INSECT PESTS IN TUSCAN VINEYARDS UNDER CLIMATE CHANGES Patrizia Sacchetti1, Bruno Bagnoli2, Marzia Cistiana Rosi1, Antonio Belcari1
1 Department of Agriculture, Food, Environment and Forestry, Florence University 2 Department for Innovation in Biological Agro-Food and Forest Systems (DIBAF), Tuscia University
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement nº 810176. This document reflects only the author’s view and the Commission is not responsible for any use that may be made of the information it contains. 1 Contents
Part 1 – Overview of abiotic factors influence on insects
Part 2 – Main insect pests in Tuscan vineyards
Part 3 – Case study: the grape phylloxera
2 2 Overview of abiotic factors influence on insects
Main abiotic factors are:
Temperature Relative Humidity Rain Wind Soil
3 3 Part 1 – Overview of abiotic factors influence on insects
Effect of temperature on insects
Insects are poikilothermic animals
«Insect growth is faster as the temperature increases, up to the minimum, after which development slows for lethal temperature»
10 20 30 40 (From Wilson and Barnett, 1983) °C
4 4 Part 1 – Overview of abiotic factors influence on insects
Temperature-dependent growth is useful for modelling...
Thc = Thermal constant (thermal summation, °D) c = lower thermal threshold (developmental zero)
(T max + T min) °D = - c 2
5 5 Part 1 – Overview of abiotic factors influence on insects
Example: the olive fly, Bactrocera oleae
Thc = 379.015 °D
c = 8.99 °C
6 6 Part 1 – Overview of abiotic factors influence on insects
Maps of «dacic» risk 1956-1986
7 7 Part 1 – Overview of abiotic factors influence on insects
Maps of «dacic» risk 1970-2000
8 8 Part 1 – Overview of abiotic factors influence on insects
Maps of «dacic» risk 2010-2017
9 9 Part 1 – Overview of abiotic factors influence on insects
Grape moth in Spain
Changes in spring adult emergence and number of generations per year
(From Gutierrez et al., 2018)
1010 Part 2 – Main insect pests in Tuscan vineyards
2012 2016
150 insect pests of vineyards …in Italy about 50 insect pests, listed in the world…. although only a few species have economic importance 1111 Part 2 – Main insect pests in Tuscan vineyards
Leafhoppers (Hemiptera Cicadellidae)
Subfamily: Typhlocybinae:
1) Zygina rhamni Ferrari 2) Empoasca vitis (Göthe) 3) Jacobiasca lybica (Bg. & Zanon) 2 Subfamily : Deltocephalinae 4) Scaphoideus titanus Ball
1
4 3 1212 Part 2 – Main insect pests in Tuscan vineyards
Jacobiasca lybica
African leafhopper density increased in Sicily, causing severe damage to Nero d’Avola variety (that is more susceptible). Due to climate warming, probable spread to Northern areas.
1313 Part 2 – Main insect pests in Tuscan vineyards
Mealybugs (Hemiptera Pseudococcidae)
Planococcus ficus (Signoret)
Multivoltine, non-diapausing, highly prolific species: it develops more generations in warmer climate, not hindered by cold periods (in winter below-ground populations survive). Pseudococcus comstocki From Marchesini et al., 2018 1414 Part 2 – Main insect pests in Tuscan vineyards
Mealybugs (Hemiptera Pseudococcidae)
Species with temperature-dependent growth: they take advantage of local/global warming. Anyway population dynamic depends also on natural enemies: unknown effects of climate change on predators and parasitoids
1515 Part 2 – Main insect pests in Tuscan vineyards
Main carpophagous moths feeding on grape in Tuscany
Tortricidae Lobesia botrana (Denis & Schiffermüller) Eupoecilia ambiguella (Hübner) Argyrotaenia ljungiana (Thunberg)
Pyralidae Phycitinae Cryptoblabes gnidiella (Millière) Ephestia unicolorella woodiella Richards & Thomson
16 16 Part 2 – Main insect pests in Tuscan vineyards
Lobesia botrana European grapevine moth
Eupoecilia ambiguella Vine moth
Argyrotaenia ljungiana
17 17 Part 2 – Main insect pests in Tuscan vineyards
Cryptoblabes gnidiella Honeydew moth
Ephestia unicolorella woodiella
18 18 Part 2 – Main insect pests in Tuscan vineyards
Effects of climate change on the ratio and distribution of the two main moths
Temperature (°C) and R.H. (%) requirements for Lobesia botrana and Eupoecilia ambiguella adults (from Stellwaag, 1939)
Climatic parameters Lobesia botrana Eupoecilia ambiguella
Adult activity lower threshold from 13°C (90%) from 14° (90%) to 20° C (35%) to 25° (45%) Optimal temperature and RH range from 21°C (60%) from 19°C (100%) for adult activity and egg laying to 25°C (40-70%) to 25°C (75-100%)
Due to climate changes the vine moth nearly disappeared in South and Central Italy; in North Italy it was reduced and replaced by the European
grape moth 19 19 Part 2 – Main insect pests in Tuscan vineyards
Lobesia botrana spread in future scenarios
1980-2010 2041-2050
Applying simulation models (temperature, day-length and fruit stage), due to the expected climate warming, in Europe a wider distribution of the European grapevine moth, L. botrana, was predicted, with highest populations in warmer regions in a wide band along latitude 40°N. 20 (From Gutierrez et al., 2018) 20 Part 2 – Main insect pests in Tuscan vineyards
Lobesia botrana spread in future scenarios
In North Italy, Trento area, a dramatic increase in the number of generations was predicted using a phenological model with negative impact on crop yield, probably mitigated by the anticipated harvest. (From Caffarra et al., 2012)
21 21 Part 2 – Main insect pests in Tuscan vineyards
Lobesia botrana: climate warming is not always favourable… EGVM embryos and neoformed larvae collapsed within the egg chorion, due to the high temperatures of August 2017
22 22 Part 2 – Main insect pests in Tuscan vineyards
Climate affects also natural enemies… European grapevine moth has a very rich natural enemies complex: several predators and more than 100 parasitoids, mainly polyphagous
It is very difficult to evaluate climate direct effects and interactions Campoplex capitator Aubert among all the biotic and (Ichneumonidae Campopleginae) abiotic factors. Future Monophagous parasitoid on L. botrana scenario projections might be different. 23 23 Part 2 – Main insect pests in Tuscan vineyards
Cryptoblabes gnidiella case
In several Italian coastal areas, a more significant infestation and damage by the honeydew moth was observed. Possible main reasons: effects of global warming and wider mating disruption application for the control of L. botrana. The spread of some varieties such as Sangiovese, Montepulciano d’Abruzzo and Aglianico, with late ripening, may have contributed to increase the harmfulness of the species. 24 24 Part 3 – Case study: the grape phylloxera
Leaf galling infestation on Sangiovese
Holocycle on American grapevines 2525 Part 3 – Case study: the grape phylloxera
Changes on grape phylloxera life cycle on European grapevine
More than one century after its introduction, much knowledge is still lacking:
Distribution (soil population distribution) Relationship between soil and leaf populations Possible damage to grape production by leaf populations Genetic variability Beginners of spring infestation Possible role of sexuparae Practical aftermaths
26 26 Part 3 – Case study: the grape phylloxera
Genetic studies
In USA: biotype A and B (Granett, 1987) In Europe: many biotypes evidenced by Forneck and colleagues In Australia: a huge number of biotypes
Different groups of grape phylloxera biotypes by screening 103 European populations and 6 American ones
Great genetic variation From Forneck et al., 2000 27 27 Part 3 – Case study: the grape phylloxera
Is grape phylloxera threatening grapevine health in Europe?
According to current regulations (nurseries), there is no risk to spread the species
28 28 Part 3 – Case study: the grape phylloxera
Grape phylloxera has a temperature-dependent growth c = 8.7 °C Thc = 281.5 °D
From Raspi et al., 1987 Thermal parameters can be used for growth simulation models 2929 Part 3 – Case study: the grape phylloxera
Investigations on soil populations
Sampled 3 cultivars in different vineyards
3 1,4
2,5 1,2
1 2
0,8 1,5
0,6
1 nodosità / cm di nodosità radici nodosità / cm di nodosità radici 0,4
0,5 0,2
0 0 La Spinetta Fichino Palaia Campigiana Piano Bellavista Podere Forte Podere Forte 2 3 4 vitigno Vermentino Sangiovese Sangiovese Sangiovese Sangiovese Sangiovese Greco di Tufo Sangiovese 420A Kober 5BB 779 Paulsen portainnesto 1103 Paulsen 420 A 779 Paulsen Kober 5BB 420 A 420 A 161-49 161-49
resistenza 4 2 4 3 2 2 3 3
All the roostocks were infested by grape phylloxera, without evident differences or damage symptoms 30 30 Part 3 – Case study: the grape phylloxera
Assessment of leaf galling infestation
Farm 1
Farm 2
South North center end end
West end
3131 Part 3 – Case study: the grape phylloxera
Assessment of leaf galling infestation
Leaf galling infestation level in the three zones of the two farms
Farm 1 Farm 2
In the farm 1 the infestation started from a corner and spread through the vineyard, while in the farm 2 the infestation level was high throughout the whole vineyard In August 2017, high temperatures killed most of the leaf galling populations
32 32 Part 3 – Case study: the grape phylloxera
Damage assessment: gas exchange evaluation
Ciras-3
In collaboration with Mattii, G., Cataldo E., Salvi L.
3333 Part 3 – Case study: the grape phylloxera
Damage assessment: Net Photosynthesis
Highly infested grapevines show reduced photosynthesis
3434 Part 3 – Case study: the grape phylloxera
Damage assessment: Grape quality
Sugar content decreases as the level of the Sugar content leaf galling infestation increases
Anthocyanins Highly infested grapevines show reduced content anthocyanins content Total polyphenols Highly infested grapevines show reduced total polyphenols content (similar results for content extractable polyphenols)
Technological and phenolic analyses of grapes highlighted a reduction of the grape quality due to phylloxera infestation: grapes from heavy infested vines showed reduced sugar and polyphenol contents with significant differences between extreme levels 3535 Part 3 – Case study: the grape phylloxera
Grape phylloxera leaf galling infestation: distribution based on regional monitoring network
2016 2017
grape phylloxera grape phylloxera rare spread rare other vineyards spread other vineyards
3636 Part 3 – Case study: the grape phylloxera
Possible cause of 2017 decrease of leaf galling infestation
8.7 °C grape phylloxera
lower thermal threshold
C
° Temperature Temperature
Castiglione d' Orcia (Siena) 3737 Effects of climate change on insects pests: A complex and difficult assessment
Climate change (microclimate)
Insect pests
38 38 Conclusions Insect pests of vineyards are affected by climate changes, however climate influences the whole vineyard system as well as the natural enemies complex, with unpredictable effects Moreover, frequent rains, due to climate changes, reduce pesticide persistence (pesticide wash off) Mild winters followed by rainy and warm summers (2007, 2014 and 2016) favoured economically important species such as olive fruit fly, D. suzukii and European grapevine moth On the contrary, hot and dry summers (2017) significantly reduced population density of vineyard insect pests, despite high theorical number of generations Grape phylloxera is no exception and can represent a valuable model to study the effects of climate changes 39 39 Thanks!
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