Rotarides Mihály (szerk.): A Magyar Természettudományi Múzeum évkönyve 32. (Budapest 1939)

Szent-Ivány, J.: The migration of the Pieris brassicae in Hungary in the year 1937

Both in Hungary and Germany as in Switzerland the summer generation of the Pieris brassicae appeared in tremendous masses. In my present report I give an account of three migratory observations in the Transdanubian District: 1. From the 17-th July till the 24-th July 1937 I worked in the Biological Institute of Tihany and at the same time I was devoted to zoological observations and collectings on the Tihany peninsula. The Pieris brassicae appeared here in tremendous masses. On one occasion I observed also the migration of the animal. On the 21-th July they flew to a height of 1—15 metres above the surface of the Balaton lake in stripes of about 5—600 m. towards the east of the Tihany peninsula (See fig. 1.), the flying-direction was NE

—SW. The two banks are in 3 km. distance of each other. The movement began in the morning about 9 o'clock and lasted till evening but not with the same intensity. The largest masses I observed about noon between 10 and 12 o'clock. Those, which arrived at nightfall, occupied the walls of the Sport Hotel, which is very near to the beach of the Balaton lake, later on disturbed here they flew to and fro in groups of 30—40 round the arc-lamps of the Hotel-terrace. It was a quite unusual sight to see these large whites to fly around our lamp. I have to mention, that we had in that period a warm summer-weather. The temperature on July 21 at 7 o'clock in the morning was 23.2 degrees, at 12 o'clock in the midday 27.8 degrees and at 9 o'clock in the evening 23.1 degrees Celsius. The weather was clear, a soft breeze was blowing all the day long. In the next table I give the meteorological data of the Biological Institution of Tihany from the 18-th till the 25-th July 1937: July 1937. Tihany. Observer: F. HOLLY Temperature oî ear Winddirection Rain Day 7

h 14h 21h Max. Min. 7

h l

4

h 21« 7-i4

h 14-21 h 21-7

h 18 18.9 25.0 23.2 26.6 17.8 NW

2 NEj W

i n y ny 19 21.0 23.6 21.6 28.5 18.5 S

l NW

3 0 65 6.5 oi3h50'-17hSt. 20 22.0 28.0 22.6 28.6 18.2 E

i 0 0 • • 21 23.2 27.8 23.1 28.6 19.5 E

i NE

1 NW

1 22 22.8 27.8 23.0 28.6 19.1 0 s

t NW, 0.1 0.3 0.4 23 19.5 21.6 21.5 23.2 19.2 s 0 ny 24 21.6 29.6 26.2 30.0 18.0 0 0 s

l 5.0 5.0 0li20-0h50'St. 25 21.0 28 2 25.0 29.0 19.0 N

! s

i 27.0 17.0 0.40-6.30 St. °=rain, ny = rain in immeasurable quautities (less than 0.1 mm.), St. = storm*