PERSISTENCE AND DISPERSAL OF THE NUCLEAR POLYHEDROSIS VIRUS OF NEODIPRION SERTIFER (GEOFFROY) (HYMENOPTERA: DIPRIONIDAE) IN A VIRUS-FREE LODGEPOLE PINE PLANTATION IN SWEDEN

1988 ◽  
Vol 120 (10) ◽  
pp. 887-892 ◽  
Author(s):  
Einar Olofsson
Keyword(s):  
Nuclear Polyhedrosis Virus ◽  
Lodgepole Pine ◽  
Larval Mortality ◽  
Neodiprion Sertifer ◽  
Experimental Plot ◽  
Pine Plantation ◽  
Larval Population ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
High Level

AbstractAn outbreak of Neodiprion sertifer (Geoffroy) was studied in a lodgepole pine plantation. It was the first tree generation on a 60-ha peatland area. The nuclear polyhedrosis virus (NPV) of N. sertifer was not found in the larval population or in the soil. Within a 1.7-ha experimental plot, a 0.35-ha block was treated with NPV and the ensuing epizootic was studied during three successive summers. The treatment caused 50% mortality of fourth- and fifth-instar larvae. The NPV persisted in the treated block and gradually dispersed into the adjacent blocks. After 2 years, larval mortality was 78% in the treated block and 21% at a distance of 110–125 m from it. The larval population remained at a high level and the outbreak expanded from the experimental plot to the entire 60-ha area in the years following the virus treatment, but few virus-diseased colonies were observed outside the experimental plot. Thus, the capability of this NPV to persist and spread was not sufficient to control and contain the sawfly outbreak.

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.

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.

Transmission of Nuclear Polyhedrosis Virus Prior to Death of Infected Loblolly Pine Sawfly, Neodiprion taedae linearis Ross, on Loblolly Pine

1998 ◽  
Vol 33 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Seth Y. Young
Keyword(s):  
Digestive Tract ◽  
Loblolly Pine ◽  
Nuclear Polyhedrosis Virus ◽  
Secondary Transmission ◽  
Pine Sawfly ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
High Level ◽  
Neodiprion Taedae Linearis

Nuclear polyhedrosis virus (NPV) was transmitted by infected loblolly pine sawfly, Neodiprion taedae linearis Ross, larvae prior to death on loblolly, pine. Third instars reared on pine foliage previously fed upon for 24 h by NPV-infected larvae at densities of 4 and 16 per terminal resulted in up to 69.9 and 93.1% mortality, respectively, in previously unexposed cohorts. Third instars reared on pine foliage wetted with washings from frass of infected larvae also resulted in a high level of mortality. Results suggest that a high level of secondary transmission of NPV occurs before death of primary-infected larvae. This transmission appears to be the result of NPV in the digestive tract released either through regurgitation or in the feces.

PERSISTENCE OF NEODIPRION SERTIFER (HYMENOPTERA: DIPRIONIDAE) NUCLEAR POLYHEDROSIS VIRUS ON PINUS CONTORTA FOLIAGE

1983 ◽  
Vol 115 (7) ◽  
pp. 869-873 ◽  
Author(s):  
W. J. Kaupp
Keyword(s):  
Pinus Contorta ◽  
Nuclear Polyhedrosis Virus ◽  
Neodiprion Sertifer ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis

AbstractThe persistence of Neodiprion sertifer nuclear polyhedrosis virus (NPV) on Pinus contorta foliage samples collected from sawfly infested plantations located throughout Britain was studied. Sawfly density and disease epizootiology varied between localities. Results from the bioassay of branch samples, divided into bark, needle base and foliage samples, indicated that N. sertifer NPV produced during a single virus epizootic can persist for at least 2 years on the pine foliage. Bark and needle base samples were found to be contaminated with NPV more often than foliage samples, perhaps reflecting the effect of weathering on the persistence of virus on the needle surface.

APPLICATION OF A NUCLEAR POLYHEDROSIS VIRUS OF NEODIPRION TAEDAE LINEARIS ROSS ON PINE: PERSISTENCE AND EFFECT OF TIMING ON LARVAL MORTALITY1,2,3

1986 ◽  
Vol 21 (3) ◽  
pp. 193-200
Author(s):  
S. Y. Young ◽  
W. C. Yearian
Keyword(s):  
Loblolly Pine ◽  
Nuclear Polyhedrosis Virus ◽  
Larval Mortality ◽  
Egg Hatch ◽  
Pine Sawfly ◽  
First Instar ◽  
Untreated Check ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Neodiprion Taedae Linearis

The persistence of a nuclear polyhedrosis virus (NPV) of the loblolly pine sawfly, Neodiprion taedae linearis Ross, on loblolly pine, Pinus taedae L., and the larval mortality in sawfly colonies sprayed from the ground during the egg stage were determined. When sawfly colonies and surrounding foliage on pine were sprayed with NPV one week prior to egg hatch, larval mortality was lower than in colonies treated as first-instar and was similar to mortality in colonies treated as third-instar. Percent larval mortality was not increased by the addition of 3.0% Shade® + 0.1% Trition CS-7 to the NPV suspension sprayed. Application of NPV at monthly intervals prior to egg hatch to either sawfly egg colonies and surrounding foliage or only to the foliage surrounding colonies resulted in loss of much of the NPV activity during the first month. Application of NPV at the highest rate (107 PIB/ml) to the eggs and surrounding foliage was the only treatment to significantly increase mortality over the untreated check at one and two months prior to egg hatch (P = 0.05).

INTRA- AND INTER-COLONY TRANSMISSION OF A NUCLEAR POLYHEDROSIS VIRUS OF THE LOBLOLLY PINE SAWFLY, NEODIPRION TAEDAE LINEARIS ROSS, ON PINE1,2

1987 ◽  
Vol 22 (1) ◽  
pp. 29-34 ◽  
Author(s):  
S. Y. Young ◽  
W. C. Yearian
Keyword(s):  
Loblolly Pine ◽  
Nuclear Polyhedrosis Virus ◽  
Secondary Transmission ◽  
Pine Sawfly ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
High Level ◽  
Neodiprion Taedae Linearis

A high level (37 – 98%) of secondary transmission of a nuclear polyhedrosis virus from primary infected larvae (PIL) of the loblolly pine sawfly, Neodiprion taedae linearis Ross (Hymenoptera: Diprionidae), to other members of the same colony occurred on loblolly pine, Pine taeda L., in Arkansas. Intra-colony transmission was significantly (P < 0.05) related to PIL density (No. of PIL/colony) but not to PIL instar at death. Inter-colony secondary transmission from PIL-infected colonies was lower (2 – 50%) than intra-colony transmission. Inter-colony transmission was greater when the PIL colony was placed in the lower canopy than in the upper canopy. Regardless of placement of the PIL colony (upper or lower canopy), mortality in other non-PIL colonies, was highest in the upper canopy. Migration of infected larvae is discussed relative to these findings.

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