STUDIES ON OSCINELLA FRIT LINN.

Data, collected in Sweden during the year 1927, indicate the existence of considerable variation in extent of infestation of the grain of different varieties, sown at the same time. Also they suggest that sterility or "blindness" of grain may be a varietal character.     

THE EFFECTS OF SPRAY TREATMENTS ON INFESTATION OF THE OAT CROP BY THE FRIT FLY (OSCINELLA FRIT L.)

Criteria are given for the timing and assessment of the effect of sprays on experimental plots, based on biological observations at Silwood Park from 1950 to 1955 and on previous work.
A preliminary experiment on small plots in 1952 indicated that 'blanket spraying' with DDT and parathion throughout the life of the crop gave protection against both tiller and grain attack. A more detailed replicated plot trial in 1953 showed that for oats planted on 22 April two carefully timed tiller sprays with parathion reduced tiller infestation from 31 to 3%. Six panicle sprays at weekly intervals reduced a heavy grain attack of 60% to 13%. Dieldrin was also effective but significantly less so than parathion. Much of the damage to the crop was caused by weed growth following initial loss of the primary oat shoots.
In 1954 and 1955 two and three parathion sprays were applied to 2-acre fields in order to study recolonization. Despite almost complete control of the tiller generation, a normal evenly distributed infestation of the panicles was found.
It is concluded that good control of the tiller generation may best be achieved by a spray programme based on knowledge of the phenology of the fly combined with that of the crop. The first general emergence in early May is likely to be critical.
Reinvasion of a sprayed crop may take place within 4–5 days and panicle infestation may not be causally related to tiller infestation in the same field.     

EXPERIMENTS ON THE MODE OF ACTION OF DIELDRIN SEED-DRESSINGS AGAINST SEEDLING ATTACK BY THE LARVAL FRIT FLY, OSCINELLA FRIT L

Experiments with dieldrin seed-dressings were done to see whether the conditions favouring their action against wheat bulb fly larvae apply also to frit fly.
Experiments with oats and wheat in boxes and a small field trial with oats showed that fewer newly hatched larvae were killed when dieldrin-treated seed was sown deeply than when sown 1/4 - 1/2 in. deep; shallow sowing probably puts the insecticide where the larvae are likely to meet it before they attack the plant. Kill was never complete even with dieldrin applied at almost forty times more than the highest rate normally used. This is partly because some larvae hatch from eggs on the plant and these, unlike those from soil eggs, can enter the shoot without touching the seed dressing.
Even in the most favourable circumstances (large doses of dieldrin applied to the shallow-sown seed and the plant at the one-leaf stage at the time of attack) there was little evidence that frit fly larvae are killed inside the shoot by systemic action of dieldrin translocated from the seed. This is not because the pales which normally surround the oat seed impair the uptake of insecticide, or because of any other factor specific to oats. Frit fly larvae also survived in wheat from seed dressed with doses of dieldrin that can kill almost all wheat bulb fly larvae by systemic action. Possible reasons for this difference are discussed.     

保定市蝇种及季节分布初步调查

蝇类在世界各地的分布极为广泛,种类繁多,每年出现季节较长,与人群接触极为频繁,因而常为传染各病的媒介,在我国已往对蝇类的分布及其与传染病的关系,所作的调查研究并不太多。姚、袁等氏(1929)在北京调查结果,发现在多数蝇类的体内含有大肠杆菌,且自肠内分离出痢疾杆菌,以及结肠内阿米巴、赤痢内阿米巴包囊,及鞭毛虫,纤     

西藏胡颓子属的研究

笔者在编写《西藏植物志》胡颓子科时,仅参考了1977年以前所采集的、并仅存于中国科学院植物研究所所植物分类室的腊叶标本,其他研究室或研究所的标本尚未见到,因此只记载了胡颓子属1个种、即牛奶子Elaeagnus umbellata Thunb.。最近又观察了中国科学院植物研究所生态室和青海高原生物研究所植物标本室标本,以及易同培同志采集的标本。     

济南常见蝇类的种类及其季节消长的调查

本文记述了1960年5月至1961年4月在济南市市区及郊区采用臭鱼诱捕及人工不定期采集对蝇类的种类及季节消长的调查结果。济南市蝇类的种类前人先后报告共有22种, 此次调查共发现42种, 其中21种为本地区的首次记录。蝇类季节消长总的情况是:自3—11月份在室外均可捕获到蝇类, 8月为其高峰:最常见种类的高峰如下:大头金蝇、银绿蝇均在8月, 舍蝇在10月, 市蝇为8、10两个月, 格氏丽蝇则在5月。全年诱得的蝇类总数中以大头金蝇为最多(18.06％):银绿蝇次之(16.64％):再次之为舍蝇(15.49％)及市蝇(15.06％)等。不同场所诱得的蝇类中占比例最高的蝇种则各不相同;北郊厕所以大头金蝇为最多(34.6％), 北郊马厩则以舍蝇(30.94％)、市蝇(30.06％)居首位, 市区食堂、酱园及南郊垃圾堆则以银绿蝇为最多(分别为37.54％、27.11％及19.36％)。此外, 对不同场所常见蝇类组成的季节变化本文也进行了分析。     

青岛蝇类及其季节消长的调查

关于青岛地区蝇类的记载,Karl氏(1935)曾报告有Ophyra chalcogaster(Wd.)、Fannia canicularis(L.)、Myiospila meditabunda(Fab.)及 Graphomyia rufitibia Stein等4种,郭郛氏(1952,1952a)记述了 Sarcophaga melanura Mg.、Sarcophaga similisMeade、Sarcophaga pergrina R.-D.、Lucilia ampullacea Vill.及 Lucilia illustris(Mg.)