Mortality of the Lobate Lac Scale Paratachardina pseudolobata (Hemiptera: Kerriidae) at Near or Below Freezing Temperatures

Juang-Horng Chong, Amy L. Roda, Catharine M. Mannion

Abstract


The ability of the invasive lobate lac scale, Paratachardina pseudolobata Kondo & Gullan, to survive exposure to near or below freezing temperatures (-25, -15, -10, -5, 0, 5, and 10°C) for extended durations (6, 12, 24, 48, and 72 h) was assessed in the laboratory. Exposure at 10°C for 6 to 72 h did not cause significant mortality in immature and adult lobate lac scales. All nymphs and adults were killed after exposure to very low temperatures (-25 to -10°C) for 6 h. All nymphs were killed within 24 h at -5, 0, and 5 oC, while about 2% of adults were still alive after 72 h at 0 and 5°C. Results suggested that the range expansion of the lobate lac scale in the United States will be limited by winter temperature. The lobate lac scale may have a higher potential to invade areas where the average winter temperature do not drop below freezing for an extended duration (3 or more consecutive days), such as southern Florida, Rio Grande Valley in Texas, and Colorado river Delta between California and Arizona.

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