Biological characteristics and ovipositing time forecast of Eriococcus abeliceae
Abstract：Eriococcus abeliceae Kuwana is one of the most important pests attacki
ng many kinds of garden trees. It occurred one generation per year in Xining, an
d overwintered as 2nd instar nymphs in bark crevices. It began to damage trees w
hen 2nd instar nymphs developed into 3rd instar nymphs in late March of next yea
r. Adult females started to lay eggs in early May, and the duration for eggs was
18-23 days. The fecundity was from 134 to 424 eggs per female with the average
of 287 eggs. Eggs began to hatch in early June and the hatching rates was 100%.
It was found 3 instars in females and 2 instars in males. The developmental thre
shold temperature and effective accumulated temperature for egg were determined
under natural temperature in lab. The results showed that the threshold temperat
ure was 12.98℃ and the effective accumulated temperature was 39.03 degreeda
y. The predicting equation for the rate of development was N=(39.03±2.66)/
T-(12.98±0.18).