Life History of an Exotic Soft Scale Insect Phalacrococcus howertoni (Hemiptera: Coccidae) Found in Florida

Kaushalya G. Amarasekare, Catharine M. Mannion


We investigated the life history of an exotic soft scale insect, Phalacrococcus howertoni Hodges and Hodgson that damages croton and several other economically important ornamental and fruit plants in Florida. There was no difference in the development, survival, and reproduction of this scale insect species when reared either on croton or on buttonwood at 27 ± 1°C, 12:12 (L:D) h and 65% R. H. The scale insect practiced ovoviviparity. We observed that eggs that came out from vulva hatched to first instars immediately. Newly hatched nymphs had a tendency stay underneath the female body for somewhat less than approximately 24 h and then disperse throughout the leaf area for feeding. Females went through 3 immature stages (first, second, and third-instar) prior to becoming adults, while males had 4 immature stages (first, second, third (‘pre-pupa’), and fourth instar (’pupa’)). Survival in the first instars was the lowest (50.0-50.9%), while the survivorship of the other instars was as follows: second instars (88.9-90.0%), third instar males (92.9-93.7%), third instar females (92.9-94.8%) and fourth-instar males (96.0-97.6%).Thus, approximately 40% of the first instars survived to adults. The pre-oviposition period was 17.6-19.1 d and the oviposition period was 13.9-15.5 d. Lifetime fertility was in the range of 382.4-394.7 live first instars per female. Intrinsic rate of increase (rm) was 0.091-0.095. The lifespan of adult males was very short (less than 1 d) at 27 ± 1°C compared to that of adult females (60.3-61.5 d).

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