1991-1993 Yıllarında yapılan bu çalışmada Spodoptera littoralis'in pupalarına topikal aplikasyon ve yumurtalarına daldırma şeklinde juvenil hormon analoğu methoprene uygulanmıştır. Bir günlük pupalar ile bir günlük yumurtalar bileşiğe çok duyarlı olmuşlardır. Oysa 3 günlük yumurtalar daha az duyarlı olurken, 4 günlük pupalar bileşiğe duyarsız olmuşlar ve uygulanan en yüksek dozdan (20 µg) bile etkilenmemişlerdir.

The experiments were carried under the controlled laboratory conditions of 24±2ºC temperature, 60±5 RH and 14:10 h photoperiod between 1991-1993 in Ankara University, Agricultural Faculty, Plant Protection Department. Juvenile hormone analogue methoprene whose effect has been proved against closed site pests was tested on pupae and eggs of Spodoptera littoralis  which is the important pest of cotton and vegetables in Turkey. Treatments were as topical application to 1-4 days old  pupae and dipping to 1-3 days old eggs. According to the results, 1 day old pupae and eggs were determined as more susceptible to methoprene than 4 days old pupae and 3 days old eggs, respectively. Pupa-adult intermediates occurred.