Effect of temperature on life history and population growth parameters of Planococcus citri (Homoptera, Pseudococcidae) on coleus [Solenostemon scutellarioides (L.) Codd.]

Abstract

The development, life history, reproduction, and population growth parameters of Planococcus citri Risso on coleus [Solenostemon scutellarioides (L.) Codd.] were studied at various temperatures ranging from 10 to 37ºC, 70±10% RH, and photoperiod length of 16: 8 h (L: D). Females and males successfully developed into adults at from 15 to 32ºC and 18 to 32ºC, respectively. All first instars died at 10, 12, and 37ºC. Lower temperatures (10, 12, and 15ºC) caused higher egg mortality than did higher temperatures (32, 35, and 37ºC). At all temperatures (except 15ºC), the highest percentage of nymphal mortality was observed in the first instar. The sex ratio was female-biased between 15 and 30ºC, but there was a slightly higher number of males at 32ºC. The highest adult longevities of females and males were obtained at 18 and 25°C, respectively. The pre-oviposition, oviposition, and post-oviposition periods were significantly different at various temperatures. The highest fecundity was observed at 23ºC. The shortest and longest oviposition periods occurred at 32 and 18ºC, respectively. Maximum values of the intrinsic rate of natural increase (rm), net reproduction rate (R0), and finite rate of increase (λ) and the shortest mean generation time (T) and doubling time (DT) were obtained at 25ºC. Our findings showed citrus mealybug performances to be highly affected by temperature

Laboratory Studies on the Development and Life Table Parameters of Planococcus citri (Risso) (Hemiptera, Pseudococcidae) at Different Temperatures

“…The development time from egg to adult female of P. citri decreased gradually for laboratory rearing from 25˚C to 15˚C). It increased at temperatures higher than 25˚C (Goldasteh et al, 2009). These data are in agreement with the results of Walton and Pringle (2005) o C was the best degree of temperature for the citrus mealybug, P. citri life because it resulted in the highest oviposition (362.3 eggs/female), and adult longevity (11.7 days).…”

“…These data are in agreement with the results of Walton and Pringle (2005) o C was the best degree of temperature for the citrus mealybug, P. citri life because it resulted in the highest oviposition (362.3 eggs/female), and adult longevity (11.7 days). Results of Goldasteh et al (2009) indicate that 25°C is the optimal temperature for P. citri development among the tested temperatures.…”

“…No significant difference was observed between the number of eggs laid by females of P. citri reared either at 25 or 30˚C, while other females reared at 20 ºC and fed on the same food (potato tubers) gave fewer number of eggs for each female and siginificant difference were found among these females and other reared under controlled condition of 25 and 30˚C . However, Goldasteh et al (2009) noted that the highest number of eggs laid per female of P. citri was recorded at 23˚C. Chong et al (2003) found that temperature had a strong influence on fecundity of the madeira Mealybug, Phenacoccus madeirensis.…”

“…Results of Goldasteh et al (2009) indicated that at 35˚C, the survival rate of the second-instar nymphs of P. citri was 5%, but all of them died during the third instar. At 15˚C, none of the females were successful in oviposition.…”

“…Generally, the male nymphal periods of citrus mealybug reared under laboratory condition (at 20˚C to 30˚C) were reduced gradually by increasing the rearing degree of temperature for the four tested nymphal instars. However, Goldasteh et al (2009) mentioned that females and males of Planococcus citri had the highest average longevity at 18 and 20˚C, respectively. The lowest longevity of both females and males occurred at 25˚C.…”