Forficula auricularia

Herhold, Hollister W, Davis, Steven R, Degrey, Samuel P & Grimaldi, David A, 2023, COMPARATIVE ANATOMY OF THE INSECT TRACHEAL SYSTEM PART 1: INTRODUCTION, APTERYGOTES, PALEOPTERA, POLYNEOPTERA, Bulletin of the American Museum of Natural History 459 (1), pp. 1-184 : 1-184

Forficula auricularia

“Common earwig”

Figures 47 (lateral), 48 (dorsal), 49 (ventral)

Plates 26 (lateral), 27 (dorsal), 28 (ventral)

DESCRIPTION: HEAD: H-DCT and H-VCT thick, of similar diameter; H-DCTs curve inward slightly such that left and right tracheae nearly touch before turning laterally outward on entry to head capsule; H-VCTs both proceed straight into head. H-DCT with several branches just anterior of cervix: H-DCC, H-DCT-Dvi, H-Oc, and H-Ant. H-DCC present. H-DCT-Dvi running laterally and dorsad. H-Oc arcing laterally, with several small tracheae extending into eye, then continuing anteriorly and ventrad via H-Oc-Md to link with ventral H-Md. H-Ant extends anteriorly through head into antenna; left side of Forficula as H-Ant-Ft with H-Ft branching off H-Ant near base of antenna; H-Ft branches off H-VCTsourced H-Md on right side. H-Ant with multiple tracheae in Anisolabis ; likely present in Forficula but not visible in this scan. H-VCT likewise with several branches just anterior of cervix: H-VCTVi, H-VC, and H-Mx-Md. H-VCT-Vi running laterally and ventrad, like dorsal trachea. H-VC branches directly from H-VCT. Both H-VC with H-VC-Dvi run directly anteriad, extending as far as frontal area. H-Ft-Lbr absent. H-Mx-Md running anteriad and slightly laterally, with several branches: H-Lbm runs ventrad, with short H-LbmPlp; H-Mx running ventrad, with short H-MxPlp. Remaining H-Md branch runs anteriad, with H-Oc-Md connection from H-DCT; H-Md-Ant branching dorsally on right side to join H-Ant from H-DCT; H-Ft branching from H-Md on right side.

THORAX: Distance between T2-S and T3-S much shorter in F. auricularia (See fig. 43 ).

ABDOMEN: Abdominal tracheae of F. auricularia consistent with description of overall dermapteran tracheae above except for direction of visceral tracheae. A6..7-VLT-Vi similar to their anterior counterparts, except A6..7-VLT-Vi extend posteriorly rather than anteriorly, and do not extend beyond segment boundaries; A5-A6 appears to be dividing line for visceral tracheae from median longitudinal trunk, where A2..5- VLT-Vi tracheae extend anteriorly and A6..7- VLT-Vi extend posteriorly. A2..7-VLT-Vi not bilaterally symmetric; right side tracheae larger in cross-sectional area than left. Right side tracheae, while extending into body, also do not supply exact same areas/organs as those from left side. A3-DLT-Mvi and A4-DLT-Mvi on left side extend directly toward the posterior, with A3-DLT-Mvi ending near A7-DB. A3-DLT-Mvi on right side much reduced from left side counterpart, extending posteriorly as far as A4. A4-DLT-Mvi highly modified; after extending toward the middle of the body, continues well into A8 and A9, where it turns toward body wall in large arc that results in trachea pointing anteriorly. A4-DLT-Mvi with similar loop on right as on left, but much shorter, with apex of loop reaching as far as A5-DB. Extensive branching/tracheation in A7 and A8 for cercal (forceps) muscles.

Figures

FIGURE 43. Dermaptera thoraces, dorsal view: A. Forficula, B. Anisolabis.

FIGURE 47. Forficula auricularia (Dermaptera: Forficulidae), lateral view.

FIGURE 48. Forficula auricularia (Dermaptera: Forficulidae), dorsal view.

FIGURE 49. Forficula auricularia (Dermaptera: Forficulidae), ventral view.