Lymantria dispar L. and Malacosoma neustrium (L.) are the most serious defoliators of cork oak in the Mediterranean region. For this reason, information on their feeding behaviour are important in pest management. A non-destructive approach by using photoacoustic spectroscopy (PAS) combined with a partial least squares regression analyses (PLS), has been used to provide a rapid and cost-effective analysis to assess foliage chemistry and to estimate some nutritional indices of these insects

Bonetti, Alessandra

Cossu, C. S.

D'Acqui, Luigi Paolo

Mannu, Roberto

Verdinelli, Marcello

Lymantria dispar L. and Malacosoma neustrium (L.) are the most serious defoliators of cork oak in the Mediterranean region. For this reason, information on their feeding behaviour are important in pest management. A non-destructive approach by using photoacoustic spectroscopy (PAS) combined with a partial least squares regression analyses (PLS), has been used to provide a rapid and cost-effective analysis to assess foliage chemistry and to estimate some nutritional indices of these insects. For testing the performance of larvae, cork oak leaves for chemical, spectroscopic analysis and bioassays were collected during the cork oak vegetational season. Leaves were analysed for their water content, polyphenols, tannins, condensed tannins, amid, nitrogen and carbon according to standard chemical protocols. Waldbauer\u27s method was applied to determine the following indices: Relative Growth Rate (RGR), Relative Consumption Rate (RCR), Efficiency of Conversion of Ingested food (ECI), Approximate Digestibility (AD), Efficiency of Conversion of Digested food (ECD). Chemometrics of PAS/PLS regression analysis produced adequate prediction algorithms for the studied chemico-physical and nutritional parameters. Multivariate analysis of data showed good relationships between the consumption and utilization of food by insects and nitrogen, condensed tannins, polyphenols, water content in foliage. Moreover, the relative based PAS/PLS models enabled the prediction of some chemico-physical constituents of foliage as nitrogen (R2=0.85), condensed tannins (R2=0.72), polyphenols (R2=0.84), water (R2=0.82) and ECD and ECI indices both for Lymantria (R2=0.82; R2=0.61, respectively) and Malacosoma (R2=0.71; R2=0.66, respectively). The proposed approach showed to be very useful for investigating the insects feeding behaviour and for obtaining leaf chemico-physical data and nutritional indices acquiring only the PAS spectra that can be collected quickly and at low cost

D\u27Acqui, Luigi Paolo

Cossu, Carlo Simone

PUblication MAnagement

Photoacoustic spectroscopy for estimating nutritional indices in lepidopteran defoliators

UnissResearch

  
 
Department of Science 
for Nature and 
Environmental 
Resources of the 
University of Sassari 
Forestry and Wood 
Research Centre of the 
Italian Council for 
Agricultural Research and 
Economics 
Institute of Ecosystem Study of the 
National Research Council, 
organization unit of Sassari 
 
 
INTERNATIONAL CONGRESS 
ON CORK OAK TREES 
AND WOODLANDS 
Conservation, Management, Products  
and Challenges for the Future 
 
 
 
 
 
3° National Congress of Cork 
 
Sassari, May 25 – 26 2017 
INTERNATIONAL CONGRESS ON CORK OAK TREES AND WOODLANDS 
Conservation, Management, Products and Challenges for the Future 
 
SPONSORSHIP 
 
 
 
Comune di Sassari 
 
 
 
 
 
European Forest Institute  Accademia Italiana Scienze 
Forestali  
Società Italiana di Selvicoltura 
ed Ecologia Forestale Società di Ortoflorofrutticoltura 
Italiana 
 
  
INTERNATIONAL CONGRESS ON CORK OAK TREES AND WOODLANDS 
Conservation, Management, Products and Challenges for the Future 
 
 
ISBN  978-88-907678-0-7 
DOI  https://doi.org/10.14275/978-88-907678-0-7 
 
 
 
 
Tipiditappi 
Sughero d’albero fatto a pezzetti, 
tipi di tappi , quelli che vuoi. 
Tagliali lunghi, tagliali stretti, 
tipi di tappi, fatti da noi. 
Taglialo bene, taglialo tondo, 
tipi di tappi, quanti ne vuoi. 
Tappi di sughero per tutto il mondo, 
tipi di tappi fatti da noi. 
(Cecchi-Tognolini, Filastrocche e Canzoni) 
 
 
 
Dettori S., Fligheddu M.R., Cillara M. Editors 
 
 
 
 
 
 
Printed by 
Università degli Studi di Sassari 
Centro Stampa 
 
 
 
INTERNATIONAL CONGRESS ON CORK OAK TREES AND WOODLANDS: 
Conservation, Management, Products and Challenges for the Future 
Session 1: Ecology, ecophysiology, health and genetic resources 35 
 
ORAL PRESENTATION 
 
Session 1: Ecology, ecophysiology, health and genetic 
resources 
 
 
 
 
  
INTERNATIONAL CONGRESS ON CORK OAK TREES AND WOODLANDS 
Conservation, Management, Products and Challenges for the Future 
48 Session 1: Ecology, ecophysiology, health and genetic resources 
 
PHOTOACOUSTIC SPECTROSCOPY FOR ESTIMATING 
NUTRITIONAL INDICES IN LEPIDOPTERAN DEFOLIATORS 
D’Acqui L.P.1, Verdinelli M.2*, Cossu C.S.2, Mannu R.2, Bonetti A.1 
1 Consiglio Nazionale delle Ricerche, Istituto per lo Studio degli Ecosistemi, Sede di 
Firenze, via Madonna del Piano 10, 50019 Sesto Fiorentino, 
2 Consiglio Nazionale delle Ricerche, Istituto per lo Studio degli Ecosistemi, Sede di 
Sassari, Traversa La Crucca 3, 07100 Sassari 
*Corresponding Author: m.verdinelli@ise.cnr.it 
Lymantria dispar L. and Malacosoma neustrium (L.) are the most serious 
defoliators of cork oak in the Mediterranean region. For this reason, information 
on their feeding behaviour are important in pest management. A non-destructive 
approach by using photoacoustic spectroscopy (PAS) combined with a partial 
least squares regression analyses (PLS), has been used to provide a rapid and 
cost-effective analysis to assess foliage chemistry and to estimate some 
nutritional indices of these insects. For testing the performance of larvae, cork 
oak leaves for chemical, spectroscopic analysis and bioassays were collected 
during the cork oak vegetational season. Leaves were analysed for their water 
content, polyphenols, tannins, condensed tannins, amid, nitrogen and carbon 
according to standard chemical protocols. Waldbauer’s method was applied to 
determine the following indices: Relative Growth Rate (RGR), Relative 
Consumption Rate (RCR), Efficiency of Conversion of Ingested food (ECI), 
Approximate Digestibility (AD), Efficiency of Conversion of Digested food 
(ECD).  
Chemometrics of PAS/PLS regression analysis produced adequate prediction 
algorithms for the studied chemico-physical and nutritional parameters. 
Multivariate analysis of data showed good relationships between the 
consumption and utilization of food by insects and nitrogen, condensed tannins, 
polyphenols, water content in foliage. Moreover, the relative based PAS/PLS 
models enabled the prediction of some chemico-physical constituents of foliage 
as nitrogen (R2=0.85), condensed tannins (R2=0.72), polyphenols (R2=0.84), 
water (R2=0.82) and ECD and ECI indices both for Lymantria (R2=0.82; 
R2=0.61, respectively) and Malacosoma (R2=0.71; R2=0.66, respectively). The 
proposed approach showed to be very useful for investigating the insects 
feeding behaviour and for obtaining leaf chemico-physical data and nutritional 
indices acquiring only the PAS spectra that can be collected quickly and at low 
cost. 
Keywords: cork oak defoliators, nutritional indices, foliage chemistry, 
photoacoustic spectroscopy, Chemometrics  


Photoacoustic spectroscopy for estimating nutritional indices in Lepidopteran defoliators

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