In vitro host range of the Hz-1 nonoccluded virus in insect cell lines.

A total of 13 insect cell lines spanning 4 orders (Lepidoptera, Coleoptera, Diptera, and Homoptera) were tested for their ability to replicate the nonoccluded virus Hz-1. Only the Lepidopteran cell lines supported replication of the virus with TN-CL1 and BCIRL-HZ-AM1 producing the highest titers of 2.4 x 10(8) tissue culture infective dose (TCID)50/ml and 2.

Insect cells and their potential as stabilization barriers for DNA of multiple and single nucleopolyhedroviruses against ultraviolet-B-simulated sunlight inactivation.

A cell line from Trichoplusia ni (TN-CL1) infected with the Autographa californica multiple nucleopolyhedrovirus (AcMNPV-HPP) and a cell line from Helicoverpa zea (BCIRL-HZ-AM1) infected with the Helicoverpa zea single nucleopolyhedrovirus (HzSNPV/BrCL2) were subjected to ultraviolet-B (UV-B) irradiation at a predetermined level of exposure that would inactivate greater than 95% of the virus suspended in the liquid. The working hypothesis was that the homologous insect cells would utilize their inherent deoxyribonucleic acid (DNA) repair mechanism(s) to prevent, repair, or at least mitigate the damaging effects of UV-B light on viral DNA synthesis. We attempted to determine this by using infected cells that were subjected to UV-B irradiation at different postinoculation periods under two experimental conditions of exposure: (1) shielded, and (2) nonshielded.

Use of a colorimetric system to detect enzymes expressed by germinating conidia of entomopathogenic fungi.

An apiZYM system, with 19 substrates, was used to detect enzymes expressed by germinating conidia of Nomuraea rileyi (5 isolates), Nomuraea atypicola, Nomuraea anemonoides, Beauveria bassiana and Metarhizium anisopliae. Similar enzyme profiles were obtained for two of the N. rileyi isolates (Mississippi, Ecuador) regardless of whether culture medium (Sabouraud-maltose-yeast) or cuticle (from larvae of Trichoplusia ni, Heliothis zea or Heliothis virescens) were used as substrates.

Restriction endonuclease cleavage patterns of commercial and serially passaged isolates of Heliothis baculovirus.

The restriction endonuclease patterns of three Baculovirus isolates (Br, Vh, El) from Heliothis zea having different passages and production histories were compared. Digestion of the ds DNA genomes of the three isolates with EcoRI, HindIII, and XhoI showed no major difference in the cleavage patterns, although submolar fragments were detected. One of the commercial isolates (Vh) was serially passaged 20 times through larvae of H.

In vitro host range of five baculoviruses in lepidopteran cell lines.

The in vitro host range of five nuclear polyhedrosis viruses (NPV) was assessed in five lepidopteran cell lines from three genera. Multiple-enveloped baculoviruses of Autographa californica (ACMNPV), Trichoplusia ni (TNMNPV), and Galleria mellonella (GMMNPV) replicated in cells of T. ni, Spodoptera frugiperda, and Heliothis virescens to a titer of approximately 10(7) TCID50/ml.

Entomopathogens as insecticides.

Entomopathogens, diseases of insects, are suggested as a possible new generation of safe, selective insecticides. Over a thousand pathogens have been isolated from insects. Many of these, associated with major insect pests, are potential candidates for development into microbial insecticides.