (29.4% and 25.9% respectively) between those of host varieties and nonhosts. In a behavioural assay (choice test) using an olfactometer the steam distillates of host palms were more attractive (pc0.05, ANOVA, Scheffe's test) to the red weevil than those of the nonhosts. C. nucifera form aurancica was more , attractive (79.9% attraction to the baited arm) than typica. Between young and old palms of C. nucifera form typica, no significant difference (p>O.OB, ANOVA, Scheffe's test) in the behavioural activity was observed. The alternate hosts showed moderate activity.

Histopathological Pattern of Abnormal Uterine Bleeding in Endometrial Biopsies

“…The most susceptible varieties against R. ferrugineus were Karbalain (~25%), Dhedhi (21%), Fasli, Aseel (~19%) and Eidan Shah (18%) during both the years of studies. Similar results were reported previously by Baloch et al [3] These results are in agreement with the findings of Gunawardena and Swarnakanthi [15] and Oehlschlager et al [16]. Pheromone trapping system is one of the modern techniques in Pakistan which helps to control the insect population and various diseases.…”

Effects of Lead Acetate on Light Protein of Drosophila melanoigaster

“…During the experimental period 169 adults of R. ferrugineus were captured through pheromone traps. These results are in agreement with the findings of Gunawardena and Swarnakanthi [15] and Oehlschlager et al [16]. Pheromone trapping system is one of the modern techniques in Pakistan which helps to control the insect population and various diseases.…”

Volatile constituents of tea stems (Camellia sinensis L.O. Kuntze) as semiochemicals to attract low country live wood termite (Glyptotermes dilatatus Bugnion & Popoff), in Sri Lanka

“…The use of host plant volatiles and insect pheromones have been successfully developed as an environmentally friendly pest control strategy to control economically important insect pests. It has been reported that volatile compounds produced by the host plant coconut attracts the red weevil (Rynchophorus ferrugineus), and this strategy is now employed in combination with the aggregation pheromone of red weevil as an alternative, eco-friendly method to control red weevil of coconut plantations in Sri Lanka (Gunawardana & Swarnakanthi, 1995). Gunawardana and Dissanayake (2000) reported the isolation of volatiles, n-hexanal, n-hexanol, n-pentanol and cis-3-hexanol from the steam distillate of banana stems and investigated the synergistic effect of these compounds when blended with the pheromone.…”