COMPARATIVE ANATOMY OF THE INSECT TRACHEAL SYSTEM PART 1: INTRODUCTION, APTERYGOTES, PALEOPTERA, POLYNEOPTERA Author Herhold, Hollister W Author Davis, Steven R Author Degrey, Samuel P Author Grimaldi, David A text Bulletin of the American Museum of Natural History 2023 2023-03-31 459 1 1 184 http://dx.doi.org/10.5531/sd.sp.55 journal article 10.5531/sd.sp.55 eb1717dc-9526-481c-a859-7ca8fd036425 0003-0090 7730159 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. FIGURE 44. Anisolabis maritima ( Dermaptera : Anisolabididae ) lateral view. FIGURE 45. Anisolabis maritima ( Dermaptera : Anisolabididae ) dorsal (left) and ventral (right) views. FIGURE 46. Internal views of Anisolabis , showing variation between left and right side in origin of visceral tracheae along dorsal longitudinal trunk. A. Right side. B. Left side. THORAX: Distance between T 2- S and T 3- 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. A 6..7-VLT-Vi similar to their anterior counterparts, except A 6..7-VLT-Vi extend posteriorly rather than anteriorly, and do not extend beyond segment boundaries; A 5- A 6 appears to be dividing line for visceral tracheae from median longitudinal trunk, where A 2..5- VLT-Vi tracheae extend anteriorly and A 6..7- VLT-Vi extend posteriorly. A 2..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. A 3-DLT-Mvi and A 4-DLT-Mvi on left side extend directly toward the posterior, with A 3-DLT-Mvi ending near A 7-DB. A 3-DLT-Mvi on right side much reduced from left side counterpart, extending posteriorly as far as A 4. A 4-DLT-Mvi highly modified; after extending toward the middle of the body, continues well into A 8 and A 9, where it turns toward body wall in large arc that results in trachea pointing anteriorly. A 4-DLT-Mvi with similar loop on right as on left, but much shorter, with apex of loop reaching as far as A 5-DB. Extensive branching/tracheation in A 7 and A 8 for cercal (forceps) muscles.