The utility of a universal DNA ‘barcode’ fragment of 658 base pairs of the Cytochrome C Oxidase I (COI) gene for the recognition of all animal species has been a widely debated topic on theoretical and practical levels. Regardless of its challenges, large amounts of COI sequence data have been produced in the last two decades. To optimally use the data towards reliable species identification will require further steps to validate the method and reference libraries. The fruit fly tribe Dacini holds about a thousand species, of which eighty are pests of economic concern, including some of the world’s foremost fruit and vegetable pests, and there are many morphologically cryptic species complexes in the tribe. Where previous studies showed limited success in using COI to identify Dacini, our results with a highly curated morphological dataset indicate high congruence between morphology and COI: 90% of the species in our 5,576 sequences, 262-species global dataset can be identified with COI alone based on a monophyly criterion. However, in some key pest species belonging to complexes that were previously thought diagnosable with COI, we found that expanded sampling and independent validation of identifications using genomic data revealed introgression of mitochondrial DNA. We find that the informative SNPs are uniformly distributed across the COI gene, and we provide recommendations for standardization. We conclude that reliable molecular identifications with COI require extensive species coverage, population sampling, and genomics-supported reference identifications before they can be validated as a “diagnostic” marker for specific groups.

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A fruit fly survey in the Sinharaja and Knuckles National Parks in Sri Lanka (2016), using traps baited with the male lures methyl eugenol, cue-lure, and zingerone, yielded 21 species of Dacini fruit flies. Of these, three species, viz. Bactroceraamarambalensis Drew, B.dongnaiae Drew & Romig, and B.rubigina (Wang & Zhao), are new country occurrence records, and Dacus (Mellesis) ancoralis Leblanc & Doorenweerd, sp. n. is described as a new species. The Sri Lankan Dacini fruit fly fauna is now comprised of 39 species.

Trichogramma chilonis and T. achaeae are egg parasitoids, considered as ideal candidates for managing the cabbage looper (Trichoplusia ni) through augmentative release. Mass rearing with steady supply of parasitoid is necessary to promote augmentative release. Numbers of factors contribute to the steady supply of parasitoids. Corcyra cephalonica eggs are extensively used for mass rearing. When there is an excess supply of host eggs, those eggs should be stored and used for parasitization when needs arise. Further, steady supply of parasitoids can be assured if parasitized eggs can be stored when there is excess supply. Adult parasitoids should be maintained as a parent stock and they should be fed with suitable food at the right concentration using a suitable feeding technique. In addition, it is important to know how many generations of parasitoids can be run continuously on C. cephalonica eggs without losing the parasitization capacity. These aspects were studied with the objective of improving the existing mass rearing protocol. T. achaeae and T. chilonis accepted stored eggs for parasitization, but the level of acceptance significantly varied with storage durations. The C. cephalonica eggs stored for two weeks at 4 or 8 °C were acceptable for parasitization. Pupal stage of both parasitoids within parasitized eggs can be stored upto two weeks at 4 °C or four weeks at 8 °C while maintaining at least 70% adult emergence. Performance of emerging adults in terms of parasitism significantly varied with storage duration. Bee honey was a better type of food source compared with glucose, fructose and sucrose for feeding parasitoids. The parasitoid adults can be fed with 50% bee honey using drop method successfully. Both species responded differently for number of generations that can be run on C. cephalonica eggs. It was four generations for T. achaeae and eight for T. chilonis.

10.3 ± 1.9, 7.5 ± 1.3, 38.1 ± 3.5 and 69.1 ± 3.1per day, respectively. L1, L2, L3 and L4 consumed adult aphids at the rates of 3.3 ± 0.6, 3.3 ± 0.6, 12.1 ± 0.9 and 25.1 ± 1.7per day, respectively. Female beetles consumed 1624.1 ± 0.2 nymphs and 1204.3 ± 1.3