To transport entomopathogenic nematodes, it is necessary to store them in a manner such that a significant proportion of them survive after being stored and are reactivated when dispersed in water. The present invention provides storage by mixing an aqueous cream of clean third stage infective juveniles (J3) of nematodes with clay. The clay may be in chip form, or calcined, milled and sieved, but comporises from about 33 percent (by weight) to 67 percent (by weight) of the homogeneous mixture. Alternatively a layer of the aqueous cream may be placed on a layer of clay, then covered with another layer of clay. In another variation of the invention, the nematode cream is spread on an absorbent substrate which is then placed on a layer of clay while the relative humidity is reduced to 60 percent, to dry the nematode cream. Preferred clays are attapulgite clays, diatomaceous clays and kieselguhr. The nematodes are preferably of the family Steinernematidae or Heterorhabditidae.
Third stage juvenile (J3) entomopathogenic nematodes are prepared for storage by being induced into a state of cryptobiosis. The induction of cryptobiosis is effected by mixing an aqueous cream of the J3 nematodes with anhydrous, small particles (average maximum dimension less than 300 .mu.m) of non-fibrous cellulose. The proportions of the aqueous cream and non-fibrous cellulose particles are such that, after equilibration, the mixture has a water activity in the range 0.80 to 0.995. Preferably an anti-fungal agent is included in the aqueous cream. To store the cryptobiotic J3 nematodes, the mixture is preferably kept in a container, fitted with an attachment which maintains the water activity in the container at a required value. The attachment includes a rigid tube that connects the interior of the container with a chamber that is vented to ambient atmosphere by small apparatus. When in use the chamber contains water-absorbent material saturated with water or with a saturated salt solution, and the tube contains an air-permeable plug. An alternative attachment comprises a plastic envelope, one face of which is stuck to the wall of the container. Small apertures in the face are aligned with apertures in the container wall. Small apertures in the other face connect the inside of the envelope to ambient atmosphere. In use, the envelope contains a water-absorbent material saturated with water or a salt solution, and at least one spacer member.
Third stage juvenile (J3) entomopathogenic nematodes are prepared for storage by being induced into a state of cryptobiosis. The induction of cryptobiosis is effected by mixing an aqueous cream of the J3 nematodes with anhydrous, small particles of non-fibrous cellulose. The cryptobiotic J3 nematodes are stored in a container, fitted with an attachment which maintains the water activity in the container at a required value. The attachment includes a rigid tube that connects the interior of the container with a chamber that is vented to ambient atmosphere by small apparatus. The chamber contains water-absorbent material saturated with water or with a saturated salt solution, and the tube contains an air-permeable plug. An alternative attachment comprises a plastic envelope as the chamber, one face of which is stuck to the wall of the container. Small aperatures in the face are aligned with apertures in the container wall. Small apertures in the other face connect the inside of the envelope to ambient atmosphere.
The present invention teaches method for culturing nematode pesticidal compositions, to produce at a high yield, and generate biotic compositions that are effective as insecticides with high pesticidal activity and preventive effects.
Methods for protecting plants from insects are provided. Such methods comprise: applying a formulation comprising partially-desiccated nematodes and a carrier to plant surfaces growing above the surface of the ground (i.e., foliage). Such formulations have a water activity (Aw) of which is less then 0.998 and greater than 0.935. The carrier comprises water and a substance which maintains the water activity of the formulation at levels of from about 0.980 Aw to about 0.940 Aw for a period of 24 hours when the formulation is exposed to air at 70% relative humidity and 25.degree. C. In one embodiment, the carrier is a solution or gel comprising water and a water-retentive polymer. In another embodiment, the carrier is a solution which comprises water and a humectant. In a further embodiment, the formulation comprises both a water-retentive polymer and a humectant. Preferably, the formulation further comprises an ultraviolet (UV) light protectant. In another aspect, the present invention relates to the formulations that are used in such methods.
The present invention provides a method for the aquaculture of marine deposit feeders, such as Arenicola marina and Arenicola defodiens. The method comprises providing a foodstuff such as brewery yeast or waste from fish farms within the substrate housing the worms. The foodstuff is conveniently particulate or microparticulate to aid intimate admixture with a substrate, which is typically sand.
