MXPA99004821A - A baculovirus for the control of insect pests - Google Patents

Abstract

A novel Plutella xylostella baculovirus (PxMNPV) which is useful for the control of insect pests has been isolated. A variety of insect pests may be controlled by application of an insecticidally effective amount of the baculovirus to the locus or vicinity of the target insect.

Description

A BÁCULOVIRUS FOR THE CONTROL OF PESTS CAUSED BY INSECTS Background? L IrtygntQ Field of the Invention The invention relates to a báculovirus for Plutella xylost? Lla, which can be used for the biological control of pests caused by insects.

Description of Known Technique Chemical pesticides or fungicides are the most commonly used control agents against pests caused by insects in agriculture and forests, as well as in diseases caused by fungi. These agents are used annually in the United States, exceeding 350 billion pounds, to control pests and diseases in forest, agricultural and residential areas. Unfortunately, broad-spectrum insecticides and fungicides have adverse impacts not only on their target organisms but also on beneficial insects and fungi and, consequently, on the entire ecosystem. Insect-borne pests can also become resistant to these chemicals, so that new populations of pests can develop from insects that are resistant to these pesticides. Moreover, chemical residues present environmental risks and possible concerns regarding health.

The interest in biological agents to control insects and fungi is increasing as a consequence of the concern regarding the use of chemical pesticides. Biological control of pests caused by insects presents an alternative means to control pests that may play a role in integrated pest management and reduce the need for chemical pesticides. Generally, natural control agents have slight adverse ecological impact due to their specificity with respect to the target host. Long-term environmental risks and health concerns are not a factor with biological control agents because chemical residues are not present. However, biological control agents can suffer several disadvantages compared to chemical pesticides, including production cost, efficacy and stability.

Viruses that cause natural epizootic diseases within populations caused by insects are among the entomopathogens, which have developed as biological pesticides. A variety of viruses, including baculoviruses, are known to be valuable biological control agents for insects.

The báculoviruses are a huge group of viruses that are infectious only in arthropods (L.

K. Miller, Vector of Virus for Genetic Engineering in Invertebrates, in "Genetic Engineering in Plant Sciences", N. Panopoulous, Ed., Praeger Publ., No.., P. 203-224, 1981; Carstens, 1980, "Báculovirus - Friend of Man, Enemy of the Insects? "Trends and Biochemical Science, 52: 107-110; Harrap and Payne," The Structural Properties and the Identification of Viruses caused by Insects * in Advances in Research on Virus, M.A., Lawfer, F.B. Bang, K. Maramorosh and K.M: Smith, Eds., Vol. 25, pgs. 273-355, Academic Press, N. Y., 1979).

In nature, infection is initiated when an insect ingests food contaminated with baculovirus particles, typically in the form of occlusion bodies (OB) that are composed of multiple viral particles embedded in a protein crystal containing the virus.

When consumed by susceptible insects, the protein crystal of the occlusion bodies dissolves in the alkaline environment of the insect's belly, releasing individual virus particles that invade the epithelial cells that cover the belly. Within the cell, the báculovirus migrates to the nucleus where reproduction takes place. Generally, two forms of báculovirus, occluded and extracellular virus (CVD) are produced during viral reproduction. Each of these viral particles, as well as the OB itself, have capsules or casings. Initially, extracellular viruses (ECV) are produced, acquiring an envelope as it leaves the cocoon of the cell surface. This extracellular virus (CVD) can then infect other cells within the insect, including fatty body cells, epidermal and hemolymphatic cells. After this initial stage of infection, the virus is produced, which occludes in occlusion bodies. The formation of occlusion bodies continues until the cell finally dies or is destroyed by lysine. Some báculoviruses infect all tissues in the host insect, so that at the end of the infectious process, the whole insect becomes liquid, releasing extremely large numbers of occlusion bodies that then become responsible for spreading the infection to others. insects See "The biology of the baculoviruses" by R. G. Granados and B. A. Federici, Eds., Vol. I and I !, CRC Press, Boca Raton, Fia., 1986.

Many báculoviruses infect insects that are pests of commercially important agricultural and forestry crops. Said báculoviruses are, therefore, potentially valuable as biological control agents. To date, a variety of different báculovirus have been registered for use as insecticides by the Environmental Protection Agency in E.U.A. One of these, the multiple polyhedral nuclear virus Autographa callfornlca (AcMNEV) is well recognized for its use as a biocontrol agent due to its wide range of Lepidoptera hosts. Another báculovirus, Anagrapha falcifera, multiple nuclear polyhedrosis virus (AfMNPV) was recently isolated from a celery worm and differs from AcMNPV in both its REN pattern and in its highest degree of infection for the larval subflexa Heliothis. The AfMNPV is approximately equally infectious for H. zea as for the larva of H. virescens and has a wide range that infects more than 30 species among 10 families of the order of the Lepidoptera.

Summary of the Invention We have discovered a novel bilavirus Pluteila xylostella that is useful for the control of pests caused by insects. A variety of pests caused by insects can be controlled by applying an insecticidally effective amount of the báculovirus to the locus or to the proximity of the insect in question.

According to this discovery, the purpose of this invention is to provide a roundabout báculovirus that is useful as a biological control agent to control pests caused by insects.

It is also an object of this invention to provide a báculovirus that is effective for the control of a wide range of pests caused by insects, including Plutella xylostella, without the use of chemical insecticides.

Another object of the invention is to provide a method for controlling pests caused by insects by the use of báculoviruses as biological control agents.

Other objects and advantages of the present invention will become apparent from the following description.

Detailed Description of the Invention The novel báculovirus for Plutella xylostella of this invention is a virus of multiple nuclear polyhedrosis that belongs to the family of Baculoviridae, and is hereby referred to as PxMNPV. This báculovirus was originally isolated from the larvae of the moth with diamond back, the Plutella xylostella, and the plaque were purified three times in Heliothis virescens cells. Microscopically, the virus isolated from the infected larvae was occluded in many multiple units in a protein crystal or body of occlusion (OB). In contrast to other known baculoviruses, PxMNPV is highly effective against P. xylostella. Moreover, PxMNPV is infectious not only for its homologous host, but also for a variety of other pests caused by insects.

The aforementioned PxMNPV of the present invention has been deposited under the Budapest Treaty in the American Type Culture Collection (12301 Parklawn Drive, Rockville, Maryland, 20852, USA) on September 27, 1996, and has been assigned the Deposit No. ATCC VR 2543.

For the purposes of this Invention, any isolation or clone of the d virus is effective. multiple nuclear polyhedrosis of Plutella xylostella (PxMNPV) that have the ATCC VR-2543 identifying features and that retain the ability to infect pests caused by insects, particularly P. xylostella.

Mass production of PxMNPV can be achieved using either conventional in vivo or in vitro techniques. In any of these cases, the virus that is collected is in the form of the occlusion bodies (OB) themselves that are produced in the host, as well as in cell cultures. In case of in vivo production, the virus typically spreads in larvae of susceptible species of insects, such as P. xylostella, Heliothis virescens, Helicoverpa zea, Trichoplusia ni, Spodoptera frugiperda, Heliothis subflexa and Spodoptera exigua. However, T. ni, H. Virescens and P. xylostella are preferred since these are the most susceptible hosts. Briefly, larvae of the host insect are raised on the basis of a conventional artificial diet and treated with a suspension of PxMNPV occlusion bodies. Infected larvae are collected, usually at death or before liquefaction, in about 2-5 days, homogenized and filtered to remove lumpy particles. The resulting homogenate can then be centrifuged to sediment a considerable waste, the float is discarded and the sediment is suspended in sterilized water or another vehicle and the spinning process is repeated.

An appropriate cell lytic agent, such as sodium deoxycholate can be added to the suspension during the process to remove any bacteria and contaminating cells. The final suspension already washed contains OB of PxMNVP, it can be retained and saved for later use. By way of example, the in vivo propagation processes that are suitable for use in the present instrument are described in detail by Hosteter and Puttler (U.S. Patent No. 4,911,913), the content of which is incorporated by reference herein. instrument.

Although the virus can be propagated in vivo, as described, such techniques are generally susceptible to contamination and entail intensive work. Therefore, in the preferred content, the virus is produced in cell culture. Mass production of the virus can be achieved in vitro using conventional techniques, such as described by Mclntosh (U.S. Patent No. 5,405,770, published April 11, 1995), or by Mclntosh and Ignoffo (1989, J. Invertebrate Pathology, 54: 97-102), the content of each of which is incorporated for reference in this instrument. According to this method, the cells of an appropriate insect cell line are integrated into a conventional culture medium and inoculated with the extracellular virus PxMNPV (ECV). Sources of inoculum or inocula include, for example, the infectious hemolymphatic (containing ECV) collected by bleeding from an infected insect, approximately two days after infection, or by the release of the OB virus by alkaline treatment. Of course, once a cell line has been infected, the ECV can be collected as described below and used to infect fresh cell cultures. A variety of insect cell lines are suitable for use in the present instrument, including but not limited to Heliothis subflexa (BCIRL-HS-AM1) (Mclntosh, US Patent No. 5,405,770), Plutella xylostella (BCIRL-PxEM1 ) (Kariuki, C, 1996, doctoral thesis); Spodoptera frugiperda (IPLB-SF21) (Vaughn et al., 1977, In Vitro, 13: 213-217); Trichoplusia ni (TN-CL1) (Mclntosh et al., 1974, In Vitro, 10: 1-5); Heliothis viriscens (BCIRL-HV-AM1) (Mclntosh et al., 1981, J. Invertebr. Pathol., 37: 258-264) and Heliothis zea (BCIRL-HZ-FB33) (Mclntosh et al., unpublished) . The highest yields of occlusion bodies have been obtained using the cell line of T. ni (TN CL1), and its use is, therefore, preferred. Other Lepidoptera cell lines suitable for use in the present instrument can be prepared using conventional techniques of the art. After inoculation, the cell culture is incubated for a sufficient time and under effective conditions that allow the virus to be produced.

During in vitro cell culture, both the occluded virus (OB) and the extracellular free virus (CVD) are produced, although the relative proportions may vary with the particular cell line that is used (ie, the TN-CL1 provides the higher proportion of OB). Both the ECV and the OB are effective as biocontrol agents, but the OBs may be more resistant to some environmental factors, such as desiccation. Viral agents (ECV and OB) can then be collected or harvested from the culture float using conventional techniques of the trade. The virus can be recovered, for example, by centrifugation and concentration of the float of the culture medium as described by Mclntosh and Ignoffo (1981, J. Invert, Pathology, 37: 258-264) or by Ignoffo and Mclntosh (1986, J. Invert, Pathology, 48: 289-295), the content of each of which is incorporated for reference in this instrument.

The virus can then be purified by conventional centrifugation of declining sucrose and plaque assay. The culture conditions including cell density, multiplicity of infection, time, temperature and means are not critical and can be easily determined by the practitioner skilled in the art.

As a practical matter, it is envisaged that the commercial formulas of the subject's viral pesticidal agent would be prepared directly from the cell culture, the larval homogenates or fractions derived from said homogenates, obviating the need to isolate the virus in its pure form. . Other suitable means could easily be determined by the artisan skilled in the art. Of course, for applications that demand a high degree of specificity, that is, a high level of predictability of the response that is intended by both organisms, the objective and the non-objective of this study, it would normally be preferred to prepare the pure or substantially pure virus formula. For example, it is possible that foreign substances in the larval material could have an undesirable effect with respect to the intended activity.

The potential of the PxMNPV dictates that it be applied jointly with a suitable transport or vehicle, agronomically acceptable, in the way that is used in the trade. Without limiting the foregoing, inert solids, such as talcum, vermiculite, cellulose or sugars, powders susceptible to moistening and inert liquids such as water or vegetable oils, are illustrative of the chemical carriers that are suitable. The virus can also be formulated in combination with conventional additives such as adherents, insect attractants (i.e., an insecticide that attracts insects, or an "attractant"), surface active substances, wetting agents, UV stabilizers, or other biological control agents or chemical insecticides to increase the insecticidal activity.

Depending on the substrate, the target species, the mode of application and the type of response desired, the concentration of the virus in the final compound can vary considerably, but typically should be at least between 5 x 1011 to 5 x 1012 occlusion bodies per acre. Factors such as phytotoxicity to the treated plant and tolerance of the non-target species can be used by the skilled artisan when determining the maximum level.

In the case of pathogenic insects such as viruses, it may be preferable to use biological transports to distribute the pathogen. A biological transport of this nature could be, for example, a species of insect that is closely related to the target species, but which, in itself, is relatively unaffected by the pathogen. In this disclosure, the word "transport" is defined to include both biological transport and inert chemical transport.

The level of the virus is administered in an amount effective to induce infection as predetermined by the routine examination. When the final response is plague mortality, an "effective amount" or "pesticidally effective amount" is defined as the way to denominate those amounts of virus that will result in a significant degree of mortality of a group examined compared to a group untreated The effective amount actually used may vary with the species of the pest, the stage of larval development, the nature of the substrate, the type of vehicle or transport, the period of! treatment and other related factors.

To be effective, the virus must be ingested by the insect; therefore, the virus must be applied directly to the target pests, or to the locus of the pest to be controlled or its environment. In the case of plants infested with the target pest, the virus will typically be applied to plant surfaces, such as foliage, either by spraying or sprinkling.

The viral pesticide included in this instrument is effective in controlling a variety of insects. Without wishing to limit ourselves to this, the pests of particular interest known as vulnerable to treatment are agronomically important insects, especially those of the order of the Lepidoptera, and specifically the moth with diamond back (Plutella xylostella), the tobacco worm (Heliothis virescens) , the corn worm (Helicoverpa zea), the cabbage worm (Tríchoplusia ni), the beetleworm (Spodoptera exigua), the Heliothis subflexa and the autumn worm (Spodoptem frugiperda).

The following examples are intended only to illustrate the invention in more detail and are not intended to limit the scope of the invention, which is defined by the claims.

Example 1 Endonuclear Restriction Analysis PxMNPV DNA was compared with those of the following báculoviruses: Autographa califomica (AcMNPV), Anagrapha falcifera (AfMNPV), Heliothis zea (HzSNPV), Helicoverpa armígera (HaMNPV), and Anticarsia gemmatalis (AgMNPV). The DNA of each of these viruses was subjected to endonucleate restriction analysis using four different enzymes: Hindlll, Xhol, BstlIE, and BamHl. The digestion profiles of the enzymes were prepared and analyzed using conventional techniques such as those described in Mclntosh and Ignoffo (1986, Intervirology, 25: 172-176), the content of which was incorporated for reference in the present instrument. After the comparison, the digestion profiles showed that the PxMNPV DNA profiles differed from those of all the other viruses, especially in the restriction fragment length polymorphism (RFLP) generated by the above HINDIII and BamHT.

In addition to this, DNA hybridization studies of the baculoviruses were performed using a tube labeled as non-radioactive DNA of the PxMNPV, the results showed that the PxMNPV was distinctive, although related to the AcMNPV.

Example 2 Neutralization tests PxMNPV was compared with AcMNPV and AfMNPV using an antibody neutralization assay. Several attenuated solutions (or dilutions) of AcMNPV rabbit antiserum shown in Table 1 were mixed with several dilutions of each virus and incubated for 2 hours at 28 ° C. The treated samples were then inoculated into cultures of susceptible cells, then incubated and examined during the 7 days after inoculation. The complete neutralization of the infectivity of an isolated virus by a high dilution of a known antiserum indicates that the isolation is identical to, or closely related to, the virus that was used to prepare the antiserum. The highest dilution of antisera resulting in zero CPE (production of OBs) is considered as the neutralizing concentrate.

The results are shown in Tables 1a, b and c. No cytopathic effect (CPE), that is, absence of production of OBs in the inoculated cells, indicates that the virus has been neutralized by the antibody. As shown in Table 1.a, in the 103TCID dose, the neutralizing concentrate of the AcMNPV is 1: 512, while the neutralizing concentrate of the PxMNPV is 1: 8 (Table 1b). On the other hand, the AfMNPV, which is a variant of the AcMNPV, has a neutralizing concentrate of 1: 256 (Table 1c), confirming its close relationship with the AcMNPV.

Example 3 Cultivation of Insect Cells Six different cell lines of Lepidoptera were compared for their ability to grow and reproduce PxMNPV. The cell lines used were Heliothis subflexa (BCIRL-HS-AM1) (US Patent, Mclntosh, No. 5,405,770), Spodoptera frugiperda (IPLB-SF21) (Vaughn et al., 1977, In Vitro, 13: 213 -217), Trichoplusia ni (TN-CL1) (Mclntosh et al., 1974, In Vitro, 10: 1-5), Plutella xylostella BCIRL-PxEM1 (Kariuki, C, 1996, Doctoral thesis), Heliothis virescens (BCIRL-HV-AM1) (Mclntosh et al., 1981, In Vitro, 17: 649-650) and Heliothis zea (BCIRL-HZ-FB33) (Mclptosh et al., Unpublished). In Vitro studies were performed as described in the Mclntosh patent (US Patent No. 5,405,770) or in Mclntosh (1991, J. Invertebr.

Pathol., 57: 441-4421) the contents of each of which will be incised for reference in the present instrument.

A clone of PxMNPV was used to inoculate cultures of all cell lines. The inoculated cells were incubated at a temperature of 28 ° C for 7 days in a medium dβ TC199-MK containing 10% of fetal bovine serum and penicillin and streptomycin. Viral concentrates (TCIDso) were assayed using TN-CL1 cells as the indicator cell line and OBs were enumerated as previously described by Mclntosh et al., [1985, Interlogology 23: 150-156 and 1989, J. Invertebrate Pathology, idem] the content of each of which is unoffered for reference in this instrument.

All six cell lines were susceptible to PxMNPV, with TN-CL3 producing the highest number of OBs per cell.

Example 4 Biological assays The PxMNPV was compared with two other báculoviruses, the AcMNPV and the AfMNPV, for its effectiveness against seven Lepidoptera pests using the normal biological assay as described in Ignoffo (1966, J. Invertebr. Pathol., 8: 531-536 ) and Ignoffo et al. (1974, Environmental Entomology, 3: 1 7-119), the content of each of which is unoffered for reference in this instrument. The effectiveness against the following pests was examined: the moth with diamond-shaped back (Plutella xylostella), the tobacco worm (Heliothis virescens), the corn worm (Helicoverpa zea), the cabbage worm (Trichoplusia ni), the beetleworm (Spodoptera exigua), the Heliothis subflexa and the autumn worm (Spodoptera frugiperda). Larvae of each species were placed twenty-four hours old on artificial dietary surfaces inoculated with various concentrations of OBs in a continuous feed assay. The mortality of the larvae was recorded on a daily basis, and was used to calculate the dose necessary to eliminate 50% of the insects (LCso) as well as the time necessary to achieve 50% mortality (LTso).

The results are shown in Tables 2a, b and c. As shown in the Table 2a, the PxMNPV was the most effective báculovirus against P. xylostella, requiring a LCM dose of only 5.54 OB per cm2. In contrast, LCso values for AcMNPV and AfMNPV against P. xylostella were 11,600 OB per cm (Table 2b) and 9.224 OB per cm 2 (Table 2c), respectively. With respect to the other pests caused by insects that were examined, the PxMNPV was also effective in comparison with the AcMNPV and the AfMNPV. In addition, the PxMNPV was the most effective against another important pest in the West and Southwest of the United States, the beetworm (S. exigua). The LCso values for the three baculoviruses against this pest were 69.61 OB per cm2 (PxMNPV), of 200.84 OB per cm2 (AcMNPV) and 167.59 OB per cm2 (AfMNPV) (Tables 2a, b and c).

The values of lethal time fifty (LTso) for PxMNPV, AcMNPV and AfMNPV against P. xylostella were 6 days, 100 days (extroplateados) and 132 days i (extroplateados), respectively, indicating that the PxMNPV eliminated the larva of the diamondback moth more quickly than the other báculovirus. A faster elimination results in less damage, caused by the plague caused by the insect, to the treated plants.

It is understood that the above detailed description is provided simply by way of illustration and that any modification or variation can be made therein provided the spirit and scope of the Invention is conserved.

Table 1: Neutralization reactions of the three different báculoviruses caused by Rabbit Antiserum of Autographa californica Multiple Nuclear Polyhedron Virus. • a) AcMNPV (wt) / Antiserum • - AcMNPV Anti-Concentration Virus Dilution (TCIDso l '\) serum 10s 104 103 10z 1 8 - - - 1 16 - - ~ 1 32 H ~ - 1 64 ++ ~ - 1 128 + + H ~ 1 256 ++ - + - 1 512 ++ ++ H 1 1024 ++ ++ - + 1 2048 ++ ++ ++ 1 4096 ++ ++ 1 8192 ++ ++ ++ C ontrol ++ ++ ++ + OB present - Absent OB [~ J Neutralizing concentration in various doses of virus 1 b) PxNPVCLI. Antiserum - AcMNPV Anti-Concentrated Virus Dilution (TCID50 / ml) serum 10s 104 103 10z 1 8 ++ - + H 1 16 ++ ++. + __ 1 32 ++ ++ _ + [..] 1 64 + + ++ - + - + 1 128 ++ ++ ++. + 1 256 ++ ++ ++ - + 1 512 ++ ++ - + 1 1024 ++ ++ ++ ++ 2048 + + ++ ++ ++ 1 4096 ++ ++ ++ 1 8192 ++ ++ ++ ++ C ontrol ++ ++ ++ + OB present - Absent OB [-] Neutralizing concentration in various dose of virus O AfNMPVCLI / Antiserum - • AcMNPV Anti-Concentration Virus Dilution (TCIDso / ml) serum 10 * 104 103 10z 1 8 - - - 1. 16 H - - 1 32 + - H - 1. 64 ++ + - - 1 128 + + + - - 1 256 ++ + - H 1 512 ++ ++ + - 1 1024 ++ ++ + - 1 2048 ++ ++ + - 1 4096 ++ ++ + - 1: 8192 ++ ++ + - C ontrol ++ ++ + - + OB present - Absent OB [-] Neutralizing concentration in various doses of virus Table 2 Susceptibility of the various larval neonates from the lepidoptera to the báculoviruses a) PxMNPVCL3 Insect Curve + SE LCso (95% FL) a RRb Plutella xylostella 0.60 + 0.03 5.54 (3.10-8.91) Helicovefa zea 0.88 + 0.03 36.79 (26.37-50.85) 6.64 Hellothis subflexa 1.38 + 0.05 24.06 (18.53-30.87) 4.34 Heliothis virescens 1.39 + 0.05 6.38 (4.96-8.12) 1.15 Trichoplusia ni 1.17 + 0.04 7.36 (5.49-9.67) 1.33 Spodoptera frugiperda 0.57 + 0.03 576.53 (331.27-1186.48) 104.07 Spodoptera exigua 2.09 + 0.09 69.61 (55.84-85.45) 12.56 a = OB / cmz (FL = Fiduciary Limits) b =; Proportion of resistance n = 150 b) AcMNPV (wt) Insect Curve + SE LCso (95% FL) * RRB Plutella xylostella 1.02 + a04 11600.22 (8534.89-4658.63 15776.59) Helicovefa zea 1.02 + 0.04"3.06 (2.07-4.27) 1.23 Heliothis subfíexa 1.18 + 0.04 22.12 (16.81-28.86) 8.88 Heliothis virescens 1.52 ± 0.06 4.73 (3.71-5.95) 1.89 Trichoplusia ni 1.31 + 0.06 2.49 (1.83-3.28) - Spodoptera frugiperda 1.04 + 0.05 606.72 (435.10-900.31) 243.66 Spodoptera exigua 1.59 + 0.06 200.84 (161.27-250.94) 80.66 a = OB / cm (FL = Fiduciary Limits) b = Proportion of resistance n = 150 Table 2 c) AfMNPVCLI Insect Curve + SE LCso (95% FL) 'RR "Plutella xylostella 0.82 + 0.03 9224.48 (6480.63-3859.6 13229.39) Helicovefa zea 0.86 + 0.03 76.23 (54.36-107.19) 31.89 Heliothis subflexa 1.86 + 0.08 4.29 (3.46 -5.28) 1.79 Heliothis vi scens 1.50 + 0.06 3.37 (2.61-4.27) 1.41 Trichoplusia ni 1.34 + 0.07 2.39 (1.77-3.10) Spodoptera frugiperda 1.00 + 0.04 186.31 (137.47-256.14) 77.95 Spodoptera exigua 1.47 + 0.06 167.59 (131.88-212.46) ) 70.12 a = ÓB / cmz (FL = Fiduciary Limits) b = Proportion of resistance n = 150

Claims (7)

ma:

1. A viral agent comprising a biologically pure multiple polyhedrosis virus of Plutella xylostella containing all the characteristics that identify ATCC VR-2543.

2. The viral agent of claim number 1 wherein said virus is occluded in an occlusion body.

3. An insecticidal compound comprising the virus of claim number 1 and an agronomically acceptable transport.

4. The insecticidal compound of claim 3, wherein said transport is inert.

5. A method for controlling insects comprising the application of an insecticidally effective amount of the viral agent of claim number 1 to the locus of said insects.

6. The method of claim number 5 in which these insects are of the order of Lepidoptera.

7. The method of claim 6 in which said insects are selected from the group consisting of Plutella xylostella, Helicovefa zea, Heliothis subflexa, Heliothis virescens, Trichoplusia ni, Spodoptera frugiperda and Spodoptera exigua. The method of claim number 6, in which said insects are selected from the group consisting of Plutella xylostella, Helicovefa zea, Heliothis vírescens and Spodoptera exigua.