| The Erannis anker aria Staudinger is one of the major pests of larch forest. The biological characters, temperature influence on growth and the sex hormone were studied at laboratory and in the field at Jining, Inner Mongolia. And the thesis compared the different influences bore by two parasitized plants. Larix principis-rupprechtii Mayr and Quercus wutaishica Mary, on larval development duration and pupal weight. The result shows:1. E. anker aria was one generation in a single year and overwintered as egg on cones at Ulanqab, Inner Mongolia. Larvae presented from early May to July. Pupae occurred from mid-later June to early-mid September. Adults emerged from September to October. The larval stage was about19.96±0.86days, the prepupa3.93±0.95days. the pupa stage about108.4±13.17days at the temperature of20℃, RH70%at laboratory. Pupae gathered mainly at the distance of30-90cm around the stem base in the depth of4-8cm surface soil. The adults emerged mostly at20:00-24:00and females mainly at6:00-8:00and12:00-16:00of the day. Adults could mate immediately after emergence. Mating duration was about20-260min and the most last50-150min. At the temperature of20℃, the longevity of copulated female and male was5.56=1.47and3.95±0.95days, respectively. and the fecundity was162.17±69.99eggs per female, but on the contrary, the longevity of un-copulated female and mail was8.03±2.90and4.38±1.59days, respectively, and the fecundity was164.09±81.30eggs per female but the eggs could not hatch. At the temperature of15℃, the longevity of un-copulated female and mail was14.48=6.67and6.64±1.76days, respectively, and fecundity was145.71±76.83eggs per female.2. The temperature affects the growth, development and survival rate of E. Anker aria parasitizing on the L.principis-rupprechtii. In the scope of19-29℃, all the hibernating eggs can be hatched out. but the hatching ratio is0at the temperature of31℃. Under different temperatures, the survival rate, pupation rate and emergence rate of the larvae at different instars appeared differently. Among the temperature of15-29℃, all the larvae could develop to the pupa stage, and at the temperature of19℃larvae developed fast. But the most suitable temperature for pupae is15℃. At the temperature of25℃, the larvae grow the fastest and prepupal period is the shortest. There also existed remarkable significant quadratic regression relationships between the temperature and developmental rates of E. ankeraria. Based on the direct optimal method, the developmental threshold temperatures of E. ankeraria in each instar larvae from the1st instar to the5th instar, larval, prepupa stages were3.53.4.78.5.47.5.77.11.82,4.28and5.59℃. respectively, and the corresponding effective accumulated temperatures were107.90,60.47,64.87,74.84,138.77,459.77and86.72day-degrees, respectively. The pupal weight, egg laying amount and spawning rhythm were most sensitive to temperature change. There is significant difference between the maturity durations of male and female. The males of this species emerged earlier than females at different temperature, which shows that E. Ankeraria belongs to proandry.3. The larva duration of E. Ankeraria parasitizing on the L. principis-rupprechtii and O. wutaishica is17.63±1.54d and17.31±1.12d, respectively, showing that the difference is not obvious. The weight of pupa fed Q. wutaishica is0.1385±0.0272g, being heavier than that of the pupa fed L. principis-rupprechtii, the latter weights0.1206±0.0259g.4.The sex pheromone gland of female E. Ankeraria lie probably in abdomen, accurately the8th-9th section. For the male, its results of EAG reaction match their age. |
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