Welsh Journals

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PLANT PESTS IN GLAMORGAN. III. By H. W. THOMPSON, M.Sc., F.R.E.S. The following records of pest occurrences in Glamorgan were made in 1933. The species listed are the pests of growing crops or other products of commercial value and therefore of economic importance. Many of the records are based on a large number of observations of actual attack. The insects recorded have been grouped in each Order in accordance with the host plants attacked-Cereals, Potatoes, Pulse Crops, and so on. Several of the Insect Orders con- tain no harmful species and in the case of others only a very few species have been noticed to be causing appreciable injury. COLLEMBOLA. In this order Bourletiella hortensis Fitch has been noticed injuring Mangolds in all parts of the county. A condition known as Strangle is caused to seedling plants by their attack. Onychiurus armatus Tulb. was recorded at Penarth on Narcissus bulbs in January. DERMAPTERA. The Common Earwig Forficula auricularia L. caused some injury to Dahlias and Chrysanthemum blooms in late summer. THYSANOPTERA. Species. Locality. Host Plant and Date. Thrips cerealium Hal. Vale of Glam. Feeding upon developing grain during the sum- mer. Frankliniella robusta Drope, Cardiff, Slight injury to peas, Uzel Llantwit Major July. Thrips tabaci Lind Sully, Pencoed, Associated with "Spotted etc. Wilt" transmission on tomato, etc., June and July. Heliothrips haemorrhoi- Cardiff On various greenhouse dalis Bche. plants, July, etc. Thrips vulgatissima Cardiff On rose, November. HEMIPTERA. (a) Heteroptera.