Silica penetrates into the delicate tissues of the insect. As a result its injury leads to dehydration and infection, and consequently death.
Dr Abe V Rotor
Living with Nature School on Blog
Paaralang Bayan sa Himpapawid with Ms Melly C Tenorio
738 DZRB AM Band, 8 to 9 evening class, Monday to Friday
Rhinocerus beetle (Oryctes rhinocerus) is a scourge of coconut,drastically reducing production, if not killing the tree at any stage. Right, a healthy tree can produce up to 50 nuts every two month.Mode of attack by both the larva (grub) and the adult characterized by boring into the very heart of the crown destroying the unopened bud leaves. Right, damage bud after emergence. Heavy infestation results in the decapitation of the standing tree.
Noticed that coconut trees growing along or close to sandy shores are seldom attacked by coconut beetle - Oryctes rhinoceros, a scourge of coconut whose larva and adult burrow into the bud and destroy the whole top or crown of the tree.
Farmers broadcast sand into the leaf axils of coconut trees in their early development stage until they have grown too tall to be reached.The scientific explanation to this practice is that sand (or silica, the raw material in making glass) is very sharp. Under the microscope each particle is a glass shard which can penetrate without difficulty the soft joints (conjunctiva) of the insect's armor. This is the insect's "Achilles heel," so to speak.
As the insect moves, the silica penetrates into the delicate tissues of the insect. As a result its injury leads to dehydration and infection, and consequently death.
If you have young coconuts growing at home and you find signs of the pest, scoop some sand and sprinkle it in between the leaf stalks - or axils. This is safer than using chemical insecticide. And you practically spend nothing, except work and patience.~
Palm Sunday is a nemesis to the coconut trees, and to the coconut industry, the mainstay of the Philippine economy in coconut-based areas. Thousands of trees are sacrificed for their young leaves made into paslaspas during Palm Sunday (Holy Week). Young trees are killed for the bud leaves as well as for the the core or ubod which is made into fresh lumpia, a popular delicacy.
Coconut tree stripped of their young leaves for palaspas are easy target of the coconut beetle. The inflicted wound attracts the fecund female rhinoceros beetle to lay eggs, and the wound serves as entry for the newly hatch grubs which ultimately will bore and destroy the tree. Adult beetles are likewise lured to attack wounded trees. Analogous to this is that, after a typhoon, infestation rises sharply. Weakened condition of wounded trees exacerbate the damage which leads to premature death. Coconut trees are known to live productively for fifty years,and even longer.
Today there's a serious pest of coconut - Scale Insects (Aspidiotus destructor). Several provinces particularly in Region 4 have been placed under emergency. Harvesting young leaves of coconut for handicraft, culinary, palaspas, and the like, further predisposes infested coconut trees to succumb. The young leaves are the ultimate defence when the older leaves are heavily infested with the scale insect.