P. TREMATERRA, Some aspects of the sexual behaviour of the Lepidoptera Pyralidae infesting stored-products 87 Anz. Sch~idlingskde.,Pflanzenschutz, Umweltschutz 70, 87-91 (1997) 9 1997, Blackwell Wissenschafts-Verlag,Berlin ISSN 0340-7330 Dipartimento di Scienze Animali, Vegetali e dell'Ambiente, University of Molise, Campobasso, Italy Some aspects of the sexual behaviour of the Lepidoptera Pyralidae infesting stored-products ~ By P. TREMATERRA Abstract Research on moth sexual behaviour has focused primarily on female pheromones and male behavioural responses to them. Although several researches on moth sex pheromones have demonstrated that the complete sequence of courtship behaviour also involves male pheromones and other types of communication, relatively little work has been done on the connection between pheromones and extrusible organs or with sound production. Many insects have airborne sound re- ceptors, which function primarily in intraspecific communi- cation, whilst in others hearing serves to warn a potential threat from a predator. Certain pyralid moths infesting stored food, such as the Galleriinae Achroia grisella F., Gatteria meUonella L., and Cor- cyra cephalonica (Staint.), and the Phycitinae Ephestia cautella (Walker), Ephestia kuehniella Zeller and Plodia interpunctella (Hiibner) have acquired the additional ability to generate sounds by wing-fanning for intraspecific communication and pair forming. The courtship of these Lepidoptera Pyralidae has been examined and several studies have been made on the male orientation to the pheromone produced by the calling female and also on the behaviour of the male after the female has been located. The paper gives details on the role of ultrasound production in the courtship behaviour and discusses the role of other signals in pair forming. stia elutella (Hb.) and Plodia interpunctella (Hb.) was re- ported by MULLENand TSAO (1971), whilst the hearing ability of Ephestia kuehniella Z. Was reported by P~trz and ZHA~rrIEV (!976). Ultrasonic emission in the mating behaviour of E. cautella, E. kuehniella and P. inter- punctella has been recently reported by TREMATErtRA and PAVAN(1994, 1995). The courtship of these phyticine moths has received at- tention in the literature: several studies have been made on the male orientation to the pheromone produced by the calling female (TRAYNIE~t, 1968; KENNEDY and MARSH, 1984), whereas other reports have dealt more with beha- viour after the male has located the female (BARRER and HILL, 1977 a-b, 1980). Research on moth courtship behaviour has focused pri- marily on female pheromones and male behavioural re- sponses to them. Although several studies on moth sex pheromones have demonstrated that the complete se- quence of courtship behavi0ur also involves male phero- mones and other types of communication, relatively little work has been done on the connection between phero- mones and extrusible organs or with sound productio n (BIRCHand HEFETZ, 1987; SPANGLER,1988; EWING, 1989; QUARTEY and COAKER, 1993; MANKIN and HAOS'rRuM, 1995; LEVINSON and LEVINSON, 1995; TREMATERRA, 1995). 1 Introduction Many insects have sound receptors: in Orthoptera, He- miptera, Lepidoptera and Diptera these receivers function primarily in intraspeeific communication (SPANGL~R and HIVVENMWCER, 1988), while in others Neu- roptera, Lepidoptera and Coleoptera hearing serves to warn of a potential threat from a predator (Rov.DERand TREAT, 1961~ SPANGLER, 1988). Certain pyralid moths, such as the galleriine wax moths Achroia grisella F. and Galleria mellonella L. and the rice moth Corcyra cephalonica (Staint.), have acquired the ad- ditional ability to generate sounds by wing fanning for intraspecific communication and pair forming (SvANGLER et al., 1984; SPANGLER, 1985, 1987; TREMATERRA, 1992). In these species the male's sound producing organ is located in front of the tegulae, rounded plates that cover the fo- rewing insertions. "The tymbals" are finely corrugated in A. grisella and G. mellonella, or bear a series of striations, as in C. cephalonica. The hearing ability of other pyralid moths infesting stored products such as Ephestia cauteUa (Walk.), Ephe- 1 Paper presented to XX International Congress of Ento- mology, section Urban and Stored Products Entomology. 2 Pyralid moths ear and hearing There are several types of sound and vibration recep, tion systems within the moth group. Not all of these hea- ring systems detect the ultrasonic echolocating cries of bats. Evidence for the use of ears in sexual communica- tion has been established for noctuid and pyralid species (SVANCLER, 1984, 1987 and 1988; SVANGLER et al., 1984; GWYNNE and EDWARDS, 1986; SURLYKKE and GOGALA, 1986; TREMATErd~ and PAVAN,1994, 1995). Pyralid moths typically have tympanic hearing organs located on the pleural-ventral surface of the first abdomi- nal segment (AcEE, 1969; MULLEN and TSAO, 1971 a-b; CoRo and FERNANDEZ, 1972; Coao, 1973). The organ con- sists of a thin tympanum of varying transparency tightly stretched over a cavity. The anterior part of the tympa- num usually consists of a thicker, less flexible, opaque, papillate membrane referred to as the counter tympanum, which gives the tympanum a sort of U shape. Hearing organs in the flour moth, E. kuehniella, are served by nerves that carry axons from the tympanic acoustic cells, which extend from the paratympanic re- gion in the first abdominal segment to the thoracic gan- glion (PeREZ and ZHANTIEV, 1976). The tympanic nerves U.S. CopyrightCl ....... CenterCode Statement:0340-7330/97/7005-0087511.00/0