WO1995005741A1

WO1995005741A1 - Insect baculovirus compositions

Info

Publication number: WO1995005741A1
Application number: PCT/US1994/009405
Authority: WO
Inventors: John Lindsey Flexner; David Alexander Marsden; Daniel Wallace Sherrod
Original assignee: E.I. Du Pont De Nemours And Company
Priority date: 1993-08-25
Filing date: 1994-08-24
Publication date: 1995-03-02
Also published as: AU7634794A

Abstract

Insecticidal compositions and their use to control insects and reduce crop damage comprising one or more baculoviruses and agents that induce insecticidal, growth-regulatory, and/or anti-feedant effects, wherein the agent acts to reduce overall insect feeding until the insects are overcome by the virus.

Description

INSECT BACtJ OVTRUS COMPOSITIONS BACKGROUND OF THE INVENTION This invention pertains to insecticidal compositions comprising insect baculoviruses and agents that induce insecticidal, growth-regulatory, and/or anti-feedant effects, and their use to control insects in both agronomic and nonagronomic environments. These compositions afford effective biological control of agronomically important insect pests, and result in significantly reduced crop damage.

Biological agents are often more attractive than traditional chemical means for control of insect pests. Bacterial, viral, and fungal agents, as well as predatory nematodes, can provide effective control of target pest populations in an environmentally benign manner. The disclosed combinations of biological agents with natural or synthetic chemical agents afford superior insect control through the combined effects of each component.

Insecticidal activity of baculoviruses is dependent upon intracellular replication and accumulation of viral particles to levels which compromise cellular function and integrity, and upon spread of the virus within the host. The time lapse from the initiation of infection to the onset of death is therefore dependent upon the size of the initial inoculum and the virulence of the virus, but usually ranges from 4 to 20 days or longer. During this delay, infected insects continue to consume plant material, resulting in substantial crop damage before effective suppression of insect activity is achieved. Thus, insect baculoviruses, although capable of controlling a target population, may do so only after considerable crop damage has occurred. Agents that inhibit insect activity, especially feeding, during the latent period following initial infection are in great demand. Certain combinations of insect baculoviruses and chemical insecticides are known. U.S. Patent No. 4,668,511 discloses a baculovirus from Spodoptera littoralis or Mamestra brassicae and a photostable pyrethrinoid for control of Noctuid lepidoptera. U.S. Patent No. 5,075,111 discloses a baculovirus from Mamestra brassicae and a pyrethrinoid for control of Plutella xylostella. Luttrell et al., J Economic Entomology, (1979), 72(1), 57-60 discloses a polyhedrosis virus of Heliothis zea and permethrin or methomyl for control of Heliothis zea. Ramakrishnan et al., Proc. Nat. Acad. Sci., India (1975), 46(B), I & II, 110-116, J. Era. Res., (1978), 2(1) and J Ent. Res., (1983), 7(2), 173-179 disclose a nuclear polyhedrosis virus of Spodoptera litura in combination with pyrethrin. Mohamed et al., J. Entomol. Sci., (1989), 24(4), 539-544 disclose a cytoplasmic virus of Heliothis virescens in combination with methomyl.

U.S. Patent No. 5,124,149 discloses the use of fluorescent brighteners to accelerate the rate of gypsy moth mortality caused by Lymantria dispar nuclear polyhedrosis virus. Shapiro et al, abstract entitled "Effect of Neem Seed Extract Upon Gypsy Moth and its Nuclear Polyhedrosis Virus", Knowledge Express (TM),

24 June 1993, discloses a combination of a Neem extract with a nuclear polyhedrosis virus of Gypsy Moth.

None of these references discloses the combinations of insect baculoviruses and chemical or biological agents disclosed in the present invention. Moreover, although these references demonstrate increased mortality when insects are treated with combinations of insect baculoviruses and insecticides, there is no evidence of decreased plant tissue destruction when these combinations are applied. On the contrary, many references teach combinations of insect baculoviruses with feeding stimulants in attempts to increase uptake of free virus particles by target insects, thus exacerbating crop damage.

SUMMARY OF THE INVENTION This invention pertains to insecticidal compositions comprising at least one of a select group of baculoviruses and at least one of a select group of chemical or biological agents. These compositions effectively control target insect populations while minimizing plant tissue destruction.

The insect baculoviruses are selected from the group: multiply occluded nuclear polyhedrosis virus of Autographa californica (AcMNPV, Acal® ), multiply occluded nuclear polyhedrosis virus of Spodoptera exigua (SeMNPV, Spod-X® ), singly occluded nuclear polyhedrosis virus of Heliothis armigera (HaSNPN , singly occluded nuclear polyhedrosis virus of Heliothis zea (HzSΝPN), granulosis virus of Plutella xylostella (PxGN), nuclear polyhedrosis virus of Heliothis virescens (HvΝPN), nuclear polyhedrosis virus of Anticarsia gemmatalis (AgMΝPV), nuclear polyhedrosis virus of Anagraphafalcifera (AfMΝPV), and granulosis virus of Cydia pomonella (CpGV). The term "chemical agent(s)" is employed hereafter for the sake of simplicity.

That term includes both chemical and biological materials and encompasses natural and synthetic materials employed at doses at which they act to control insects by virtue of their antifeedant properties. Although natural insect antifeedants are ubiquitous, their utility as insecticidal products has been limited due to their non-lethal character. Accordingly, application of insect antifeedants temporarily suspends insect feeding for a limited period of time. However, once the product has degraded, feeding continues unabated. It should therefore be appreciated that the primary benefit of this invention is achieved by the complementary balance between the chemical agent and virus such that significant crop protection is afforded at relatively low rates of chemical agents. Ideally, the chemical agent is employed at the minimum level necessary to discourage feeding until the virus effects mortality.

Preferred chemical agents are traditional chemical insecticides, which when applied at certain low rates, behave primarily as insect antifeedants, such as carbamates and pyretliroids. Also preferred are Bacillus thuringiensis strains and insect antifeedants, particularly, Neem tree extracts. Specifically preferred compositions of this invention comprise one or more of the viruses: AcMNPV, SeMNPV;

HzSNPV and HaSNPV with one or more of the chemical agents: methomyl, esfenvalerate, and azadirachtin, one of the active ingredients of the Neem tree extract.

DETAILS OF THE INVENTION The viruses employed in the compositions of this invention are available commercially or can be isolated from infected insect populations by known methods. Harvested viruses can be incubated and reproduced as will be obvious to one skilled in the art. For leading references to the isolation, characterization and harvesting of baculoviruses see Shapiro, M. In The Biology of Baculoviruses; Grandos, R. R. and Federici, B. A., Ed.; CRC Press: Boca Raton, FL, 1986; pp 31-62; Adams, J. R. and Bonami, J. R. In Atlas of Invertebrate Viruses; Adams, J. R. and Bonami, J. R., Ed.; CRC Press: Boca Raton, FL, 1991; pp 9-30; and Viruses of Invertebrates; Kurstak, E., Ed., Marcel Dekker, Inc., New York, NY, 1991.

Contemplated carbamates include: bendiocarb, butocarboxime, butoxycarboxime, carbofuran, carbosulfan, carbaryl, cloethocarb, fenobucarb, isoprocarb, methomyl, oxamyl, pirimicarb, promecarb and thiodicarb. Contemplated pyrethroids include: deltamethrin, cypermethrin, cyfluthrin, fenvalerate, esfenvalerate, flucythrinate, permethrin, tralomethrin and cyhalothrin. Other contemplated chemical agents include nitromethylenes and nitroguanidines such as imidacloprid, triazinones such as pymetrozine, thioureas such as diafenthiuron, hydrazids such as tebufenozide, and pyrroles such as 4-bromo-2-(4-chlorophenyl)-l-(ethoxymethyl)-5- (trifluoromethyl)pyrrole-3-carbonitrile. Contemplated insect antifeedants include: azadirachtin, Amitraz® , 2-benzoxazolinone, 6-methoxy-2-benzoxazolinone, chlorodimeform HC1, guazatine triacetate, glaucolide, pennyroyal oil, toxol, toxyl angelate, ajugarin I, L-alanine, DL-α-aminobutyric acid, L-cystine, fentin acetate, fentin hydroxide, friedelin, gossypol, L-histidine, L-methionine, plumbagin, polygodial, salannin, L-serine, triphenyltin hydroxide, L-tyrosine, ugandensidial, warburganal, absinthin, angelicin, bergapten, caryoptin, caryoptionol, clerodendrin, dictamnine, dihydrocaryoptin, evoxine, japonin, kokusagine, peucedanin, phytol, pimpinllin, piperenone, psoralen, shiromodiol, skimmianine, and xanthotoxin. The most preferred insect antifeedants are extracts from the Neem tree, a tree from the Meliaceae family, Azadirachta indica, which are potent natural insecticides. The most active ingredient is thought to be azadirachtin; however, several other insecticidal components have been isolated from Neem such as salannin and meliantriol. The term "Neem" is used throughout to mean antifeedant extracts from the Neem tree. For a discussion of insect feeding deterrents see Warthen, J. D and Morgan, E. D. In CRC Handbook of Natural Pesticides; Volume VI, Morgan, E. D. and Mandava, N. M., Ed., CRC Press: Boca Raton, FL, 1991; pp 23-134.

Certain combinations of active ingredients comprising the compositions of the present invention are listed in Table 1.

Table 1

Chemical Agent oxamyl methomyl fenvalerate esfenvalerate

Neem extract oxamyl methomyl fenvalerate esfenvalerate

Neem extract and Sons, Inc., New York, 1961, pp 81-96; and Hance et al., Weed Control Handbook, 8th Ed., Blackwell Scientific Publications, Oxford, 1989.

In the following examples, all percentages are by weight and all formulations are prepared in conventional ways. Example A

Wettable Powder insecticide baculovirus 65.0% dodecylphenol polyethylene glycol ether 2.0% sodium ligninsulfonate 4.0% sodium silicoaluminate 6.0% montmorillonite (calcined) 23.0%.

Example Gr nule insecticide/ baculovirus 10.0% attapulgite granules (low volatile matter, 0.71/0.30 mm; U.S.S. No.

25-50 sieves) 90.0%.

Example C Extruded Pellet insecticide/baculovirus 25.0% anhydrous sodium sulfate 10.0% crude calcium ligninsulfonate 5.0% sodium alkylnaphthalenesulfonate 1.0% calcium/magnesium bentonite 59.0%. The compositions of this invention exhibit activity against a wide spectrum of foliar-feeding, fruit-feeding, stem feeding and seed-feeding lepidopterous pests which are pests of growing and stored agronomic crops, forestry, greenhouse crops, ornamentals, nursery crops, stored food and fiber products, and households. Those skilled in the art will appreciate that not all compositions are equally effective against all growth stages of all pests. Nevertheless, all of the compositions of this invention display activity against eggs, larvae and adults of the Order Lepidoptera. Specifically, the compositions are active against fall armyworm (Spodoptera frugiperda), tobacco budworm (Heliothis virescens), corn earworm (Heliothis zea), American bollworm (Heliothis armigera), beet armyworm (Spodoptera exigua), diamondback moth (Plutella xylostella) and cabbage looper (Trichoplusia ni).

Compositions of this invention can also be mixed with one or more other insecticides, fungicides, acaricides, or other biologically active compounds to form a multi-component pesticide giving an even broader spectrum of agricultural protection. 8

Examples of other agricultural protectants with which compounds of this invention can be formulated are: insecticides such as avermectin B, monocrotophos, tetrachlorvinphos, malathion, parathion-methyl, diazinon, profenofos, sulprofos, triflumuron, diflubenzuron, methoprene, buprofezin, thiodicarb, acephate, azinphosmethyl, chlorpyrifos, dimethoate, fipronil, flufenprox, fonophos, isofenphos, methidathion, metha-midophos, phosmet, phosphamidon, phosalone, pirimicarb, phorate, terbufos, trichlorfon, methoxychlor, bifenthrin, biphenate, tefluthrin, fenpropathrin, fluvalinate, imidacloprid, metaldehyde and rotenone; and fungicides such as carbendazim, thiuram, dodine, maneb, chloroneb, benomyl, cymoxanil, fenpropidine, fenpropimorph, triadimefon, captan, thiophanate-methyl, thiabendazole, phosethyl-Al, chlorothalonil, dichloran, metalaxyl, captafol^ iprodione, oxadixyl, vinclozolin, kasugamycin, myclobutanil, tebuconazole, difenoconazole, diniconazole, fluquinconazole, ipconazole, metconazole, penconazole, propiconazole, uniconzole, flutriafol, prochloraz, pyrifenox, fenarimol, triadimenol, diclobutrazol, copper oxychloride, furalaxyl, folpet, flusilazol, blasticidin S, diclomezine, edifenphos, isoprothiolane, iprobenfos, mepronil, neo-asozin, pencycuron, probenazole, pyroquilon, tricyclazole, validamycin, and flutolanil.

In certain instances, combinations with other insecticides having a similiar spectrum of control but a different mode of action will be particularly advantageous for resistance management. Lepidopterous pests are controlled and protection of agronomic, horticultural and specialty crops, animal and human health is achieved by applying one or more of the compositions of this invention, in an effective amount, to the environment of the pests including the agronomic and/or nonagronomic locus of infestation, to the area to be protected, or directly on the pests to be controlled. The present invention is not limited to joint application of the baculovirus and arthropodicide, that is, as a mixture. A variant of this method is application of the baculovirus component followed by application of the arthropodicide component, or vice versa. Thus, the present invention further comprises a method for the control of insects and protection of agronomic and/or nonagronomic crops, comprising applying one or more of the compositions containing at least one baculovirus and at least one insecticide, in an effective amount, to the environment of the pests including the agronomic and/or nonagronomic locus of infestation, to the area to be protected, or directly on the pests to be controlled or successive applications of two compositions, one composition containing one or more baculoviruses the other composition containing at least one of the defined insecticides, the successive applications being conducted in either order. A preferred method of application is by spraying. Alternatively, granular formulations of these compounds can be applied to the plant foliage or the soil. Other methods of application include direct and residual sprays, aerial sprays, seed coats, microencapsulations, systemic uptake, -14-

Table 3

Table 4

•13-

Table 2a

foggers, aerosols, dusts and many others. The compositions can be incorporated into baits that are consumed by the insects or in devices such as traps and the like.

The compositions of this invention can be applied in their pure state, but most often application will be of a formulation comprising one or more baculoviruses and one or more insecticides with suitable carriers, diluents, and surfactants and possibly in combination with a food (bait) depending on the contemplated end use. A preferred method of application involves spraying a water dispersion or refined oil solution of the compounds. Combinations with spray oils, spray oil concentrations, spreader stickers, adjuvants, solvents, and synergists often enhance compound efficacy. The rate of application required for effective control will depend on such factors as the species of insect to be controlled, the pest's life cycle, life stage, its size, location, time of year, host crop or animal, feeding behavior, mating behavior, ambient moisture, temperature, and the like. Under normal circumstances, application rates of about 0.01 to 0.05 kg of active ingredient per hectare are sufficient to control pests in agronomic ecosystems, but as little as 0.001 kg/hectare may be sufficient or as much as 1 kg hectare may be required. For nonagronomic applications, effective use rates will range from about 1.0 to 50 mg/square meter but as little as 0.1 mg/square meter may be sufficient or as much as 150 mg/square meter may be required. The following tests demonstrate the control efficacy of compounds of this invention on specific pests. The pest control protection afforded by the compounds is not limited, however, to these species.

Test Protocol for Tests A-C Baculoviruses were obtained from Crop Genetics International (10150 Old Columbia Road, Columbia, MD, 21046) as freeze-dried samples. Methomyl and esfenvalerate were used as 40% active wettable powder. Neem was acquired from Agridyne Technologies Inc. (417 Wakava Way, Salt Lake City, Utah, 84108) as a 3% azardirachtin active emulsifϊable concentrate (Azatin® ). Stock solutions of Spodoptera exigua (Spod-X® ) were prepared by adding 50 mg of virus (2.75 x 10⁹ occlusion bodies per gram) to 50 mL of distilled water or 10 mg to 100 mL of distilled water to obtain a 1000 or 100 ppm solutions, respectively. Esfenvalerate stock solution was prepared by dissolving 50 mg in 100 mL of water to obtain a 200 ppm stock solution. The test solutions were prepared by diluting the stock solutions with water or by combining the stock solutions and diluting with water. A stock solution of Nu-Film-17, a sticker-spreader from Miller Chemical and Fertilization, was prepared by adding 20 mL of Nu-Film- 17 with 20 mL of water to yield a 50% Nu-Film- 17 solution.

Four-week old soybean plants grown in 4-inch square (10.16 cm²) pots were sprayed to run-off with 50 mL of the test solutions containing either the virus, the insecticide, the insecticide plus virus, or the dispersant alone. The plants were sprayed using an automatic turntable with hand-held spray appartus atomizing at 20 p.s.i.

(137 kPa) The plants were allowed to dry and the leaves were removed from the top trifoliates (new growth). The leaf surface area was determined by using a surface-area reader (Li-Cor Model 3100). The leaves were then placed into an 8 ounce (230 mL) cup containing 3 inch x 0.75 inch (7.62 cm x 1.91cm) piece of water-moistened filter paper.

Five 3 -day old larvae of Spodoptera exigua were placed on each leaf. The cups were then placed in a dark 27°C incubator for the remainder of the test. After 120 h, mortality of the larvae were determined and the leaf surface area was measured to determine the amount of plant material consumed. Test D Protocol

Spod-X® was obtained from Crop Genetics International (10150 Old Columbia

Road, Columbia, MD, 21046) as a freeze-dried sample. A stock solution of Spod-X® was prepared by adding 10 mg of virus (2.75 x 10⁹ occlusion bodies per gram) to

100 mL of distilled water to obtain 100 ppm viral solution. A fenvalerate stock solution was prepared by dissolving 10 mg of 97% technical material in 50 mL of a 3 : 1 acetone: water solution. This was then diluted with 150 mL of water to obtain a 50 ppm viral solution. To 100 mL of this solution was added 11.1 mL of the Spod-X® stock solution to yield a solution that was 45 ppm fenvalerate and 10 ppm Spod-X® . To the remaining 100 mL of the fenvalerate solution was added 11.1 mL of water to obtain a 45 ppm fenvalerate solution. A stock solution of Nu-Film-17 (Miller Chemical and

Fertilization) was prepared by adding 50 mL of Nu-Film-17 to 50 mL of water. To each of the treatment solutions was added 556 μl of the Nu-Film-17 stock solution. In addition, 556 μl of the Nu-Film-17 stock solution was added to 111.1 mL of distilled water to yield 0.25% Nu-Film-17 treatment solution. Four- week old soybean plants grown in 4-inch square (10.16 cm²) pots were sprayed to run-off with 50 mL of the test solutions containing either the virus, the insecticide, the insecticide plus virus, or sticker-spreader alone. The plants were allowed to dry and 1.5 inch (3.81 cm) diameter leaf disks were excised from the plant and placed, one disk per well, into 16-well HIS (high impact styrene) trays. The bottom of each cell contained a 1 x 0.75 inch (2.54 x 1.91 cm) piece of water-moistened filter paper. Adequate precautions were taken to ensure that there was no cross- contamination between treatments. Three-day old insects of uniform size were selected and transferred to the plant disks, one insect per disk. After the insects were transferred, the HIS trays were placed in a dark 27°C incubator for the remainder of the test. Mortality assessments were made at 48, 96 and 120 h. Only the 120 h data is reported. After 120 h, the amount of leaf material consumed was determined by using a surface- area reader (Li-Cor Model 3100). One tray, each containing 16 wells, was used per treatment. Mortality data was determined as a percentage of insects dead (out of a total of 16). Leaf area consumed is an average of the 16 leaf disks per tray.

Test Protocol E Neem extract was obtained from Agridyne Technologies Inc. (417 Wakava Way,

Salt Lake City, Utah, 84108) as a 3% azardirachtin active emulsifiable concentrate (Azatin® ). A stock solution of 1000 ppm Azatin® was prepared by adding 333 μl of formulated Azatin® to 9.7 mL distilled water. A 200 ppm solution of Azatin® was then prepared by diluting 10 mL of this stock solution in 40 mL of distilled water. A 1000 ppm stock solution of Acal® was prepared by adding 50 mgs of Acal® to 50 mL of distilled water. Polyhedra were counted using the technique described below. Occlusion body (OB) counts were 2.5 X 10⁶ OBs/mL (2500 OBs/μl) in the 1000 ppm stock solution of Acal® . One mL of this solution was diluted in 9 mL water to yield a 250 OBs/ μl solution. The virus dose was delivered in 5 μl volumes. For each virus dose, 50 μl of insect diet diluted 1 :3 with distilled water was placed into the wells of a 128 well bioassay tray. The diet preparation is described below. The diet plugs are allowed to solidify and then innoculated with lμl of the 250 OBs/μl virus dose. The trays were then placed under heat lamps and allowed to dry for 10 minutes. One insect was placed into each well containing diet, covered with a lid, and placed in a growth chamber set at 27° C under constant darkness for 24 h or until the entire plug was eaten. After the larvae had consumed the diet plug they were transferred onto leaves excised from 4 day old soybean plants treated with 50 mL of 200 ppm Azatin® . Leaves were run through the surface area meter described above before being infested with 5 day old larvae. Four larvae were placed on each leaf and five leaves were used per treatment. The larvae were then monitored every 12 h for signs of feeding depression and mortality. At each observation, the average of the five leaf readings were taken and surviving larvae transferred to new leaves prepared as above.

Polyhedra Counting Procedure An Improved Neubauer hemacytometer (0.1 mm deep) and cover slip was cleaned with 70% alcohol and blotted dry. A stock 1000 ppm solution of the virus was prepared by dissolving 50 mg of virus sample in 50 mL of distilled water and sonicating for 5 minutes to ensure an even dispersion. To 1 ml of the stock solution was added 9 mL of distilled water. Then 10 μl of this diluted stock solution was loaded onto each grid of the hemacytometer. The hemacytometer was then allowed to settle for 5 minutes. Using the 40X objective on a compound microscope, all the virus particles present in each of the four corner subgrids and the central subgrid were counted. After counting the occlusion bodies (Obs) on both grids of the hemacytometer, the average of the two counts were computed and recorded. The computation was determined as follows: OBs/ml = avg. count x 5 xlO^ x dilution factor. Standard Lepidoptera Diet Preparation An agar mixture was prepared by combining 1000 mL of water, 37 g of bacto agar and 68 g of sucrose crystals in a 5-liter beaker. The beaker was then placed into a microwave oven and heated until the solution became clear. A flour mixture was prepared by mixing 78 g of soy flour, 68 g of wheat germ flour, 19 g of wesson salt mix, 10 g of alphacel and 700 mL of water. An acid mixture was prepared by combining 2 g of sorbic acid, 10 g of methyl paraben, 8 g of ascorbic acid, 23 of vitamin mix and 5 mL of propionic/phosphoric acid mix. The propionic/phosphoric acid mixture was prepared by combining a mixure of 418 mL of propionic acid in 82 mL distilled water with a mixture of 42 mL phosphoric acid in 458 mL distilled water. The flour and acid mixtures from above were placed into a 10-quart (11.01 L) diet cooker (Groen TDB 6-10) and stirred at medium to high speed. The heated Agar preparation was then placed into the diet cooker and the contents of the diet cooker were stirred for 15 minutes. This diet mixture was then transferred to a 15-quart (16.52 L) stainless steel pot and kept at 50° C in a water bath. The diet mixture was stirred continuously during the bioassay process. Antibiotics were withheld from the diet to prevent interaction with microorganisms.

TEST RESULTS TEST A Esfenvalerate plus virus of Spodoptera exigua (SeMNPV on Beet Armyworm A 1 ppm test solution of Spod-X® was prepared by combining 6 mL of the 100 ppm stock solution of Spod-X® with 594 mL of distilled water. The stock solution of esfenvalerate was diluted with water to obtain a test solution of 100 and 12.5 ppm. A solution containing both Spod-X® and esfenvalerate was prepared by mixing 50 mg of esfenvalerate and 100 mL of the 1 ppm Spod-X® test solution. This solution of esfenvalerate and Spod-X® was then diluted with the 1 ppm Spod-X® solution to obtain test solutions of 100 and 12.5 ppm esfenvalerate containing 1 ppm Spod-X® . To each test solution was added 250 μl of the Nu-Film-17 stock solution. Results are reported to the nearest whole number.

Esfenvalerate 100 68 1

Esfenvalerate + SeMNPV 100 + 1 92 2

As can be readily observed from the data above, esfenvalerate at 12.5 and 100 ppm results in intermediate levels of insect mortality and significant reduction in leaf consumption. SeMNPV at 1 ppm exhibits significant mortality, but almost no feeding inhibition, thus resulting in significant crop damage. However, the combination of esfenvalerlate and SeMNPV results in higher mortality than either agent alone, as well as significantly reduced leaf consumption.

TEST S Methomyl plus virus of Spodoptera exigua f SeMNPV) on beet armyworm A 15 ppm solution of Spod-X® was prepared by combining 8.8 mL of the

100 ppm stock solution of Spod-X® with 50 mL of distilled water. A 100 ppm solution of methomyl was prepared by combining 250 mg of methomyl and 100 mL of water. To 25 mL of this solution was added to 25 mL of water to obtain a 50 ppm solution. To this, 8.8 mL of the Spod-X® solution was then added to yield 42.5 ppm methomyl/ 15 ppm Spod-X® solution. To each test solution was added 294 μl of the Nu-Film-17 stock solution. Results of this experiment are presented below, rounded to the nearest whole number.

The combination of methomyl and virus at the indicated rates effected 100% insect mortality at 120 h with substantially zero damage to the plant.

TES C Neem extract plus virus of Spodoptera exigua (SeMNPV on beet armyworm Spod-X (30 mg) in 10 mL of water was sonicated to aid in dispersion. To this mixture was added 90 mL of water to obtain a 300 ppm solution. 10 mL of this solution was combined with 90 mL of water to yield a 30 ppm Spod-X® solution. To 25 mL of this solution was added 25 mL of water to obtain a 15 ppm solution of Spod-X® . A 1000 ppm solution of Azatin® was prepared by adding 333 μl of Azatin® to 9.7 mL of water. This solution was further diluted with 90 mL of water to yield a 100 ppm Azatin® solution. This solution was further diluted to obtain 50, 25, 12.5, 6.25, 3.1, and 1.6 ppm solutions of Azatin® . The 25 mL of the 50 ppm solution of Azatin® was combined with 25 mL of 30 ppm Spod-X® solution to yield a solution of 25 ppm Azatin® and 15 ppm Spod-X® solution. Results are as reported hereafter to the nearest whole number.

Treatment Rate Percentage mortality at Average leaf (ppm) 120 hours eaten (cm²)

Neem extract 1.6 20 3

SeMNPV 15 100 4

Neem extract + SeMNPV 1.6 + 15 92 1

TEST D Fenvalerate plus virus of Spodoptera exigua (SeMNPV) on beet armyworm Results for a fenvalerate- virus combination containing 0.25% Nu-Film-17, is as reported hereafter (to the nearest whole number).

Treatment Rate Percentage mortality at Average leaf (ppm) 144 hours eaten (cm²)

Fenvalerate 45 63 1

SeMNPV 10 100 2

Fenvalerate + SeMNPV 45 + 10 94 1

TEST E Neem extract plus virus of Autographa californica fAcMNPV) on cabbage looper Results are reported to the nearest whole number for Neem extract antifeedant plus virus.

Treatment Rate Percentage mortality at Average leaf 122.5 hours eaten (cm²)

Neem extract 200 ppm 50 9

AcMNPV 250 OBs 45 62

Neem extract + AcMNPV 200 + 250 65 7

Claims

CLAIMS 1. An arthropodicidal composition comprising a chemical agent selected from at least one member of the group:

(i) carbamates,

(ii) pyrethroids,

(iii) Bacillus thuringiensis strains, (iv) insect antifeedants,

and at least one member selected from the group of baculoviruses:

I multiply occluded nuclear polyhedrosis virus of Spodoptera exigua

(SeMNPV),

II multiply occluded nuclear polyhedrosis virus of Autographa californica (AcMNPV),

III singly occluded nuclear polyhedrosis viruses of Heliothis armigera

(HaSNPV),

IV granulosis viruses of Plutella xylostella (PxGV),

V singly occluded nuclear polyhedrosis viruses of Heliothis zea (HzSNPV),

VI nuclear polyhedrosis virus of Anticarsia gemmatalis (AgMNPV), Nil nuclear polyhedrosis virus of Anagrapha falcifera (AfMΝPV), and VIII granulosis virus of Cydia pomonella (CpGV).

2. A composition according to Claim 1 wherein the baculovirus is at least one member selected from the group I, II and V.

3. A composition according to Claim 2 wherein the chemical agent is a carbamate or pyrethroid.

4. A composition according to Claim 2 wherein the chemical agent is an insect antifeedant.

5. A composition according to Claim 4 wherein the antifeedant is the Νeem tree extract.

6. A composition according to Claim 3 wherein the baculovirus is I or II.

7. A composition according to Claim 6 wherein the baculovirus is I and the chemical agent is methomyl.

8. A composition according to Claim 1 wherein the chemical agent is employed at a concentration that insures it will act substantially as an antifeedant to provide crop protection while the virus acts substantially to effect insect mortality.

9. A method for controlling insects comprising applying to the insects or to their environment an insecticidally effective amount of a composition according to Claim 1.