Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1917-12-03
Distributing of Parasites il
Large Number to Re-estab-
IiSh Control Advocated

"A number of plantations have haC
| an unusual amount of leaf-hopper II
one or more fields at some time dur
ing the year." states H. P. Agee, di
rector of the Hawaiian planters ex
pertinent station in his report to tn.
annual meeting of the Hawaiian Sugar
Planters association.
Continuing the report says, in part
In certain cases the damage wa:
extensive and severe. Among the
plantations mentioned are the follow
ing: On OAHU the Oahu Sugar com
pany, Eva Plantation company, Waia
lua Agricultural company; on Kauai
Kekaha Sugar company and Lihue
plantation; on Hawaii, Olaa Sugar
company, Hawaiian Agricultural com
pany, Waiakea plantation, Hakalau
Sugar company and the Pacific Sugar
mill.
."At Eva fields of H-109 cane were
affected, particularly the plant cane
At Kekaha there was an outbreak in
some of the .lowland fields, worse
than they had had since the early
leaf-hopper days. At Olaa the severe
outbreak Of last year has continued
and increased in area and severity
Where leaf-hoppers were doing such
destructive work in connection with
the leaf-roller at Pahala for the two
previous years, this year they have
been reduced to point where they
are scarce.
These outbreaks of the last three
years have caused some concern. Mr..
Muir says that he has been asked II
the parasites are playing out but
states that he can see no reason tc
believe that such a thing is happen.
ing. He holds the opinion that under
favorable conditions which have been
the normal conditions of the past ten
years or so, the parasites are able
tc hold the lea:-hoppers in check so
that the damage is small. When these
conditions are upset the leaf-hopp ers
multiply rapidly and damage is done
before the parasites regain control.
Mr.. Muir points out that the disturb
ing factor may, have occurred months
previously. and among these factors
he enumerates the normal winter in
crease in hoppers; heavy transforms,
particularly If accompanied by high
winds; the harvesting of large areas,
particularly isolated areas, and es-
pecially If they are burnt over; and
the migration of leaf-hoppers to areas
that have been free from the pest
and hence clear of the parasites.
These and other factors lead, ac-
cording to Mr.. Muir. to one result. the
freeing of the leafhoppers from their
parasites, and he advocates distribut-
ing the parasites artificially in large
numbers in order to re-establish their
control of the pest This can best be
done by placing a quantity Of mid.
ribs of the cane leaves which carry
the parasitiZed leaf-hopper eggs at ir,
tervals across new area, properly
protecting them from drying out Re.
cent observations have led Mr.. Muir
to believe that much can be accom-.
plished by this method of contending
with leaf-hopper outbreaks which may
be expected from time to time
New Leaf-Hopper Parasites
THE breeding of the Formosan
leaf-hopper egg parasites has been
continued by Mr.. Swezey and Mr.
Undertake, and colonies were sent
out whenever available to planta-
tons where conditions were suitable.
Thirty colonies of the Ootetrastichus
species were distributed. and this