fi&$$!$t~~ (Sci.
Bull.
Fat.
Agr., Kvushu Univ.)
%40% % 4 4 197-205 (1986)
The Mycetangia and the Mode of the Fungus Transmission
in the Weevil Genus Euops (Coleoptera: Attelabidae)
YOSHIHISA SAWADA and KATSURA M O R I M O T O
Entomological Laboratory, Faculty of Agriculture,
Kyushu University 46-01, Fukuoka 812
Metacoxa and metasternal process of Euops splendidus $2 in caudal view,
Fig. 1
abdomen removed.
Ditto, with spore masses “a” and “b”.
Fig. 2
Metacoxa and metasternal process of E u o p s splendidus 3 in caudal view,
Fig. 3
abdomen removed.
Spore mass “a” between metacoxa and metasternal Iprocess of E u p o s spleFig. 4
ndidus 8.
Bifurcate hairs along the hind margin of me:acoxa
i’ Euops splendidus ?
Fig. 5
Ditto, with adhered spores.
Fig. 6
MtCx, metacoxa; MtSP,metasternal p r o c e s s ; Y h SiTurc e ‘-! IV SMa, s p o r e tilass
‘.a”; SMb, s p o r e m a s s ‘.b”.
F i g . I Hind wall of metacoxal cavity at the base of abdomen of Euops splendidus
2, in frontal view, thorax removed.
Fig. 8 Ditto, with spore mass “c” in the hollow.
Fig. 9 Ditto of Euops splendidus 8, showing simpler structure.
Fig. 10 Pores and microtrichia in the hollow of metacoxal cavity of Euops splendidus 9.
Fig. 11 Metasternum and abdomen of Euops pusttrlosus 9, showing characteristic
pubescences, in ventral view, legs removed.
Fig. 12 Internal view of the female venter of Euops splendidus, showing ventral
glands, digestive and reproductive organs removed.
Figs. 13, 14 Longitudinal section of the venter of Euops lespedezae koreanus 9,
showing relative position of the erect pubescences and gland openings
Sl, slit; MtCx, metacoxa; VI-V4, 1st to 4th ventrites; RI f--R3r, R4, erect pubescences of front row on 1st ventrite to rear row on 3rd ventrite and row on
the 4th ventrite; PB3, porose band on 3rd ventrite; VG, ventral glands.
E r e c t p u b e s c e n c e s o n t h e f e m a l e venter oi” Euops splendidus.
Fig. 15
Openings of ventral glands on the female venter of Euops splendidus, E :rect
Fig. 16
pubexenIces removed.
PB2, PO* .ose b a n d o n 2 n d v e n t r i t e ; R2f, R2r, f r o n t a n d r e a r r o w s o f erec:t PUbestence s.
Fig. 17
Fin. 18
Rolled up cradle and weevils, Euoys konoi.
A bite on the leaf strip, sho\\ing inoculated spores by Euops splendidus 9.
wood-inhabiting insects. In “Symbiosis”, ed.
by S. M. Henry, Academic Press, New York
and London, 2: pp. 141-205
Giese, R. L. 1965 The columbian timber beetle Corthylus columbianus (Coleoptera : Scolytidae). V. A description of the mycetangia. Can. Em., 99: 54-58
-TBT-q! 1 9 5 9 ;5 t. Yi‘Z ax&?&. sar;@: E1&
E&En’. =gs$& &g, 117-146 W
yqBE$ 1926 +q o & b Q/I $ Apoderus fulvus
Roelofs, &jCz I CLIP y is F Y7* -: Euops aceri
Kono (sp. nov.) 03 &q&k. $j~#$+$&$, 38:
217-224
y$JB$ns 1928 ;5 b 9 I z Apoderus jekeli Roel o f s _a v’ 12 II/ y & \ 97. -: E u o p s punctatostriata Motschulsky f. aceri KBno OS&&&.
$l&j$$$#~~~, 19 : 652-667
KBno, H. 1930 Die biologischen Gruppen der
Rhynchitinen, Attelabinen und Apoderinen.
Jour. Fat. Agr., Hokkaido Imp. Univ., 29: 136, 4 pls.
Morimoto, K. 1962 Key to families, subfamilies, tribes and genera of the superfamily
Curculionoidea of Japan excluding Scolytidae, Platypodidae and Cossoninae. Jour.
Fat. Agr., Kyushu C’niv., 12: 21-66
&ji $I? 1 9 6 4 % P 9 7’ 5 ~~$&$I~‘;“/& tj&#. 4 y
+3 hQ+.--?Jl,, 2: l-7
Nakashima, T. 1975 Several types of the mycetangia found in Platypodid Ambrosia
beetles (Coleoptera : Platypodidae). Ins.
Matsum., n. s., I: l-69
,q# @ 1 9 5 0 xt~Y7*;D+~~. Ki’ra., 3 :
102-107
Sawada, Y. and K. Morimoto 1985 A revision
of the genus Euops Schoenherr (Coleoptera:
Attelabidae)from Japan, Korea and Taiwan.
Jour. Fat. Agr., Kyushu Univ., 3: 175-195
Sharp, D. 1889 The rhynchophorous Coleoptera
of Japan. Trans. Ent. Sot. London, 1889:
41-75
Voss, E.
1930 Coleopterorum Catalogus (110)
Curculionidae : Attelabinae. Junk, Berlin
Voss, E. 1953 Coleopterorum Catalogus supplementa. Attelabinae. Junk, ‘s-Gravenhage
Summary
The mycetangia and the ventral glands are newly discovered in the females of
the weevil genus E u p o s .
The mycetangia containing fungal spores are observed in the metacoxal cavity
in 3 places, a membraneous groove between the metasternal process and the metacoxa (Figs. 2, 4, SMa), a f o l d o f t h e i n t e r s e g m e n t a l m e m b r a n e b e t w e e n t h e
metasternal process and the venter (Fig. 2, SMb), a n d a s h a l l o w h o l l o w o n t h e
hind wall of the metacoxal cavity (Figs. 7, 8, SMc). The last is porose and microsetose (Fig. 10). A few rows of characteristic bifurcate hairs are present along
hind margin of the metacoxa (Figs. 5, 6).
The females of this genus have special pubescences on the venter, which are
arranged transversely in two rows on the first to third ventrites and one row on the
f o u r t h ventrite (Fig. 11). Their adjoining pubescences are overlapped at the flattened and undulated apical part (Fig. 15), and large exocrine glands (Fig. 12)
open in ,a row just behind the front row of the pubescences (Figs. 13, 14, 16).
T h e s e c r e t i n g fluid from the glands may be sucked up into the space between the
overlapped pubescences by a capillary action.
Before rolling up a cradle, the female cuts the lateral portion of leaf to form
a strip at first leaving the upper end uncut, and then “walks around and bites” the
strip surface at regular intervals. A mass of spores are observed in these bites
made on the strip (Fig. 18) probably due to direct transmission from her mycetangia.
When the female rolls up a cradle, she throughly brushes it up with her
pubescences for several minutes and cuts it off from the leaf. The fallen cradle
IV
9 ;if b v/1 5
aDnz+~~nz~~42&2~~
205
gets moldy soon with special fungi, which are whitish in Euops splendidus a n d
These fungi are not yet determined.
The mycetangia, ventral glands, erect pubescences, “biting” and “brushing” behaviors are apparently connected with the transmission of the symbiotic fungi to
the cradle. These symbiotic organs are absent in the other genera of the Attelabidae and the male of Euops studied.
lespedezae, or yellowish in E. konoi.