中国四川蝇科五新种（双翅目）

记述采自中国四川雅安地区及附近山区蝇科５新种：亮绿翠蝇Ｎｅｏｍｙｉａ ｎｉｔｅｌｉｖｉｒｉｄａ,ｓｐ．ｎｏｖ．;名山妙蝇Ｍｙｏｓｐｉｌａ ｍｉｎｇｓｈａｎａｎａ,ｓｐ．ｎｏｖ．;广叶阳蝇Ｈｅｌｉｎａｐｌａｔｙｃｅｒｃａ,ｓｐ．ｎｏｖ．;西南阳蝇Ｈｅｌｉｎａ ｘｉｎａｎａｎａ,ｓｐ．ｎｏｖ．;圆尾圆蝇Ｍｙｄａｅａ ｄｉｓｃｏｃｅｒｃａ,ｓｐ．ｎｏｖ．。模式标本存北京军事医学科学院医学昆虫标本馆。     

Measurement of predatory behaviour in cow dung-colonising insect larvae, using compound-specific 13C-tracing of dietary fatty acids

Studies of the trophic interactions between organisms in opaque environments where direct observation can be difficult, such as soil or leaf litter, often require the use of indirect inferential approaches. Here, the use of compound-specific ¹³C-tracing of dietary biomarker fatty acids is evaluated as a method for studying predation by larvae of the dung-breeding fly, Mesembrina meridiana (Diptera: Muscidae); the technique was used to differentiate dung from high-enrichment ¹³C-labelled prey in their gut contents. Potential prey, ¹³C-labelled larvae of the dung-breeding fly, Neomyia cornicina (Diptera: Muscidae), were placed into unlabelled dung microcosms in the laboratory. A single 7-day-old M. meridiana larva was allowed to feed in each microcosm for 8 h. The magnitude of increases in the δ¹³C values of fatty acids (i14:0, 14:0, i15:0, a15:0, 15:0, 16:0 and 18:0) in the gut contents, relative to those of M. meridiana deprived of prey, demonstrated the predation of N. cornicina larvae which were estimated to have constituted at least 35% of the average dietary wet mass of these M. meridiana larvae. The tracing of specific labelled compounds increased confidence in dietary assessment and helped to avoid systematic errors associated with compound-dependent efficiency of assimilation in the gut. The results demonstrate the potential value of this method in helping to elucidate trophic interactions in predator–prey systems within opaque environments. The precision of the quantitative dietary estimation that arose from these isotopic data was superior to that generated using fatty acid distributional data, a widely used and evidentially independent line of evidence.     

Effects of ingestion of dung containing ivermectin on aspects of behaviour in the fly Neomyia cornicina

Abstract. Adults of the dung fly Neomyia cornicina (Fabricius) were fed continuously on either dung containing no ivermectin (control dung) or dung containing 0.125 μg g^-1or 0.25 μ g^-1ivermectin (wet weight).Comparisons were made between the behaviour of flies during the first 24 h of dung feeding and that observed after 96 h of feeding.Subsequent experiments investigated the effects of ivermectin ingestion on three measures of locomotory ability: escape time, time to re-right, and capture time.
Analysis of behavioural data showed a significant reduction in the activity of ivermectin-fed flies compared to that of the controls.After 96 h of feeding on dung containing ivermectin, there was a significant increase in the duration of time spent standing and a reduction in duration and frequency of walking and grooming behaviours compared to controls.
Seventy-two hours after the onset of dung feeding, flies fed dung containing ivermectin took significantly longer to escape from a glass tube and to re-right themselves after overturning than flies fed control dung.The time taken to capture flies that had fed on dung containing ivermectin at 0.25 μg g^-1was significantly shorter than that required to catch control flies when flies from the different treatment groups were presented blind and randomly.