DNA barcoding of lepidopteran hosts and their parasitoids at Chulalongkorn University area, Kaeng Khoi district, Saraburi province

Abstract

Relationships between caterpillars and their parasitoids are poorly known due to the limitation of insect rearing and accurate identification. However, this knowledge is very important for controlling agricultural insect pests using parasitoids as natural enemies in biological control programmes and also for understanding interactions between caterpillar hosts and their parasitoids. During the recent decades, DNA barcoding technique has been developed and used for molecular identification, it could help identify both caterpillars and their parasitoids accurately and fast, also solve the problems about insect rearing. This research aims to preliminary study the relationships between caterpillars and their parasitoids at Chulalongkorn University Area, Kaeng Khoi District, Saraburi Province, Thailand. A total of 28 collecting trips, every 2 weeks started from November 2015 - November 2016, caterpillars were collected by hand. In total 5,673 caterpillars which are classified into 25 lepidopteran families were recorded. Noctuidae was the most abundance caterpillars discovered from this study while Drepanidae, Gracilariidae and Nolidae were the least abundance of caterpillars. Off these, 340 (~6%) caterpillars were parasitised by parasitoids. DNA barcoding revealed 124 provisional species of parasitised caterpillars and 113 provisional species of parasitoids. The most abundant caterpillar hosts belonged to Haritalodes derogate (family Crambidae) and for the parasitoid, tachinid fly, Peribaea sp.1 was the most frequently parasitoid recorded from the parasitised caterpillars. Orvasca subnotata and Cotesia sp.1 was the most frequently recorded of host-parasitoid interaction in study area. In term of host-parasitoid specificity, 80% were specialist parasitoids and only 20% were generalist parasitoids. DNA barcoding method is a rapid and powerful tool for identifying lepidopteran hosts and parasitoids and highly effective on resolving complex host–parasitoid relationships by constructing molecular food web of trophic interactions in poorly for study areas of tropic region. Host–parasitoid relationships from the databases can be applied for selecting potential natural enemies when there are outbreaks of lepidopteran pests in agricultural areas.