lo Aug., 1912.] The Olive. 471 



the writer can ascertain it is not doing any damage in the phintations here. 

 It attacks chiefly the branches at the l)utt. sometimes also the fruit. Its 

 attack is noticeable by the formation of galls on the shonts. The fullv- 

 grown insect is greenish white in colour and the larvae yellowish. 



The Olive Twig Borer {Polycaon confertiis). — This beetle is reddish 

 brown in colour and about \ inch in length. Tt makes its attack by boring 

 into the twigs, usually close to the axile of the leaves. So far as can be 

 ascertained, it is not present in this country, and in America, where it 

 IS found, it has as yet done so little damage that it has received verv little 

 attention. 



Thrips. — During the flowering season of the olive countless millions of 

 these tiny insects swarm over the trees. It is hard to estimate the extent 

 of the damage that may be attributed to^ their presence, or to what extent 

 they affect the .setting of the fruit. It is doubtful whether the)- interfere to 

 anv great extent in the latter case, as heavy crops have been observed in 

 seasons when the insects were excessively numerous. Several species of 

 the familv {Tliripidcc) are native to Au.stralia, but the imported ones are 

 most commorilv met with. Judging by the varying appearance and size, 

 tl.ere i.suallv appears to be more than one species present on the olive. 



Treatment. — Owing to the number and variety of our spring blooming 

 plants, Thrips have every opportunity of multiplying during the flowering 

 season of the olive, so that it seems well nigh impossible to suppress them. 

 The Cape Weed proves a great harbour for them, and, consequently, it 

 should be got rid of among the trees. Fumigating with hvdrocvanic acid 

 gas will, no doubt, prove an effective remedy, if it can be economically 

 applied. Mr. French recommends the use of " Benzole Emulsion,"' or 

 white oil soap (i pound to each gallon of water used, and applied at 

 130 degrees Fahr.). 



Dry-Rot. — Th^ Californian (Station) Report for 1895-96. 1896-97 

 (]j. 235), gives the description of a disease which is not defniitely named, 

 but which cau.ses a gradual rotting of the fruits in spots. It appears in 

 that State to attack chiefly the Nevadillo olives. Reference is also made 

 Id a similar disease in Bulletin 62 of the Arizona Experiment Station. In 

 this ca.se it appears more commonly on the Columbella olives. A similar, 

 or identical, trouble is occurring here in a mild form on two varieties 

 of olives. It appears fir.st, just when the fruit is ripening, bv a slight 

 indentation or contraction of the skin of the fruit, gradually as the fruit 

 becomes riper the spots become more marked, and they become darker in 

 colour, extending in diameter and depth, and reaching right to the stone. 

 The affected parts .subside greatly, and tissues become dry and brown, 

 similar in some respects to the effects of Bitter Pit. The trouble usuallv 

 occurs towards the apex of the fruit, and is more marked in the wet years 

 than in the dry According to Mr. McAlpine, it is one of the Micro- 

 diplodia. Since it has confined itself to two varieties, and then appears 

 only in a very mild form, it has not called for any special investigation. 



(To be continued.) 



