Search

Giglio,A.,Perrotta,E.,Talarico,F.,ZettoBrandmayr,T.andFerrero,E.A.2013. Sensilla on maxillary and labial pal ps in a helicophagous ground beetlelarva (Coleoptera, Carabidae). — Acta Zoologica (Stockholm) 94: 324–330.Sensilla on the labial and maxillary palp of Carabus lefebvrei Dejean, 1826 larvaewere investigated using scanning and tr ansmission electron microscopy. Twoidentical sets of sensilla were present on the tips of both palp pairs, and four mor-phological types of sensilla were identified: sensilla basiconica types 1 and 2, sen-sillacoeloconicaandsensilladigitiformia.Ultrastructureindicatesthatthesensillabasiconica type 1 and coeloconica have a chemical role as gustatory and olfactoryreceptors, respectively,while sensilla basiconica type 2are mechanoreceptors andthe sensilla digitiformia are probably thermo- and hygroreceptors. Their functionisdiscussedinrelationtospecializedpreydetectionandhabitatadaptations.Anita Giglio, Department of Ecology, University of Calabria, Via P. Bucci,I-87036 Arcavacata di Rende, Italy. E-mail: anita.giglio@unical.itIntroductionCarabid beetles are a family of Coleoptera widely spread in allterrestrial habitats where most of them are important preda-tors. Many species are specialists, but the majority are polyph-agous, and anyway their prey is located via visual, olfactoryand tactile cues (Wheater 1989). In carabid beetle adults, pre-vious studies on adult carabid beetles have revealed that thereare correlations between body form and habits (e.g. feeding,locomotory, burrowing and flying) (Evans 1983; Forsythe1991). It is well known that some larval features (mandibleshape, general body form, urogomphi morphology and feed-ing behaviour) (Zetto Brandmayr et al. 1993, 1998, 2007)and sensory equipment of adult and larvae (Altner and Bauer1982; Spence and Sutcliffe 1982; Bauer and Kredler 1988,1993; Bauer et al. 1998; Di Giulio et al. 2003, 2009; Giglioet al. 2003, 2008; Talarico et al. 2007) are correlated with themain selective pressures of the habitat. Then, it is evident thatbiotic components such as predation may be important indetermining population size, spatial distribution and activityof carabid beetles, and their morphological adaptations areconsequent upon the ability to detect their prey. Moreover,many studies show that food availability is relevant for fitnessbecause fecundity and larval developmental performance areinfluenced by diet (Hengeveld 1979a,b,c, 1981; Forsythe1983, 1991; Lovei and Sunderland 1996; Luff 2003; Saska2008; Sasakawa 2009).The object of this study is Carabus lefebvrei Dejean, 1826,an Italian endemic species that lives in the beech, oak, chest-nut and pine forests of the Central and Southern Appennines,from lower altitudes to about 1500 m a.s.l. It is a spring repro-ducing species, active from April until September, and hiber-nates as adult. Eggs are laid in humus-rich soils in April–June,and larvae are active on the surface of the leaf litter from Juneto August (Thiele 1977; Turin et al. 2003). Larvae moult tothepupalstageinacellduginthegroundbythethirdinstarlarva. The pupa is exarate and p roduces a defensive secretionby abdominal glands (Giglio et al. 2009). The habit of adultsand larvae is typically of a snail-eating predator: adults showprolongedandnarrowedheadasinCychrus spp. (cychriza-tion), and larvae have broad tergite projections to protect theabdominal spiracles (Turin et al. 2003).In this paper, we describe the ultrastructure of the sensorycomplement of C. lefebvrei larvae on labial and maxillary palpsinvolved in prey searching to provide a morphological basisfor future behavioural and electrophysiological studies.Materials and MethodsSamples collection and rearingCarabus lefebvrei males and females were collected by handfrom under rotten bark of pine trees in the Catena Costieramountains (39 19¢N, 16 7¢E, 900–1000 m a.s.l.; Southern

The relationship of morphometrical and androgen receptor evaluations of the main testicular interstitium cellular element (Leydig cells) in the domestic pig provided interesting numerical and morphological features during the different aging stages. As early as 25 days (a period in which the pig is sexually immature) there was a low number of Leydig cells (1.46 x 10(8)) with respect to a 78% and 35% increase in the adult (2.48 x 108) and aged (1.78 x 10(8)) animal, respectively. Interestingly, when the volume density of Leydig cells was considered, the average volume of these cells seemed to be high (75%) in the aged pig with respect to the young immature animal whereas a lower increase (27%) was observed for the adult animal. Moreover, the evaluation of testosterone receptor binding sites in the testis at the various stages of development also displayed a differentiated pattern since elevated testosterone receptor binding levels of the high dissociation affinity type were obtained for the adult pig. Thus, from the combined morphological variations of Leydig cells and testosterone receptor binding activity, it appears that this androgenic receptor component exerts distinct autocrine effects on the different functional features of some testicular tissue constituents at the different aging stages of the domestic pig.