NORTH-WESTERN JOURNAL OF ZOOLOGY 7 (2): 352-355 ©NwjZ, Oradea, Romania, 2011 Article No.: 111215 www.herp-or.uv.ro/nwjz Phenology and notes on the behaviour of Cucujus cinnaberinus: points for understanding the conservation of the saproxylic beetle Jakub HORÁK1,* and Karel CHOBOT2 1. Department of Biodiversity Indicators, Silva Tarouca Research Institute for Landscape and Ornamental Gardening, Květnové náměstí 391, CZ-252 43 Průhonice, Czech Republic 2. Agency for Nature Conservation and Landscape Protection of the Czech Republic, Nuselská 39, CZ-140 00 Prague 4, Czech Republic * Corresponding author, J. Horák, E-mail: [email protected] Received: 01. January 2011 / Accepted: 21. May 2011 / Available online: 03. November 2011 Abstract. Cucujus cinnaberinus is a saproxylic beetle distributed throughout Europe. This species is often red- listed (including the IUCN) and is protected in Natura 2000. We studied this beetle in detail in the Czech Republic (the centre of its area of distribution) and also used comparisons of published data within its whole area of distribution. We present a summary of the phenology and notes on the behaviour of a species of beetle that should be the focus of conservation biology. The monitoring of Cucujus cinnaberinus can be difficult because it lives underneath bark and is hidden for most of its life. Larvae can be found throughout the year because they undergo two or more years of development and pupate in summer. The best chance of finding adults outside of the under-bark environment is at the time of mating activities (spring-summer), when adults leave the under-bark microhabitat to search for a mate. Our results are presented as a potential tool for the conservation of this species. Keywords: Coleoptera, Cucujidae, dead wood, monitoring, nature conservation, Natura 2000. Cucujus cinnaberinus (Scopoli, 1763) is a threatened Our study area was located in the eastern part saproxylic beetle that is a candidate for becoming of Polabí lowland (200-350 m a. s. l.), where one of an umbrella species (Horák et al. 2008, Mazzei et the largest populations of C. cinnaberinus occurs in al. 2011). The member states of the European Un- the Czech Republic [see Horák et al. (2010) for a ion are required by law to protect this beetle and description of the study sites and habitat types]. its habitats because it is listed in the EU Habitats The research was carried out from 2006 to Directive. This species is the sole representative of 2007. A total of 167 dead wood samples were in- its genus and family in the IUCN (International vestigated. We searched for this species in the Union for Conservation of Nature) Red List (Bailie same intervals throughout the whole study (i.e. at & Groombridge 1996). It is also listed in most of least two samplings in two different localities per the European red-list assessments, including in the month). One strip of bark (approximately 0.30 × Czech Republic (Jelínek 2005), Slovakia (Holecová 0.30 m) was randomly peeled from the dead & Franc 2001), Germany (Geiser 1998), Sweden wood. During the next two years (2008-2009), the (Gärdenfors 2005), Finland (Rassi et al. 2001), species was studied occasionally, and these results Norway (Kålås et al. 2006), Latvia (Šternbergs are not presented in Fig. 1. They are included in 1998) and Poland (Pawlowski et al. 2002). the discussion. Our main goals were to describe the phenol- We present the data on the phenology of the ogy and provide notes on the behaviour of Cucu- study species (i.e. the population densities found jus cinnaberinus in the Czech Republic whilst con- in the samples during the seasons). December was sidering published data from its entire area of dis- placed at the beginning and January at the end to tribution. We searched accessible historical and re- better fit the regression curve of the phenological cent literature, beginning in 1763 with a descrip- trend of the adults in Fig. 1. Our sampling data in- tion using the Linnaean system by J.A. Scopoli cluded information on the phenology and behav- (Scopoli 1763). The most historical and recent iour of the study species, which we compared sources only repeated themselves or only added with reports in the literature and data obtained by fragmentary information, such as beetle is rare, oc- our colleagues. curs in lowlands, under the bark of oaks (e.g. Letzner Pupal chambers and larval and adult 1871), followed by geographical information like fragments seemed to be more season resistant. The rare in Germany, occurs in Prater (e.g. Erichson pupal chambers of the study species can be 1845), for example. confused with those of other beetles (e.g. Rhagium Phenology and behaviour of Cucujus cinnaberinus 353 spp. – Cerambycidae). Thus, we did not analyse October (Mertlik, Pohřebačka, pers. comm. 2009). the presence of fragments and pupal chambers for The flying abilities of this species are probably the phenological investigation of the study much better than those of other endangered bee- species. tles, as this species is able to exploit secondary When sampling the bark we did not find any habitats and spread throughout an area (e.g. adult from May to July (Fig. 1), although active Horák et al. 2010). adults were observed outside the under-bark We observed copulation under the bark of a environment from April to June (our own poplar snag in late February, probably due to the observations; Bogusch, Rzy, pers. comm. 2009). mild weather in winter 2007-2008. Mocek (2007) The illustrative curve in Fig. 1 shows that the observed copulation twice in the second half of presence of adults declined throughout the April under the bark of poplars. Palm (1941) wrote summer months, and most adults were found in that adults copulate in May or June, also in the February. Larvae were present in each month, under-bark environment of dead wood. Copula- whereas pupae were only found in August (Fig. tion was also observed in mid-May (Bussler 2002). 1). In the case of the larvae, the results might have This species is probably able to copulate immedi- been distorted by their occasional gregarious ately at the beginning of the vegetation season, fin- behaviour, and they might also have been ishing such activities in early summer, which co- influenced by the relatively small size of the incides with its flying activities. There are only a sample strips. few descriptions of epigamic behaviour. Mocek We did not directly observe any flying activ- (2007) reported that the male holds the female’s ity. However, during another study using flying antennae in its mandibles and climbs onto her interception traps, several adults of the study spe- back for copulation, although cucujids are known cies were trapped from May to July (Horák 2011). to copulate back-to-back with the beetles facing Schlaghamerský et al. (2008) reported the trapping opposite directions, like true bugs (Crawson & success of Cucujus cinnaberinus with flying inter- Ellis 1969). The back-to-back position corresponds ception traps from April to May. Thus, the major- with the inverted genitalia of the male and is nor- ity of flying activities probably occur from mid- mal in Cucujidae (Crawson & Ellis 1969; see the spring to mid-summer. The flying activity of descriptions in Lee & Satô 2007). One other adap- adults has been observed in the evening (e.g. Bus- tation has been found for normal copulation, as sler 2002). It is probable that the study species is described by Mocek (2007). Males have sucking more disposed towards flying after overwintering, pads on their forelegs for holding onto the fe- during the time of its mating activities. One adult males, similar to those of diving beetles (Boukal, was also observed flying in a non-forest habitat in Pardubice, pers. comm. 2008). Figure 1. Phenology of Cucujus cinnaberinus – individuals found in the samples taken from our study area during each month of sampling. 354 J. Horák & K. Chobot Adults of C. cinnaberinus are timid and quickly Pupae were described and illustrated by Palm hide under the bark when exposed (Palm 1941). (1941). The pupal chambers are oval shaped and Based on our observations, when adults are dis- are located under the bark and made from chips. turbed they initially become cataleptic – they bow The chambers are probably made to protect the their head down with the antennae to the front pupae against predators during the period when and tuck their feet under the body with their the species is most vulnerable. The pupae were ac- knees facing upwards (the same as in illustration tive, rotating and wriggling when disturbed. We in Frisch 1736). Following this behaviour they es- only found pupae in August. Mazzei et al. (2011) caped and hid under the bark. Adult is probably indicated the first pupal rearing in early July. The not able to emerge through bark and must search next generation of adults emerge in late summer for crevices in the bark instead. Thus, adults were or early autumn after a short period of pupation. mostly observed near crevices or the edges of Palm (1941) wrote that pupation takes 10 days, bark. Also, the mycelia of basidiomycetes seemed and the pupae emerge as adult in only 10-20 min- to be barriers to their movement under the bark. utes. Mazzei et al. (2011) observed emergence after We observed freshly dead adults in pupal cham- only 6-7 days in the laboratory. Full colouration bers overgrown with mycelia (except on the inte- takes an additional two weeks to complete, during rior). which time the adults stay under the bark, from We found most of the adults in February. This where they emerge.