712 FKUIT CULTURE IN FOREIGN COUNTRIES. 



meaning blackness, and indicating the outward appearance of the af- 

 fected trees. The disorder is now generally believed to be caused by a 

 fungus either identical or closely allied to the Dematium monophyllum, 

 already alluded to as one of the most damaging parasites of the orange 

 tree. Trees standing on very moist ground are especially subject to its 

 attacks, though dry ground does not give immunity when the foliage is 

 luxuriant; removing excess of moisture from the soil and liberal prun- 

 ing so as to admit light and air, are both preventive and cure for the 

 disorder. 



The olive tree has many enemies amongst the insect tribe, and the 

 following is a list of those most frequently encountered: 



The olive bug (Lecunium olece), which fastens itself to the green parts 

 of the tree and sucks its j uices. Pruning the infested limbs, and thereby 

 giving free access to light and air, is the most efficient remedy, and the 

 larger affected parts are to be smeared over with petroleum. 



The olive moth (Aeophora olivetta, also Oruga minadora) does damage 

 chiefly in the caterpillar state. Bernard describes its appearance thus : 



Ifc is about? millimeters in length, and is composed of twelve segments, the body 

 is of the same color as the under side of the olive leaves and sometimes yellowish ; its 

 mandibles are at first black, and later on they grow yellow. It frequently penetrates 

 under the bark of the twigs, and causes the formation of the s. c. agallas (gall-nuts) 

 upon them. It also introduces itself into the fruit, eating the pulp and even the 

 kernel itsfclf. The perfect insect is greenish white in color, has four wings and two 

 large antennae. Careful cleaning and pruning, removing all visible nests, and the ap- 

 plication of petroleum or of a solution of lime to the limbs are the means usually suc- 

 cessful in fighting this pest. It seems to be established that this insect is never found 

 on a tree infested with the olive bug. 



The olive fly (Dacus olecB) is an insect about 5 millimeters in length, 

 yellowish red in color, with three black stripes on the abdomen, wings 

 larger than its body, and of a golden color with black striae. This in- 

 sect lays its minute eggs upon the nascent fruit, and the worm burrows 

 galleries into it and feeds upon the pulp. When the caterpillar has 

 reached its full size, it resembles that of the olive moth, but it has only 

 11 segments instead of 12, and its mandibles are always black. When 

 this insect has obtained a foothold, it is best to gather the fruit at once 

 (even though it be green and yield but very little oil), as this prevents 

 the propagation of the pest and may thereby avert more serious dam- 

 age the following season. 



The olive flea (pulguilla del.olivo) derives its name from its peculiar 

 mode of rising, which looks more like jumping than flying. It is about 

 5 millimeters long, has transparent ovoid wings dotted with yellow, 

 thread-like antennae, and greenish abdomen. The larva, or worm, is 

 light green, with head of a dark red. It places itself usually on the 

 petioles of the leaves and buds; its time of fecundation coincides with 

 the blossoming of the olive. The larvae are deposited on a layer of a 

 whitish downy matter called by the country people algodon del olivo 



