<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>An alternative control method to the use of chemical insecticides against soil dwelling insect pests is the application of entomopathogenic nematodes formulated in alginate beads for enhanced shelf life. The aim was to compare the benefit on nematode survival and infectivity of: (i) pre-conditioning of juveniles, and (ii) coating of alginate beads. The nematodes <italic>Steinernema glaseri</italic>, <italic>Steinernema carpocapsae,</italic> and <italic>Heterorhabditis bacteriophora</italic> were reproduced in last instar larvae of the wax moth <italic>Galleria mellonella</italic> and the infective juveniles emerged were subjected to two capture treatments: white traps and plaster of Paris, the latter was utilized as a pre-conditioning treatment. A total of 1,000 infective juveniles were formulated in each sodium alginate bead with or without an alginate coating. The beads were stored at 23 ± 3°C and a bidistilled water suspension of nematodes was set as a control. The survivorship of these formulates and their infectivity on <italic>Galleria mellonella</italic> larvae were evaluated every 7 d post-formulation (dpf). In beads without pre-conditioning juveniles nor coating, <italic>Steinernema carpocapsae</italic> had the higher survival rate (58.8%), the longest survival time (28 dpf) and the higher infectivity (100%) as well. Pre-conditioning improved the survival and infectivity of <italic>Steinernema glaseri</italic> by 22.5% at 21 dpf and 70.0% at 14 dpf, respectively. Alginate coating increased survival (21.7%) and infectivity (95%) of <italic>Heterorhabditis bacteriophora</italic> for up to 28 dpf. The combination of pre-conditioning and coating slightly favored the survival (10% for up to 14 dpf) of <italic>Steinernema glaseri</italic> and infectivity (100% for up to 35 dpf) of <italic>Steinernema carpocapsae</italic>. Non pre-conditioned <italic>Steinernema carpocapsae</italic> formulated in uncoated beads was the combination with better performance in survivorship (58.8%) and infectivity (100%) at 28 dpf. It was concluded that non pre-conditioned <italic>Steinernema carpocapsae</italic> formulated in uncoated beads was the combination with better survivorship and infectivity.</p>
</abstract>

An alternative control method to the use of chemical insecticides against soil dwelling insect pests is the application of entomopathogenic nematodes formulated in alginate beads for enhanced shelf life. The aim was to compare the benefit on nematode survival and infectivity of: (i) pre-conditioning of juveniles, and (ii) coating of alginate beads. The nematodes Steinernema glaseri, Steinernema carpocapsae, and Heterorhabditis bacteriophora were reproduced in last instar larvae of the wax moth Galleria mellonella and the infective juveniles emerged were subjected to two capture treatments: white traps and plaster of Paris, the latter was utilized as a pre-conditioning treatment. A total of 1,000 infective juveniles were formulated in each sodium alginate bead with or without an alginate coating. The beads were stored at 23 ± 3°C and a bidistilled water suspension of nematodes was set as a control. The survivorship of these formulates and their infectivity on Galleria mellonella larvae were evaluated every 7 d post-formulation (dpf). In beads without pre-conditioning juveniles nor coating, Steinernema carpocapsae had the higher survival rate (58.8%), the longest survival time (28 dpf) and the higher infectivity (100%) as well. Pre-conditioning improved the survival and infectivity of Steinernema glaseri by 22.5% at 21 dpf and 70.0% at 14 dpf, respectively. Alginate coating increased survival (21.7%) and infectivity (95%) of Heterorhabditis bacteriophora for up to 28 dpf. The combination of pre-conditioning and coating slightly favored the survival (10% for up to 14 dpf) of Steinernema glaseri and infectivity (100% for up to 35 dpf) of Steinernema carpocapsae. Non pre-conditioned Steinernema carpocapsae formulated in uncoated beads was the combination with better performance in survivorship (58.8%) and infectivity (100%) at 28 dpf. It was concluded that non pre-conditioned Steinernema carpocapsae formulated in uncoated beads was the combination with better survivorship and infectivity.

Survival and Infectivity of Entomopathogenic Nematodes Formulated in Sodium Alginate Beads

Journal of Nematology

This work is licensed under the Creative Commons Attribution 4.0 International License.

running-head

An alternative control method to the use of chemical insecticides against soil dwelling insect pests is the application of entomopathogenic nematodes...

		Survival rate after formulation (%)
Factor	Treatment	7 d	14 d	21 d	28 d	35 d	MSt (days ± SE)
EPN	Sg	15	0	0	0	0	8.05 ± 0.079
	Sc	79	79	58.8	58.8	0	26.07 ± 0.389
	Hb	93.5	93.5	51.4	0	0	22.00 ± 0.209
Prec	Sg-Prec	39.6	39.6	22.5	0	0	13.21 ± 0.262
	Sc-Prec	53.3	23	9.8	0	0	13.02 ± 0.218
	Hb-Prec	69.3	69.3	7.6	0	0	14.69 ± 0.182
C	Sg-C	20	0	0	0	0	8.40 ± 0.088
	Sc-C	79	79	41.6	41.6	0	26.96 ± 0.355
	Hb-C	100	100	30.5	21.7	0	22.22 ± 0.262
Prec-C	Sg-Prec-C	40	0	0	0	0	9.80 ± 0.108
	Sc-Prec-C	74.4	67.8	31.5	31.5	10	22.06 ± 0.372
	Hb-Prec-C	92.4	0	0	0	0	13.46 ± 0.058

		Infectivity after formulation (%)^a
Factor	Treatment	7 d	14 d	21 d	28 d	35 d	Mean IN (% ± SE)	F	P
EPN	Sg	15b	0b	0b	0b	0b	3 ± 2.19bc	6.28	0.023
	Sc	100a	100a	100a	100a	0a	80 ± 9.18a
	Hb	90a	100a	0b	0b	0a	38 ± 10.8ac
Prec	Sg-Prec	75a	70a	0a	0a	0a	29 ± 9.5bc	5.79	0.006
	Sc-Prec	100a	100a	55a	0a	0a	51 ± 11.3a
	Hb-Prec	100a	90a	0a	0a	0a	38 ± 10.8ac
C	Sg-C	35b	0b	0b	0b	0a	7 ± 3.3b	219.59	<0.001
	Sc-C	100a	100a	100a	80a	0a	76 ± 9.58a
	Hb-C	100a	100a	90a	95a	0a	77 ± 9a
Prec-C	Sg-Prec-C	40b	10b	0b	00b	0b	10 ± 5.7b	160.54	<0.001
	Sc-Prec-C	100a	100a	90a	90a	100a	96 ± 2.7a
	Hb-Prec-C	90a	10b	0b	0b	0b	20 ± 8.46b

Survival and Infectivity of Entomopathogenic Nematodes Formulated in Sodium Alginate Beads

Pubblicato online: 17 ott 2018

Pagine: 273 - 280

DOI: https://doi.org/10.21307/jofnem-2018-037

Parole chiave
Biological control, Coating, Pre-conditioning, .

© 2018 Jaime Ruiz-Vega et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Survival and Infectivity of Entomopathogenic Nematodes Formulated in Sodium Alginate Beads

Pubblicato online: 17 ott 2018

Pagine: 273 - 280

DOI: https://doi.org/10.21307/jofnem-2018-037

Parole chiaveBiological control, Coating, Pre-conditioning, .

© 2018 Jaime Ruiz-Vega et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Parole chiave
Biological control, Coating, Pre-conditioning, .