The record-union., 1894-10-04
THE RHIZOBIIDO.
Wonderful Natural Agency That De-
feats Fruit Pests.
1t, With the vedaIia Cardinals, Comes
as a Savior for Orchardists'
Crops From the Scale.

September that six miles north there
were citrus orchards that had been en-
tirely freed of the black scale (Lecdltiaenl
oLede) by some of the last imported lady
bird beetles. He says
l arranged at once to visit these
orange orchards and, in company with
Messrs. Wright, Howland and Packard
of Pomona, Mr.. Snow of Santa Barbara
and Mr.. Kruckeberg Of Los Angeles,
proceeded first to the orchard of NJ. G.
Hemenway, where had been introduced
fifteen of the lady-bird beetles last Octo-
ber. This orchard, which consists of
orange and lemon trees, was very dirty
with the fungus which always disfigures
scale-infested trees, and the carcasSes OF
old last year scales were exceedingly
abundant. Upon close examination it
was found that there were almost no
young scales.
An occasional young black scale (Le-
canium oleael and in one place several
soft, brown scales Lecanium hesper-
ldum) were, after long looking, diScOy-
cred, while the little beetles were ex-
ceedingly abundant. Each Of the party
secured several hundred 10 take away,
that they might continue the good work
OF devouring the bEghting scale in other
orchards. This was TO me an exceedingly
interesting object lesson. l had read how
the Nedalia cardinals had cleaned out
the cottony cushion scale, and here saw
how even the more destructive black
scale had been devoured by the later I'M
portatiOn from Australia. The principal
agents which had been so beneficial to
Mr.. Hemenway proved to be Rhizobius
| toowoombae, small, black beetle with
brown head and thoraX. RhiZobiuS de-
| bills, which is about the same size as the
other, but is entirely black above and be-
low, and the RhiZobius ventralis, which
is larger, entirely black above, with
short light hairs, and brown below. The
first mentioned were much the more
abundant.
One-half mile west Of Mr.. Hemenway's
orchard is the citrus orchard of &. r.
Halls, and between this and the other an
orchard belonging TO an Indian woman.
Into the former hive lady-birdS were in
troduced last autumn, but into the latter
none had ever been introduced. / care
fully examined both orchards TO find in
Vulnerable lady-bird beetles and almost
no scale, though the signs OF their devas-
tatiug presence last season were no less
apparent than in the orchard of Mr.. Hem
enWay. On Saturday, the next day,
Messrs. Rowland and Packard of Po-
mona, Mr.. and Mrs. Thompson of Pasa-
dena, Dr. " ood bridge Of Los Angeles
and myself visited the ], ,70O-acre estate of
Hon. Elwood Cooper of ElIwOod, four
teen miles northwest of Santa Barbara,
where the beetles were first introduced,
and where they have been watched very
carefully by MIR. Cooper, to whom more
than to any one else we are indebted for
these saviors Of the orchards of California.
We first visited the large olive orchard,
where the beetles were originally intro
duced. Mr.. HoWland, himself large
olive grower at Pomona, saw this orchard
two years ago. He said the transforma-
ton was most marvellous, indeed. Two
years ago it was filthy with the secretion
OF the black scale, crowded with millions
Of these terrible pests, and he thought
utterly ruined. Now it was clean, bright
and vigorous. We could find no living
scale, and only one of the little benefact-
Ors, which we found after repeated trials.
1t had evidently remained behind to clean
up the few remaining scales, which we
were unable to find,
We next visited large walnut or
chard. and here also found Rhizobius
debilis and r. toowoombae hard at work
in force, cleaning out the aphids. Mr..
Cooper next took us to titty-acre orchard
of olives, where RhiZobiids were intro
duced last October, and which at that
time was suffering tearfully from the
black scale. The beetles were introduced
at one end of the orchard, and are just
now completing their blessed work at the
other end, about one-half mile distant.
We could see the altered foliage and re-
newed yigor while many rods away.
Upon examination we found the little
beetles in countless multitudes and the
scales nearly gone, while at the end of
the orchard where the beetles were first
introduced, which l carefully examined
yesterday september l7th) there are al
most no scales nor beetles. To show the
importance of this, Mr.. Cooper tells me
that he used to spend from %, 900 to 80, eco
annually in spraying this orchard, and
even then the results were far from satis-
iactory-not to be compared with the
work of the Rhizobiids. We found all
the species taken in the other orchards,
but the RhiZobius Ventralls was by far
the most numerous.
Mr.. Cooper thinks this the most effect
i've enemy Of the black scale. In two
hours, the time at our disposal, we Sc
cured thousands of the beetles to take
away with us. Mr.. Packard said he
would agree to secure peck if he could
be given three days to do it in. Indeed,
Albert koebele, to whose skill and etli-
cheney California owes both vedalia and
these later-introduced benetactors, esti-
mated that single pair of Rhizobiids
could produce 10 1000, 900, 600 i'll a single
year. No one eau visit Mr.. Cooper's
place and not be convinced that his esti-
mate is a reasonable one.
Returning 10 Claremont [ introduced
the thousands of BEETLES / secured into
the Olmstead olive orchard two miles
east OF Pomona; the orange orchard OF
Mrs. LOOMS at North Pomona, and in
the olive orchard of Rev. Mr.. Loop of
Claremont. The insects secured from
olives were placed on olive trees, and
those taken from orange trees were put on
orange trees. In every case they were
put on trees with thick foliage which
were infested with black scale. [ counted
lS9 young, vigorous scales on single
olive Leaf, and in each case introduced on
trees nearby trees of the other kind.
Thus the olive were close to orange and
vice versa.
Inext visited orchards where colonies of
the beetles had been introduced in small
numbers some months ago. Among
others, the orchards of Messrs. G. L. Fer
ris and Drehr OF Claremont. and of Mr..
Rowland OF Pomona. In the two former
L could find no beetles, but in the lat
ter the beetles were present and breeding,
which shows that it is not any climatic
peculiarity that has destroyed them. 1t
may be that only males or minated
females, or females that had laid all their
eggs were introduced. More likely bird
or lizard had eaten them up. / suggested
to the Claremont fruit-growers that it
would be more than wisdom TO introduce
many of the beetles in Il single orchard,
and nine gentlemen at once acted on the
suggestion, and engaged me to come at
once and secure more of these tiny
friends. Yesterday / worked in the large
Cooper orchard ali day. and secured sew
eral thousand of the beetles. To-day l
shall take as many from the orange or
chards before mentioned. These Will be
liberated in olive and orange orchards at
Claremont early Tomorrow morning. /
found Alexander Craw. the entomologist.
hard at work at Mr.. Cooper's, collecting
and sending out the beetles. | feel GER
tain that he had 100000 Gagged ready to be