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METHODS OF INVESTIGATING THE BIONOMICS OF THE COMMON CRANE‐FLY, TIPULA PALUDOS A MEIGEN, TOGETHER WITH SOME RESULTS
Author(s) -
BARNES H. F.
Publication year - 1937
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1937.tb05038.x
Subject(s) - biology , hatching , bionomics , larva , pupa , zoology , horticulture , toxicology , botany
SUMMARY1 Full‐grown larvae of Tip & paludosa Meigen were obtained by application to the soil of an emulsion of orthodichlorobenzene, and it is suggested that the larvae become non‐susceptible to this treatment about 6 weeks before pupation. The larvae were reared in pota of soil containing germinating and growing wheat. 2 The adult crane‐flies were kept in glass tubes for longevity trials which showed that on the average the males lived about 7 and the females 4–5 days. Mating and oviposition took place in these tubes. 3 Twenty‐seven females laid 5408 eggs, averaging 200 each. About 45 per cent of the eggs were laid the day the female emerged and 40 per cent the fist day after. It is believed that these figures are too low as the regular observations stopped a t 7 p.m. G.S.T. and it is suggested that 75 per cent of the eggs are in reality laid by midnight on the actual day of emergence and 10 per cent on the first day after. The eggs were kept damp in solid watch‐glasses which xere stood in water in culture dishes. 4 It is shown that by the time the peak of crane‐flies on the wing has been reached, the peak of eggs in the soil will already have been passed. 5 Hatching took place 11–15 days after the emergence of the parent crane‐fly, 2498 hatching from 5408 eggs. The young larvae were kept in Petri dishes and fed on wheat rootlets, clover or chickweed leaves, pieces of cabbage leaves, slices of potato or bran. By the time the 3rd instar was reached about 54 per cent mortality had occurred, chiefly owing to larvae escaping and cannibalism (576 survived out of 1257). This stage was reached in roughly 14 days. 6 The breeding potential was as follows: 51 per cent of the nearly full‐grown larvae emerged as adults (this figure is low because of the number of larvae escaping); 75 per cent of the available eggs were laid by the females; 46 per cent of the eggs laid hatched, and 46 per cent of the larvae survived the fist two instars. In other words, under the conditions of the experiment, on the average, one female crane‐fly laid 200 eggs, 92 larvae hatched and 44 survived the first two instars.