Field Application - some guidelines
1. Soil temperature at the time of application (and preferably even after application), should range from 18-300°C.
2. Nematodes should be applied to moist soils. Pre and Post-application of irrigation and continued moderate moisture is necessary.
3. Application should be done preferably in the morning or evening to avoid exposure of EPN by to UV radiation and high temperature.
4. High spray volumes should be applied to reach optimum depth.
5. A dosage rate of 2.5-7.5 billion/ha is consistent in the fields for pest control results. About 50 EPN/flying insect are sufficient.
6. Repetition of application is required for insects like white grub.
7. About four week duration of trial is needed normally. For lepidopteran insects, 3 to 7 days duration is sufficient.
8. Flood jet nozzle is fairly effective for spray.
Methods of application
1. Spraying: As with chemical insecticides, spraying nematode directly on to the soil surface or foliage is the most commonly used application method.
2. Trickle irrigation: Button type of trickle irrigation outlet is used to deliver the nematodes to the area on one side of the plant.
3. Capsule: Capsule prepared from wheat bran (5% w/w) with calcium alginate containing 1000-2000 nematode/capsule is applied. Capsules are buried in soil or under dairy compost. About 70-80 capsules per plant could be used.
4. Liquid Baits: Desiccated nematodes (S. feltiae) are mixed with 56% sucrose solution (Georgis, 1990).
5. Pellet Baits: Capinera et al., (1987) used wheat bait pellets from wheat bran-wheat flour (50% each), locust bean gum (18mg/ml of water) and corn oil.
6. Nylon pack cloth bands: Nematodes can be applied to nylon pack cloth bands lined with fleece or terrycloth that is wrapped around tree trunks to control gypsy moth larvae, Lymontria dispar (Kaya et al., 1995)
7. Cardboard band: S. carpocapsae incorporated into cardboard band placed around the trunk of apple trees as an artificial bark substrate, infected 23-73% of codling moth pre-pupae that moved under the barks
8. Punch and Syringe method: This is used in case of forest trees. Inoculation hole is made by hammer and delivery of about 1 ml of nematode containing medium (aerated 12% gelatin with 4000 nematodes/ml) is done by syringe.
Dosage / Frequency of Application
Webb and Capinera (1995) applied S. carpocapsae to squash (Cucurbita pepo) twice per week, at a rate of 3 billion nematodes per acre to control pickleworm, Diaphania nitidalis, an important pest of cucurbits in Florida. The percentage of fruit damaged by pickleworm in the treated plots varied from 0 to 9%. Damage in untreated plots ranged from 33% to 60%. Blossom damage was also significantly reduced with application of nematodes. Even one billion nematodes per acre were as effective as permethrin, although neither treatment was completely effective when pickleworms were abundant. More frequent applications may be necessary to achieve control with a reduced rate of nematodes. Different researchers have put the ideal dosage rate at 1-7.5 billion nematodes per hectare (Webb and Capinera, 1995; Shannag and Capinera, 1995).
Webb, S.E. & Capinera, J.L. 1995 publ. (1996). Management of pickleworm with entomopathogenic nematodes. Proceedings of Florida State Horticultural Society 108: 242-245
Shannag, H.K. & Capinera, J.L. (1995). Evaluation of entomopathogenic nematode species for the control of melonworm (Lepidoptera: Pyralidae). Environmental Entomology 24: 1, 143-148.
Application methods
Table 1: Application methods for Entomopathogenic nematodes
Application method Pest Reference
Overhead sprinkler system Artichoke plum moth Bari & Kaya ,1984
Injection into larval galleries Zezeura pyrina Abdel Kawy et al., 1992 ; Deseo,1982
With liq fertilizer Diabrotica undecemlineata Poinar et al., 1983
Bait formulation Epsky & Capinera , 1988
Spinning dic sprayers Plutella xylostella Mason et al., 1999
Spraying and irrigation Temnorhinus mendicus, Pectinophora gossypiella Tacconi 1998; Gouge et al., 1996
Knapsack sprayer Conorhynchus mendicus Akalach & Wright 1995
Spraying in dung tubs Fly maggot Choo et al., 1996
Calcium alginate capsules Musca domestica Renn 1995
Sprayed on soil Helicoverpa zea Cabanillas & Raulston 1996
Bark sprays with backpack sprayer Podosesia aureocincta Smith et al., 1996