EFFECTS OF A FLUORESCENT BRIGHTENER ON THE ACTIVITY OF ANAGRAPHA-FALCIFERA (LEPIDOPTERA, NOCTUIDAE) NUCLEAR POLYHEDROSIS-VIRUS TO 4 NOCTUIDPESTS

The influence of Calcofluor white M2R (=Tinopal LPW = fluorescent brig htener 28), a fluorescent brightener, on the laboratory activity of a nuclear polyhedrosis virus (AfMNPV) isolated from the celery looper An agrapha falcifera (Kirby) was determined. The species challenged with and without M2R included Heliothis virescens (Fabricius), Helicoverpa zea (Boddie), Spodoptera exigua (Hubner), and Trichoplusia ni (Hubner) , all economically important pest species of a number of food and fibe r crops. Levels of enhancement as determined by LC(50) values varied f rom 2.9- to 13.6-fold, whereas levels of LC(95) values ranged from 3.7 - to 16-fold, depending on the species. The greatest enhancement occur red among T. ni larvae. LT(50) values were significantly affected part icularly when lower concentrations of polyhedra were fed. The presence of M2R reduced LT(50) values up to 2.1-fold among the species tested. The optimum concentrations for M2R enhancement were between 0.25 and 1% (wt/vol). Choice tests between water- and M2R-treated diet showed t hat larvae preferred non-M2R-treated diet. The implications of these d ata for use of M2R as an adjuvant for AfMNPV and other baculoviruses a re discussed. (C) 1996 Academic Press, Inc.