Population structure of the banana weevil, an introduced pest in the Canary Islands, studied by RAPD analysis

Abstract

The banana weevil (BW), Cosmopolites sordidus (Coleoptera: Curculionidae), is one of the most important insect pests of bananas and plantains. The mobility and the origin of BW infestations at the Canary Islands (Tenerife, La Gomera and La Palma) have been analysed using Random Amplified Polymorphic DNA (RAPD) as molecular markers. Populations from Costa Rica, Colombia, Uganda and Madeira were also included for comparison. One hundred and fifteen reproducible bands from eight primers were obtained. The level of polymorphism in the populations from the Canary Islands (40-62%) was in the range of those found in other populations. Nei's genetic distances, pair-wise fixation index (FST) values indicate that the closest populations are Tenerife populations among themselves (Nei's genetic distance=0.054-0.100; FST=0.091-0.157) and Costa Rica and Colombia populations (Nei's genetic distance=0.049; FST=0.113). Our results indicate the existence of BW local biotypes with limited gene flow and affected by genetic drift. These results are compatible with a unique event of colonization at Tenerife; whereas, the outbreaks in La Gomera and La Palma may come from independent introductions. The Madeira population is phylogenetically and geographically closer to the Canary Islands populations, suggesting that it is the most likely source of the insects introduced in the Canary Islands.

Simulated Soil Moisture and Planting Material Health on the Behaviour of Cosmopolites sordidus, Germar (Coleoptera: Curculionidae)

“…Abera et al (1997) however gave a definite amount of up to 22 mature egg follicles from a single female adult in Uganda, which compares well with the limit potential fecundity of weevils reported in Ghana, which was a maximum of 17 mature egg follicles per female. These variations in inherent fecundity could be evidence of the existence of endemic banana weevil biotypes as reported by Magaña et al (2007) and Twesigye et al (2018).…”

Genetic variation among species, races, forms and inbred lines of lac insects belonging to the genus Kerria (Homoptera, Tachardiidae)

“…Despite the limitation posed by reproducibility, unless reaction conditions are stringent (Baruffi et al , 1995 and Bertin et al , 2007), this technique offers the advantages of simplicity, independence from prior DNA sequence information, and the evaluation of a large number of loci across the genome (Hadrys et al , 1992; Lynch and Milligan, 1994; Weising et al , 2005), besides providing the basis for developing more reliable SCAR (sequence characterized amplified regions) markers (Kethidi et al , 2003). The technique has already been widely employed for assessing the genetic diversity of other insect populations (Reyes and Ochando, 1998; Castiglioni and Bicudo, 2005; Dvorak et al , 2006; Lopes-Da-Silva and Vieira, 2007; Martins et al , 2007; Magaña et al , 2007; Karam et al , 2007; Sosa-Gomez et al , 2008; Sharma et al , 2009). …”