Performance of Trichogramma chilonis on different host

Abstract

The laboratory experiment was conducted during 2017-2018 to study the different biological attributes of Trichogramma chilonis Ishii as influenced by host eggs of different ages. Significantly maximum percent egg parasitization was noticed on eggs of Helicoverpa armigera (Hübner) with 62.39 percent which was at par with the Corcyra cephalonica (Stainton) eggs (60.36 percent). This was followed by Earias vittella Fabricius 46.31 percent. Less parasitized eggs were recorded in Leucinodes orbonalis Guenée (10.35 percent). Age of host eggs significantly affected the parasitization by T. chilonis. The maximum parasitization (58.87 percent) was noticed in fresh eggs i.e. 24 hrs old followed by 48 hrs (44.91 percent) while 72 hrs old eggs were less preferred by T. chilonis and could parasitize only 30.56 percent. Development period for parasitoid ranged between 8.66 to 9.44 days on different host eggs. The highest adult parasitoid longevity (7.22 days) was observed from the parasitized eggs of H. armigera which was at par with C. cephalonica (7.10 days), E. vittella (6.88 days) and L. orbonalis (6.88 days). However, the different lepidopteran eggs as well as age of host eggs did not show significant differences pertaining to percent adult parasitoid emergence. Fresh host eggs of 24 hrs could produce more female progeny of T. chilonis (54.30 percent) compared to 72 hrs old eggs (42.65 percent). The sex ratio (male: female) of emerging parasitoid progeny was observed highest on 24 hrs old eggs (1:1.55) followed by 48 hrs old eggs (1:1.23) while lowest sex ratio was observed on the eggs of 72 hrs old age (1:0.95). The maximum per day fecundity of T. chilonis was noticed on the 24 hrs old eggs (6.75) followed by 48 hrs old eggs (4.80). The lowest fecundity (2.05) of T. chilonis was observed on the 72 hrs old eggs, whereas the highest male-female ratio and fecundity was noticed on eggs of E. vittella among different hosts.