Fertility schedules of unaspis yanonensis (Hemiptera: Diaspididae) in relation to daily temperature

Abstract

Summary Fertility schedules of Unaspis yanonensis on citrus leaves were investigated from 1962 to 1971 for the first generation and from 1964 to 1971 for the second generation, at the Okitsu Branch of the Fruit Tree Research Station in Shizuoka Prefecture. The fertility curves were commonly characterized by a first major peak and a few subsequent minor peaks, although their shapes differed from year to year. Models estimating these fertility curves of each generation were constructed in relation to the fluctuations in average daily temperature, on the assumption that the curve was composed of two peaks, i.e., bimodal. Estimated curves were well fitted to observed ones.

Post-diapause development and multimodal oviposition activity of arrowhead scale, Unaspis yanonensis (Homoptera: Diaspididae) and its modeling

“…Adachi and Korenaga (1991) reported variable fecundities of 150 to 334 crawlers per overwintering female in Shizuoka Prefecture, Japan. The total fecundity of most overwintered females in our study was much higher than those in the previous studies in Japan where the results were obtained either by direct field observations (Adachi and Korenaga, 1991) or by estimations from a regression model between ovarian egg numbers and body lengths (Korenaga and Sakagami, 1978). Our study exploited laboratory observations of individual U. yanonensis females and their progeny.…”

“…For these reasons the discrepancy might occur during the later peak period. Also, many researchers may have reported two occurrence peaks in the field condition (Murakami, 1970;Adachi and Korenaga, 1991). To increase fitting ability of the model to the field circumstances, 560 D.-S. KIM et al it is required to include the individual variations of oviposition activity of females into the model and to exclude the 4th oviposition from the model.…”

“…The arrowhead scale typically shows bimodal oviposition activities per generation separated by a resting period, resulting in two distinct peaks in appearance of hatched nymphs (crawlers) in the field (Murakami, 1970;Adachi and Korenaga, 1991). Adachi and Korenaga (1991) developed a bimodal fertility model to predict the occurrence of U. yanonensis crawlers in the field.…”

“…Adachi and Korenaga (1991) developed a bimodal fertility model to predict the occurrence of U. yanonensis crawlers in the field. As this model was developed from empirical observations and under arbitrarily selected temperature threshold in Japan, it is expected for the model to have limitations in application to a field with different environmental conditions, i.e., citrus orchards in Jeju, Korea.…”

Temperature-dependent Fecundity of Summer Generation Adults of Unaspis yanonensis (Hemiptera: Diaspididae)

“…즉 화살깍지벌레 월동암컷은 실 험실 조건(24℃)에서 최대 4회의 산란 주기를 갖는다 . 이런 특이한 산란주기는 포장상태에서는 두 차례의 약충 발생기로 나타난다 (Murakami, 1970;Adachi and Korenaga, 1991;Kim et al, 2007). …”