1 Mar., 1902. ] QUEENSLAND AGRICULTURAL JOURNAL, 213 
Vegetable Pathology. 
By HENRY TRYON, 
Entomologist and Vegetable Pathologist. 
GRAPE FRUIT-ROTS. 
(Prares XVI. ann XVII.) 
Two forms at least of Fruit Rot of the grape, brought about by distinct 
agencies, have recently constituted subjects of complaint. 
1. Sun-scatp anp Brees (Plate XVI.)—In the February number of the 
Queensland Agricultural Journal (Vol. X., page 107) occurs a reference to some 
observations made by Professor J. Jablonowsky, State Entomologist at Budapest, 
relating to an instance of the display of an habit by bees, under exceptional 
arcumstances, of attacking previously uninjured grape berries, after having for 
a while exclusively directed attention to such as had their skins already broken. 
With respect to the incident now under notice, examples of the common 
Honey Bee (Apis mellifera) and of an indigenous Wasp (Polistes variabilis, 
Fabr.) were submitted as actual grape depredators also, and as causing the 
injuries that the fruit exhibited and the destructive changes that it had 
undergone. 
The grapes, partially ripened, had been derived from one of the direct 
bearers, amongst the American types of grape vines, known as the Iona. And 
not only were the damaged berries, that preponderated, dull brown in 
colour and more or less outwardly collapsed, but in many instances 
had been almost wholly deprived of their pulp and juice content, evidently in 
each case through a more or less conspicuous jagged-edged opening, that 
occurred upon the exposed face; pips and empty grape skin alone remaining. 
‘These appearances indicated on Plate XVI., that represents a portion of a 
thus injured bunch, favoured the alleged explanation regarding their origin. 
On closer examination, however, it was soon perceived that many of the affected 
berries, distended with their pulp and juice to a normal or even to an excessive 
degree, merely manifested on their exposed surfaces an area of brown 
colouration, that was traversed by a more or less gaping skin-fissure, extending 
almost across them, through which the subjacent tissue was accessible. Others, 
again, presented merely the bruise-like area of discolouration and a special 
turgidity, no fissure having as yet arisen, much less surface depression or 
collapse. It was also remarked that the injury was almost wholly confined to 
one face of the grape bunch. 
A few leaves, still attached to the bunch of grapes conditioned as 
described, had their borders narrowly occupied by an almost continuous band 
of reddish-brown discolouration interrupted along its inner edge. 
These features, presented by the leaves and fruit, are quite characteristic 
of sun-scald, a recognised form of injury pertaining to the grape vine, and 
one that might be expected to have occurred during the present vintage in South 
Queensland, in consequence of the phenomenally hot, dry windy weather that 
had been experienced during the few days that had preceded the manifesta~ 
tion of the injury complained of. 
The prevalence, moreover, of comparative arid conditions had removed the 
ordinary source of supply whence bees and wasps derive their usual sustenance, 
and in this absence of flowers the exposed sweet and juicy pulp of the Iona 
grape had furnished the food substances they needed. 
None of the berries exhibited injuries, such as it might be anticipated 
would be exclusively occasioned by one or other of the Hymenoptera named. 
But that these had availed themselves of the gaping fissures in the skins, that 
