The morphology and regular pattern of prothoracic glands of

Spodoptera litura

were researched by dissecting these glands from the 4

th

instar larvae to pupation. The result showed that the prothoracic glands of

S.litura

were in pair with Y-type

consisted of 53 round or oval cells

surrounded with transparent vaginal tunica

and located in the tracheal plexus of the first spiracle. The cells of prothoracic glands kept steady because of no mitosis from the 4

th

instar larvae to pupation. The diameter of prothoracic gland cells was increased gradually during larval developments

the diameter of prothoracic gland cells from the larva at the first day of the 4

th

 instar was (28.80±0.47) μm

while the diameter of prothoracic gland cells from the larva at the last day of 6 instar was (92.22±2.43) μm. There were significant relevance between the diameter of prothoracic gland cells and the weight of larva during the larval development

r=0.826

P=0.000

Y=82.1

X

0.263

. There were also significant relevance between the diameter of prothoracic gland cells and the body length of larva during the larval development

r= 0.886

P=0.000

Y = e

(4.781-1.863/Z)

.