The Endoparasitoid Aenasius bambawalei Hayat (Hymenoptera, Encyrtidae) has been synonymized with Aenasius arizonensis (Girault) (Hymenoptera, Encyrtidae) in 2014. It is a newly emerged parasitoid of mealybug Phenacoccus solenopsis Tinsley (Hemiptera, Pseudococcidae) and it has been found an efficient insect control tool. There is little information available on parasitoid origin factors responsible for modulation of mealybug physiology. Parasitoid’s venom contains biologically active proteins that have potential applications in pest management, some of them also have medicinal importance but venom components of A. arizonensis have not been studied yet. Venom glands tissues of A. tarizonensis were used for transcriptomic study and transcriptomic database was developed by using high throughput RNA sequencing approaches using Illumina Technology. The transcriptomic data of A. arizonensis venom glands was analysed by utilizing high throughput sequencing Illumina technology and de novo assemblies were constructed, containing 30,267,259 sequences reads which yielded 30,154,362 contigs and 8,507 unigenes which had significant BLAST homologies n the NR database. The database sequences showed homology to 2666 Nasonia vitripennis genes, 2065 Copidosoma floridanum genes, 1660 Ceratosolen solmsi genes, 1598 Trichogramma pretiosum genes and 1192 Cerapachys biroi genes. Further analysis was performed by selecting some genes encoding venom proteins which are potentially involved in the disruption of host immune system, developemental arrest and host paralysis. Sequenced mRNAs predicted to encode full length ORFs of Calreticulin, Arginine kinase and serine protease precursor proteins were identified, and tissue specific expression of these putative venom proteins was performed by RT-PCR which reveals that venom genes were not only exclusively expressed in venom tissues but also conserved in all carcasses of the parasitoid species. Application of crude venom and expressed proteins on cultured cell lines showed valuable results for understanding that there are paralytic factors in parasitoid venom which cause cell death. Whereas in functional analysis of microinjections, venom treated with heat and proteinase showed non-significant mortality which suggests that bioactive components of the crude venom were proteins which lost their biological activities upon heat treatments. Additionally, results also demonstrated that transcriptome de novo assembly allows useful venom gene expression analysis in species lacking genome sequence database which ultimately provide useful information for devising control tools for insect pest. This work also contributes to the understanding of the molecular and physiological bases of host parasitoid interaction in insects that may provide an unexplored resource for diverse biotechnological application and useful information for entomologists seeking to devise sustainable control strategies for cotton mealybug.