Dispersal differences of a pest and a protected Cerambyx species (Coleoptera: Cerambycidae) in oak open woodlands: a mark–recapture comparative study

Abstract

Abstract. 1. Cerambyx welensii (Cw) and Cerambyx cerdo (Cc) are two large saproxylic beetles living on Quercus trees in the Western Palearctic whose current pest and legal status differs markedly. Cw is an emerging pest involved in oak decline while Cc is an internationally protected species.2. Acquiring knowledge of the ecology, demography and behaviour of Cw and Cc in forests harbouring mixed populations is a demanding task to optimise their management or protection. Here, we report the results of a mark-recapture study on the flight behaviour and dispersal potential of both species in holm oak open woodlands.3. Average flights, dispersal rates and diffusion models were remarkably similar in Cw and Cc, reflecting a low-dispersal tendency and sedentary behaviour. However, a subset of adults in both species exhibited a huge propensity to disperse and flew more than 1 km. An aggregated distribution of dispersal distances suggested that a behavioural polymorphism might underlie the flight pattern.4. Adults moved preferentially in those spatial directions with neighbouring trees, while prevailing winds did not significantly affect dispersal patterns. The main interspecific differences were as follows: (i) Cc performed longer crosswind flights than Cw on windy days; (ii) Cc tended to fly farther than Cw at low temperatures; and (iii) adult feeding improved dispersal but only in small Cw females. Moon phase did not affect flight activity.5. The results are discussed in an effort to interpret how these ecological and behavioural differences might shape the life history of both congeneric species when they live in sympatry in dehesa woodlands.

Monitoring and management of Cerambyx cerdo in the Mediterranean region – a review and the potential role of citizen science

“…This is an open question in European oak woodlands dominated by Quercus species, where C. cerdo is considered by many forest practitioners as a serious pest (Sallé et al 2014), even if it might be confused with other Cerambyx spp. known to attack healthy trees in managed forest systems (Torres-Vila et al 2017, Wang 2017. To address these issues, the citizen science paradigm for C. cerdo monitoring and habitat management should be seen not only as citizens collecting good data sets, but as a deeper collaboration amongst different knowledge bodies and perspectives, within a community based environmental monitoring and learning network.…”

“…This strict protection regime can create conflicts when there is an economic interest in oaks and stakeholders may wish to cut down trees or branches colonised by C. cerdo to protect woodlands (Buse et al 2016). However, the significance of the pest status of the protected C. cerdo should be carefully assessed and disentangled from that of similar species such as C. scopolii and C. welensii which are not protected under the HD and can be associated with C. cerdo (Buse et al 2008b, Torres-Vila et al 2017, Wang 2017. It is thus very important to assess whether and in which conditions C. cerdo can be a serious pest for oak woodlands.…”

“…Several sampling methods have been applied to study C. cerdo populations, including visual censuses of adult exit holes to assess microhabitat requirements (Buse et al 2007, Regnery et al 2013, Albert et al 2013, Oleksa and Klejdysz 2017, comparison of evening transects, night surveys of trunks, pitfall and bait traps for distribution and population monitoring of adult beetles in a Natura 2000 network (Vrezec et al 2012) and bait traps to estimate dispersal in a Mediterranean woodland pasture (Torres-Vila et al 2017). Most of the available studies come from central Europe and focus on microhabitat selection in open landscapes, as summarized in Table 2.…”

“…The species is also assessed at the Mediterranean level as "Least Concern" since it has a large geographical range and is abundant in the region, although sub-populations are often scattered and there is a low probability that the habitat would recover if destroyed in the future (Buse et al 2016). Major threats for the species are the decline in the number of old trees situated in open or semi-open landscapes (Buse et al 2007, Albert et al 2013, fragmentation and isolation of sub-populations (Buse et al 2016, but see Torres-Vila et al 2017), changes in habitat and landscape structure such as plantations with exotic plants and alteration of grazing regimes (Buse et al 2016, Oleksa andKlejdysz 2017), and forest sanitary measures (Luce 1997, Horak et al 2010, Buse et al 2016. In fact, Cerambyx spp.…”

“…In fact, Cerambyx spp. are considered serious pests of oak stands in the Mediterranean basin (Martín et al 2005, Sallé et al 2014, Torres-Vila et al 2017, where seminatural Holm oak (Quercus ilex) and Cork oak (Quercus suber) forests are traditionally exploited for pasture and firewood or cork production respectively (Bergmeier et al 2010). Considering that the species has this double interest for Mediterranean forest management, mandatory monitoring under the HD perhaps should be aimed at assessing both conservation and pest status of C. cerdo.…”