Movement of Nuclear Polyhedrosis Virus into Velvetbean Caterpillar (Lepidoptera: Noctuidae) Larval Populations on Soybean by Nabis roseipennis (Heteroptera: Nabidae) Nymphs

1992 ◽  
Vol 27 (2) ◽  
pp. 126-134 ◽  
Author(s):  
S. Y. Young ◽  
W. C. Yearian
Keyword(s):  
Nuclear Polyhedrosis Virus ◽  
Larval Mortality ◽  
Anticarsia Gemmatalis ◽  
Velvetbean Caterpillar ◽  
Nabis Roseipennis ◽  
Polyhedrosis Virus ◽  
Soybean Plants ◽  
Nuclear Polyhedrosis ◽  
Mixed Age ◽  
Lepidoptera Noctuidae

Nabis roseipennis Reuter nymphs that preyed on larvae of the nuclear polyhedrosis virus (NPV) infected velvetbean caterpillar, Anticarsia gemmatalis (Hübner), excreted the virus (AgNPV) for several days thereafter. Based on bioassays, fifth instar and second instar nymphs excreted 84.7 × 105 and 9.7 × 105 polyhedral inclusion bodies (PIB) per nymph, respectively. The AgNPV-contaminated nymphs effectively disseminated the virus via the feces over soybean plants where it served as inoculum to initiate disease in larval populations of A. gemmatalis caged in the field. Larval mortality from AgNPV ranged from 11.4 to 48.5% over treatments in two tests. Larval mortality in treatments where the source of virus inoculum was AgNPV-contaminated fifth instar nymphs was similar to that in treatments where the source of viral inoculum was diseased larvae. Larval mortality resulting from AgNPV dissemination by the nymphs was usually higher in treatments containing fifth instar nymphs than in those with second instar nymphs. Dissemination of NPV by fifth instar nymphs was higher in mixed-age than in uniformed-age A. gemmatalis larval populations. This was not the case with the smaller second instar nymphs.

NUCLEAR POLYHEDROSIS VIRUS TRANSMISSION IN MULTIPLE GENERATIONS OF ANTICARSIA GEMMATALIS (LEPIDOPTERA: NOCTUIDAE) CAGED ON SOYBEAN

1989 ◽  
Vol 24 (1) ◽  
pp. 133-141
Author(s):  
S. Y. Young ◽  
W. C. Yearian
Keyword(s):  
Nuclear Polyhedrosis Virus ◽  
Larval Mortality ◽  
Virus Transmission ◽  
Anticarsia Gemmatalis ◽  
Velvetbean Caterpillar ◽  
Larval Population ◽  
Multiple Generations ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Lepidoptera Noctuidae

Transmission of a nuclear polyhedrosis virus (AgNPV) of the velvetbean caterpillar, Anticarsis gemmatalis Hübner, in multiple generations on caged soybeans was examined. Introduction of primary infected larvae into larval populations on soybean resulted in low levels of mortality in the initially uninfected population in generation one. Larval mortality levels increased in succeeding generations and were higher in treatments with greater larval population density. The increase in epizootic development was much less, however, when the plants were not infested for one larval generation. AgNPV concentrations on foliage and in soil generally reflected the mortality levels from AgNPV in the respective treatments.

scholarly journals Enhanced activity of Anticarsia gemmatalis Hüb. (Lepidoptera: Noctuidae) nuclear polyhedrosis virus by boric acid in the laboratory

1997 ◽  
Vol 26 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Lauro Morales ◽  
Flávio Moscardi ◽  
Daniel R. Sosa-Gómez ◽  
Fábio E. Paro ◽  
Ivanilda L. Soldorio
Keyword(s):  
Boric Acid ◽  
Nuclear Polyhedrosis Virus ◽  
Larval Mortality ◽  
Lethal Concentration ◽  
Anticarsia Gemmatalis ◽  
Median Lethal Concentration ◽  
Lethal Time ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Lepidoptera Noctuidae

Boric acid concentrations (0.02,0.03,0.045,0.067 and 0.101 g/100 ml of diet) were evaluated in combination with the Anticarsia gemmatalis Hüb. nuclear polyhedrosis virus (AgNPV) for enhanced virali activity against the insect. Seven days after inoculation, the median lethal concentration (LC50) was 1.52 x 10(5) for the AgNPV alone and 7.95 x 10² for the NPV mixed with 0.045g of boric acid/100 ml of diet. At subsequent evaluation dates (9,11 and 14 days after inoculation) LC50's for NPV+boric acid were ca. 4x lower than those observed for the NPV alone. The median lethal time (LT50) was 13.6 days when the NPV was used alone, while, when in mixture with increasing concentrations of boric acid, LT50 values ranged from 13.7 days (boric acid at 0.02g/100 ml of diet) to 7.4 days (boric acid at 0.101 g/ml of diet). Therefore, boric acid added to the AgNPV significantly increased A. gemmatalis larval mortality and shortened mortality time by the pathogen.

THE STRIPED LYNX SPIDER, OXYOPES SALTICUS HENTZ (ARANEAE: OXYOPIDAE), AS A VECTOR OF A NUCLEAR POLYHEDROSIS VIRUS IN ANTICARSIA GEMMATALIS HÜBNER (LEPIDOPTERA: NOCTUIDAE)1

1988 ◽  
Vol 23 (4) ◽  
pp. 394-398 ◽  
Author(s):  
T. J. Kring ◽  
S. Y. Young ◽  
W. C. Yearian
Keyword(s):  
Inclusion Bodies ◽  
Nuclear Polyhedrosis Virus ◽  
Test Period ◽  
Anticarsia Gemmatalis ◽  
Infected Larva ◽  
Laboratory Activity ◽  
Active Virus ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Lepidoptera Noctuidae

The potential for transmission of a nuclear polyhedrosis virus of Anticarsia gemmatalis Hübner (AgNPV) by the striped lynx spider, Oxyopes salticus Hentz, was examined in the laboratory. Activity of the virus in excreta of O. salticus which had fed on an AgNPV - infected A. gemmatalis larva was bioassayed on alternate days over a 14 - day period. Oxyopes salticus excreta contained an average of 3.3 ± 2.2 × 104 polyhedral inclusion bodies per spider over the test period, with 95% of the active virus excreted within 24 hrs of ingestion. The amount of virus excreted was significant because only a mean of 1.2% of the total virus present in infected larva was consumed by the spider. The results suggest that O. salticus, and probably other spider predators in soybeans, may be important in dissemination of AgNPV in A. gemmatalis populations.

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