Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
Effects of pesticides upon slug, land snail, annelid,
nematode and arthropod populations in horticultural
soils in Galicia
(North-West Spain)
Preliminary results.
Authors:
• Castillejo, J.
• Iglesias, J.
Department of Animal Biology
Faculty of Biology
University of Santiago de Compostela
E-15782 Galica. Spain
OBJETIVES:
Study the effect of
Phasmarabditis nematode strains
on arable soil infaunae
Assess the impact of some
molluscicides on non-target soil
invertebrates
Infaune monitored
MOLLUSCICIDES TESTED:
• Phasmarhabditis
• Metaldehyde
• Cow slurry/Slug Eggs Killer
• Herbicides/Slug Eggs Killer
Round Worms
Slugs
Snails
Earthworms
Springtails Coleoptera
NO TILLED parcel for 5 years before trials
• Ecosystem soil no disturbed
• Animal colony soil established
First Parcel
50 cm depth TILLED parcel, ploughed yearly
• Destroyed ecosystem soil
• New animal soil reorganitation
• New soil colonisation
Second Parcel
1.4 m
1.4 m
2 m2
PARCEL miniPLOTS
• Six replicates for each crops/test
• Six controls plots/random selection
• Monthly sampling
2.6 m
2.6 m
Pontecesures O Grove Santiago
TEMPERATURE (ºC) 13-14 >14 12-13
RAINFALL (mm) 1300-1500 1100-1300 1200-1300
MOISTURE (%) 23.85 34.68 42.44
POROSITY (%) 59.53 77.20 71.89
AIR CONTENT (%) 35.68 42.52 29.45
FRACTION > 2 mm (g) 00.20 45.45 02.49
GROSS SAND (%) 51.18 59.91 36.42
THIN SAND (%) 41.37 20.98 45.87
SLIME (%) 02.80 16.42 11.23
CLAY (%) 04.64 00.267 06.46
pH 05.4 07.4 05.1
pK 04.9 07.2 04.2
pV 05.7 06.5 04.9
C/N Relation 09.58 18.66 08.82
C (meq/100 g) 01.15 03.95 02.56
N (meq/100 g) 00.12 00.21 00.29
Na (meq/100 g) 00.00 00.55 00.25
K (meq/100 g) 00.13 00.13 00.20
Ca (meq/100 g) 01.51 20.90 01.5
Mg (meq/100 g) 00.77 00.67 00.7
Al (meq/100 g) 00.25 00.25 00.91
Soil analyses
Edaphic Analyses For the granulometric
analysis, we took 1kg soil
sample. Once in the
laboratory the soil was
dried at room
temperature, and sieved
through a 2-mm sieve.
The fraction > 2 mm
constitute the gravel.
With the fraction < 2 mm
we did the following
analysis: one part was
used for the
granulometries, and we
separated the thick sand
(2-0.2 mm); the thin
sand, big lime (0.05-0.02)
and clay (<0.0002 mm).
The other part is used for
chemical analysis: pH,
total N2, Organic carbon,
Relation Carbon/Nitrogen
and Oxidable organic
matter. Same soil was
used to make analysis of
moisture, air content and
porosity.
SEASONAL HORTICULTURAL CROPS
CHARDS (Beta vulgaris) LETTUCE (Lactuca sativa)
BRUSSELS SPROUTS CAULIFLOWER
AREA FOR INFAUNAE SAMPLING
14 m2
2 m2
DIGGING for Earthworms, Lands Snails and Macroarthropods
20 cm deep
25 cm
SAMPLING MONTHLY
Surface: 0.0625 x 6 = 0.4 m2
Volumen: 0.0125 m3
SEASONS AND MONTHS
Spring: March, April and May
Summer: June, July and August
Autumn: September, October and November
Winter: December, January, February
Sieves Column
SEARCHING
Inside Soil Samples
for Lands Snails,
Earthworms and Arthropods
PUNCHING for
nematode, mite
and springtail soil
samples
TESTING COMPOUNDS
on NO TILLED arable soil for 5 years
MOLLUSCICIDES SPRAYED ON miniPLOTS before seasonal planting
• Phasmarhabditis nematode strains
• Metaldehyde pellets
• Cow slurry/Slug Eggs Killer
METALDEHYDE: 3 g/m2 of mini-pellets
(Caraquim, Massó Chemical Industries)
containing 5% Metaldehyde, broadcasted evenly
over the surface of the central area of the plots on
the same day of planting
Phasmarhabditis nematode strains:
3 x 105 nematodes m-2 (Nemaslug)
COW SLURRY: 2 litres m-2 of bovine-manure
(equivalent to 20 m3 / hectare)
TARGETS:
• Earthworms
• Slugs and Snails
• Arthropods
First Parcel
Data will be analysed using SPSSx for significance
Before starting experiments the soil fauna was assessed on every plot
and its spatial distribution was homogeneous
Periphery • Phasmarhabditis
Centre •Phasmarhabditis
•Metaldehyde
•Cow slurry + Phasmarhabditis
Before starting experiments the soil fauna was assessed on every plot
and its spatial distribution was homogeneous
MORFOLOGÍA EXTERNA DE LAS LOMBRICES
FIGURA 185. Anélidos oligoquetos. Morfología externa de Lumbricus
MORFOLOGÍA EXTERNA
1. Animales terrestres o marinos
2. Alargados con metamería Homónoma
3. No tienen podios, las sedas se insertan
directamente en el cuerpo
4. Tamaño: Chaetogaster mide 0,5 mm y
Megascolex (Megascolécido) mide 3 m
5. Cuerpo formado por anillos que se repiten,
dividido en 3 zona:
Protomio (no segmento)
Metastomio
Pigidio (no segemento)
6. Poros genitales ♀♀: lumbrícidos seg. 14
7. Poros geniales ♂♂: segmento 15 (posición varía
con las especies)
8. Poros de las espermatecas
9. Poros de los nefridios: un par por segmento
10. Poros dorsales
11. Clitelo: espesamiento glandular
Forma anular
Forma de herradura
Tubérculos pubertarios
Formación del capullo
12. Quetas por anillo (8)
DISPOSICIÓN Y ESTRUCTURA DE LAS QUETAS
Esophagus
Pharynx
Gizzard Crop Calciferous
glands
Intestine
Digestive system
1. CÓPULA: surcos o canales
exteriores
2. Clitelo con glándulas de la
albúmina producen capullo.
Fecundación dentro del
capullo: capullo + óvulo +
esperma = se cierra el
limoncillo, puede haber
hasta 20 huevos dentro del
capullo
3. El desarrollo es directo, no
hay metamorfosis, ni larvas
de vida libre, del capullo
sale una lombriz igual que
el adulto
CÓPULA
El capullo de lombriz
DISTRIBUCIÓN VERTICAL DE LAS LOMBRICES
Epigeas
Anécicas
Endogeas
Epigeas
Endogeas
Anécicas
SPECIES of EARTHWORMS FOUND
•Lumbricus terrestris
•Lumbricus castaneus
•Lumbricus rubelus
•Lumbricus friendi
•Allobophora oliveirae
•Allobophora caliginosa
•Allobophora parva
•Eisenia eiseni
•Eisenia veneta
•Eisenia foetida
•Dendrobaena octaedra
•Dendrobaena madeirensis
•Dendrobaena rubida
TYPE OF TERRESTRIAL ANNELID WORMS
•EPIGEIC: Top soil species
•ENDOGEIC: Inside soil species
•ANECIC: Vertical burrow soil species
LAND SNAIL SPECIES MONITORED •Deroceras reticulatum
•Arion intermedius
•Arion ater
•Ponentina ponentina
•Oxychillus sp.
*Number of Oligochaete worms
for 1.2 m2/ for Season
Phasmarhabditis vs Earthworms*
0
10
20
30
40
50
60
70
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 14 49 66 25 0 24
Nema Centre 11 45 37 5 1 40
Nema Periph 4 37 38 21 8 24
Nema Once 6 35 23 5 1 8
Nema+Cow 20 39 26 7 3 16
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
Periphery
Centre
• Six replicates for each crops/test
• Six controls plots
• Monthly sampling
SAMPLING MONTHLY
Surface: 0.0625 x 6 = 0.4 m2
Volumen: 0.0125 m3
SEASONS AND MONTHS
Spring: March, April and May
Summer: June, July and August
Autumn: September, October and November
Winter: December, January, February
*Lumbricus juveniles and adults for 1.2 m2
Phasmarhabditis vs *Lumbricus Earthworms
0
10
20
30
40
50
60
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 4 44 57 21 0 9
Nema Centre 4 39 21 3 0 32
Nema Periph 2 27 21 17 6 18
Nema Once 4 10 14 2 1 1
Nema+Cow 1 14 12 6 0 4
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
•Lumbricus terrestris
•Lumbricus castaneus
•Lumbricus rubelus
•Lumbricus friendi
• EPIGEIC: Top soil species
• ANECIC: Vertical burrow soil species
Phasmarhabditis vs Lumbricus friendi anecic worms
0
10
20
30
40
50
60
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 3 41 49 21 0 6
Nema Centre 2 5 5 2 0 0
Nema Periph 0 5 7 5 0 0
Nema Once 0 5 11 2 0 1
Nema+Cow 1 12 6 4 0 2
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
•EPIGEIC: Top soil species
•ENDOGEIC: Inside soil species
•ANECIC: Vertical burrow soil species
Data will be analysed using SPSSx for significance
Periphery
Centre
Phasmarhabditis vs Lumbricus rubellus epigeic worms
0
2
4
6
8
10
12
14
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 1 3 8 0 0 3
Nema Centre 0 3 6 0 0 2
Nema Periph 0 13 6 0 2 1
Nema Once 4 5 3 0 1 0
Nema+Cow 0 2 4 2 0 2
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2 •EPIGEIC: Top soil species
•ENDOGEIC: Inside soil species
•ANECIC: Vertical burrow soil species
Data will be analysed using SPSSx for significance
* Number of Oligochaete for 1.2 m2
Phasmarhabditis vs Lumbricus juveniles Earthworms
0
5
10
15
20
25
30
35
40
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 2 14 11 4 0 22
Nema Centre 4 34 9 1 0 29
Nema Periph 2 22 7 12 4 17
Nema Once 1 16 12 2 2 23
Nema+Cow 1 27 10 2 1 13
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
Data will be analysed using SPSSx for significance
* Slugs for 1.2 m2
Phasmarhabditis vs Deroceras reticulatum Slugs
0
20
40
60
80
100
120
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 31 25 65 89 31 7
Nema Centre 56 17 66 89 17 14
Nema Periph 36 21 55 75 26 27
Nema Once 38 26 98 92 31 27
Nema+Cow 40 25 84 90 19 12
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
Periphery
Centre
Data will be analysed using SPSSx for significance
Phasmarhabditis vs Arion intermedius Slugs
0
5
10
15
20
25
30
35
40
45
50
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 6 10 27 18 7 7
Nema Centre 8 6 35 24 6 10
Nema Periph 5 12 39 22 1 7
Nema Once 22 8 47 24 8 5
Nema+Cow 13 4 36 15 5 5
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* Slugs for 1.2 m2
Phasmarhabditis vs Arion ater Slugs
0
1
2
3
4
5
6
7
8
9
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 0 1 8 0 0 1
Nema Centre 0 5 5 2 0 0
Nema Periph 0 0 5 4 0 1
Nema Once 0 3 4 6 0 0
Nema+Cow 0 6 8 5 0 0
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Phasmarhabditis vs Oxychilus Snails
0
5
10
15
20
25
30
35
40
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 1 11 24 6 2 4
Nema Centre 1 17 34 11 1 3
Nema Periph 1 13 28 10 1 2
Nema Once 0 12 14 12 1 6
Nema+Cow 4 6 25 4 1 10
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
Phasmarhabditis vs Ponentina Snails
0
1
2
3
4
5
6
7
Control
Nema Centre
Nema Periph
Nema Once
Nema+Cow
Control 3 4 2 6 2 1
Nema Centre 2 0 2 1 1 1
Nema Periph 6 2 0 2 5 4
Nema Once 5 0 0 2 0 2
Nema+Cow 3 2 0 3 0 1
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
*Number of Oligochaete worms for 1.2 m2
Lumbricus, Allobophora, Eisenia, Dendrobaena Genera Periphery
Centre
Metaldehyde and Cow Slurry vs Earthworms
0
10
20
30
40
50
60
70
Control
Meta Centre
Nema+Cow
Control 14 49 66 25 0 24
Meta Centre 1 28 27 5 0 7
Nema+Cow 20 39 26 7 3 16
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
Collateral effect on bordering areas
•EPIGEIC: Top soil species
•ENDOGEIC: Inside soil species
•ANECIC: Vertical burrow soil species
Metaldehyde, Cow slurry vs *Lumbricus Earthworms
0
10
20
30
40
50
60
Control
Meta Centre
Nema+Cow
Control 4 44 57 21 0 9
Meta Centre 1 15 21 3 0 2
Nema+Cow 1 14 12 6 0 4
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
*Lumbricus juveniles and adults for 1.2 m2
Collateral effect on bordering areas
•EPIGEIC: Top soil species
•ENDOGEIC: Inside soil species
•ANECIC: Vertical burrow soil species
Metaldehyde, Cow slurry vs Lumbricus friendi anecic worms
0
10
20
30
40
50
60
Control
Meta Centre
Nema+Cow
Control 3 41 49 21 0 6
Meta Centre 1 4 5 2 0 2
Nema+Cow 1 12 6 4 0 2
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
•EPIGEIC: Top soil species
•ENDOGEIC: Inside soil species
•ANECIC: Vertical burrow soil species
Periphery
Centre
Metaldehyde, Cow slurry vs Lumbricus rubellus epigeic worms
0
2
4
6
8
10
12
14
16
18
Control
Meta Centre
Nema+Cow
Control 1 3 8 0 0 3
Meta Centre 0 11 16 1 0 1
Nema+Cow 0 2 4 2 0 2
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
Periphery
Centre
0
5
10
15
20
25
30
Control
Meta Centre
Nema+Cow
Control 2 14 11 4 0 22
Meta Centre 3 19 12 0 1 9
Nema+Cow 1 27 10 2 1 13
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
Metaldehide, Cow Slurry vs Lumbricus juveniles Earthworms
* for 1.2 m2
•EPIGEIC: Top soil species
•ENDOGEIC: Inside soil species
•ANECIC: Vertical burrow soil species
Metaldehyde, Cow Slurry vs Deroceras reticulatum slugs
0
10
20
30
40
50
60
70
80
90
100
Control
Meta Centre
Nema+Cow
Control 31 25 65 89 31 7
Meta Centre 55 16 72 73 17 8
Nema+Cow 40 25 84 90 19 12
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2 Periphery
Centre
Collateral effect on bordering areas
Metladehyde, Cow Slurry vs Arion intermedius Slugs
0
10
20
30
40
50
60
Control
Meta Centre
Nema+Cow
Control 6 10 27 18 7 7
Meta Centre 14 9 54 44 6 4
Nema+Cow 13 4 36 15 5 5
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
Metaldehyde, Cow Slurry vs Arion ater Slugs
0
1
2
3
4
5
6
7
8
9
Control
Meta Centre
Nema+Cow
Control 0 1 8 0 0 1
Meta Centre 0 0 2 1 0 1
Nema+Cow 0 6 8 5 0 0
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
Metaldehyde, Cow Slurry vs Oxychilus Snails
0
5
10
15
20
25
30
35
Control
Meta Centre
Nema+Cow
Control 1 11 24 6 2 4
Meta Centre 2 11 30 5 0 14
Nema+Cow 4 6 25 4 1 10
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
Metaldehyde, Cow Slurry vs Ponentina Snails
0
1
2
3
4
5
6
7
8
9
10
Control
Meta Centre
Nema+Cow
Control 3 4 2 6 2 1
Meta Centre 9 0 1 8 0 1
Nema+Cow 3 2 0 3 0 1
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
Phasmarhabditis, Cow Slurry, Metaldehyde vs Coleoptera
0
10
20
30
40
50
60
70
80
Control 43 16 29 27 22 19
Nema Centre 45 28 21 25 9 5
Nema Periph 69 24 26 18 20 3
Nema+Cow 30 35 21 30 11 6
Nema Once 62 25 30 20 19 13
Metaldehide 37 15 21 16 14 15
Summer 99 Autumn 99 Winter 99 Spring 00 Summer 00 Autumn 00
Periphery
Centre
Collateral effect on bordering areas
TESTING COMPOUNDS ON ARABLE Soil, 50 cm depth ploughed yearly before trials
MOLLUSCICIDES SPRAYED ON miniPLOTS • Phasmarhabditis nematode strains
• Metaldehyde pellets
• Herbicide Centrol H, Ioxynil active principle/Slug Eggs Killer
METALDEHYDE: 3 g/m2 of mini-pellets (Caraquim,
Massó Chemical Industries) containing 5%
Metaldehyde, broadcasted evenly over the surface of
the central area of the plots on the same day of
planting
Phasmarhabditis nematode strains:
3 x 105 nematodes m-2 (Nemaslug)
HERBICIDE: Comercial name Certrol H
Composition Ioxynil 12% ; MECOPROP 36% .
Manufacture Comercial Quimica MASSO S.A
Activity Herbicide
Second Parcel
Data will be analysed using SPSSx for significance
Before starting experiments the soil fauna was assessed on every plot
and its spatial distribution was homogeneous
Periphery (Nothing)
Centre
Phasmarhabditis
Metaldehyde
Ioxynil (Herbicide)
Phasmarhabditis + Ioxynil
Phasmarhabditis + Metaldehyde
14 m2
2 m2
Collateral effect on bordering areas
* Earthworms for 1.2 m2
Phasmarhabditis vs Oligochaete Worms*
0
1
2
3
4
5
6
7
8
Control
Nematode
Nema+Ioxy
Nema+Meta
Control 4 3 1 7
Nematode 3 2 1 3
Nema+Ioxy 0 1 3 6
Nema+Meta 1 0 3 5
Winter 99 Spring 00 Summer 00 Autumn 00
Periphery
Centre
Collateral effect on bordering areas
EARTHWORMS
• Allobophora oliveirae (Epig.)
• Allobophora caliginosa (Endog.)
• Dendrobaena octaedra (Epig.)
Phasmarhabditis vs Deroceras reticulatum Slugs
0
2
4
6
8
10
12
Control
Nematode
Nema+Ioxy
Nema+Meta
Control 0 1 1 8
Nematode 0 2 1 11
Nema+Ioxy 0 4 1 4
Nema+Meta 0 1 3 4
Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
LAND SNAIL
• Deroceras reticulatum
• Arion intermedius
• Arion ater
• Cepaea nemoralis
Phasmarhabditis vs Coleoptera Arthropods*
0
5
10
15
20
25
30
35 Control
Nematode
Nema+Ioxy
Nema+Meta
Control 1 11 30 9
Nematode 3 23 32 15
Nema+Ioxy 2 26 26 19
Nema+Meta 1 18 22 17
Winter 99 Spring 00 Summer 00 Autumn 00
O.COLEOPTERA
G. Harpalus
G. Anisodactylus
G. Amara
G. Acupalpus
G. Poecilus
G. Calathus
G. Claenius
G. Xantolinus
*Number of Coleoptora for 1.2 m2
Collateral effect on bordering areas
Metaldehyde, Ioxynil vs Oligochaete Worms
0
1
2
3
4
5
6
7
8
Control
Metaldehide
Ioxynil
Nema+Ioxy
Nema+Meta
Control 4 3 1 7
Metaldehide 2 2 5 5
Ioxynil 2 2 3 7
Nema+Ioxy 0 1 3 6
Nema+Meta 1 0 3 5
Winter 99 Spring 00 Summer 00 Autumn 00
Periphery
Centre
Collateral effect on bordering areas
* Earthworms for 1.2 m2
EARTHWORMS
Allobophora oliveirae (Epig.)
• Allobophora caliginosa (Endog.)
• Dendrobaena octaedra (Epig.)
Metaldehyde, Ioxynil vs Deroceras reticulatum Slugs
0
1
2
3
4
5
6
7
8
9
Control
Metaldehide
Ioxynil
Nema+Ioxy
Nema+Meta
Control 0 1 1 8
Metaldehide 0 0 0 5
Ioxynil 0 1 0 5
Nema+Ioxy 0 4 1 4
Nema+Meta 0 1 3 4
Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
Metaldehyde, Ioxynil vs Coloptera Arthropods
0
10
20
30
40
50 Control
Metaldehide
Ioxynil
Nema+Ioxy
Nema+Meta
Control 1 11 30 9
Metaldehide 4 22 19 7
Ioxynil 4 25 46 10
Nema+Ioxy 2 26 26 19
Nema+Meta 1 18 22 17
Winter 99 Spring 00 Summer 00 Autumn 00
* for 1.2 m2
Collateral effect on bordering areas
Impact on Crops
Soil Infaunae
Impact on Adjacent Areas
Soil Infaunae
Oligo. Slugs Snails Arthr. Oligo. Slugs Snails Arthr.
Phasmarhabditis Yes No No No Yes No No No
Phasmarh. Once Yes –— –— No Yes No No No
Cow Slurry Yes –— –— No Yes No No No
Herbicide: Ioxynil –— –— –— –— –— –— –— –—
Metaldehyde Yes –— –— No Yes No No No
–— In Process
PRELIMINARY CONCLUSIONS. During this trial was observed:
•1.- Phasmarhabditis hermaphrodita strains scattered on arable soils at 3 x 105 strain-nematodes
for m2 reduce the population of earthworms. The effect is more significant on anecic Oligochaetes
than on epiegeic species.
•2.- Phasmarhabditis hermaphrodita strains used a molluscicide dose on horticultural crops have
collateral effect on bordering areas earthworm populations.
•3.- The effect of Phasmarhabditis nematode strains on earthworms could persist for more than two
years on arable soils and bordering areas.
•4.- Phasmarhabditis strains haven't any effect on Slug, Snail, Coleoptera and Crane fly populations,
neither in direct application zones nor in bordering areas.
•5.- Metaldehyde mini-pellets, used as molluscicide (3 g/m2) has similar effects on anecic
earthworms than Phasmarhabditis strains in direct application areas and adjacent zones.
•6.- Metaldehyde applied on arable soils in molluscicide doses haven't any collateral effects on
adjacent areas slug, snail and Coleoptera populations.
•7.- Cow slurry applied on arable soil as nitrogen fertilizer (20 m3 / hectare) have collateral effects on
adjacent areas anecic earthworm populations, and no effect on others animals popultions monitored.
•8.- On Ioxynil (Herbicide) effects upon slug eggs we haven't enough field trials, we are working on.
Tested on standard artificial soil work destroying slug eggs.
•9.- The molluscicides compounds tested on 50 cm-depth-ploughed-parcel were deterred by the
ploughing disturbance effect on infauna structure populations caused by farming. Perhaps, one year
period could be necessary for reorganise infauna ecosystem parcels after deep ploughing farm works.