Cyrtogenius luteus, (Blandford) (Blandford)

Flechtmann, Carlos A. H. & Atkinson, Thomas H., 2018, Oldest record of Cyrtogenius luteus (Blandford) (Coleoptera: Curculionidae: Scolytinae) from South America with notes on its distribution in Brazil, Insecta Mundi 645, pp. 1-4 : 2

C. luteus

were collected from the following localities.

SÃO PAULO: Lençóis Paulista, Fazenda Rio Claro , Duraflora , cerrado fragment, 22°47′32.51″S 49°1′9.29″W, α-pinene-baited FIT, 29-IX-2006, C.A.H. Flechtmann ( MEFEIS, 1) ; Lençóis Paulista , Fazenda Rio Claro , Duraflora, Eucalyptus grandis stand planted Jul 2001, 22°49′19.0″S 48°53′36.5″W, pheromone/kairomone-baited FIT, 23-II–27-IV-2007, C.A.H. Flechtmann (MEFEIS, 5) .

PARANÁ: Telêmaco Borba, Fazenda Monte Alegre , Klabin , Pinus taeda stand planted Dec 1989, 24°18′56.2″S 50°30′37.5″W, pheromone/kairomone-baited FIT, 14-VI-2006 – 18-V-2007, C.A.H. Flecht- mann (MEFEIS, 94, UTIC, 20); Telêmaco Borba, Fazenda Monte Alegre , Klabin , mixed araucaria forest fragment, 24°19′10″S 50°34′15″W, pheromone/kairomone-baited FIT, 09-III-2007, C.A.H. Flechtmann ( MEFEIS, 5).

RIO GRANDE DO SUL: Santa Maria, Fundação Estadual de Pesquisa Agropecuária , naturally regenerated Pinus taeda stand planted ca. 1985, 29°40′8.03”S 53°55′16.90”W, ethanol-baited FIT, 17-XI- 2011 – 29-V-2012, C.A.H. Flechtmann ( MEFEIS, 10) .

In Telêmaco Borba, a variety of lures were used. Most specimens of C. luteus were captured in traps baited with ethanol + α-pinene (39 specimens), followed by those with ethanol + α-pinene + sulcatol (31), α-pinene alone (22), and α-pinene + sulcatol (19). Traps baited with sulcatol alone or sulcatol + ethanol trapped only one specimen each, while traps baited with only ethanol had zero catches. These results suggest that the kairomone α-pinene is the major attractant among those tested and may be synergized by ethanol. Similar results were obtained by other researchers, which used α-pinene in combination with other kairomones or pheromones ( Fan et al. 2010; Faccoli et al. 2012; Gómez 2015). The sex ratio of trapped C. luteus in Telêmaco Borba was very close to 1:1, in all combinations of lures. At this site sampling was done for one full year and C. luteus was trapped during the entire period. However, for most localities the majority of the specimens were trapped in March, a month of high temperatures. Similar results were obtained in Uruguay ( Gómez et al. 2017). In Santa Maria we set traps at heights varying from 0.5 m until 6.0 above ground, at 0.5 m increments, and specimens were evenly trapped between 1.0 m and 6.0 m height, showing there is no flight height preference in this species.

Even though the literature shows there is a high association of C. luteus with Pinaceae , we trapped specimens in areas dominated by broadleaf trees: A eucalyptus stand, a cerrado fragment, a savanna formation (Lençóis Paulista), and also in an araucaria forest fragment (Telêmaco Borba). It is possible that C. luteus is colonizing the native Brazilian conifer, Araucaria angustifolia (Bert.) ( Araucariaceae ), present in the forest named for it. Eucalyptus , however, belongs to the Myrtaceae and there are no conifers in the Brazilian cerrado. Both of these sites are more than 30 km from the nearest pine plantations (Agudos, São Paulo, where we trapped extensively from 1982 to 1997 without finding C. luteus ). It is also possible C. luteus is not strictly associated with pines, as indicated by Murayama (1957) who cited Cornus controversa Hemsl. (Cornaceae) as a host. Despite the fact that C. luteus was found in different localities, there was no obvious damage to live trees, as was observed in Italy ( Faccoli et al. 2012). Cyrtogenius luteus is considered to be able to attack live trees, but this happens very rarely and it is considered a secondary species ( Chen et al. 1999).

In most cases, it is very difficult to determine how and when an exotic species was introduced into a new locality. In many cases the species is established several years before it is first collected and reported ( Haack and Rabaglia 2013). We also trapped between 1999 and 2001 in another stand of Pinus taeda L. in Telêmaco Borba , in the vicinity of the pine stand where C. luteus was trapped (ca. 13 km), with similar lures used to trap this species in this present report (2006 – 2007) and no specimens were trapped at that time (Flechtmann, unpublished). Our earliest records of C. luteus in Brazil date from 2006 from the states of São Paulo and Paraná, three years earlier than those reported from Uruguay ( Gómez et al. 2012). It is likely that the initial introduction into South America may have been into Brazil, possibly in São Paulo (most important ports) and spread southward to Rio Grande do Sul and later Uruguay.