Forest entomology . Genus Pityogenes. Fig. IIS.—Markings o/Tomicus acumin-atus on stem of Scots pine after the baricivas scraped off. The genus Pityogenes, accordingto Fowler, contains three species,but I have only one species, viz., P. bidentatus, which in many dis-tricts is very common. Barbey, who may be considered as a leadingGerman authority, places P. bidentatus in the genus Tomicus, but Iventure to think that Fowlers separation is a very good one, on theground that in Pityogenes in the males only the apex is excavate,and is furnished with strong teeth, and also that the females havea de
Forest entomology . Genus Pityogenes. Fig. IIS.—Markings o/Tomicus acumin-atus on stem of Scots pine after the baricivas scraped off. The genus Pityogenes, accordingto Fowler, contains three species,but I have only one species, viz., P. bidentatus, which in many dis-tricts is very common. Barbey, who may be considered as a leadingGerman authority, places P. bidentatus in the genus Tomicus, but Iventure to think that Fowlers separation is a very good one, on theground that in Pityogenes in the males only the apex is excavate,and is furnished with strong teeth, and also that the females havea deep impression at the apex of the elytra near suture. Under astrong lens this character is well maintained,—so much so, that thethorax has a quite nipped -like appearance. COLEOPTERA— 123. Fig. 119.—Markings of Pity-ogenes bidentatus (initialstage). PlTTOGENES BIDENTATUS (Herbst.) Pityogenes bidens (Fabr.) This is a common beetle, but, being small in size, is very apt tobe overlooked. Its breeding-places may be broadly divided into twoclasses—viz., on small dead fir-branches,and on sickly trees, say from 18 inchesand upwards, which have been trans-planted in the nursery - lines, or thosewhich have been transplanted in youngwoods. As regards the former class of food-materials, and as forming a commence-ment in the study of its life-history, itmay be looked for amongst the smallbranches of Scots pine, chiefly on theunder side of the branch, either wheretrees have been felled during the previouswinter, or on branches which have beenbroken off by the wind. The small bore-holes, together with the frass, reveal theabode of the insect. If the thin bark beremoved carefully, we may find a star-shaped marking, as in fig. 119. This isa typical beginning of the markings ofthis
Size: 1203px × 2078px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisheredinburghwblackwoo
