| Abstract/Contents: | "An insect monitoring study was conducted in 1995 and 1996 to build on data generated in 1994 and to enable superintendents to predict the occurrence of key insect pests in advance of significant damage. Weekly black light trap counts of adult insect pests of turf were collected from April 17 - October 17, 1995. In 1996 the study period was lengthened to March 1 - December 1, 1996 to better characterize insect populations. Key results include: Black turfgrass ataenius (BTA) continued to be the most damaging pest detected, particularly in the non-desert areas of Southern California. Cool-season greens, tees, fairways and roughs were infested, but insecticide applications were made primarily to greens. The proximity of golf courses to rivers, wooded areas and/or livestock operations seemed to increase the chances of a BTA infestation. Up to five generations of BTA were observed from March through November, with the highest populations occurring in July, August and September. Black light trap data on adult BTA was effectively used to predict the appearance of BTA grubs. During the summer months, grubs were most likely to be found 1 - 14 days after a peak adult population. Grubs were most commonly found at the thatch-soil interface. Masked chafer grubs demonstrated different behaviors in Low Desert golf courses vs. inland courses vs. costal courses. At coastal courses, chafer grubs have not been identified as causing serious problems during the three years of this study. Despite this fact, we have seen high numbers of chafer adults at coastal courses, with one large peak of activity seen very consistently in the last week of June. At inland courses, the adult population dynamics were similar to coastal locations, but the grub stages of the chafer actually caused damage on tees, fairways and roughs (but not on greens) at some inland lcations during July and August. In the Low Desert, chafer grubs caused severe damage on greens and tees at many golf courses during July and August, and may have been mis-identified as black turfgrass ataenius grubs in some cases. Two peaks of adult chafer activity were observed in the desert -- one in late May/early June, and another in late August/early September. It is likely that a different species of chafer is responsible for each peak. Black cutworm and common armyworm adults had 4-5 key peaks between June and October, but were constantly present at low levels at all other times. The highest populations occurred in June and in October, with several superintendents reporting the season's worst worm infestations as late as November. Larval infestations were worst 2 weeks after adult moth peaks. Damage was worst following aerification. 1996 populations were substantially lower than 1995 populations at almost all test locations. Overall damage from insects was worst in July, August and September when turf is most stressed and therefore least likely to resist feeding. Monitoring programs for BTA, chafers, cutworms and armyworms were developed to help avoid serious insect damage, and are described below." |
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