DEVELOPMENT OF NUCLEAR POLYHEDROSIS VIRUS FOR CONTROL OF GYPSY MOTH (LEPIDOPTERA: LYMANTRIIDAE) IN ONTARIO. I. AERIAL SPRAY TRIALS IN 1988

1991 ◽  
Vol 123 (3) ◽  
pp. 601-609 ◽  
Author(s):  
J.C. Cunningham ◽  
W.J. Kaupp ◽  
G.M. Howse
Keyword(s):  
Virus Infection ◽  
Gypsy Moth ◽  
Microscopic Examination ◽  
Inclusion Bodies ◽  
Nuclear Polyhedrosis Virus ◽  
Egg Mass ◽  
The Third ◽  
First Instar ◽  
Nuclear Polyhedrosis ◽  
Treated Plot

AbstractA double application of Disparvirus, a nuclear polyhidrosis virus, at 1.25 × 1012 polyhedral inclusion bodies (PIB) per hectare, giving a total of 2.5 × 1012 PIB per hectare, was applied aerially on three plots in an emitted volume of 10.0 L per hectare. The two applications were 3 days apart and most larvae were in the first instar. Three plots were selected as untreated checks; each was paired with a treated plot on the basis of pre-spray gypsy moth egg-mass numbers and locality. The pre-spray egg-mass counts ranged from 1430 to 8520 per hectare in the six plots. Assessment of the treatment was based on numbers of pupae and fall egg masses as well as on estimates of defoliation and on microscopic examination of larvae collected at weekly intervals to determine the incidence of virus infection. Between 12 and 19 days post-spray, 49, 61, and 85% of the larvae were infected with virus in the three treated plots compared with 3, 7, and 14%, respectively, of larvae in the check plots. Red oak was 14% defoliated in two of the treated plots compared with 82 and 90% in their corresponding check plots. The third plot suffered 46% defoliation due to leaf-eating caterpillars other than gypsy moth; defoliation in its corresponding check plot was 31%. Reductions in egg-mass numbers in the treated plots were 76, 93, and 98% compared with an increase of 56% and decreases of 50 and 70%, respectively, in corresponding check plots. Corrected population reductions (Abbott’s formula) were 84, 85, and 92% in the three treated plots.

DEVELOPMENT OF NUCLEAR POLYHEDROSIS VIRUS FOR CONTROL OF GYPSY MOTH (LEPIDOPTERA: LYMANTRIIDAE) IN ONTARIO. II. REDUCTION IN DOSAGE AND EMITTED VOLUME (1989 AND 1990)

1993 ◽  
Vol 125 (3) ◽  
pp. 489-498 ◽  
Author(s):  
J.C. Cunningham ◽  
W.J. Kaupp ◽  
R.A. Fleming ◽  
K.W. Brown ◽  
T. Burns
Keyword(s):  
Gypsy Moth ◽  
Inclusion Bodies ◽  
Nuclear Polyhedrosis Virus ◽  
Larval Instar ◽  
Egg Mass ◽  
Current Recommendation ◽  
First Instar ◽  
Untreated Check ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis

AbstractA double application of 1.25 × 1012 (total 2.5 × 1012) polyhedral inclusion bodies (PIB) of Disparvirus (nuclear polyhedrosis virus) in an emitted volume of 10.0 L per ha gave acceptable control of gypsy moth, Lymantria dispar (L.), larvae in 1988. More aerial spray trials were conducted in 1989 and 1990 to test a reduced dosage and volume of Disparvirus. Dosage on all plots, applied when larvae were mainly in their first instar, was a double treatment of 5 × 1011 PIB per ha, 3–5 days apart, giving a total of 1012 PIB per ha. The aqueous tank mix contained 25% (v/v) molasses, 10% (w/v) Orzan LS, and 2% (v/v) Rhoplex B60A sticker. Emitted volumes of 10.0 L per ha and 5.0 L per ha were each tested on three replicated plots in 1989, and 5.0 L per ha and 2.5 L per ha were each tested on three replicated plots in 1990. In both 1989 and 1990, three untreated check plots were paired with treated plots on the basis of pre-spray egg-mass densities.The treatments were assessed by counts of pupae in burlap traps, estimates of defoliation, and change in numbers of egg masses in the treated and check plots. Better control was obtained with the reduced dosage at 10.0 L per ha and 5.0 L per ha than at 2.5 L per ha. Using the aqueous formulation described above, a double application of 5 × 1011 PIB per ha at 5.0 L per ha applied at the peak of the first larval instar is the current recommendation for control of gypsy moth in Ontario using nuclear polyhedrosis virus.

Hydraulic Spray Application of Gypchek as a Homeowner Control Tactic Against Gypsy Moth (Lepidoptera: Lymantriidae)

1990 ◽  
Vol 25 (3) ◽  
pp. 383-393 ◽  
Author(s):  
R. E. Webb ◽  
J. D. Podgwaite ◽  
M. Shapiro ◽  
K. M. Tatman ◽  
L. W. Douglass
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Inclusion Bodies ◽  
Treatment Effects ◽  
Nuclear Polyhedrosis Virus ◽  
Spray Application ◽  
Laboratory Bioassay ◽  
Early Season ◽  
Late Season ◽  
Nuclear Polyhedrosis

Gypsy moth, Lymantria dispar L., nuclear polyhedrosis virus (NPV) was applied by ground equipment at the rate of 2.5 × 1012 polyhedral inclusion bodies (PIB's) per ha to the lower half of ten trees (per plot) in homeowner-sized plots in Hardford and Baltimore Counties, MD, in 1986. A laboratory bioassay of field collected larvae indicated that a highly significant (P < 0.001) increase in early season mortality of gypsy moth larvae due to NPV occurred in the zone of spray, compared to mortality in a similar foliage zone in untreated plots. Late-season treatment effects varied greatly, in apparent response to significant (P < 0.05) area effects.

Effects of Blankophor BBH, a Virus-Enhancing Adjuvant, on Mortality of Gypsy Moth (Lepidoptera: Lymantriidae)

1999 ◽  
Vol 34 (4) ◽  
pp. 391-403 ◽  
Author(s):  
R. E. Webb ◽  
R. A. Peiffer ◽  
R. W. Fuester ◽  
M. A. Valenti ◽  
K. W. Thorpe ◽  
...  
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Inclusion Bodies ◽  
Nuclear Polyhedrosis Virus ◽  
Obvious Effect ◽  
Virus Dose ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Second Wave

We examined aspects of the gypsy moth, Lymantria dispar (L.)/nuclear polyhedrosis virus relationship, and the effects of Blankophor BBH on that relationship, that might impact the timing of virus kill in a cohort of treated larvae. We studied this relationship both for virus and enhancer applied together and separately. We found that a portion of larvae ingesting virus polyhedral inclusion bodies die later (more than 4 wk after infection) in the season, and that this can be affected by the presence of Blankophor BBH if the virus dose is above a certain level (in this study, 107 polyhedral inclusion bodies per 378 liters). Furthermore, the pattern of mortality resulting from virus ingestion was elucidated. This pattern was affected by Blankophor BBH, but only when the virus dose was above a certain higher level (in this study, 1011 inclusion bodies per 378 liters). We also found that Blankophor BBH alone had no obvious effect on the course of the disease in gypsy moth larvae that had previously ingested virus; it caused neither an increase in mortality, a decrease in time to kill, nor any obvious effect on the pattern of kill. Most larvae died between 18 and 29 d. Few larvae ingesting virus died earlier (13 to 17 d); however, about 5% of the larvae died later than 30 d after infection, which may be late enough to contribute to the second wave of mortality. A combination of Blankophor BBH at 0.5% and virus at 1011 inclusion bodies resulted in an increase in mortality and a decrease in time of kill compared with that seen for that level of virus without the enhancer, while eliminating the “tail” of mortality occurring 30 d after infection. However, a combination of Blankophor BBH at 0.5% and virus at 109 inclusion bodies still give higher mortality than expected with the virus alone, but did not decrease the time of kill or eliminate the “tail.”

The effect of gypsy moth metamorphosis on the development of nuclear polyhedrosis virus infection

1991 ◽  
Vol 57 (3) ◽  
pp. 352-361 ◽  
Author(s):  
Kathleen D. Murray ◽  
Kathleen S. Shields ◽  
John P. Burand ◽  
Joseph S. Elkinton
Keyword(s):  
Virus Infection ◽  
Gypsy Moth ◽  
Nuclear Polyhedrosis Virus ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis
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