Abu ElEla S.A., ElSayed W.M.

Impact of enriched CO2 fumigation effects on plant-insect interaction: feeding behaviour and growth of early and late instar larvae of the cotton leaf worm Spodoptera littoralis (Lepidoptera: Noctuidae)

Number: 351, Pages: 17 - 26

The effect of enriched CO2 environments on natural plant-insect herbivore interactions is under attention. To understand such effects on insect growth and consumption, early and late instar larvae of the cotton leaf worm, Spodoptera littoralis (Lepidoptera: Noctuidae) reared on the cotton plant leaves Gossypium barbadens (Malvacae) grown under either ambient (350 PPM) or high (700 PPM) CO2 atmospheres. Despite consuming more foliage, the mean larval fresh weight of the early (2nd) and late (4th) instar larvae increased insignificantly with age when fed cotton plant leaves from both ambient and enriched CO2 regimes. Early and late Spodoptera littoralis larvae reared on high CO2-grown Gossypium barbadens consumed 32.87%, 44.98% respectively more foliage than larvae reared on low CO2-grown cotton plant. Larval duration for early and late larvae reared on high CO2-grown plants was longer compared with ambient treatments. The Consumption rate (CR) was decreased through the studied instars, with a high significant difference only between the 2nd instars. There was a tendency for ECI and ECD to decrease with age for larvae fed leaves from enriched CO2 treatment. Differences in growth responses of early and late instar larvae to lower nitrogen and high-CO2 grown foliage may be due to the inability of early instar larvae to efficiently process the increased flow of food through the gut caused by additional consumption of high CO2 foliage.  Under enriched CO2 regime cotton plant shoot and root are significantly stimulate length, fresh and dry weights compared with ambient regime.

DOI: http://doi.org/10.25221/fee.351.2

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