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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #242586
Title: Paratachardina pseudolobata (Cocccoidea: Kerriidae): bionomics in Florida

Author
item HOWARD, FOREST - University Of Florida
item Pemberton, Robert
item SCHROER, SIBYLLE - University Of Florida
item HODGES, GREG - Florida Department Of Agriculture And Consumer Services

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2009
Publication Date: N/A
Citation: N/A

Interpretive Summary: The lobate lac scale is a serious pest of native and ornamental woody plants in southern Florida and the Bahamas. Life history data were collected to better understand the pest in Florida. Males are absent in Florida populations and the females can produce offspring without males. Scales develop to adults in 15-19 weeks and the crawlers of the next generation were observed in 21 weeks. The number of crawlers observed each month was similar throughout the year. Lobate lac scales subjected to a simulated light frost (-3oC) in a temperature chamber had low survival. A few crawlers isolated without their plant hosts were found to be able to survive 18 days. Large collections of lobate lac scales examined for parasitoid emergence holes found that parasitism has not exceeded 1%. These results indicate that the scale has at least two generations each year, and reproduces all year. The crawler stage, because of its ability to survive without host plants, may be source of spread of the pest. The lobate lac scale’s inability to tolerate simulated frost suggests that it will not survive areas with frequent frosts. Natural parasitism remains low indicated the need for biological control.

Technical Abstract: Observations on the bionomics of lobate lac scale, Paratachardina pseudolobata Kondo & Gullan in Florida are reported. Lobate lac scale infests primarily the branches and main stems of <2 cm in dia; rarely were they found on stems larger than 4 cm in dia or on leaves and never on roots. They produce honeydew, but ants did not tend the scales nor did ants appear attracted to the honeydew, which is ejected from the scale instead of being present in collectable droplets. Males are absent in Florida populations of the lobate lac scale so females are parthenogenetic and ovoviviparous. The scales developed to adult female in 15-19 weeks. Crawlers of second generation were present 21 weeks after young crawlers of the previous generation were placed on a host plant. The pre-imaginal stadia were: first instar 8-11 weeks; second instar 7-8 weeks. The numbers of crawlers counted per month on host plants were notably uniform throughout the year, but there was evidence of a slight increase in crawler production during the warmer months. Lobate lac scales subjected to a simulated light frost of -3oC had a low survival rate. In a test of survival of lobate lac scales without a host, one of 22 crawlers survived 14 days, and three of 32 survived 18 days. Based on the numbers of exit holes in mature female tests the rate of parasitism since this pest was found in Florida has not surpassed >1%.