The Effect of Four Different Host Plants on the Larval Development of the Cotton Leafworm Spodoptera littoralis (Bois.)

The scientific aaproach for this study required the establishment of a standard laboratory colony of Spodoptera littoralis. Out of the initial colony 3000 larvae, were dealed into 4 groups, each one was subjected to one specific diet for ten successive generations. Four common host plants were chosen for this study: castor beans, sweet potato, cotton and alfalfa. Experiments were carried out on the fifth and tenth generation offsprings of the standard laboratory colony, to evaluate the effect of the four diets on larval duration and the net increase in larval weight/day for a period of ten days (from 4th to 14th day). With respect to larval duration, castor and alfalfa were similar in their effect whereas larvae required 15 days to develop. Sweet potato and cotton were similar in their effect where larvae took 19 days approximately. The net increase in larval weights was highest with castor and alfalfa. Zusammenfassung Uber die Wirkung verschiedener Nahrungspflanzen auf die Raupen der Baumwolleule Spodoptera littoralis (Bois.) In Laborzuchten wurden 750 Raupen von S. littoralis an Castorbohne, Suskartoffel, Baumwolle und Alfalfa aufgezogen. Wahrend der 5. und 10. Generation wurde 10 Tage lang die Wirkung der 4 Nahrungsarten auf die Raupenentwicklung und die Zunahme dcs Raupengewichts pro Tag ermittelt. Hinsichtlich der Entwicklungszeit verhielten sich Castoi -bohne und Alfalfa gleich (15 Tage). An Suskartoffeln und Baumwolle war die Entwicklung verlangert (19 Tage). Die tagliche Zunahme des Raupengewichts war am hochsten bei Castorbohne und Alfalfa.