AbstractsBiology & Animal Science

Ecology and Biology of Redbay Ambrosia Beetle (Xyleborus glabratus Eichhoff)

by Gurpreet S Brar

Institution: University of Florida
Department: Entomology and Nematology
Year: 2012
Keywords: ambrosia  – avocado  – beetle  – flight  – funnel  – laurel  – lauricola  – raffaelia  – redbay  – traps  – wilt; Entomology and Nematology
Record ID: 1976038
Full text PDF: http://ufdc.ufl.edu/UFE0044906


The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is a non-native species transmits the fungus Raffaelea lauricola that causes laurel wilt disease in trees of the family Lauraceae. The life cycle and development of X. glabratus were studied in logs of three hosts that it colonizes in North America: avocado (Persea americana), redbay (Persea borbonia) and swampbay (Persea palustris) at 25 ± 2°C. Similar developmental patterns were observed in the three hosts. Teneral adults were first encountered on the 31st, 30th, and 26th day after gallery initiation in these hosts, respectively. The life cycle appears to be overlapping. Three larval instars were observed in all three hosts. Xyleborus glabratus  was successfully reared on soaked swampbay logs and about 2.8 times as many female adults emerged from each log than were inoculated, with emergence continuing for about 240 days and maximum emergence taking place between 120-150 days after gallery initiation. Xyleborus glabratus successfully completed its life cycle at 24, 28, 32°C when development and life cycle were studied at temperatures ranging from 12-36°C in avocado logs. Development of egg and pupal stages of X. glabratus were studied at temperatures between 12-36°C. Developmental rates of the egg and pupal stages increased in linear fashion over the range of 16-28°C. Estimates for the lower developmental threshold for egg and pupal stages were estimated to be 10.9 ± 0.5°C and 11.3 ± 0.6°C and the degree-days (DD) for development were 55.3 ± 3.3 DD and 69 ± 4.5 DD respectively. The optimal temperature for life cycle and development of egg and pupal stages was around 28°C. Daylight flight rhythm studies showed that X. glabratus flies mostly between 1600 and 1800 h daylight saving time. In a trapping study to determine flight behavior, the largest number of beetles was trapped at heights of 35-100 cm above the ground. Seasonality of X. glabratus in north Florida studied from Mar 2010-Dec 2011 showed three peaks of trap catches occurred during Apr 2010, Oct 2010 and Mar 2011. Funnel traps with 8, 12, 16 funnels per trap captured similar numbers of X. glabratus, but significantly more than with 4 funnels per trap. New manuka lures trapped significantly more X. glabratus than lures aged 2, 4 and 6 wk.