Cyclocephala tucumana Brethes, 1904

Rodrigues, Sérgio Roberto & EntomoBrasilis, Andrezza Santos Cocco, 2024, Antennal ultrastructure of three species of Cyclocephala Dejean, 1821 (Coleoptera: Scarabaeidae), EntomoBrasilis (e 1079) 17, pp. 1-8 : 4-5

Cyclocephala tucumana Brethes, 1904

In terms of the sensillae distribution within the antennae, the following statistics were observed: female antennae had a total of 6,814 sensillae, with the majority being type I placoid (96.581%), coeloconic (3.39%) and basiconic (0.03%); male antennae had a total of 6,333 sensillae, with the majority Significant differences were observed between male and female specimens in terms of the length of the proximal, medial, and distal flagellomeres of the lamellae. Here are the specific statistical results: length of proximal flagellomere of the lamella (t =12.36; df=4; P <0.0001), but no significant differences were found for width (t =1.55; df=2; P <0.13); lenght of medial flagellomere of the lamella (t =4.48; df=2; P <0.02), but no significant differences were observed for width (t =0.42; df=2; P <0.37); length of distal flagellomere of the lamella (t =19.69; df=3; P <0.0001), but no significant differences were observed for width (t =0.49; df=2; P <0.36) ( Table 1 and Figure 7 ).

In terms of the distribution of sensillae within the antennae, the following statistics were observed: female antennae contained a total of 1,981 sensillae, with the majority being type I placoid (93.13%), coeloconic (6.42%) and basiconic (0.45%); male antennae contained a total of 3,756 sensillae, with the majority being type I, II and III placoid (97.34%), coeloconic (2.64%) and basiconic (0.02%) ( Table 2) .

Regarding the dimensions of placoid sensillae, the average diameters in females and males were as follows: type I placoid sensilla: 7.68 ± 1.39 µm in females and 6.52 ± 1.14 µm in males; type II placoid sensilla: 6.0 ± 1.95 µm in females and 5.34 ± 0.57 µm in males ; type III placoid sensilla: 10.07 ± 1.38 µm in females and 9.40 ± 1.98 µm in males .

Interestingly, the inner surface of medial and proximal flagellomeres of the lamellae of females exhibited both homogeneous and heterogeneous areas, while the inner surface of medial and proximal flagellomeres of the lamellae of males showed predominantly a heterogeneous area ( Figure 7 ).

Figures

Figure 7. Antennal lamella of Cyclocephala tucumana Bretes, 1904: A, C, E, G) left female lamellae; B, D, F, H) right male lamellae. (dl) distal flagellomere of lamella; (ex) outer surface; (in) inner surface; (ml) medial flagellomere of lamella; (pl) proximal flagellomere of lamella. Scale = 100 µm.