Jul 17, 1995 - L. S. KERSHAW, 1J. D. PODGWAITE,:l s. P. COOK, K. W. THORPE,. R. R. FARRAR, JR., R. L. RIDGWAY, R. W. FUESTER,4. M. SHAPIRO,.
FOREST ENTOMOLOGY
Blankophor BBH as an Enhancer of Nuclear Polyhedrosis Virus in Arborist Treatments Against the Gypsy Moth (Lepidoptera: Lymantriidae) H. E. WEBB, COOK,
N. H. OILL,U
J. M. McLAUGHLIN,1
L. S. KERSHAW, 1 J. D. PODGWAITE,:l
K. W. THORPE, R. R. FARRAR, JR., R. L. RIDGWAY, R. W. FUESTER,4 R. J. ARGAUER,5 L. VENABLES,6 AND G. B. WHITE
Insect Biocontrol Laboratory, Agricultural H.esearch Service, Building 402, BARe-East
s.
P.
M. SHAPIRO,
Beltsville, MD 2070.'5
J. Econ. Entoll1ol.89(4): 957-962 (1996) Doses of a commercial candidate formu.latic;m of gypsy moth nuclear polyhedrosis virus (LdMNPV) were applied with and without several concentrations of an enhancing adjuvant, B1ankophor BBlI, to individual trees against natural gypsy moth, LlJl1umtria di-spar (L.), populations. Amounts of Blankophor BBH adhering to foliage after application were nwasun,d at 1,322, 227, and 37 ILgig dry weight of leaf for the 0 ..'5,0.1, and 0.02% treatments, respectively. The highest dose of the candidate formulation used without the adjuvant failed to increase significantly 1st-generation after-treatment LdMNPV mortality (direct infection caused by feeding on applied virus) above background levels, to reduce late season (instars .') and 6) larval populations in treated trees or to provide significant foliage protection. However, Blankophor BBlI added to tbe tank mix at concentrations of 0.5 or 0.1 % (wt: vol) resulted in sip;nificantly increased levels of 1st-generation after-treatment LdMNPV, significantly reduced late-season larval populations, and significant levels of foliage protection, compared with untreatl.'d control trees. The resulting recommended tank mix (0.1% Blankophor BBlI and 2X 1010 PIBs per 7.'5liters final spray solution per tree) should give excellent foliage protection against gypsy motb at a cost of about $3 per tree.
ABSTRACT
KEY WORDS LlJlIlantria dispar, ment, stilbene disulfonic acid
adjuvant, formulation, optical blightener, virus enhance-
THE Nl:CLEAR POLYHEDROSIS vims (LdMNPV) of the gypsy moth, Lymantria dispar (L.), has demonstratt'd potential as a gypsy moth control material for liSt' on shade trees (Webb et al. 1990). The additioIl of certain stilbene disulfonic acid derived optical brighteners was shown in laboratory studies to dt'crt'ase sharply the LCso and LTso (the time rt'quired to achieve 50% mortality) of LdMNPV (Shnpiro nnd Robertson 1992). These results were confirmt'd in the field against early-instar (Webb PI aI. 1994b) and late-instar (Webb et al. 1994a) ~vpsy moth larvae. Applied alone, these optical brighteners are not directly toxic to gypsy moth larvae (Shapiro and Robertson 1992) but can enThis artidt' rt'ports tilt' rt'sults of research only. Mention of a proprit'tary prod\ll't dOl'Snot l'onstitutt' an endorsement or a recolll\lll'ndation for its \1St'by USDA. I ))pJawart'Statt' Uniw;sitv. Dowr, DE 19901. ~Dt',ยท.'ast"1. . ;1 Ce\ltt'r for Biolo~kal Control, USDA Forest Service, Hamden. CT Oli514. I lknelkiallns(.,.ts Illtrodul'tion Hes('arl'h.USDA-AHS,Newark. DE 19;13. .1 :>OJ[)
Emirnllllll'ntal Cht'lIlistryLaboratory.USDA-AHS,Beltsville, 20;05.
":>Olaryland Departnlt'nt of A~ricultur(', Forest Pest Mana~eIlll'nt. Annapolis,MD 21401.
hance the efficacy of any natural vims present, giving significant levels of control if natmal vims levels are high (Webb et a!. 1994a, b), but a miuimal response if natural virus levels are low (Webb
