A Survey of Five Stem-Feeding Insect Pests of Wheat in the Northern Great Plains
The wheat stem sawfly, Cephas cinctus Norton, the wheat stem maggot, Meromyza americana Fitch, the Hessian fly, Mayetiola destructor (Say), the wheat jointworm, Tetramesa tritici (Fitch), and the wheat strawworm, Tetramesa grandis (Riley), have long been considered wheat pests in the northern Great Plains. This paper reports results of surveys for these pests conducted over 3 yrs in parts of Montana (10 counties), North Dakota (14 counties), South Dakota (1 county), Nebraska (4 counties) and Wyoming (1 county). Fields were randomly selected and a mean of 191 stems were sampled from each field. The percentage of stems infested with each pest was recorded. The percentage of parasitized wheat stem sawfly larvae also was noted. The wheat stem sawfly, wheat stem maggot, and Hessian fly were the most commonly encountered pests, recorded in nearly every county. Wheat stem sawfly density was twice that of wheat stem maggot (7% vs 3.2%) in infested fields. Wheat stem sawfly densities exceeded 10% in 4 counties: Da...
Hessian Fly (Diptera: Cecidomyiidae) Damage and Forage Production of Winter Wheat
Effect of Hessian fly, Mayetiola destructor (Say), damage on the forage production of susceptible and resistant cultivars of soft red winter wheat, Triticum aestivum L., was investigated in three experiments. Hessian fly damage reduced total dry matter yield of forage by 14 to 46%. Damage in all experiments was greatest during the first cutting when plants were in the seedling stage. Total forage yield declined linearly with increasing percentage of infested tillers when January infestations exceeded about 10%infested tillers. Low to moderate levels of Hessian fly damage reduced forage yield primarily by a reduction in tiller size and weight rather than tiller density. Severe infestations reduced tiller size and density. Hessian fly damage did not greatly affect crude protein or acid detergent fiber content of forage. Our study documents the potential risk of severe Hessian fly damage to wheat forage production. The economic benefit of using host plant resistance to control the Hessian fly in winter wheat grown for forage averaged $105/ha in these studies.
Mite population density analysis of stored dried apricots in Turkey
The aim of this study was to determine the population density of mite species attacking stored dried apricots in Malatya, Elazig and Izmir regions of Turkey. Storage construction types and duration of storage were also considered. The samples were collected during 2000–2003 in the most important apricot producing areas (Malatya and Elazig) and the exporting center (Izmir). Frequency of occurrence and rates of intensity of infestations were determined (16.50% from Malatya, 3.19% from Elazig and 80.49% from Izmir). A total of 16 mite species belonging to 13 genera and 11 families were identified during the surveys. The pest species Carpoglyphus lactis (L.) (Astigmata: Carpoglyphidae) was the most abundant species recorded (69.14% of samples). The highest infestation value recorded was 15,534 mites per kg.