A new ascovirus was isolated from Spodoptera exigua in Indonesia and was tentatively assigned as a new species, Spodoptera exigua ascovirus 5a (SeAV-5a) according to the present ICTV ascovirus naming scheme based on DNA restriction fragment length polymorphism (RFLP), hybridization, formation of occlusion body, tissue tropism and host spectrum. SeAV-5a replicated primarily in the fat body of susceptible hosts. SeAV-5a could be transmitted to S. frugiperda, Pseudoplusia includens and Trichoplusia ni, but not to Heliothis virescens. Infection with SeAV-5a arrested growth of the hosts, but prolonged their survival, which continued up to 33 days. Clusters of virions were seen inside the characteristic vesicles. Occasionally, virions were contained within vacuoles (one to five per vacuole) and some virions were embedded in occlusion bodies. The size of the SeAV-5a virion was 347i134 nm ; however, aberrant long secondary viral products were also seen. The presence of occlusion body and Southern hybridization and Western immunoblot analyses suggest that SeAV-5a is more closely related to S. frugiperda ascovirus 1a (SfAV-1a) than to Trichoplusia ni ascovirus 2 (TnAV-2). Certain regions of the 182 kb genome of SeAV-5a showed hybridization to that of SfAV-1a. Two fragments in each of the SfAV-1a EcoRI and HindIII digests hybridized to the SeAV-5a genomic DNA probe. Five to eight HindIII and EcoRI fragments in SeAV-5a DNA hybridized to the SfAV-1a genomic probe.
1 The Philippines is the second largest producer of coconut products and, in some areas, coconut farming is the main source of livelihood. 2 A damaging armoured scale insect (Hemiptera: Diaspididae) infesting coconut palms was first found in the Philippines on Luzon Island (Batangas province) in 2009, and is now affecting most of the provinces of southern Luzon. 3 The scale pest is still spreading in the Visayan Islands and Mindanao. 4 Infestation stops photosynthesis; the leaves yellow and dry; fruits form less nutmeat and the coconut-water is sour; weak new leaflets bend over or break off; and the tree dies in 6 months or less. 5 The scale pest is identified in the present study as Aspidiotus rigidus Reyne; it presents a significant quarantine threat to coconut-producing countries worldwide. 6 Characters enabling the identification of A. rigidus, its host range and distribution are given. 7 Some literature on the natural enemies and control of A. rigidus is reviewed briefly.
The complete nucleotide sequences of genomic segments S1, S3 and S4 from Bombyx mori cypovirus 1 (BmCPV-1) have been determined. The segments consisted of 4190, 3846 and 3262 nucleotides encoding putative proteins of 1333, 1239 and 1058 amino acids with molecular masses of approximately 148, 140 and 120 kDa (p148, p140 and p120, respectively). All segments possess a single open reading frame. Homology searches showed that all three proteins have homologies to proteins of Rice ragged stunt virus, a member of the genus Oryzavirus within the family Reoviridae. Partial homologies of p140 to structural proteins in other viruses were also found. The predicted molecular masses and the homologies with structural proteins in other viruses lead us to suggest that S1, S3 and S4 encode the capsid proteins VP1, VP3, and VP4, respectively, of BmCPV-1.
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