Philippine Journal of Science
152 (1): 351-356, February 2023
ISSN 0031 – 7683
Date Received: 28 Jul 2022

Morphological Characterization and Species Verification
Using Cytochrome C Oxidase Subunit I (COI) of Two
Laguna Populations of the Cacao Pachyrhynchine Beetle,
Pachyrhynchus moniliferus Germar,
1823 (Coleoptera: Curculionidae)

Kimberly Ann S. Domingo, Barbara L. Caoili, and Sheryl A. Yap*

Institute of Weed Science, Entomology, and Plant Pathology, College of Agriculture
and Food Science, University of the Philippines Los Baños, College, Laguna 4031

*Corresponding author: sayap3@up.edu.ph

[Download]
Domingo KA et al. 2023. Morphological Characterization and Species Verification Using Cytochrome C
Oxidase Subunit I (COI) of Two Laguna Populations of the Cacao Pachyrhynchine Beetle,
Pachyrhynchus moniliferus Germar, 1823 (Coleoptera: Curculionidae). Philipp J Sci 152(1): 351–356.
https://doi.org/10.56899/152.01.27

 

ABSTRACT

Pachyrhynchus moniliferus Germar is one of the major insect pests in cacao plantations in Luzon Island, Philippines. It is morphologically very similar to other Pachyrhynchus species and, thus, often mistakenly identified. Consequently, inappropriate control measures are applied. Herein, two P. moniliferus populations from Laguna province, one from Los Baños and the other from Magdalena (Philippines), were morphologically examined and DNA barcoded. The Magdalena population has a bigger body size, as well as a longer and wider rostrum compared to the Los Baños population. Comparison between the Folmer fragment of the COI gene of the Pachyrhynchus from Los Baños and Magdalena to the nucleotide sequences in the GenBank revealed a best match of only 87% identity to P. speciosus Waterhouse (KU953498.1) and 88% to P. orbifer Waterhouse (KU953440.1), respectively. The COI sequence of P. moniliferus presented here is the first DNA barcode reported for this species (GenBank Accession Numbers: MT038197.2–MT038204.2). We recommend conducting more thorough morphometric studies in conjunction with genetic diversity analyses on the different P. moniliferus populations across the Philippine islands.