S. Mahunka szerk.: Folia Entomologica Hungarica 48. (Budapest, 1987)

Sex ratio of L

5 larvae and adults in two years (Budapest, 1983-84; monthly averages) TV V VT VTI Vin TX L5 N - - 35 115 197 55 5 male % - - 88.6 46.1 53.3 36.3 80 AN- 3 35 11 95 45 129 male % - 66.6 62.9 54.5 78.9 42.2 34.2 1984 L5 N 27 1 22 277 164 30 31 5 male % 70.3 100 63.6 56.7 48.2 46.7 35.4 60 A N 553 29 52 57 65 38 90 36 male % 39.7 18 48.1 49.1 86.2 44.7 54.4 33.3 5. Overwintering As it is well known overwintering takes place at the base of the pine tree and in the litter around the tree. In all our samples about 40 % of the individuals left the tree in autumn, in Vácrátót larvae and adults in similar proportion whereas in Budapest í.13, L4, L5 larvae and adults left the tree in increasingly high percentage (Table 4). Table 4. Distribution of individuals during overwintering (Budapest, 16.11.1984) L

3 L

4 L

5 g ? N N 3 192 12 88 144 439 bark % 100 88.6 50 55.6 40.2 65.1 litter % 0 11.4 50 44.4 59.8 34.9 6. Wing polymorphism In our studies, among the more than 3000 females collected throughout Hungary no sem*macropterous individual was found. Macropterous females developed among the first females and after copulation mostly migrated from the stands. Proportion of macropterous females is given in the literature (c. f. HELTÖVAARA 1984) 1-3 %. In Hungary In several samples considerably higher proportion were found: Vácrátót 4.2 %, Veresegyháza 5%, Budapest 11.6%, Ágasegyháza 20%, Darány 47% (actually increasing in N-S direction through Hungary). HELIÖVAARA (loc. cit.) by cutting of various parts of the trees, by crowding the population with transferred bugs and by nitrogéné fertilizing could not induce an increase in percentage of macropterous females and concluded that the aging of the stands with growth of trees and slow chemical changes may increase macropterous frequency. In Bugac on a Pinus silvestris tree burnt on one side in a damaging forest fire, all eight females found were macropterous. Previous forest or litter fire was reported from Darány and another locality (Békásmegyer, where a high proportion macropterous females was found but individuals were not counted) but we have no exact data concerning the location of burnt trees, thus, further studies are needed to support the above assumption between Are and the proportion of the migrating form.