Note: A new pest,Liriomyza trifolii, on cotton in the Büyük Menderes Valley, Turkey
The study was conducted to evaluateLiriomyza trifolii (Burgess) in the cotton fields of the Büyük Menderes Valley, Turkey, from 1999 to 2000. Leaves were sampled weekly from the middle of June to the middle of August and kept in the laboratory to observe emerging leafminers. Leafminers were initially found on cotton leaves from 35 to 66 days after sowing. The numbers of larval mines varied from one to four per leaf. The largest number of infested leaves was observed in Aydın (Center), where 18.8% and 17.7% of the sampled leaves were infested in 1999 and 2000, respectively. We conclude thatL. trifolii is a potential pest in the cotton fields of Turkey and more research is needed.
Leafminers in vegetables, ornamental plants and weeds in Indonesia: Surveys of host crops, species composition and parasitoids
Extensive surveys of vegetable, ornamental and weedy plant species were conducted in highland and lowland vegetable production areas in Indonesia with the aim of recording leafminer species present and their associated natural enemies. The most common dipterous species reared from samples was the pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae). This introduced pest was particularly serious in highland vegetables in Java, Sumatra and South Sulawesi, causing yield losses as high as 60-70%. Another alien species, the vegetable leafminer, Liriomyza sativae Blanchard, contributed to problems in lowland areas on the north coast of West Java, where cucumbers were heavily damaged. An Asian leafminer species, Chromatomyia horticola Goureau, was more common in snow peas (Pisum sp.). Intensive sampling of leafminer-infested leaves from surveyed host plants yielded 11 species of hymenopteran parasitoids: 10 eulophids (Asecodes sp., Chrysocharis sp., Cirrospilus ambiguus (Hansson and LaSalle), Closterocerus sp., Hemiptarsenus varicornis (Girault), Neochrysocharis formosa (Westwood), Neochrysocharis sp., Pnigalio sp., Quadrastichus sp., Zagrammosoma sp.) and 1 eucoilid (Gronotoma sp.). The most abundant parasitoid species was H. varicornis. Levels of parasitism varied among crops and growing seasons, but were usually low, especially on potato (< 3%). Surveys revealed that most farmers (63%) attempted to control leafminers by applying insecticides twice weekly although these applications were neither effective nor economical according to responses of about 72% of the farmers. An integrated pest management approach is suggested that emphasizes IPM training for vegetable farmers and includes reductionor elimination of broad spectrum chemicals that would adversely affect parasitoids that may already be present as well as those that may be introduced. The initiation of a classical biological control programme is recommended to enhance the limited parasitoid complex present in Indonesia and increase levels of biological control.
Comparative studies of α-Lactalbumin and lysozyme: Echidna lysozyme
Summaryα-Lactalbumin is a modifier protein for galactosyl transferase in the biosynthesis of lactose and lysozyme catalyses the cleavage of β(1–4) glycosidic linkages. It is now generally believed that α-lactalbumin and lysozyme have diverged from a common ancestor. Comparative studies of these proteins from several species are reported here.The presence of lactose and lactose synthetase activity is shown in mature milk samples from a variety of placental mammals (eutheria) and a pouch bearing mammal (marsupialia). The isolation of the α-lactalbumins involved and their properties are compared.The position is different in the milk samples of monotremes. The α-lactalbumin, lactose and lactose synthetase activity levels in the two platypus samples studied are very low. The levels of lactose and lactose synthetase activity in some echidna(Tachyglossus aculeatus) samples are low, but appreciable in others. No α-lactalbumin is present. The lysozyme activity is appreciable, some samples containing a different lysozyme from that present in others. One of these (designated echidna lysozyme I) is capable of lactose synthetase modifier activity in the presence of bovine “A protein”.The properties of this lysozyme are compared with those of lysozymes and α-lactalbumins from a variety of species and their significance is discussed.