12 



The ventro-distal ridge terminus, here termed the subalare tendon attachment point (STAP) 

 is generally spatulate and broadly separated from its dorsal components. This section forms 

 a very large attachment point for a long section of very stiff membrane or tendon which 

 is connected to PRA+PRJ. It is the latter which is joined to the subalare and finally the 

 M79 muscle. 



Median Plate (MED). 



The median plate is composed of FM1 proximally and FM2 distally (Fig. 3). Anteriorly, 

 FM1 is fused to the proximal margin of the anterior medial basivenale (BMA), while FM2 

 is fused to the proximal margin of the posterior medial basivenale (BMP). The proximal 

 margin of FM1 is fused to 2Ax, the postero-proximal margin is loosely associated with 

 lAx distal arch terminus and the postero-distal margin is fused to the third axillary (3 Ax). 

 Therefore, the junction between lAx+2Ax and 3 Ax is mediated by FM1. FM1 and FM2 

 may be separated, or partially or fully fused. FM1 is generally very large. Although FM1 

 can be greatly reduced, a small remnant always remains to mediate the junction between 

 lAx+2Ax and 3 Ax. 



Third Axillary (3Ax). 



The third axillary is composed of the cubital, anal and jugal axalaria and fulcalaria (AXCu 

 + AXA + AXJ + FCu + FA + FJ) (Fig.9). 



The head of 3Ax is composed of AXCu proximally. FCu medially and FA distally. The 

 neck is composed of AXCu proximally and FA distally. The prong lies at the proximal 

 margin of the neck and articulates with the detached AXCu fragment. The prong is often 

 extended posteriorly and proximally to form a ridge. In some scarabaeoids FA and/or 

 AXCu is greatly enlarged, forming a distinct arm. 



The tail is composed of AXA proximally and FJ distally. These two sclerites are often 

 separated by a medial weakening which is termed the window. The detached AXCu 

 fragment is a small, separated piece of 3Ax, specifically AXCu (Figs. 3b. 9). The M71 

 muscle inserts into this fragment, which, when contracted, pulls it down causing the 

 proximal part of 3Ax to sink down and the distal part to lift and slightly rotate. This allows 

 3Ax to fold upon itself. The folding is mediated by the detached AXCu fragment and the 

 3Ax neck prong. 



The Wing Base 



First Basal Plate (IBP). 



The first basal plate is composed of the precostal and costal fulcalaria and basivenalia 

 (FPC + BPC + FC + BC collectively known as the humeral plate (HP)), the anterior 

 subcostal basivenale (BScA). the posterior subcostal basivenale (BScP hidden beneath 

 BScA), the subcosta anterior vein base (ScA bulge) and the radial basivenale (BR) (Figs. 3, 

 10). IBP is articulated to lAx. 2Ax and MED (Fig.3). 



