Search Results (2)

Sound is an important medium of communication among insects. Some longhorn beetles produce sounds during their daily activities, and these sounds play a role in courtship, predation, and defense. However, whether there are differences in the sounds emitted by longhorn beetles and how to distinguish and recognize these sounds have not been investigated in detail. Here, the sounds of Glenea cantor (Fabricius), Moechotypa diphysis (Pascoe), and Psacothea hilaris (Pascoe) were collected, and the differences in their stridulatory organs were observed and compared using scanning electron microscopy (SEM). The characteristics of their sounds were analyzed using MATLAB. Linear prediction cepstral coefficients (LPCC) and Mel frequency cepstral coefficients (MFCC) were used to extract the sound features, and the support vector machine (SVM) model was used to identify the sounds of three species. The results showed that the stridulatory organs of three species of longhorn beetles differed in morphology and time domain, and the combination of MFCC and SVM had a better recognition ability. The difference in the stridulatory organs of longhorn beetles may be an important reason for the differences in the sounds they produce, and we discussed the application of insect sounds in insect classification. Full article

Antimicrobial peptides (AMPs) are the frontline innate defense system evolutionarily preserved in insects to combat invading pathogens. These AMPs could serve as an alternative to classical antibiotics to overcome the burden of treating multidrug resistant bacteria. Psacotheasin, a knottin type AMP was isolated from Psacothea hilaris and shown to exhibit antimicrobial activity, especially against fungi through apoptosis mediated cell death. In this study, we aimed to identify novel probable AMPs from Psacothea hilaris, the yellow spotted longicorn beetle. The beetle was immunized with the two bacterial strains (E. coli and S. aureus), and the yeast strain C. albicans. After immunization, total RNA was isolated and sequenced in Illumina platform. Then, beetle transcriptome was de novo assembled and searched for putative AMPs with the known physiochemical features of the AMPs. A selection of AMP candidates were synthesized and tested for antimicrobial activity. Four peptides showed stronger activity against E. coli than the control AMP, melittin while one peptide showed similar activity against S. aureus. Moreover, four peptides and two peptides showed antifungal activity stronger than and similar to melittin, respectively. Collectively one peptide showed both antibacterial and antifungal activity superior to melittin; thus, it provides a potent antimicrobial peptide. All the peptides showed no hemolysis in all the tested concentrations. These results suggest that in silico mining of insects’ transcriptome could be a promising tool to obtain and optimize novel AMPs for human needs. Full article