scholarly journals The First Study on Nuclear Polyhedrosis Virus Histopathological and Morphological Effects on the Strawberry Pest, Pentodon Algerinum (coleoptera: Scarabaeidae)

Author(s):  
Samah, M.M. Abd El-Aziz ◽  
Magda, H. Rady ◽  
Bouthaina, A. Merdan ◽  
Abd El-Salam A.M.E ◽  
Hany, M. Hussein ◽  
...  

In Egypt, strawberry is an economically important crop that has recently been destroyed by Pentodon algerinum, a worldwide polyphagous destructive insect pest. This study aimed to distinguish, for the first time, the histopathological and morphological effects of Spodoptera littoralis Nuclear polyhedrosis virus (SpliNPV) and Pentodon algerinum Nuclear polyhedrosis virus (PNPV) on Pentodon algerinum third instar larvae to confirm their success as safe alternative control agents against this pest. The results showed that PNPV and SpliNPV affected Pentodon larvae by the same effects in causing the following: integument deformation and rupture; the destruction of the hypodermal layer resulting in the inhibition of the process of molting into the pupa stage, reducing pest survival; larva leg corrosion, which prevents its spreading; the rupture of fat bodies, which leads to the loss of stored energetic materials; the distortion of muscle sarcolemma and fibers resulting in weakness and softness; the tracheal cuticular layer destruction, which inhibits breathing; midgut rupture with cells detaching from each other; irregular cytoplasm distribution; the loss of the columnar shape of cells; the appearance of vacuoles between cells, which results in their inability to feed or to digest; the swelling, softness, liquefaction, and, lastly, death of the larva.

1976 ◽  
Vol 108 (11) ◽  
pp. 1221-1222 ◽  
Author(s):  
W. A. Smirnoff ◽  
J. N. McNeil ◽  
J. R. Valero

A natural virus epizootic, caused by a nuclear polyhedrosis virus, was observed in several populations of the European skipper, Thymelicus lineola (Ochs .), at Normandin, Que., in 1974 (Smirnoff 1974). A substantial supply of this virus was collected and experiments were conducted under laboratory and field conditions to evaluate its pathogenicity against the skipper, its possible transmission from one generation to the next, and its potential as a means of control of T. lineola, a serious insect pest of forage crops in several regions of Quebec (McNeil et al. 1975).


Author(s):  
Muhammad Bilal Ayyub ◽  
Ahmad Nawaz ◽  
Muhammad Jalal Arif ◽  
Luqman Amrao

Abstract The tropical armyworm, Spodoptera litura Fabricius (Noctuidae; Lepidoptera), is among the most harmful pests causing economic loss in the quality and production of a variety of crops, particularly cotton. Entomopathogens play an important role in insect pest management. The nuclear polyhedrosis virus (NPV) isolate of S. litura (V-SpltNPV) was isolated from infected larvae in a cotton crop, and viral occlusion bodies were confirmed, using an inverted microscope. The pathogenicity of V-SpltNPV against 2nd, 3rd, and 4th larval instars of S. litura was evaluated at various concentrations (1 × 104 to 1 × 108 OBs/ml). Mortality rate was high (37.65–96.82%) in early instar larvae against tested concentrations. LC50 and LT50 values increased with increasing larval age. There was 689,865 times increase in LC50 value (1.35 × 102 OBs/ml) for 2nd instar larvae to LC50 value (6.90 × 105 OBs/ml) for 4th instar larvae. LT50 values enhanced from 4.99 days for 2nd instar larvae to 7.49 days for 4th instar larvae, due to a decrease in efficacy of NPVs with the increasing age of larvae. In a greenhouse experiment, a combined application of spinosad with V-SpltNPV (1 × 108 OBs/ml) caused (100%) mortality of 2nd instar larvae. A single application of V-SpltNPV (1 × 108 OBs/ml) resulted to mean mortality (52.63%) of tested larvae. The native isolate V-SpltNPV seems to have a potential to be used in integrated manner with other IPM tactics to significantly reduce the use of toxic chemical pesticides.


1998 ◽  
Vol 38 (6) ◽  
pp. 601 ◽  
Author(s):  
B. C. G. Scholz ◽  
C. J. Monsour ◽  
M. P. Zalucki

Summary. Helicoverpa armigera is a serious insect pest of sweet corn in Australia and is becoming increasingly difficult to manage with conventional chemical insecticides due to resistance problems. A number of alternative H. armigera control options were evaluated in sweet corn and compared with deltamethrin and no action (control). The alternative tactics evaluated were: heliothis nuclear polyhedrosis virus plus Trichogramma nr. brassicae releases; Bacillus thuringiensis; and Trichogramma alone. The H. zea nuclear polyhedrosis virus + Trichogramma plots had the lowest cob damage (6.0%), followed by the B. thuringiensis plots (12.0%), Trichogramma alone plots (20.2%), control plots (23.2%) and deltamethrin plots (53.5%). There was no evidence to suggest that the Trichogramma nr. brassicae releases had any impact on H. armigera egg mortality. However, there was a large natural population of Trichogramma pretiosum in all plots. The application of deltamethrin reduced the action of these wasps and predators, resulting in higher larval infestation and significantly more cob damage. The findings indicate that the pathogens heliothis nuclear polyhedrosis virus and B. thuringiensis can effectively control H. armigera when their action complements high natural levels of egg parasitism, and that they have potential for use in integrated pest management programs in sweet corn.


Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 704
Author(s):  
Qian Yu ◽  
Pengfei Chang ◽  
Xiaoxuan Liu ◽  
Peng Lü ◽  
Qi Tang ◽  
...  

Recombinant adeno-associated virus (AAV) vectors have broad application prospects in the field of gene therapy. The establishment of low-cost and large-scale manufacturing is now the general agenda for industry. The baculovirus-insect cell/larva expression system has great potential for these applications due to its scalability and predictable biosafety. To establish a more efficient production system, Bombyx mori pupae were used as a new platform and infected with recombinant Bombyx mori nuclear polyhedrosis virus (BmNPV). The production of a chimeric recombinant adeno-associated virus (rAAV) serotype 2/human bocavirus type-1 (HBoV1) vector was used to evaluate the efficiency of this new baculovirus expression vector (BEV)–insect expression system. For this purpose, we constructed two recombinant BmNPVs, which were named rBmNPV/AAV2Rep-HBoV1Cap and rBmNPV/AAV2ITR-eGFP. The yields of rAAV2/HBoV1 derived from the rBmNPV/AAV2Rep-HBoV1Cap and rBmNPV/AAV2ITR-eGFP co-infected BmN cells exceeded 2 × 104 vector genomes (VG) per cell. The rBmNPV/AAV2Rep-HBoV1Cap and rBmNPV/AAV2ITR-eGFP can express stably for at least five passages. Significantly, rAAV2/HBoV1 could be efficiently generated from BmNPV-infected silkworm larvae and pupae at average yields of 2.52 × 1012 VG/larva and 4.6 × 1012 VG/pupa, respectively. However, the vectors produced from the larvae and pupae had a high percentage of empty particles, which suggests that further optimization is required for this platform in the future. Our work shows that silkworm pupae, as an efficient bioreactor, have great potential for application in the production of gene therapy vectors.


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