ی. شیبو واردانان

The “jewel beetle” - Belionota prasina (Thunberg, 1789), is a polyphagous insect pest found throughout India and its neighboring countries. To develop semiochemical-based pest control strategies, we must first comprehend the entire morphological features of the insect’s antennal sensory structure. This is the first study report revealing the morphology and ultrastructure of antennal sensillae of male and female of B. prasine using light and scanning electron microscopy. Both antennae are serrated in appearance with 11 antennomers. In both sexes, Böhm sensilla, sensilla trichodea, sensilla basiconica, sensilla chaetica, and multiporous grooved peg sensilla are common. Sexual dimorphism is present in the case of length and width (basal and distal) of entire antenna as well as each antennomer. Male antennomeres are larger and more robust. The antenna of B. prasina shows a high degree of sexual dimorphism. The C4 type aporous serrated sensilla chaetica, which serves a tactile function, are highly specific to male antennae. The sensilla basiconica subtype 4 is found in female antennomeres while multigrooved are pegs present only in male antennomerers. The number and type of sensillae are greater in males than females. Apical fossae are present dorsally and ventrally on each male antennomere. The function and distribution of all types of sensilla are explained and illustrated in this paper.

Insect caste development and their morphological divergence are not yet studied well, especially in ants. However, the role of developmental and genetic integration in evolution is contentious. In our study, we tried to reveal the quantitative genetics selection responses, phylogenetic signal, and evolutionary origin of weaver ant female castes (queen, major and minor). The widening and lengthening of the head region, as well as the well-developed mandibular process, are the major heritable characteristics found in the major worker ants. We hypothesized that these conserved and heritable characteristics may help the major worker ants for defense, foraging purposes and other nest-building function aspects. However, in the case of minor worker, small heads and the reduced mandibular process are the more heritable characteristics. Compared to worker ants, in queen, the highly heritable and conserved morphological character is well-developed thoracic regions and large-sized abdomen. It is interesting to note that there is no detectable phylogenetic signal across the female cast of the Asian weaver ants, which suggests that the caste development and morphological divergence are environmentally modulated not evolutionary conserved. From this study, we concluded that caste-specific morphological shape and size are highly conserved traits and these traits are modulated by their niche preferences.