Discovery of a predaceous drosophilid Acletoxenus indicus Malloch in South China, with descriptions of the taxonomic, ecological and molecular characters (Diptera: Drosophilidae)
Author
Yu, Guoyue
Author
Wu, Liang
Author
Lu, Jinming
Author
Chen, Hongwei
text
Journal of Natural History
2012
2012-02-29
46
5 - 6
349
354
http://dx.doi.org/10.1080/00222933.2011.639466
journal article
276132
10.1080/00222933.2011.639466
61c4bac1-1fdd-4675-bc25-8ce4358bceb1
1464-5262
5202504
Acletoxenus indicus
Malloch
(
Figures 1
and
2
)
Acletoxenus indicus
Malloch, 1929
. Ann Mag Nat Hist, 31: 545.
Description
Some characters not mentioned in
Malloch (1929)
are given below. Measuring in
5♂
and
5♀
adults: BL
1.96–2.22 mm
in
♂
,
1.94–2.35 mm
in
♀
; ThL
1.10–1.25 mm
in
♂
,
1.08–1.30 mm
in
♀
; WL
2.08–2.27 mm
in
♂
,
2.12–2.30 mm
in
♀
; WW
1.02–1.05 mm
in
♂
,
1.04–1.13 mm
in
♀
. Male terminalia: epandrium protruded anterad and posterolaterally much protruded ventrad, with
c.
20 short setae and pubescence (
Figure 1C
). Cercus small, separated from epandrium, pubescent and setigerous (
Figure 1C
). Surstylus almost entirely fused with epandrium, with three small setae apically on inner surface (
Figure 1C
). Hypandrium anteriorly narrow and laterally broad, with five or six setulae per side, basally with a narrow, anterad rod-like process, submedially with lobe-like process bearing four or five setulae (
Figure 1D
). Paramere bilobed, sclerotized and pointed apically, lacking sensilla, basally fused to aedeagal apodeme (
Figure 1D
). Gonopods strongly curved dorsad, pointed apicolaterally (
Figure 1D
). Aedeagus basally with two pairs of lobe-like processes (
Figure 1D
, lop): one of them small; the other curved dorsad and pointed apically (
Figure 1D
), apically with gracile membranous tube (
Figure 1D
). Aedeagal apodeme small, lobe-like (
Figure 1D
).
Specimens examined
CHINA
:
4♂
,
2♀
(
SCAU
, nos. 121002–121007),
Guangzhou
,
Guangdong
,
23
◦
09
′
N
,
113
◦
21
′
E
,
8 September 2003
, from variegated laurel (
Codiaeum variegatum
),
X.M. Wang
;
11♂
,
6♀
(
SCAU
, nos. 121008–121024),
Zhanjiang
,
Guangdong
,
21
◦
16
′
N
,
110
◦
21
′
E
,
17 April 2005
, from
Hibiscus
sp.
,
S.X. Ren
;
2♂
,
2♀
(
SCAU
, nos. 120998–121001),
Qionghai
,
Hainan
,
19
◦
16
′
N
,
110
◦
28
′
E
,
19 June 2009
, reared from immature stages collected on guava (
Psidium guajava
),
G.Y. Yu
.
Life history and habits
Larvae of
A. indicus
have been observed preying on whitefly nymphs in the following plants
Acalypha wilkesiana
,
Terminalia
catappa
,
Codiaeum variegatum
,
Psidium guajava
,
Hibiscus rosa-sinensis
.
In
Hainan Province
,
China
,
A. indicus
larvae prey on nymphs of spiralling whitefly
Aleurodicus dispersus
. The egg of
A. indicus
is covered with a white waxy incrustation which is roughened with irregular or indistinct reticulate markings. The eggs are laid singly upon the leaf surface, adjacent to the late-stage nymph or pupa of whitefly. The larva is translucent white in its early stages, and then changes to greenish as the body contents are visible through the transparent integument (
Figure 2B,C
). The larva is inactive because the colony of whiteflies around it provides sufficient food for its maturity. Noticeably, sometimes there are several larvae on one leaf. The larva secretes a mucilaginous fluid that covers the whole body in the early stages, leading to the body of larva, particularly on the dorsum, being covered with particles of extraneous matter in the later stages. Many mature larvae carry a large number of egg shells or wax of
Aleurodicus dispersus
, and these structures may also be found upon the puparium (
Figure 2C
). Pupation occurs on the underside of the leaf. The ventral surface of the puparium is flat and adheres strongly to the leaf surface. The greenish colour of the body contents is observable in the early pupal period, and then the large, deep red eyes of the developing pupa are also observable. Emergence is effected by the breaking away of the distinct lid at the anterior end. The empty puparium is white (
Figure 2D
).
Figure 2.
Acletoxenus indicus
Malloch.
(A) Adult; (B) larvae (green) preying upon spiralling whitefly on the underside of guava leaf; (C) coarctate pupae of spiralling whitefly; (D) puparium after eclosion. [This figure can be viewed in colour online.]
Distribution
China
(
Guangdong
,
Hainan
; new record);
India
.