Q-Insecticidal activity of venomous saliva from Rhynocoris fuscipes (Reduviidae) against Spodoptera litura and Helicoverpa armigera by microinjection and oral administration

Full text

J. Venom. Anim. Toxins incl. Trop. Dis.

V.17, n.4, p.486-490, 2011.

Original paper - ISSN 1678-9199.

Insecticidal activity of venomous saliva from Rhynocoris fuscipes (Reduviidae) against Spodoptera litura andHelicoverpa armigera by microinjection and oral administration

Sahayaraj K (1), Vinothkanna A (1)

(1) Crop Protection Research Centre, Department of Advanced Zoology and Biotechnology, St. Xavier’s College, Palayamkottai, Tamil Nadu, India.

Abstract: Rhynocoris fuscipes is a potential predator of many economically important pests in India. In the present study, its venomous saliva (VS) was collected by milking and diluted with HPLC grade water to different concentrations (200, 400, 600, 800 and 1000 ppm). Microinjection of Rhynocoris fuscipes VS was more toxic than its oral administration in Helicoverpa armigera (cotton bollworm) and Spodoptera litura (tobacco cutworm). Thus, R. fuscipes VS was found to be toxic to third instar S. litura and H. armigera with respective LD50s of 846.35 and 861.60 ppm/larva at 96 hours after microinjection. The current results showed that VS of Rhynocoris fuscipes caused mortality of H. armigera andS. litura. Active peptides from VS may be isolated, identified and assessed for their impact in order to ascertain how they alter the physiology of these pests, information that could be applicable in pest management programs.

Key words: salivary venom, microinjection, oral administration, mortality, Rhynocoris fuscipes, biological control.

ACKNOWLEDGEMENTS

K. Sahayaraj gratefully acknowledges the Department of Science and Technology (ref. n. SR/SO/AS - 33/2006), New Delhi, for the financial assistance. We thank the authorities of St. Xavier’s College, Palayamkottai, for the laboratory facilities and encouragement.

SUBMISSION STATUS

Received: May 19, 2011.

Accepted: September 2, 2011.

Abstract published online: September 9, 2011.

Full paper published online: November 30, 2011.

CONFLICTS OF INTEREST

There is no conflict.

FINANCIAL SOURCE

The Department of Science and Technology, Government of India, provided the financial grants (ref. n. SR/SO/AS - 33/2006).

CORRESPONDENCE TO

K. SAHAYARAJ, Crop Protection Research Centre, Department of Advanced Zoology and Biotechnology, St. Xavier’s College, Palayamkottai, 627002, Tamil Nadu, India. Phone: +91 462 24264376. Fax: +91 462 256 1765. Email: ksraj42@gmail.com.