Six-Spined Ips, Six-spined Engraver Biological Control
Ips calligraphus (Germar)
From: Frank, J. Howard and John L. Foltz, 1997, Classical Biological Control of Pest Insects of Trees in the Southern United States: A Review and Recommendations, USDA, FS, FHTET-96-20.
Native: AL, AR, FL, GA, LA, NC, OK, TN, TX, VA, WV, and North, and Bahamas, Dominican Republic, and Jamaica.
Resident natural enemies: Braconidae: Coeloides pissodes (Ashmead) -- GA, TX, and North; Torymidae: Roptrocerus xylophagorum (Ratzeburg) -- GA, LA, MS, NC, TX, VA, WV, and North and West; Pteromalidae: Tomicobia tibialis Ashmead not in South. Much information on natural enemies in the Gulf Coast states was reviewed by Kulhavy et al. (1989), and shows variation in the natural enemy complex among places and host tree species. The review does not specify the level of mortality inflicted on each of the three Ips species by each of the presumed predators and parasitoids listed, but gives the relative abundance of the presumed natural enemies. Perhaps some of the presumed natural enemies attack the three Ips species indiscriminately, but this is not known. Some of the natural enemies have not even been proven to attack Ips. For example, there is a widespread assumption that staphylinid beetles are predatory, and some authors list all staphylinid beetles (for which they are able to obtain identification) as predators, based on this assumption. Though some staphylineds are, indeed, obligate predators, others are strict fungivores or detritivores, and others are facultative predators. The quantitative effect of each staphylined species that occurs frequently or infrequently under pine bark on named Ips species apparently has not been evaluated anywhere in North America. Staphylinidae are a prime example of this problem because their taxonomy in North America has lagged behind other families, so that identification has been uncertain; consequently, forest entomologists avoided working with them or assumed they are predatory. The same is true to a lesser extent of other families of presumed natural enemies.
Biological control attempts: None known.
Biological control possibilities: See comments under Dendroctonus frontalis.
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