Bionomics and Phenology of Ataenius spretulus123
| Autor: | H. D. Niemczyk, Gerald S. Wegner |
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| Rok vydání: | 1981 |
| Předmět: | |
| Zdroj: | Annals of the Entomological Society of America. 74:374-384 |
| ISSN: | 1938-2901 0013-8746 |
| DOI: | 10.1093/aesa/74.4.374 |
| Popis: | The black turfgrass ataenius, Ataenius spretulus (Haldeman) (Scarabaeidae), is an important pest of golf course greens, tees, and fairways in Hamilton and Clermont Counties, Ohio. Eggs average 0.75 by 0.52 mm and deposited in clusters of 11 to 12 in the thatch and thatch-soil interface. Head capsule widths of larvae average 0.5, 0.83, and 1.3 mm, respectively, for the three instars. Mature larvae are ca. 8.5 mm long and possess teges of 40 to 45 hamate setae on their rasters. The root-feeding larvae have caused wilt or death of host turfgrasses, Poa annua L., P. pratensis L., and Agrostis species. Pupae average 4.7 by 2.5 mm and occupy cells excavated while still larvae 1 to 8 cm deep in the soil. There are two generations per year in southern Ohio. Oviposition periods began in May and July. First-generation adults emerged in late June to early July; second-generation emergence occurred in August. The sex ratio favored females slightly. The dispersion pattern of infestations in sampling sites best conformed to a highly contagious or logarithmic distribution for all age classes. Second-generation adults overwintered after copulating (89.7% of females inseminated), with survival of 93 ± 3%. Males and females survived winter with equal success. Population density of overwintering beetles reached 264 per 929 cm2. A day-degree system of predicting A. spretulus activity and development in the field was based on a flight activity threshold of 13°C. Seasonal life history of the insect was also correlated to plant phenology. Oviposition of first-generation eggs occurred after 100 to 150 day-degrees when Spiraea vanhouttei (Briot) Zabel and Aesculus hippocastanum L. reached full bloom and Robinia pseudoacacia L. began to blossom. Appearance of second generation eggs occurred after 650 to 710 day-degrees when Hibiscus syriacus L. began to blossom. Generation periods of 60 to 70 days were observed in the field, where soil temperatures approached or exceeded 30°C. Incidence of milky disease at sampling sites ranged from |
| Databáze: | OpenAIRE |
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