Nucleopolyhedrovirus Coocclusion Technology: A New Concept in the Development of Biological Insecticides

Abstract

Nucleopolyhedroviruses (NPV, Baculoviridae) that infect lepidopteran pests have an established record as safe and effective biological insecticides. Here, we describe a new approach for the development of NPV-based insecticides. This technology takes advantage of the unique way in which these viruses are transmitted as collective infectious units, and the genotypic diversity present in natural virus populations. A ten-step procedure is described involving genotypic variant selection, mixing, coinfection and intraspecific coocclusion of variants within viral occlusion bodies. Using two examples, we demonstrate how this approach can be used to produce highly pathogenic virus preparations for pest control. As restricted host range limits the uptake of NPV-based insecticides, this technology has recently been adapted to produce custom-designed interspecific mixtures of viruses that can be applied to control complexes of lepidopteran pests on particular crops, as long as a shared host species is available for virus production. This approach to the development of NPV-based insecticides has the potential to be applied across a broad range of NPV-pest pathosystems.

Coocclusion of Helicoverpa armigera Single Nucleopolyhedrovirus (HearSNPV) and Helicoverpa armigera Multiple Nucleopolyhedrovirus (HearMNPV): Pathogenicity and Stability in Homologous and Heterologous Hosts

“…This disparity is likely to have arisen through a combination of two factors (i) HearMNPV is less amenable to replication in cell culture than HearSNPV and, (ii) ODVs produced in cells infected by both viruses will have acquired a pseudotype reflecting the parental mixture of viruses, i.e., ODVs produced in coinfected cells will have acquired an infectious phenotype similar to that of HearSNPV and will be more infectious in cell culture than ODVs produced in cells infected by HearMNPV alone. The sharing of the protein pool derived from the transcription of both parental viruses, resulting in virion pseudotyping, is an example of cis-acting factors that modulate virion infectivity [51]. A similar approach was recently used to explore the effect of heterologous per os infection factors on the oral infectivity of HearSNPV ODVs [52].…”

A gut‐isolated Enterococcus strain (HcM7) triggers the expression of antimicrobial peptides that aid resistance to nucleopolyhedrovirus infection of Hyphantria cunea larvae

“…8,9 Nucleopolyhedrovirus (NPV) is an ecologically safe and highly pathogenic agent that can be used to control agricultural and forest pests. 10,11 A species-specific NPV has been isolated from H. cunea larvae [referred to as H. cunea nucleopolyhedrovirus (HycuNPV)], and several strains have been applied as biopesticides. [12][13][14][15] However, a higher killing rate of HycuNPVs is required for successful application of the virus and this remains an area of intense research.…”

“…The use of entomopathogens such as viruses, bacteria, fungi, and nematodes for the control of insect pests represents a novel and feasible approach for managing these pests 8,9 . Nucleopolyhedrovirus (NPV) is an ecologically safe and highly pathogenic agent that can be used to control agricultural and forest pests 10,11 . A species‐specific NPV has been isolated from H. cunea larvae [referred to as H. cunea nucleopolyhedrovirus (HycuNPV)], and several strains have been applied as biopesticides 12–15 .…”

A novel use of Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) as inoculative agent of baculoviruses

“…OBs are formed in the late phases of replication and released upon host death 4,5 . Outside their host, NPVs persist inactive as mature OBs until subsequent infections in the larval stages of new hosts occur 6–8 . However, their persistence outside the host on plant surfaces is negatively influenced by abiotic factors such as solar ultraviolet (UV) light, alkaline pH, and high temperatures 9 .…”

“…4,5 Outside their host, NPVs persist inactive as mature OBs until subsequent infections in the larval stages of new hosts occur. [6][7][8] However, their persistence outside the host on plant surfaces is negatively influenced by abiotic factors such as solar ultraviolet (UV) light, alkaline pH, and high temperatures. 9 Mostly, lepidopteran-specific baculoviruses from the genus Alphabaculovirus (NPV) and Betabaculovirus (granulovirus type, GV) have been commercially developed so far, 10 and because of their restricted host range, are considered very safe insecticides.…”