Seasonal phenology and abundance of Leucopis argenticollis, Leucopis piniperda (Diptera: Chamaemyiidae), Laricobius nigrinus (Coleoptera: Deridontidae) and Adelges tsugae (Hemiptera: Adelgidae) in the Pacific Northwest USA

Abstract Adelges tsugae infested western hemlock trees were sampled periodically for 1 year at two locations in Oregon and Washington to compare the phenology and abundance of three associated predators (Leucopis argenticollis, Leucopis piniperda, and Laricobius nigrinus) and their host. On each sample date, two 3–10 cm long terminal twigs were collected from each tree and brought to the laboratory to count all life stages of A. tsugae and the three predators. Peak larval abundance of Leucopis spp. and La. nigrinus coincided with the presence of A. tsugae adults and eggs. Leucopis spp. larvae were present for a much longer period of time than were La. nigrinus larvae. Furthermore, Leucopis spp. larvae were present during both the progrediens and sistens egg stages, while La. nigrinus larvae were only present during the progrediens egg stage. Overall, we collected 2.3–3.5 times more Leucopis spp. of all life stages than La. nigrinus. These results support the continued study of Leucopis spp. from the Pacific Northwest as biological control agents for A. tsugae in the Eastern USA.

[1]  Sarah M. Grubin,et al.  Prey Suitability and Phenology of Leucopis spp. (Diptera: Chamaemyiidae) Associated with Hemlock Woolly Adelgid (Hemiptera: Adelgidae) in the Pacific Northwest , 2011, Environmental entomology.

[2]  A. Cohen,et al.  Implementation and Status of Biological Control of the Hemlock Woolly Adelgid , 2011 .

[3]  R. Reardon,et al.  Implementation and status of biological control of the hemlock woolly adelgid , 2011 .

[4]  N. Havill,et al.  Hemlock woolly adelgid and its hemlock hosts: A global perspective , 2011 .

[5]  D. Ross,et al.  Predators Associated with the Hemlock Woolly Adelgid (Hemiptera: Adelgidae) in the Pacific Northwest , 2008, Environmental entomology.

[6]  A. Caccone,et al.  Mitochondrial DNA from Hemlock Woolly Adelgid (Hemiptera: Adelgidae) Suggests Cryptic Speciation and Pinpoints the Source of the Introduction to Eastern North America , 2006 .

[7]  J. S. Ward,et al.  Eastern Hemlock Forests: Guidelines to Minimize the Impacts of Hemlock Woolly Adelgid , 2004 .

[8]  L. Kok,et al.  Seasonal abundance and synchrony between Laricobius nigrinus (Coleoptera: Derodontidae) and its prey, the hemlock woolly adelgid (Hemiptera: Adelgidae) , 2003, The Canadian Entomologist.

[9]  V. Tanasijtshuk.  Studies on Nearctic species of Leucopis (Diptera: Chamaemyidae). I. The redescription of Nearctic Leucopis published before 1965 , 2002, Zoosystematica Rossica.

[10]  M. McClure.  Role of Wind, Birds, Deer, and Humans in the Dispersal of Hemlock Woolly Adelgid (Homoptera: Adelgidae) , 1990 .

[11]  M. McClure.  Biology and control of hemlock woolly adelgid , 1987 .

[12]  J. McAlpine,et al.  IDENTITY OF LEUCOPIS ARGENTICOLLIS AND DESCRIPTION OF A NEW SPECIES (DIPTERA: CHAMAEMYIIDAE) , 1972, The Canadian Entomologist.