2. Add different concentrations of nematodes (100, 200,
300 IJs/capsule) and mix thoroughly in the gel matrix.
3. Take 1 ml solution through hypodermic syringe and place
drops of this solution into calcium chloride solution with continuous stirring to get discrete capsules of calcium alginate
(0.4 cm diameter).
4. Allow the capsules to complex for 20–30 min and then separate
from the solution by sieving.
5. Rinse in distilled water and store in petri plates lined with wet
blotting paper.
2.5 Vermiculite and
Peat [212]
An aqueous nematode suspension is mixed homogeneously with
micronized vermiculite. This mixture is placed in a thin polythene
bag for storage. Steinernema species could be stored for 4–5 months
and Heterorhabditis species for up to 3 months at 3–5
C. The
vermiculite nematode mixture is added to the spray tank directly,
mixed in water, and applied either as spray or drench.
2.6 Clay [213]
This formulation comprises a homogenous mixture of an aqueous
cream of infective nematodes with clay. Nematodes are placed in
contact with an adsorbent clay, resulting in gradual absorption of
water from the nematodes enabling to withstand room temperatures. The formulation is called a “sandwich” because the EPNs are
stored between two layers of clay.
2.7 Pellet [214]
Pellet consists of a mixture of alfalfa meal, wheat flour, wheat bran,
corn oil, and water. This formulation is called “pesta.” The process
involves drying of granules to low moisture to prevent nematode
migration and reduce risk of contamination.
2.8 EPN Beads [215]
2.8.1 Materials Required
l
EPN–alginate–glycerol solution.
(0.5% alginate, 18% glycerol, 0.05% blue dye, 0.075% formaldehyde and EPN).
l
Ca
2+
–glycerol solution.
(2% CaCl 2 ∙2H 2 O, 18% glycerol, and 0.075% formaldehyde).
2.8.2 Procedure
1. Drop approximately 85–95 μl of the EPN–alginate–glycerol
solution into a Ca
2+
–glycerol solution.
2. Sieve the beads after 20 min polymerization time.
3. Rinse quickly with water.
4. The added glycerol induces the nematodes to enter in a state of
quiescence, immobilizing the EPN inside the beads.
2.9 Baits [216]
Baits contain a mixture of infective juveniles, an inert carrier (e.g.,
corncob grits, groundnut hulls, or wheat bran) and a feeding
148
Field Application Techniques for Control of Insect Pests
300 IJs/capsule) and mix thoroughly in the gel matrix.
3. Take 1 ml solution through hypodermic syringe and place
drops of this solution into calcium chloride solution with continuous stirring to get discrete capsules of calcium alginate
(0.4 cm diameter).
4. Allow the capsules to complex for 20–30 min and then separate
from the solution by sieving.
5. Rinse in distilled water and store in petri plates lined with wet
blotting paper.
2.5 Vermiculite and
Peat [212]
An aqueous nematode suspension is mixed homogeneously with
micronized vermiculite. This mixture is placed in a thin polythene
bag for storage. Steinernema species could be stored for 4–5 months
and Heterorhabditis species for up to 3 months at 3–5
C. The
vermiculite nematode mixture is added to the spray tank directly,
mixed in water, and applied either as spray or drench.
2.6 Clay [213]
This formulation comprises a homogenous mixture of an aqueous
cream of infective nematodes with clay. Nematodes are placed in
contact with an adsorbent clay, resulting in gradual absorption of
water from the nematodes enabling to withstand room temperatures. The formulation is called a “sandwich” because the EPNs are
stored between two layers of clay.
2.7 Pellet [214]
Pellet consists of a mixture of alfalfa meal, wheat flour, wheat bran,
corn oil, and water. This formulation is called “pesta.” The process
involves drying of granules to low moisture to prevent nematode
migration and reduce risk of contamination.
2.8 EPN Beads [215]
2.8.1 Materials Required
l
EPN–alginate–glycerol solution.
(0.5% alginate, 18% glycerol, 0.05% blue dye, 0.075% formaldehyde and EPN).
l
Ca
2+
–glycerol solution.
(2% CaCl 2 ∙2H 2 O, 18% glycerol, and 0.075% formaldehyde).
2.8.2 Procedure
1. Drop approximately 85–95 μl of the EPN–alginate–glycerol
solution into a Ca
2+
–glycerol solution.
2. Sieve the beads after 20 min polymerization time.
3. Rinse quickly with water.
4. The added glycerol induces the nematodes to enter in a state of
quiescence, immobilizing the EPN inside the beads.
2.9 Baits [216]
Baits contain a mixture of infective juveniles, an inert carrier (e.g.,
corncob grits, groundnut hulls, or wheat bran) and a feeding
148
Field Application Techniques for Control of Insect Pests