Abstract:

Insect wax is an important raw industrial chemical excreted by 2^nd instar male nymphae of the white wax scale Ericerus pela (Insecta). In the traditional technique for insect wax production, egg laying females(known as seed insects) are reared in high mountain areas in Yunnan Province and then the nymphae are transported over long distances to low mountain areas in Sichuan, Hunan Province where they produce wax. The breeding of white wax scale egg laying female and insect wax production presently do not take place in the same region. A new production model in which egg laying female rearing and wax production takes place in the same region has been developed based on biological and ecological characteristics of the white wax scale. When white wax scale eggs are incubated, the female nymphae are hatched before male nymphae. Eggs being incubated at RH 80%±10% nymphae started to hatch at 10 ℃. At 15－20 ℃ all eggs hatched in 16－20 days, with a hatching peak for female nymphae between 9－11 days, and a hatching peak for male nymphae between 14－15 days. At 25 ℃ all eggs hatched in 11－12 days, with a peak for the female nymphae between 4－5 days, and a peak for male nymphae between 10－11 days. At 30 ℃ all eggs hatched in 9－10 days, with a peak for female nymphae between 3－5 days, and a peak for male nymphae between 6-8 days. The hatching conditions for wax production were determined by the formula D =12.5-0.35 T based on the relationship between temperature and hatching rate. In the field, the formula H _{a(♀)=(31.91-0.224 K )% was established based on the relationship between effective accumulated temperature and hatch rate. In this new production model eggs were hatched in two different sites, but in the same region, and this model was able to reduce transportation costs. Based on the hatching character of white wax scale, eggs were incubated first at the egg laying female production site for 10, 15 and 18 days, and then transferred to the wax production. When egg laying females were transferred after 10 days incubation, about 65% female nymphae and 15% male nymphae were produced in the egg laying female sites. Later hatching at the wax production site resulted in 35% female nymphae and 85% male nymphae. If being transferred after 15－18 days incubation, there were about 70%－80% female nymphae and 25%－35% male nymphae produced in the egg laying female production site, while later hatching at the wax production site produced 65%－75% male nymphae and 20%－30% female nymphae. As compared to traditional wax production techniques, this new wax production model resulted in the same amount of egg laying insects, but wax production was about 30% less. Wax output using the new technique, however, can be improved by selecting the shade site and increasing the density of host plants at the wax production site. In this paper we analyze why only egg laying females are presently produced in high mountain areas and wax is produced in low mountain areas.}

Key words: Ericerus pela, hatch character, new model for insect wax production, traditional model for insect wax production.