<p>The bark-eating caterpillar (<i>Indarbela tetraonis</i> Moore) is one of the two species of insect pests known to infest guava (<i>Psidium guajava</i>). Severe infestation with this pest causes drying up of shoots, which ultimately results in substantial losses in fruit yield and quality. Genetic options are considered most eco-friendly and cost effective to mitigate such losses. DNA marker-assisted breeding of guava for improved resistance to bark-eating caterpillar is expected to increase the efficiency of developing resistant cultivars. As a prelude to this, an investigation was carried out to identify pairs of genotypes contrasting for responses to infestation by bark-eating caterpillar and for a large number of simple sequence repeat (SSR) markers, for use as putative parents to develop mapping populations for chromosomal localization of genomic regions controlling resistance to bark-eating caterpillar in guava. Dendrogram generated by 135 polymorphic SSR markers could separate five morphologically resistant and three morphologically highly susceptible genotypes into two different clusters, barring two exceptions (Bangalore Local and 7–12EC 147036). Four pairs of accessions, viz., Superior Sour Lucidum and Seedless, Portugal and Seedless, Lalit and Seedless, Spear Acid and Seedless, had contrasting response to bark-eating caterpillar and were polymorphic at 111, 103, 101, and 101, SSR loci, respectively. These contrasting pairs of accessions are suggested for use as parents to develop mapping populations to identify DNA markers linked to genomic regions controlling resistance to bark-eating caterpillar, which could help in implementing SSR marker-assisted breeding of guava for resistance to bark-eating caterpillar.</p
