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ARS Home » Research » Publications at this Location » Publication #73697
Title: ENHANCEMENT IN ACTIVITY OF HOMOLOGOUS AND HETEROLOGOUS BACULOVIRUSES INFECTIOUS TO BEET ARMYWORM (LEPIDOPTERA:NOCTUIDAE) BY AN OPTICAL BRIGHTENER

Author
item Shapiro, Martin

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/4/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: The beet armyworm is a serious agricultural pest. Years ago a naturally-occurring specific nuclear polyhedrosis virus (SeNPV) was isolated and was recently registered for use against this pest. While the virus is quite active against the beet armyworm, its killing power can be increased dramatically by the addition of selected optical brightener (Tinopal LPW). Moreover, the brightener can also increase the potencies of such broad spectrum viruses as the alfalfa looper NPV and the celery looper NPV so much that they could be used to control both the beet armyworm and other lepidopterous pest insects which might also occur in a given ecosystem. This information will benefit researchers and producers looking for alternative ways to control vegetable insect pests.

Technical Abstract: The nuclear polyhedrosis virus (NPV) from the beet armyworm, Spodoptera exigua (Hubner), was the most potent virus tested against the beet armyworm (SeNPV; LC50 = 4.1 PIB per mm2), followed by NPVs from the alfalfa looper, Autographa californica (Speyer) (AcNPV; LC50 = 92.6 PIB per mm2), and from the celery looper, Anagrapha falcifera (Kirby), (AfNPV; LC50 = 195.7 PIB per mm2). In the case of the NPV from the cotton bollworm, Heliothis armigera (Hubner)(HaNPV), the LC50 obtained for 5 replicates was 152.2 PIB per mm2, while no larval mortality was obtained for 1 replicate. In the case of the NPV from the wax moth, Galleria mellonella (L.) (GmNPV), the LC50 for 2 replicates was 173.9 PIB per mm2, while no larval mortality was obtained for 4 replicates. The addition of a selected optical brightener (Tinopal LPW) reduced the LC50s for SeNPV by 130-fold, for AcNPV for 130-fold, and for AfNPV for 300-fold. Among larvae treated with HaNPV + Tinopal LPW and GmNPV + Tinopal LPW, LC50s were dramatically reduced to 0.7 PIB per mm2 and 4.8 PIB per mm2, respectively. The addition of Tinopal LPW significantly decreased the LT50s for all viruses by 30-40%. The most efficacious combination tested was that of SeNPV + Tinopal LPW (LT50 = 2.92 d).