河北省代表地区的蝇类相

河北省地区甚广,对蝇类相的调查过去尚无详细报导。本教研组于1957年呈请学院转请省卫生厅协助。要求我省各县寄送蝇类标本,以便初步了解一下情况。采集时间分7—8月(7月下旬至 8月上旬)及 9—10月(9月中下旬至10月)两次。以便比较蝇类季节分市的不同。对寄来标本将损坏或发霉不能观察者除外,首先进行分属,然后在每一属中     

THE CIRCULATORY SYSTEM OF THE ALDER FLY SIALIS LUTARIA

This is a comprehensive account of the circulatory system of all stages of Sialis lutaria L. The circulatory organs and pathways are described. In the larva an organ for circulating blood within the terminal segment is described. In the adult, blood vessels are described in the appendages and over the surface of the brain. Associated with these vessels are two types of accessory circulatory organs, pulsatile and valvular. The rates of heart beat, of circulation and pulsation of the scutellar organs are recorded.     

FURTHER OBSERVATIONS ON THE BIOLOGY OF THE CABBAGE ROOT FLY, ERIOISCHIA BRASSJCAE BCHÉ

In 1951, eggs of Erioischia brassicae were first found in the field on 2 May, and the peak period of egg-laying occurred 19–31 May. This was up to a month later than in the period 1948-50.
The periodic removal and examination of the surface soil showed that eggs of E. brassicae were continuously present on the host plants from mid-June to early November. Plants under observation during this period showed an average of 285 eggs per plant and other plants exposed to attack from July to November showed an average of 162 eggs per plant. Peak periods of egg-laying, as indicated by numbers of eggs per plant per day, occurred in late June and early July, in mid-August and, to a less extent, in the first half of October. The plants showed no increase in the rate of infestation as the season advanced, although E. brassicae has a reproductive capacity of about 100 eggs per female and three to four generations a year.
The difference between the observed egg populations and pupal populations indicated that E. brassicae had a heavy mortality rate in its immature stages. The condition of puparia showed that the species was subject to a high degree of natural control, a fact for consideration when direct control measures are formulated.
Pupal diapause extending from October 1949 to May 1951 was observed in one specimen of E. brassicae and from October 1949 to August 1951 in one specimen of its Hymenopterous parasite, Trybliographa rapae Westw.
Tests with tar-oil winter wash showed that at a concentration of 1 1/4% it killed eggs of Erioischia brassicae and repelled gravid females for approximately a week. Laboratory tests with BHC indicated that it had no adverse effects on the eggs but was larvicidal.