A heterozygous moth genome provides insights into herbivory and detoxification

How an insect evolves to become a successful herbivore is of profound biological and practical importance. Herbivores are often adapted to feed on a specific group of evolutionarily and biochemically related host plants1, but the genetic and molecular bases for adaptation to plant defense compounds remain poorly understood2. We report the first whole-genome sequence of a basal lepidopteran species, Plutella xylostella, which contains 18,071 protein-coding and 1,412 unique genes with an expansion of gene families associated with perception and the detoxification of plant defense compounds. A recent expansion of retrotransposons near detoxification-related genes and a wider system used in the metabolism of plant defense compounds are shown to also be involved in the development of insecticide resistance. This work shows the genetic and molecular bases for the evolutionary success of this worldwide herbivore and offers wider insights into insect adaptation to plant feeding, as well as opening avenues for more sustainable pest management.Minsheng You … Simon W Baxter … et al

Isolation and Characterization of Microsatellite Loci for Cotesia plutellae (Hymenoptera: Braconidae)

Fourteen polymorphic microsatellite loci were isolated in this transcriptome-based data analysis for Cotesia plutellae, which is an important larval parasitoid of the worldwide pest Plutella xylostella. A subsequent test was performed for a wild C. plutellae population (N = 32) from Fuzhou, Fujian, southeastern China, to verify the effectiveness of the 14 microsatellite loci in future studies on C. plutellae genetic diversity. The observed number of alleles ranged from two to six. The expected and observed heterozygosity ranged from 0.123 to 0.316 and from 0.141 to 0.281, respectively. The polymorphism information content (PIC) value ranged from 0.272 to 0.622. Potentially due to the substructure of the sampled population, three of the 14 microsatellite loci deviated from Hardy—Weinberg equilibrium (HWE). Further, loci C6, C22, and C31 could be amplified in Cocobius fulvus and Encarsia japonica, suggesting the transferability of these three polymorphic loci to other species of Hymenoptera