S. Mahunka szerk.: Folia Entomologica Hungarica 34/1. (Budapest, 1981)

Table 1 Quantitative data of mass flights of some Thysanoptera species. (The number of individuals captured are presented according to periods of ten days. Keszthely, W Hungary, 1965, 1967.) Lim. denti cornis Anaph.obscurus Franki. intonsa Thr

. minitissimus (1,965) (1967) (1965) Í1967) 04.11-20 _ 0 _ 0 21-30 5 94 05. 1-10 0 1 0 398 11-20 0 7 0 14 21-31 0 2 0 0 06. 1-10 0 0 0 0 11-20 0 8 8 0 21-30 115 266 50 0 07. 1-10 5 52 11 0 11-20 0 28 66 0 21-31 0 5 82 0 08. 1-10 0 3 27 0 11-20 0 2 355 0 21-31 0 3 236 0 09. 1-10 0 1 1159 0 11-20 0 0 982 0 21-30 0 0 Results The suction trap, during the two years of operation, provided data both about mass flights of four thrips species, and about flights of some other species occurring in low abundances. In addition, rare ones or species new to the Hungarian fauna were also detected. The mass flights of the following thrips species had been shown: Limothrips denticornis Haliday, Anaphothrips obscurus (Müller), Frankliniella intonsa (Trybom), and Thrips minutissimus Linné. Flight of Limothrips denticornis females was noted during the last third of June, 1965, when on one occasion (June 26) a relatively high figure (59 specimens per 24 hours) was found In the suction trap. The air temperature of the preceding days was rising gardually. On the day of June 26 the mean air temperature was 25.5°C with a maximum of 31.5°C. Weather conditions remained unchanged during subsequent days. In spite of this, the number of flying L. denticornis declined sharply to almost nil. From the end of June no further specimens were found In the suction trap. In 1967, specimens were found sporadically, however, no mass flight was observed. As for the flight peak of 1965, it might have coincided with the onset of the ripening of cereals - the normal host-plants of this thrips species. The first individuals of Anaphothrips obscurus occured only on the last days of June, in 1965, and their numbers - slightly though - increased till the beginning of September. A peak number of specimens caught daily was 23. In 1967, only sporadic flights of the species were observed from early April. Mass flight was shown from June 24 to 25. During the two days, 266 A

. obscurus were collected. The mean air temperature of the preceding days was 19 to 20°C, the daily maximum was fluctuating between 24 and 27°C. During the days of the mass flight, mean air temperature was 23 to 24°C, with a max. at 30 to 32°C. The number of thrips dropped suddenly in the subsequent days, specimens occurred only sporadically. Frankliniella intonsa was regularly collected - albeit in low numbers - from mid April till autumn, and in both years. In 1965, the number of thrips caught was low till mid-June, and was slowly rising only at the end of this month. In July, it was again decreasing, while from midAugust there was a considerable rise in the number of individuals. The numbers of thrips collected by the trap were as follows: on 18 August 57, on the next day 100, on 1 Sept. 267, on the next