of Cucumeris and its future prospect
Agro Ecology Department
The biological control has been a big trend in north western Europe
and north America
for the past 10 years. This trend is further expanding to other
southern and eastern
On the other hand, the biological control using arthropods in
Japan is still its infant
In 1995 two natural enemies for greenhouse uses were firstly registered,
for strawberries, a predatory mite, phytoseiulus persimilis and
Enstrip for tomatoes, a
parasite wasp, Encarsia formosa against Tetranychus urticae and
But it is difficult to achieve a complete IPM program with only
Cucumeris for egg plants and strawberries, a predatory mite, Amblyseius
cucumeris, against Thrips palmi and Frankliniella occidentalis,
is expected to fill the gap in this natural enemy crunch status
in Japan. Cucumeris was registered in April, 1998.
As of December, 1998, 6 kinds of arthropod natural enemies are
2. Development of Amblyseius
Since 1991 one of major Japanese chemical corporation, Nippon
Kayaku Company, has been studying the rearing method and usage
of Amblyseius cucumeris in cooperation work with the Ministry
of Agriculture, Forestry and Fishery .
It has to be mentioned that the main reason of development of
A.cucumeris by Nippon
Kayaku was the serious damage by several thrips damage to important
difficulty of importing A.cucumeris from Europe or the U.S.A.
due to the Japanese
regulation that no insect pests should be imported to Japan commercially
preparation contains plant insect pests called live tyrophagus
mites as feeding material
The strain firstly used was introduced from north America.
It is well known fact that A.cucumeris can be reared with tyrophagus
nymph and adult.
Nippon Kayaku's method to rear the mites is to rear tyrophagus
The mite-inoculated bran is kept with very high RH for the all
The rearing cycle is about 30 days at 25 degree centigrade.
Currently A.cucumeris is produced by Techno Green Company, a subsidiary
company of Nippon Kayaku Company.
Distribution is through Tomen Corporation.
Now two companies are jointly developing further uses of A.cucumeris
3. Usage of Amblyseius cucumeris
At first stage, the natural enemy was tested against Thrips palmi
on Egg plants.
Because the main insect pests on egg plants which are not easy
to control with
chemical insecticides was Thrips palmi in early 1990.
A. cucumeris with wheat bran can be either sprinkled over leaves
of egg plants or
small paper bag which contains both A.cucumeris and bran with
is hung on each plant.
Crop Pest Dosage Release time No.of release release method
Strawberry Frankliniella .occidentalis 100 A.c./plant At the beginningof
insect occurrence unlimitednumber Sprinklingat plant base
Cucumber Thrips palmi
Eggplant Thrips plami 50-100 A.c./plant
||At the beginningof insect occurrence
||Sprinkling at plant base
At this moment, the bag system is not registered in Japan because
there are two
One is because it is more costly to produce such paper bags and
another is the
Japanese pesticide law requires additional bioefficacy data for
new use form
registration. This is because the Japanese pesticide regulation
law clearly included
natural enemies in the realm of all the pesticides and other relevant
natural products which could regulate any advantageous and disadvantageous
plants when the law was enforced in 1950.
Nowadays it is difficult to elucidate who wrote the law draft
but the part is rigidly
existing since then.
There are some opinion that natural enemies should be waived from
but also other opinions that it is worthwhile because the system
can verify the
efficacy and both environmental and ecological concerns if the
natural enemies were
It is unexpected by product that this natural enemy regulation
in Japan was already
covering most part of the recent United Nation's recommendation
on import/export of
biological control material.
5. Efficacy results
A. cucumeris performs very well against many kinds of thrips provided
released at the right timing and right conditions.
It is very important to study and learn the characteristics of
this predatory mites
otherwise it seems the natural enemy does not work well even though
are full of such failures and oversights.
Followings are main biological aspects of A.cucumeris.
i) Temperature limitation 15 to 35 degree
ii) Dispersal between plants is low. It has to be released on
each plant when the plants were not so dense.
iii) Could tolerate granular insecticides such as imidacloprid.
iv) Could be used from the transplanting timing or it is more
common usages to start
from the transplanting time.
v) At least consecutive 2 to 3 weekly releases are recommended.
vi) It can only prey on 1st and 2nd instar of thrips but with
2 to 3 applications
it could virtually suppress the whole population of thrips.
vii) Rediscovering of A.cucumeris on leaves is very encouraging
to growers to continue this
biological control method. It usually flees against light so you
will find its rear
hiding its head in the leaf tissue.
viii) Blowing with air of dried pollen or frozen ephestia eggs
ix) A.cucumeris can feed on tetranychus, tarsonemus spp. but it
is not a major natural enemy against these mites.
x) Orius spp. is well known as a good natural enemy against thrips.
Combination of A.cucumeris and Orius spp. in thrips control is
xi) One time it is said Orius is more superior to A.cucumeris
in controlling thrips. This
hypothesis is fading recent years because only A.cucumeris did
a good job without
This is partially due to high cost of Orius production, as A.cucumeris
is a relatively low cost beneficial.
When talking about "Biological Control", people tend
to insist certain beneficials are good
enough to control certain insect pests without evaluation of cost
Growers are interested in biological control but if it is not
commercially beneficial, they will not continue the system or
even start to use those beneficials.
Cucumeris is the first domestically mass reared natural enemies
In the near future, there will be more insects will be reared
Local productin of Encarsia formosa, Phytoseiulus persimilis,
Aphidius colemani, Chrysoperla carnea, Harmonia axyridis are already
being planned by some Japanese companies.
The important point is producing these insects with very competitive
to be accepted by growers and to establish an original economical
rearing system and its
Because there is no patent protection for these naturally available
living creature in general, it means there will be always harsh
competition in this world of biological control.