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Trichogrammatids (Hymenoptera: Trichogrammatidae) are the most important egg parasitoids widely used in different biocontrol programs worldwide. Since there are several species, strains, and ecotypes available, correct identification is the first step for successful biological control programs. Morphological identification remains complex due to subtle difference in male genetalia, therefore alternative molecular techniques were employed for rapid and reliable identification of this group of parasitoids. Furthermore, many of the field collected specimens are females, which are not identifiable using morphological keys. This study was carried out to unravel the discrimination success in the two molecular marker loci cytochrome oxidase I (COI) and internal transcribed spacer-2 (ITS-2) region of trichogrammatids. In achieving these objectives, the single specimen of 22 trichogrammatids belonging to 19 species were subjected to DNA extraction, PCR amplification, and sequencing. Additionally, we obtained homologous sequences from GenBank and sequences in BOLD database to understand internal relationships between the trichogrammatids. Bayesian inference phylogenetic analysis conducted with 84 and 76 sequences of COI and ITS-2 loci respectively and studied discrimination among the different species. Based on trees in comparison, we observed that there was a total of 10 and 6 out of 19 species correctly discriminate with COI and ITS-2 respectively. Our result revealed that the ITS-2 gene was less divergent than the COI gene in the majority of species and failed to differentiate all terminal clades. Therefore, we recommend that COI is suitable as the primary DNA barcode locus in trichogrammatids. Overall, we suggest that COI gene has higher discrimination power and can be considered as an appropriate molecular marker for species identification in trichogrammatids.

ITS-2-RFLP method was employed to distinguish 12 different trichogrammatids consisting of indigenous and exotic species such as Trichogrammatoidea armigera and Tr. bactrae , Trichogramma achaeae , T. chilonis , T. japonicum , T. embryophagum , T. pretiosum (Thelytokous Form—TF), T. brassicae , T. dendrolimi , T. evanescens and T. mwanzai . ITS-2 region was amplified; complete ITS-2 sequences of nine species were deposited in Genbank. The size of the amplified product ranged from 500 to 900 bp. Restriction enzyme digestion of ITS-2 region showed different banding profiles for these 12 species. Dichotomous keys using the size of the ITS-2 product and the restriction fragment length polymorphism for the enzymes (EcoRI, MseI, MvaI, and TaqI) allowed quick species identification of these trichogrammatids.

The eggs of the factitious host insect, Corcyra cephalonica (Stainton), are used for production of several natural enemies in many countries across the world. Trichogramma spp. are used widely for the biological control of lepidopterous pests on various crops in more than 30 countries covering a total area of 3.2 million ha of agricultural and forest land. A novel and simple technique for storage of eggs of C. cephalonica by vacuum packing at 500 Hg−1 and stored at 8 ± 1 °C in refrigerator was developed to enhance egg viability for production of Trichogramma species, and assessed and compared with the traditional method. The percent parasitism of vacuum packed eggs was 100.0–75.0% after storing for 7–42 days and declined to 10.0% after 70 days storage compared to 100.0, 50.0, 40.0 and 5.0% parasitism after 7, 14, 21 and 28 days, respectively, in the traditional method. The percent emergence from parasitized eggs was identical in both vacuum and non-vacuum packed eggs indicating suitability of vacuum packing eggs. The percent females ranged 50.0–59.0% in vacuum-packed eggs and 48.4–55.8% in non-vacuum packed eggs. Vacuum packing enhanced storability of C. cephalonica eggs by 3- to 4-fold as compared to the traditional method of storage.