INTRODUCTION The common green lacewing Chrysoperla carnea s.l. is an important predator in the biological control of pest aphids, scales, caterpillars and other pests of many crops (McEwen et al., 2001). A synthetic attractant for green lacewings might be useful for monitoring lacewing abundance or manipulating lace- wing population densities. The attractants for green lacewings were reviewed by Szent- királyi (2001). The relatively few compounds that are attractants include methyl eugenol (Suda & Cunningham, 1970; Umeya & Hirao, 1975), methyl salicylate (Molleman et al., 1997; James, 2003), caryophyllene (Flint et al., 1979), 2-phenylethanol (Zhu et al., 1999) and some that are chemically undefined (McEwen et al., 1994; Harrison & McEwen, 1998). In addition in a labora- tory olfactometer bioassay, tethered female green lacewings spent ca 70% of the total time flying towards reaction mixtures thought to produce indole acetaldehyde (van Emden & Hagen, 1976). This led van Emden & Hagen (1976) to suggest that indole acetaldehyde is an attractant, however, they never tested the synthetized pure compound in the laboratory or the field. In the course of field trapping in Hungary aimed at capturing female noctuids, common green lacewings (species of Chrysop- erla carnea-complex, Neuroptera: Chrysopidae) were regularly caught by traps baited with phenylacetaldehyde (Tóth et al., unpubl.). This compound is a well known attractant for several Lepidoptera (e.g. Creighton et al., 1973; Cantelo & Jacobson, 1979). The present research was undertaken to confirm this and to study the attractiveness of this compound to green lacewings. In the course of the experiments, the effectiveness of phenylacetaldehyde-baited traps (two dose levels) in capturing Chrysoperla spp. was compared with that of unbaited traps at several sites and in several habitats. This attractant, in combina- tion with other attractants, or alone, may assist in the better management of green lacewings in Integrated Pest Management (IPM) strategies used in sustainable agriculture. MATERIAL AND METHODS Trapping Tests were conducted routinely using the methods used in similar studies on pheromones and attractants (e.g. Arn et al., 1986; Roelofs & Cardé, 1977). This was done at five sites in Hungary and Italy. Traps were suspended at a height of ca 1.5–1.7 m. Green lacewings are frequently seen flying at these heights in the crown of trees. One replicate of each treatment was incorporated into a block so that individual treatments were 5–8 m apart (according to the distance between trees at the respective sites) and blocks were situated 15–20 m apart. Details of each experiment: Halásztelek, Pest county, Hungary: the test was run in a cherry orchard from May 9 – June 10, 2003, with 6 replicated blocks. Traps were inspected twice weekly. Lak, Borsod-Abaúj-Zemplén county, Hungary: the test was run in an apricot orchard from May 8 – September 19, 2003, with 5 replicated blocks. Traps were inspected twice weekly. Ciampino (RM), Italy: the test was run in a peach orchard from May 14 – July 1, 2003, with 5 replicated blocks. Traps were inspected weekly. Udine – S. Osvaldo (UD), Italy: two tests were run parallel, in an apple orchard and in a maize field, respectively, from May 22 – August 18, 2003, with 4 replicated blocks each. Traps were inspected weekly. NOTE Eur. J. Entomol. 103: 267–271, 2006 ISSN 1210-5759 Phenylacetaldehyde: A chemical attractant for common green lacewings (Chrysoperla carnea s.l., Neuroptera: Chrysopidae) MIKLÓS TÓTH 1 , ANDRÁS BOZSIK 2 , FERENC SZENTKIRÁLYI 1 , AGOSTINO LETARDI 3 , MARIA ROSARIA TABILIO 4 , MARCELLO VERDINELLI 5 , PIETRO ZANDIGIACOMO 6 , JUDIT JEKISA 1 and ISTVÁN SZARUKÁN 2 1 Plant Protection Institute, HAS, Budapest, Hungary; e-mails: h2371tot@ella.hu, h2404sze@ella.hu 2 University of Debrecen, Faculty of Agricultural Sciences, Department of Plant Protection, Debrecen, Hungary; e-mails: bozsik@helios.date.hu, asbolt@helios.date.hu 3 ENEA – C.R. Casaccia, Biotec-SIC, S. Maria di Galeria, Roma, Italy; e-mail: aletardi@casaccia.enea.it 4 Istituto Sperimentale per la Frutticoltura di Roma, Ciampino Aeroporto (RM), Italy; e-mail: tab55@mclink.it 5 Dipartimento di Protezione delle Piante, Sezione di Entomologia agraria Università degli Studi & Sez. Ecologia applicata e Controllo biologico I.S.E. [ex I.R.Co.B.A.] C.N.R, Sassari, Italy 6 Dipartimento Biologia applicata alla Difesa delle Piante Università degli Studi di Udine, Italy Keywords. Neuroptera, Chrysopidae, Chrysoperla, green lacewings, attractant, phenylacetaldehyde Abstract. At five sites in Hungary and Italy, traps baited with phenylacetaldehyde caught significantly higher numbers (10 to 100 times more) of green lacewings than unbaited traps, which demonstrates that this compound is an attractant. Traps with three bait dispensers usually caught more than those with one dispenser, but the difference was significant only at two out of five test sites. There was no difference in the numbers caught by sticky delta and funnel traps baited with phenylacetaldehyde. However, funnel traps could be adapted to catch living green lacewings. The vast majority of the specimens belonged to the Chrysoperla carnea spe- cies complex. Ch. carnea sensu lato dominated the catches at all sites. At some sites 3–11% of the insects caught were Ch. lucasina Lacroix. Phenylacetaldehyde-baited traps were attractive to both sexes, but generally more females were caught than males. Funnel traps baited with three dispensers of phenylacetaldehyde caught green lacewing adults throughout the season in Hungary. 267