Amillarus singularis ( Aurivillius, 1922 )

Santos-Silva, Antonio & Galileo, Maria Helena M., 1857, OnAmillarusThomson, 1857 (Coleoptera: Cerambycidae): Types, Variation, and a New Synonym, The Coleopterists Bulletin 1857 (4), pp. 805-811 : 805-811

Amillarus singularis ( Aurivillius, 1922) ( Figs. 14–17 )

Didymonycha singularis Aurivillius 1922: 435 . Amillarus singularis ; Breuning 1962: 34. Trichogrammopsis ruficollis Breuning 1948: 42 .

New synonymy.

Aurivillius (1922) described and figured D. singularis ( Figs. 15–17 ) and affirmed that the elytral apex in this species is truncate. However, he did not write anything about the presence or not of spines at the outer and sutural angles. Actually, the drawing in the original description suggests that they are absent.

Breuning (1948) described Trichogrammopsis ruficollis ( Fig. 14 ) and reported that the elytral apex is emarginate with a small spine at the outer angle and a very small spine at the sutural angle.

Breuning (1962) presented a key to the species of Amillarus (translated):

“1. The sutural apical angle of the elytron indicated but without spine............................2

- This angle with spine...................................3

2. Pronotum with two posterior whitish bands ............................................ singularis Auriv.

- Pronotum without these bands....................... .............................................. apicalis Thoms.

3. The sutural apical angle of the elytron with a small spine........................... ruficollis Breun.

- This angle with a long spine......................... ............................................ secunda Tippm. ”

This key has several problems. The elytral apex in A. apicalis is extremely variable; the spines at the elytral apex of the paratype of A. secundus are distinctly shorter than in the holotype, and not so different from that in many species of A. apicalis . The whitish bands on the pronotum of the holotype of D. singularis are not so different from the lighter area at the same position in the holotype of A. ruficollis . And, most important, the elytral apex in A. ruficollis is almost identical to that of D. singularis (actually, the spines are slightly longer in the latter than in the former). It seems evident that Breuning was deceived by the original descriptions by Aurivillius and Tippmann (mainly by the drawings).

Based on high-resolution photographs of the holotypes of D. singularis and T. ruficollis , there is no doubt that the latter is a junior synonym of the former. Examination of photographs of the holotypes of A. ruficollis ( Fig. 14 ) and A. singularis ( Fig. 15 ) shows a single reliable difference between these species and A. apicalis : the pubescence on the head, pronotum, and elytra is much more conspicuous, practically obscuring the integument on the head and pronotum.

Unfortunately, we could not study a specimen that agrees with these holotypes to confirm or not if there are other differences.

Geographic Distribution. Ecuador, Peru.

Figures

Figs. 7–14. 7) Amillarus apicalis, holotype; 8) Labels for holotype of A. apicalis; 9) Amillarus mutabilis, syntype; 10) Didymonycha secunda, holotype male, elytral apices; 11) D. secunda ab. infuscata, “holotype” male, elytral apices; 12) D. secunda, holotype male, elytral apex, drawing by Tippmann (1951); 13) D. secunda ab. infuscata, “holotype” male, elytral apex, drawing by Tippmann (1951); 14) Trichogrammopsis ruficollis, holotype male.

Figs. 15–17. Didymonycha singularis, holotype. 15) Dorsal habitus; 16) Lateral habitus; 17) Labels.