Title
PRELIMINARY NOTES ON THE HABITS OF TRIMERIA
HOWARDI, A NEOTROPICAL COMMUNAL MASARID
WASP, WITH DESCRIPTION OF THE MATURE LARVA
(HYMENOPTERA : VESPOIDEA)
Author(s)
Zucchi, Ronaldo; YAMANE, Seiki; SAKAGAMI, Shoichi F.
Citation
Insecta matsumurana. Series entomology. New series, 8: 47-57
Issue Date
1976-07
DOI
Doc URL
http://hdl.handle.net/2115/9783
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Hokkaido University Collection of Scholarly and Academic Papers : HUSCAP
INSECTA MATSUMURANA
NEW SERIES
8:
47-57
JULY,
1976
PRELIMINARY NOTES ON THE HABITS OF TRIMERIA HOWARDI,
A NEOTROPICAL COMMUNAL MAS ARID WASP, WITH
DESCRIPTION OF THE MATURE LARVA
(HYMENOPTERA: VESPOIDEA)
Studies on the vespoid larvae. II.
By
RONALDO ZUCCHI, SEIKI YAMANE,
and
By SK. Y.
SHIJICHI
F.
SAKAGAMI
Abstract
ZUCCHI, R., YAMANE, SK., and SAKAGAMI, S.F. 1976. Preliminary notes on the habits of
Trimeria howardi, a Neotropical communal masarid wasp, with description of the mature larva
(Hymenoptera: Vespoidea). Ins. matsum. n.s. 8: 47-57, 1 tab., 2 pIs.
Trimeria howardi excavates heterodalous nests in soil. The brood cell is excavated, not
built in a cavity. An empty cell receives first either an egg or the larval food. Provisioning is
successive. Often two or more females are found in the same nests. Most of such nests are
tentatively interpreted as communal, but some nests suggest quasisociality. The mature
larva is described and compared with that of two other genera. The larva is similar to that of
Pseudomasaris edwardsii, both with the mandibles feeble, antennae large, and c1ypeus located
above the line connecting the mandibular bases. An unusual number (seven) of antennal
sensillae and a remarkably minute atrial opening are characteristic of Trimeria howardi.
A uthors' addresses. ZUCCHI, R.: Departamento de Biologia, Faculdade de Filosofia,
Ciencias e Letras de Ribeirao Preto, Universidade de sao Paulo, Ribeirao Preto, Estado
de sao Paulo, 14,100, Brasil. YAMANE, SK.: Entomological Institute, Faculty of Agriculture,
Hokkaid6 University, Sapporo, 060 Japan. SAKAGAMI, S.F.: Zoological Institute, Faculty of
Science, Hokkaid6 University, Sapporo, 060 Japan.
Contents
Introduction ....................................................... ; .......... 49
Bionomic notes ............................................................... .49
Description of the mature larva ................................................ 50
Acknowledgements ............................................................ 52
References .................................................................... 52
Plates ....... " .............. , ................................................ 53
INTRODUCTION
The family Masaridae occupies a peculiar position within the Vespoidea.
Except one predaceous genus Euparagia, all other genera so far studied provision
their nests with pollen and nectar. Thus they are the vespoid counterpart of the
bees evolved from the Sphecoidea, though far less successful than the latter in
species number, extent of distribution and morpho-functional specialization to
melliferous habits. Up to the present the habits of several genera have been
recorded as reviewed by Richards (1962), Malyshev (1968), Torchio (1970) and
Iwata (1971). But the amount of information is still insufficient to give a precise
bionomic perspective of the family. In 1971, two of us (R.Z. & S.F.S.) found
nests of Trimeria howardi Bertoni 1911 in Ribeirao Preto, State of Sao Paulo, and
started bionomic observations. As the work is still in continuation, here are
given only some important findings as a preliminary report, together with the
description of the mature larva by Sk. Y.
BIONOMIC NOTES
Nests are excavated in soil. The main burrow is nearly vertical and about
4 mm wide and 6.0-15.0 cm (m 9.0) deep. The entrance is provided with a
neatly built vertical turret (Fig. 9) 1-7 mm in height (m 3.07) and 2.9 mm in inner
diameter. A variable number (1-24, m 7.3) of approximately horizontal laterals
issue from the main burrow (=heterodalous type by Malyshev, 1935) and the
brood cells are excavated at their ends, never built in hollow cavities (=synodalous)
as in some Ceramius species. Most laterals have an only cell, but rarely two
(6.9%) or three (1.1%) cells (=parodalous). Cells are horizontal, elongate oval
with the inner walls smooth and polished.
Curiously, the order of oviposition and food provisioning is irregular. There
were found three cells each with an egg deposited at the bottom (Fig. 13) and four
cells each with a food mass without egg. This might relate to the presence of two
or more females in the same nest as referred to below. Provisioning is certainly
progressive. There were found some open cells with food and small to medium
sized larvae, while no closed cell with such contents. The larval food is made
from pollen and nectar, and relatively solid, with an irregular annulation (Figs.
11,12) which probably corresponds to successive foraging trips.
Nests are often reused as proved by the remains of old cells with empty
cocoons scattering around the main burrow. The species is possibly bivoltine.
Three incipient nests apparently newly excavated, each containing a fresh female,
were found on January 19, April 29 and May 5, 1972. But, reflecting the
subtropical climate, it is difficult to distinguish the generations clearly. The
winter (June to early August) is passed by prepupae.
Often several nests are found side by side, with a distance of 3-4 cm from
each other (Fig. 10). The occurrence of two or more females in the same nest, in
the other species only once recorded in Ceramius lichtensteini (Brauns, 1910, d.
Iwata, 1971), is fairly common in T. howardi. Among 30 nests examined, 18
contained a single female. The number of females in other 12 nests were 2 <f<f
(7 nests), 3 (1), 4 (3), 7 (1). Further, 8 out of 35 nests contained one male during
January to May. Judging from the composition of brood cells, most of these
males were not born in the nests concerned but joiners from other nests. By the
49
parsimonious nornl, most nests with two or more females are tentatively interpreted as communal, i.e., each female cares her own brood cell. But there are some
nests which suggest more advanced social types, jUdging from cell composition
and adult conditions. Two cases are cited. Nest 4-29- IV: Only one open cell
containing a young larva and food mass. No remain of old cells. Two females
both with fully developed ovary*. This nest is regarded as quasisocial (Michener,
1969, 1974) and one female is apparently a joiner from the outside. Nest 4-4-V:
One cell with egg and food, several empty cocoons, and seven females. Four
females with a fully developed ovary, two heavily worn and with developed ovaries,
and one newborn. Apparently the nest was reused. The relation of the first
mentioned four females can be interpreted as quasisocial, while the two older
females may be either their elder sisters or the females of the last generation.
Anyhow, the association is not eusocial, even if containing two successive generations. It is possible but not certain that some ovarially undeveloped females are
responsible for the deposition of larval food in a cell before it receives egg as
mentioned above. Consequently, the social type of Trimeria howardi is regarded
as communal, though some nests show quasisociality, despite the species is subsocial,
i.e., the larvae are in contact with adult females (ef. Michener, 1969, 1974). The
habits described above will be compared elsewhere with those in other genera.
DESCRIPTION OF THE MATURE LARVA
The mature larva is described and compared with that of two other species,
Pseudamasaris edwardsii (Cresson) (melliferous) and Euparagia scutellaris Cresson
(predaceous). both described by Torchio (1970).
Head: Nearly circular in frontal view; integument weakly sclerotized; with
mandibular apices, anterior tentorial pits, maxillary palps, galeae, labial palps,
salivary lips, especially ventral one, pigmented; setae and sensoria nearly lacking on
head capsule; mid-cranial sulcus (mcs) weak, visible only at upper portion; vertex
(v) round, not indented; frons not separated from epicranial area by distinct lines;
antennae (ant) large and distinctly projecting conically, each with about seven
minute sensillae at the center; temporal bands (tmb) narrow and weak; anterior tentorial pits (atp) located at dorsolateral angles of clypeus (elP) , large and distinct;
postoccipital sulcus (pas), hypostomal sulci (hs) and pleurostomal sulci (Plst) well
developed; epistomal sulcus (es) complete, lateral sides converging dorsally; midpoint of the ventral margin of clypeus nearly at the level of mandibular bases;
clypeus broadly emarginate below; labrum (1m) distinctly narrower than clypeus,
with ventral margin strongly emarginate medially; labrum and palate without
distinct sclerotized patch or conical sensillae; mandibles (md) somewhat elongate,
tridentate, tapered and pigmented apically; outer tooth largest, median tooth smallest and sharply tapered; inner apical surface concaved; abductor apodeme (Fig. 6)
much shorter than adductor apodeme (Fig. 7), the latter bearing a rudimentary
branch at half distance from the base; maxillae (mx) of moderate shape and size;
separation of cardo from stipes indistinct; stipes each with maxillary palp (mplp)
and galea (ga) , the latter being more developed than the former; salivary opening
surrounded by transverse salivary lips (sl) located apically on prelabium (prlb);
•
In this species, two ovaries seem to develop alternately.
two fully developed ovaries.
50
Virtually no female had
salivary lips not serrate apically, simple, ventral lip being more prominent than
dorsal one; labial palps (IPIP) small and less developed than maxillary palps and
galeae; prelabium and postlabium (PI b) of normal shape and size.
Body: N early white in alcoholized specimens; subcylindrical, strongly
decurved; head not hidden, appressed against abdominal sterna; integument without setae, microscopic denticles sparse; intersegmental lines distinct; dorsolateral
and lateral tubercles developed; spiracle not elevated above cuticle; atrial opening (ato) remarkably small; atrial walls smooth, lacking spines or denticles;
primary tracheal opening (pto) without spines; diameter of primary tracheal opening
distinctly larger than that of atrial opening.
Comparison with two other species: The results of the present comparison are
synoptically given in Table 1.
Table 1.
Morphological comparison of the larvae
of three masarid genera.
Trimeria howardi
Vertex
Mid-cranial
sulcus
Antennae
Pseudomasaris edwardsii
Euparagia scutellaris
round
incomplete
indented
"=PTrimeria
large; located
somewhat high on
head; projecting
about seven
large; located somewhat
high on head; convex
"=PTrimeria
incomplete, but rather
developed
normal; located low on
head; slightly produced
three in a straight line
three in a triangle
indistinct medially*
"=PTrimeria
"=PTrimeria
medially produced;
ventral to the level
of mandibular bases
as wide as clypeus;
spinulate
broadened; with three
teeth
"=PPseudomasaris
Antennal
sensillae
Epistomal sulcus complete
Ventral margin
medially emarginate;
of clypeus
at the level of mandibular bases
Labrum
narrower than
c1ypeus; not spinulate
Mandibles
somewhat elongate;
with three teeth
Atrial opening
very small; smaller
than primary tracheal
opening
Body tubercles
developed
* "Distinct centrally"
wider than clypeus; not
spinulate
somewhat elongate;
with two teeth
moderate; larger than
primary tracheal
opening
not developed
"=PTrimeria
in the original description, but indistinct in the associated figure.
Reflecting the different food habits, two distinct types of larvae are
recognized in the mas arid wasps, i.e., the Eumenid type (Eumeninae-Vespinae
complex by Torchio) represented by Euparagia and the Non-Eumenid type
(Polistinae-Polybiinae complex by Torchio) involving Pseudomasaris and
Trimeria. The latter type is characterized by the somewhat elongate and feeble
mandibles, remarkably developed antennae, and clypeus located above the line
connecting the mandibular bases. The mandibles more degenerated than in
Eumenidae may relate to the pollenivorous habits. The derived characters
common to the three masarid genera are yet not decided. The large antennae
could be regarded as a derived character for Masarini, but further comparative
studies are necessary. The characters peculiar to Trimeria are as follows: 1)
antennal sensillae are unusually numerous (seven), whereas in other vespid groups
they are almost always three (e.g. see Reid, 1942); 2) atrial opening of spiracles is
51
unusually small. It must be mentioned that pollen grains attached to the body
were larger than the diameter of atrial opening (Fig. 8). In aculeate larvae,
two devices to prevent the invasion of various alien particles in spiracles, diminution of primary tracheal opening (Euparagia and Pseudomasaris), and development
of atrial and collar processes on the inner wall (Vespa and Dolichovespula, Sk.
Yamane, 1976; Bombus, Ritcher, 1933), are adopted. The diminution of atrial
opening in Trimeria may represent a third filtering device.
ACKNOWLEDGEMENTS
The work was aided by grants from Funda~ao de Amparo a Pesquisas de
Estado de Sao Paulo. In particular we thank Messrs. Zualdo A. Schiavoni, Joao
J. dos Santos and A. Penatti for their helps in excavating the nests.
REFERENCES
a
Bertoni, A. de W. 1911. Contribucion
la biologia de las avispas y abejas del Parguay
(Hymenoptera). Anales Mus. Nac. Buenos Aires 12: 97-146.
Iwata, K. 1971. [Evolution of Instinct. Comparative ethology of Hymenoptera.] vi+503
pp., Mano-shoten, Yamato-City (Kanagawa Pref.). (In Japanese.)
Malyshev, S.l. 1935. The nesting habits of solitary bees. A comparative study.
Eos 11:
201-309.
Malyshev, S.l. 1968 (Eng!. Tr.). Genesis of the Hymenoptera and the Phases of Their
.Evolution. viii+319 pp., Methuen-London.
Michener, CD. 1969. Comparative social behavior of bees. Ann. Rev. Entom. 14: 299-342.
Michener, C.D. 1974. The Social Behavior of the Bees. A comparative study. xii+404
pp., Harvard Univ. Press, Cambridge-Mass.
Reid, J.A. 1942. On the classification of the larvae of the Vespidae (Hymenoptera). Trans.
R. Ent. Soc. Lond. 92: 285-331.
Richards, O.W. 1962. A Revisional Study of the Masarid Wasps (Hymenoptera, Vespoidea).
Brit. Mus. Nat. Hist., London. vii+294 pp.
Ritcher, P.O. 1933. The external morphology of larval Bremidae and key to certain
species (Hymenoptera). Ann. Ent. Soc. Amer. 26: 53-63.
Torchio P.F. 1970. The ethology of the wasp, Pseudomasaris edwardsii (Cresson), and a description of its immature forms (Hymenoptera: Vespoidea, Masaridae). Los
,Angeles County Mus. Contr. Sci. 202: 1-32.
Yamane, Sk. 1976. Morphological and taxonomic studies on vespine larvae, with reference
to the phylogeny of the subfamily Vespinae (Hymenoptera: Vespidae). Ins.
Matsum. N.S. 8: 1-45.
52
PLATES
Plate IX
Fig. 1. Lateral view of mature larva.
sp. spiracle.
Fig. 2. Frontal view of head. dim. depression in cranial wall at the origin of the frontal
muscle; lcs. labro-clypeal suture; mc. mandibular corium; other abbreviations in text.
Fig. 3. Lateral view of head. ata. anterior tentorial arm; dta. dorsal tentorial arm; other
abbreviations in text.
Figs. 4 & 5. Dorsal and inner views of mandible.
Fig. 6. Abductor apodeme.
Fig. 7. Adductor apodeme.
Fig. 8. Longitudinal section of spiracle, with pollen grains removed from the body. at.
atrium; other abbreviations in text.
54
dfai
"
/;: ..
,.
c5
-- -- -/
I"
00
00
plb
pr lb
3
(
'
(
-
5
,(
-
\
~6
55
Plate X
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
9. Female leaving the nest (departure from the turret always from the metasoma).
10. Two nests lying side by side. One female is just leaving the nest.
II. Medium sized larva with food.
12. Cell with food and small larva, and a part of main burrow.
13. Egg deposited in a cell.
14. Cocoons.
56
57
Seiki Yamane