ミノムシミノムシいといとああはれなりはれなり

Dr. Ryo ADr. Ryo ARAKAWARAKAWAEntomological Lab.Entomological Lab.

Kochi Univ.Kochi Univ.

A bagworm is A bagworm is very lovelyvery lovely

Eumeta variegata (=E. japonica)

BagwormBagworm （Ｍｉｎｏｍｕｓｈｉ）（Ｍｉｎｏｍｕｓｈｉ）

BagwormBagworm

Ｌarva of psychid moth

(Lepidoptera: Psychidae)

World: １,７００ spp.

Japan: ２１ spp.

Their outbreak hasTheir outbreak has sometimes occurred before and they sometimes occurred before and they are known as the pest of orchardare known as the pest of orchard and garden trees.and garden trees.

Eumeta variegata(Oo-minoga)ca. 5cm

Eumeta minuscula(Cha-minoga)ca. 3cm

Common bagworm in Japan

Winter season

Overwinter(diapause) insilken bag

Foraging(Larva)

PupationEmergenceOviposition

Wi　　Sp　　Su　　Au　　 Wi　　　Sp　　Su　　Au　　Wi

generation generation

Life cycle of E. variegata

After diapause termination

No foraging → E. variegata

Foraging → E. minuscula

Male of E. variegata

3－4cmpupal sheath

Female after oviposition

First instar larva of E. variegata just after hatching

1mm

Silken bag making by the 1st instar larva

Silken bag making completed

Jan. 12, 1999Asahi Shimbun

A species of parasitic fly has invaded from China.

The bagworm has fear of extinction in west Japan.

Adult of Nealsomyia rufella(Diptera: Tachinidae)

NealsomyiaNealsomyia rufellarufella

♂ ♀Small egg productive type

Oviposit on the leaf foraging by E. variegata larva

Eggs of N. rufella on the chestnut leaf

Eggs of N. rufella

Puparia of the parasitic fly and dead body of bagworm.

Gregarious parasitismGregarious parasitism（（Sep. 23, 2007 Kochi Univ.Sep. 23, 2007 Kochi Univ.））

How did N. rufella invade to Japan?

Invaded pests

Classical Classical Biological ControlBiological Control

Introduced natural enemiesfrom the original habitat of pests

permanent control

IceryaIcerya pruchasipruchasi and and RodoliaRodolia cardinaliscardinalisイセリアカイガラムシとベダリアテントウイセリアカイガラムシとベダリアテントウ

Classical Classical Biological ControlBiological Control

(The end of the 19th century)

A variety of natural agents killing another organisms in nature.

A predator, parasite, parasitoid or pathogen of another animal, especially an insect. Several species have been using as the biological control agents.

Natural EnemiesNatural Enemies

Adults are free living. Females search hosts and oviposit on, in or near the host.

ParasitoidsParasitoidsparasitic waspsparasitic flies

Larva of parasitoid consumes one or less than one host for its lifetime.

In Shandong, N. rufella was introduced from Southern China to control E. variegata in about 1990.

山東省

Shandong province

Study area in Kochi Pref.

Younger larva parasitized by the fly.

Head width of bagworm

No.

of p

upar

iain

a b

ag

Parasitic character of Parasitic character of N. N. rufellarufella

host specifichost specificmultivoltinemultivoltine (against (against univoltineunivoltine

host)host)gregariousgregarious parasitismparasitism

Life cycles of E. variegata and N. rufella

Overwinter

Pupa AdultEgg Larva (Foraging) Overwinter

Apr. Jun. Aug. Oct. Dec. Feb.

??

Univoltine (年1化性)

Multivoltine (多化性)

Mar. 22, 2000Kochi Shimbun

The density of the bagworm has extremely decreasedbecause of parasitism by invaded fly.

Dec. 14, 2001Yomiuri Shimbun

Protection of the bagworm is expected.

Jan. 29, 2002

Weekly Playboy, Japan

Dear bagworm,are you extinction?

Parasitism and alive of E. variegata

0

％

100

1999 2000Year

5029.5

90.3

19.31.1 5.6 4.0 4.4

65.9 65.1 62.3

2001 2002 2003

Parasitism

Adult emergence

Parasitism of different area

2000 2001 2002

50

％

100Nankoku

Aki

Nakamura

KubokawaSagawa

1999Year

0

We found that severalWe found that several indigenous indigenous natural enemies attacked natural enemies attacked N. N. rufellarufella

in Kochi Pref.in Kochi Pref.

Parasitic wasps emerged from the Parasitic wasps emerged from the pupariumpuparium of of N. N. rufellarufella..

Brachymeria lasus(Chalcididae) Eulophidae sp.1

Eulophidae sp.2 Eulophidae sp.3

Parasitic wasps emerged from the Parasitic wasps emerged from the pupariumpupariumof of N. N. rufellarufella..

Pteromalidae sp.1

Eupelmidae sp. Trigonalidae sp.

Pteromalidae sp.2

In 2002・ location 16/24・Silkenbag 101/854(11.8%)・Puparium 183/7.297 (2.5%)

Dominant species: Brachymeria lasus(キアシブトコバチ)

Hyperparasitism（高次寄生）

Predation by Jumping Spider (Just after adult emeregence)

Sep. 9, 2000, Kochi Univ.

Predation by Ants in Silken BagAug. 30, 2007, Kochi Univ.

Present condition of Present condition of E. E. vareiagatavareiagata and and N. N. rufellarufella in Kochi Pref.in Kochi Pref.

N. N. rufellarufella is established.is established.E. E. variegatavariegata still alive.still alive. (Not (Not

extincionextincion)) Indigenous natural enemies attack Indigenous natural enemies attack

N. N. rufellarufella..

Ecological stability

ConclusionConclusion

E. E. variegatavariegata and and N. N. rufellarufellawill continuewill continue coexistence.coexistence.

E. variegata

E. minuscula

Wanted

No need