MADRAS AGRICULTURAL JOURNAL

Active Dispersal of Trichogramma chilonis Ishii and T. pretiosum Riley Towards Host Eggs Under Confined Condition and Their Parasitisation Efficiency

Abstract

                                The active movement of two trichogrammatids viz., Trichogramma chilonis and T. pretiosum towards eggs of Leucinodes orbonalis Guenee and Corcyra cephalonica Stainton was assessed in 2cm diameter PVC tubes of 1, 2, 3, and 4 meters. The trichogrammatids moved up to 3m towards the eggs of L. orbonalis and C. cephalonica. T. chilonis showed more active movement than T.pretiosum. At a distance of 1m, 50.05 per cent of T. chilonis was recaptured on L. orbonalis egg cards which got subsequently reduced on the increase in the length of PVC tubes, which was 14. 64 per cent at 2m and 1.19 per cent at 3m and became nil in a length of 4m, while the dispersal behaviour of male and female parasitoid was compared. The female wasps were more active than male wasps and dispersed to a maximum distance of 3m in both the species. The study also showed that the preference of trichogrammatids towards the natural host (L. orbonalis) was more when compared to the factitious host (C. cephalonica). The recapture of T. chilonis and T. pretiosum at release distance of 1m was 50.05 and 28.58 per cent in L. orbonalis respectively whereas, C. cephalonica eggs attracted 41.25 and 9.66 per cent parasitoids respectively. Among T. chilonis, T. japonicum and T. pretiosum, T. pretiosum showed a higher parasitisation of 90.00 per cent and emergence of 91.03 per cent on one day old eggs of L. orbonalis. The study also showed that the age of host was a matter in parasitisation as well emergence of trichogrammatids. The increase in host age was negatively associated with parasitisation as well as emergence of trichogrammatids irrespective of species.

Key words : Trichogramma chilonis, T. pretiosum, Leucinodes orbonalis, Active dispersal, Parasitisation

Copyright @ 2019 Madras Agricultural Journal | Developed by Crystalpro All right reserved.

sequence. The Rice – Maize (T5) cropping sequence recorded the highest total N uptake and Rice – Sunflower (T1) cropping sequence registered higher total P uptake and the total K uptake was higher in Rice – Maize (T5) and Rice – Sunflower (T1) cropping sequences. Grain yield and straw yield were significantly higher under Rice – Maize (T5) and Rice – Groundnut (T7) cropping sequences. Though the Rice – Castor (T4) cropping sequence recorded highest B:C ratio of 2.08, considering the quantity of water consumption, economic yield, soil nutrients and B:C ratio, the best cropping sequence registered in Parambikulam Aliyar command area was Rice – Castor (T4) cropping sequence followed by Rice – Groundnut (T7) and Rice – Maize (T5) cropping sequences.

Key words : Cropping sequence, Nutrient dynamics, Nutrient uptake, Grain and Straw yield.

Copyright @ 2019 Madras Agricultural Journal | Developed by Crystalpro All right reserved.

Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Full Text
  • Copyright @ 2019 Madras Agricultural Journal | Developed by Crystalpro All right reserved.