103 
Part III."] Beeson : Beehole Borer of Teak. 
to bring forward facts in support of the idea that forest fires are destruc¬ 
tive to the teak borer, e.g. in the Indawgyi forests ( vide p. 11 ). Since 
then others have recorded cases in which beeholed timber is abundant 
in forests annually fired. In view of these contradictions it is necessary 
to theorise. 
If timber full of beeholes is extracted nowadays from forests that are 
never burned, and also from forests traversed by fierce fires the anomaly 
can be explained by inferring that fire-conditions and beehole production 
are not stable. In certain types of teak forest, fires are accompanied 
by profuse reproduction of teak, but in others, although teak seedlings 
readily appear, they are equally readily destroyed; in fire-protected 
forests or in moist mixed forests becoming evergreen, teak regeneration 
is scarce or non-existent. Abundant second growth of teak, particularly 
in pure or rich patches, means excellent facilities for the local increase of 
the borer and consequent overflow attack on neighbouring trees of greater 
age. Both high and low incidences of borer attack may thus be associated 
with fires, and low incidences with absence of fires. High beehole inci¬ 
dence in forests now evergreen and poor in teak postulates rather more 
extensive but not improbable changes in the flora. 
As regards the direct effect on the insect, it may be presumed that a 
ground-fire running through a teak forest will destroy ceramicus moths 
alive on that day and scorch eggs laid on the lower parts of the trunk. 
Subsequent fires are likely to be less fierce. The emergence period of 
the moth extends over at least 3 months locally [March—June ] and 
the average length of life of a moth is about a week. Assuming that 
180 moths emerge per acre (i.e., double the incidence recorded on p. 101) 
the number alive on any day will be 8 (= 16 ; hence it is doubtful 
if more 32 moths per acre, or 18 per cent will be destroyed directly by 
fire in one season. The incubation period is apparently prolonged 
and the possible destruction of eggs by a later fire is high; with inflam¬ 
mable undergrowth the zone of destruction is extended much higher 
up the bole. A smaller proportion of beeholes should be found in the 
lower parts of the bole than in the upper parts in fire-traversed areas. 
Such data as have been collected by the writer cannot be used for com¬ 
parison because of the absence of reliable past history with reference to 
fires, and until such is available the effect of fires cannot be evaluated. 
Effect of Undergrowth. —Data are contradictory : e.g. in the Okkyi 
plot absence of undergrowth is associated with a low or falling incidence ; 
in Bondaung a very sparse undergrowth is connected with a very high 
incidence ; in Mohnyin the incidence is not affected by the introduction 
of an artificial undergrowth; in Pyonchaung low incidence is connected 
with a dense stand and high incidence with an open wood and sparse 
[ 331 ] 
