An experiment to test these hypotheses measured boring beetle activity for 94 weeks from May 2002 until April 2004 against the four species of trees [4]. Groups of genotypes of trees were each treated with control conditions, irrigation, fertilization, and a combination of both irrigation and fertilization. Incidences of attack were recorded regularly using necrosis at the bore site as an indication of the presence or absence of attack. Necrosis was absent from the sycamore, sweetgum, and loblolly pine trees, thus no attacks were made against these. Insects collected from the traps were identified as predominantly Scolytidae. Among the 28 species captured--of which were predominantly identified as Scolytidae--more than 88 percent belonged to nine exotic species, which followed Coyle’s first hypothesis
An experiment to test these hypotheses measured boring beetle activity for 94 weeks from May 2002 until April 2004 against the four species of trees [4]. Groups of genotypes of trees were each treated with control conditions, irrigation, fertilization, and a combination of both irrigation and fertilization. Incidences of attack were recorded regularly using necrosis at the bore site as an indication of the presence or absence of attack. Necrosis was absent from the sycamore, sweetgum, and loblolly pine trees, thus no attacks were made against these. Insects collected from the traps were identified as predominantly Scolytidae. Among the 28 species captured--of which were predominantly identified as Scolytidae--more than 88 percent belonged to nine exotic species, which followed Coyle’s first hypothesis