A bagworm is very lovely ミノムシ いとあはれなり Dr. Ryo ARAKAWAA Entomological Lab. Kochi Univ.
Bagworm (Minomushi) Eumeta variegata (=E. japonica)
Bagworm Larva of psychid moth (Lepidoptera: Psychidae) World: 1,700 spp. Japan: 21 spp.
Their outbreak has sometimes occurred before and they are known as the pest of orchard and garden trees.
Common bagworm in Japan Eumeta variegata (Oo-minoga) ca. 5cm Winter season Eumeta minuscula (Cha-minoga) ca. 3cm
Pupation Emergence Oviposition Foraging(Larva) Overwinter (diapause) in silken bag After diapause termination No foraging E. variegata Foraging E. minuscula generation generation Wi Sp Su Au Wi Sp Su Au Wi Life cycle of E. variegata
Male of E. variegata pupal sheath 3-4cm
Female after oviposition
1mm First instar larva of E. variegata just after hatching
Silken bag making by the 1st instar larva
Silken bag making completed
A species of parasitic fly has invaded from China. The bagworm has fear of extinction in west Japan. Jan. 12, 1999 Asahi Shimbun
Adult of Nealsomyia rufella (Diptera: Tachinidae)
Nealsomyia rufella 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 parasitism (Sep. 23, 2007 Kochi Univ.)
How did N. rufella invade to Japan?
Classical Biological Control Invaded pests permanent control Introduced natural enemies from the original habitat of pests
Classical Biological Control Icerya pruchasi and Rodolia cardinalis イセリアカイガラムシとベダリアテントウ (The end of the 19th century)
Natural Enemies 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.
Parasitoids parasitic wasps parasitic flies Adults are free living. Females search hosts and oviposit on, in or near the host. Larva of parasitoid consumes one or less than one host for its lifetime.
山東省 Shandong province In Shandong, N. rufella was introduced from Southern China to control E. variegata in about 1990.
Study area in Kochi Pref.
Younger larva parasitized by the fly.
No. of puparia in a bag Head width of bagworm
Parasitic character of N. rufella host specific multivoltine (against univoltine host) gregarious parasitism
Overwinter Univoltine ( 年 1 化性 ) Pupa Adult Egg Larva (Foraging) Overwinter Multivoltine ( 多化性 )?? Apr. Jun. Aug. Oct. Dec. Feb. Life cycles of E. variegata and N. rufella
The density of the bagworm has extremely decreased because of parasitism by invaded fly. Mar. 22, 2000 Kochi Shimbun
Protection of the bagworm is expected. Dec. 14, 2001 Yomiuri Shimbun
Dear bagworm, are you extinction? Jan. 29, 2002 Weekly Playboy, Japan
50 0 %100 90.3 Parasitism 65.9 65.1 62.3 29.5 Adult emergence 1.1 5.6 4.0 4.4 19.3 1999 2000 2001 2002 2003 Year Parasitism and alive of E. variegata
50 %100 0 1999 Nankoku Nakamura Aki Sagawa Kubokawa 2000 2001 2002 Year Parasitism of different area
We found that several indigenous natural enemies attacked N. rufella in Kochi Pref.
Brachymeria lasus (Chalcididae) Eulophidae sp.1 Eulophidae sp.2 Eulophidae sp.3 Parasitic wasps emerged from the puparium of N. rufella.
Pteromalidae sp.1 Pteromalidae sp.2 Eupelmidae sp. Trigonalidae sp. Parasitic wasps emerged from the puparium of N. rufella.
Hyperparasitism( 高次寄生 ) 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 )
Predation by Jumping Spider (Just after adult emeregence) Sep. 9, 2000, Kochi Univ.
Predation by Ants in Silken Bag Aug. 30, 2007, Kochi Univ.
Present condition of E. vareiagata and N. rufella in Kochi Pref. N. rufella is established. E. variegata still alive. (Not extincion) Indigenous natural enemies attack N. rufella. Ecological stability
Conclusion E. variegata and N. rufella will continue coexistence.
Wanted E. variegata No need E. minuscula