Seasonal phenology of calico scale, Eulecanium cerasorum (Cockerell), was monitored for 3 yr on various deciduous tree species in central Kentucky. Infestations were found on 16 host species in six plant families. Calico scale is a univoltine parthenogenic species that overwinters as second instars on bark. Nymphs molted to adult females around mid-April and began producing eggs in late April. Mean fecundity ranged from 3,728 to 4,654 eggs per female, depending on host plant species. Date of first crawler hatch in 2001–2003 ranged from 21 to 26 May, corresponding to a mean accumulation of 818 ± 2 Celsius degree-days (DDC), calculated from 1 January and a base of 4.4°C. This value predicted crawler hatch within 2 d in Lexington, KY, in 2004. Crawler dispersal lasted 2 to 3 wk. Upon hatching, crawlers move to leaves where they feed during summer. Crawlers primarily settled on the abaxial side of leaves and their within-leaf distribution varied between different tree species. Settled crawlers molted in mid-July and second instars remained on leaves until late September through mid-October, when they returned to bark to overwinter. On hackberry, Celtis occidentalis L., they were concentrated toward the basal end of shoots, primarily because leaf flush continued beyond the end of the crawler dispersal period. Crawler distribution did not differ between upper and lower canopy zones. Fourteen species of parasitoids and a coccinellid beetle were reared from individual scales. Monitoring with sticky traps in tree canopies confirmed that targeting crawlers with insecticides during late May or June would not coincide with peak flight activity of the scale’s primary parasitoids.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 98 • No. 4