 The eulophid wasp, Anselmella malacia Xiao  Huang, 2006 (Hymenoptera: Eulophidae), is reared from fruits of the water apple, Syzygium samarangense, and is reported as an important phytophagous developing as seed-eaters of Syzygium species in Malaysia. Analysing specimens of pest insects infested inside of pear-shaped fruits of the cultivated water apple, S. samarangense, in Dong Thap Province, South Vietnam, a total of four insect species were recorded as the important pests for fruits of six varieties of the cultivated water apples. The hymenoteran wasp, A. malacia, is recorded for the first time from Vietnam. Further evidence is needed to prove A. malacia being an invasive pest in Vietnam. The associated hymenopteran parasitoid assemblage with the fruit infested insect pests is also provided.

Bup, Nguyen Kim

Long, Khuat Dang

Oanh, Nguyen Thi

English

Vietnam Academy of Science and Technology: Journals Online

TAP CHI SINH HOC 2019, 41(4): 7–14 
DOI: 10.15625/0866-7160/v41n4.14673 
7 
 
FIRST RECORD OF Anselmella malacia Xiao & Huang, 2006 (Hymenoptera: 
Eulophidae), A NEW INSECT PEST OF WATER APPLE (Syzygium 
samarangense) AND ITS ASSOCIATED PARASITOID IN DONG THAP 
PROVINCE, VIETNAM 
 
Nguyen Thi Oanh
1
, Nguyen Kim Bup
1
, Khuat Dang Long
2,* 
1
Dong Thap University, Cao Lanh city, Dong Thap, Vietnam 
2
Instititute of Ecology and Biological Resources, VAST, Ha Noi, Vietnam 
Received 8 September 2019, accepted 10 December 2019 
 
 
 
ABSTRACT 
The eulophid wasp, Anselmella malacia Xiao & Huang, 2006 (Hymenoptera: Eulophidae), is 
reared from fruits of the water apple, Syzygium samarangense, and is reported as an important 
phytophagous developing as seed-eaters of Syzygium species in Malaysia. Analysing specimens 
of pest insects infested inside of pear-shaped fruits of the cultivated water apple, S. 
samarangense, in Dong Thap Province, South Vietnam, a total of four insect species were 
recorded as the important pests for fruits of six varieties of the cultivated water apples. The 
hymenoteran wasp, A. malacia, is recorded for the first time from Vietnam. Further evidence is 
needed to prove A. malacia being an invasive pest in Vietnam. The associated hymenopteran 
parasitoid assemblage with the fruit infested insect pests is also provided. 
Keywords: Eulophidae, Anselmella, new pest, new record, parasitoid, phytophagous insects, 
Vietnam. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Citation: Nguyen Thi Oanh, Nguyen Kim Bup, Khuat Dang Long, 2019. First record of Anselmella malacia Xiao & 
Huang, 2006 (Hymenoptera: Eulophidae), a new insect pest of water apple (Syzygium samarangense) and its 
associated parasitoid in Dong Thap Province, Vietnam. Tap chi Sinh hoc (Journal of Biology), 41(4): 7–14. 
https://doi.org/10.15625/0866-7160/v41n4.14673. 
Corresponding author email: khuatdanglong@gmail.com 
©2019 Vietnam Academy of Science and Technology (VAST) 
Nguyen Thi Oanh et al. 
8 
INTRODUCTION 
Syzygium samarangense Merr. & Perry. 
(Myrtaceae), commonly known as wax apple, 
wax jambu, water apple, rose apple or Java 
apple, has pear-shaped fruits and is common 
in Cambodia, Laos, Thailand, Taiwan and 
Vietnam, and is also frequently cultivated in 
India, Pembe (Tanzania) and Zanzibar (Xiao 
& Huang, 2006). The water apple is growing 
in the most provinces in the southern 
Vietnam. The pear-shaped fruits are often 
juicy, with a subtle sweet taste somewhat 
resembling a common apple, and especially, 
this crop is considered as one of the special 
precious fruits of Dong Thap Province. 
Recently, during several surveys 
conducted in late March 2019 for revealing 
parasitoids of fruit flies Bactrocera spp. 
infested the water apple, we recognized a 
community of hymenopteran wasps inside of 
the fruits of cultivated water apple in several 
areas of Dong Thap Province. Among 
hymenopteran wasp adults, we recorded the 
eulophid wasp, Anselmella malacia Xiao & 
Huang, which causes a heavy damage to the 
cultivated water apples in Cao Lanh City and 
its vicinity. 
MATERIALS AND METHODS 
All the specimens examined in this study 
were collected from water apple fruits in Cao 
Lanh City, Dong Thap Province, in late 
March 2019. Since it is rather difficult to 
obtain reliable estimates of abundance of 
species inside the cavity of water apple fruits, 
the relative abundance data are collected by 
complete enumeration, counting all 
individuals found in well-defined demaging 
fruits, then the comparative abundunce of 
insect pests are expressed in percentage. 
Identification of pest insects and their 
associated parasitoids is based on the 
following literatures: Doganlar & Hassan 
(2010), Han et al. (2017), Leblanc et al. 
(2018), Li et al. (2013), Xiao et al. (2006), 
Yang et al. (2014). Anselmella malacia was 
identified by the comparison of the 
morphological characters of the pest 
population collected from six verieties of the 
cultivated water apples in Cao Lanh, Dong 
Thap, with the original description of Xiao et 
al. (2006). Measurements of A. malacia adults 
were made using a binocular microscope 
(DK3000; Meiji Techno Co., Ltd., Saitama, 
Japan). 
All the research specimens are deposited 
in the Institute of Ecology and Biological 
Resources (Ha Noi, Vietnam) and Dong Thap 
University (Cao Lanh, Dong Thap, Vietnam). 
RESULTS 
Pest insects associated with the fruit of 
cultivated water apple, Syzygium 
samarangense 
Of the most commonly sampled species, 
one was a seed-eater of Syzygium varieties: 
Anselmella malacia Xiao & Huang 
(Hymenoptera, Eulophidae), and three others 
were frugivorous insects, Bactrocera dorsalis 
(Diptera, Tephritiidae); Orgyia postica 
(Walker) (Lepidoptera, Erebidae); and Cydia 
sp. (Lepidoptera, Tortricidae) (Table 1).  
The seed-eater A. malacia and frugivore B. 
dorsalis were found as the most abundant 
species in the samples (> 50%). Especially, in 
the fruits of two varieties Hong Dao Da and 
Hoa An planted in Dong Thap Province, up to 
100% of the sampled specimens were of the 
seed-eater A. malacia. 
Seeds attacked by the seed-eater A. malacia 
contained cavities and frass made by larvae 
and were often galled with a mass of pale 
conductive tissue and parenchyma, rather than 
green cotyledons (Fig 1). The effect of the 
seed-eater and other frugivorous insects on the 
viability of the seed in samples was not 
quantified. Nevertheless, seedlings were able 
to germinate from the most severely damaged 
fruits and seeds by the end of the trial. 
Of total five insect species recorded from 
six varieties of the cultivated Syzygium 
samarangense in Cao Lanh city, Dong Thap 
Province, in addition to A. malacia, we have 
found another hymenopteran species, 
Megastigmus sp. and two lepidopteran 
First record of Anselmella malacia  
9 
species, Orgyia postica and Cydia sp. Orgyia 
postica was reported as the restrictively 
distributed fugivore in Vietnam (Waterhouse, 
1993; CABI, 2019). Another frugivorous 
insect, Cydia sp. is also an abundant pest, i.e. 
25–50% of the sampled specimens of the pest 
complex infested the water apple in Dong 
Thap Province. 
 
Table 1. Assemblage of pest insects found in fruits of  S. samarangense  
in Cao Lanh City and its vicinity 
Pest species 
Local varieties of Syzygium 
Xanh 
Duong 
Hong 
Dao Da 
Sua 
An 
Phuoc 
Hoa An Indian 
Diptera, Tephritiidae 
Bactrocera dorsalis (Hendel, 
1912) (oriental fruit fly) 
> 50% > 50% > 50% < 25% > 50% < 25% 
Hymenoptera, Eulophidae 
Anselmella malacia Xiao & 
Huang, 2006 
25–50% > 50% 25–50% < 25% > 50% - 
Torimidae 
Megastigmus sp.       
Lepidoptera  
Erebidae 
Orgyia postica (Walker, 
1955) (cocoa tussock moth) 
< 25% 25–50% < 25% < 25% 25–50% - 
Tortricidae 
Cydia sp. < 25% 25–50% - - 25–50% - 
 
 
Figure 1. Healthy water apple fruit (left) and the fruit damaged by Anselmella malacia (right) 
 
 
Figure 2. Damages inside of water apple fruits caused by Bactrocera dorsalis Xanh Duong 
variety (left), Hong Dao Da variety (middle) and Indian variety (right) 
  
 
 
 
 
 
Nguyen Thi Oanh et al. 
10 
Morphology of A. malacia collected from 
the water apple in Cao Lanh, Dong Thap 
Based on the comparative characters of 
the wasp seed-eater infested Syzygium 
samarangense in Cao Lanh city, Dong Thap 
Province, it is possible to confirm this pest is 
Anselmella malacia  Xiao & Huang rather 
than Anselmella miltoni Girault (table 2). 
 
Table 2. Comparative characters of Anselmella malacia Xiao & Hoang, 2006 
Characters 
Anselmella malacia 
(Original 
description) 
Anselmella malacia  
(from Dong Thap, 
Vietnam, n = 30) 
Eye height : Malar space 2.6 × 2.80 ± 0.18 
Head width : Head height (frontal view) 1.3 × 1.30 ± 0.04 
Head width : Head length (dorsal view) 1.95 × 2.04 ± 0.15 
Head width : Mouth width 2.4 × 2.40 ± 0.09 
Eye height : Eye length 1.2 × 1.18 ± 0.06 
POL : OOL 2.9 × 2.70 ± 0.32 
Eye length : Temple (dorsal view) 20.0 × 19.55 ± 1.06 
Scapus length : maximum width 1.9 × 1.87 ± 0.23 
MV : PMV 2.3 × 2.18 ± 0.31 
PMV : STV 0.2 × 0.25 ± 0.03 
Metasoma length : width 1.5 × 1.50 ± 0.18 
Body length (female) 2.2 mm 2.54 ± 0.16 mm 
Body length (male) 1.5–2.0 mm 1.74 ± 0.38 mm 
Notes: MV = Marginal vein; PMV = Postmarginal vein; SMV = Submarginal vein; STV = Stigmal vein. 
 
Preliminary biological characteristics of A. 
Malacia 
Emerged adults were separated into males 
and females, and pairs of males and females 
were observed separately. While sucking 
flower nectar, A. malacia females prefer 
laying their eggs inside the most soft tissue of 
flower style during the anthesis stage of fruit 
phenology of S. samarangense (Fig. 3A), 
where eggs were laid as the clusters (Fig. 3B) 
or masses (Fig. 3C) and were white or creamy 
white, oval in shape (Figs. 3B–3C). 
 
 
Figure 3. A = Hole made by A. malacia female on flower style; B and C = Clusters/masses  
of eggs inside of flower ovaries 
 
The egg stage of A. malacia overlaps with 
the petal fall stage in S. samarangense. 
Immature stage of A. malacia develops 
through a rapid stage to the middle fruit stage. 
 
  
 
First record of Anselmella malacia  
11 
Anselmella malacia enters into pupal stage 
and adults emerge, when the fruits of S. 
samarangense are in the mature stage. 
After hatched from eggs inside the 
fruilets, larvae feed on the internal tissues of 
water apple fruits, larval and pupal stages lasts 
inside the fruits. Adults are emerged inside of 
the fruit cavity, where several holes are left 
(Figs. 4 A & B). 
In this study, another hymenopteran 
wasp, Megastigmus sp. (Hymenoptera; 
Chalcidoidea: Torymidae), was found in the 
cavity of water apple fruits in Cao Lanh, 
Dong Thap (Fig. 5). In some published 
literatures (Roques et al., 1995; Roques et 
al., 2016), this wasp species was recorded 
and reported as a seed-feeding that emerged 
from seeds of wild rose, Rosa canina, in 
Ukraine. According to Doganlar & Hassan 
(2010), Australian species of Megastigmus 
were recorded as pests associated with 
Eucalyptus plants. 
 
 
Figure 4. A & B = Holes after A. malacia adults emerged outside of the fruit cavity 
 
 
Figure 5. Megastigmus sp. (Habitus, female) 
 
Hymenopteran parasitoid associated with 
the fruit infested insect pests 
One dominant parasitic wasp, 
Aprostocetus sp. (Hymenoptera: 
Chalcidoidea: Eulophidae) (Fig. 6), was 
surveyed and collected from water apple fruits 
in Cao Lanh City, Dong Thap Province, in 
March 2019, and this parasitoid is probably an 
 
Nguyen Thi Oanh et al. 
12 
egg parasitoid of A. malacia because the 
parasitic wasp was not directly reared from 
Anselmella malacia but parasitoid was 
incidentally captured inside of water apple 
fruits when the fruits were collected. 
However, two species of the genus 
Aprostocetus, A. causalis La Salle & Wu, 
from China and Thailand and A. felix La Salle, 
Yang & Lin, from Taiwan, were reported as 
fortuitous parasitoids of invasive eulophid gall 
inducers (Tetrastichinae) on Eucalyptus and 
Erythrina (Yang et al., 2014). 
 
 
Figure 6. Aprostocetus sp. (Habitus, male) 
 
DISCUSSION 
Based on the comparative morphological 
characters of the eulophids collected from 
fruits of Syzygium samarangense in Cao 
Lanh city, Dong Thap, Anselmella malacia 
was revealed as one of few gall-inducing 
hymenopteran wasps living inside of fruits 
and this pest was recorded for the first time 
in Vietnam. Inducing galls within the seed 
chamber of the fruits of the water apple 
fruits, A. malacia has emerged as a serious 
problem for all the varieties of the cultivated 
S. samarangense in Cao Lanh City, Dong 
Thap Province. 
Contrary to the frugivorous insect, 
Bactrocera dorsalis (Diptera: Tephritidae), 
which induces either an immature fruit drop 
or decay in pulp in the cultivated water apple, 
A. malacia should be considered as an issue of 
deep concern for the horticultural industry not 
only in Dong Thap Province, but all over 
Vietnam. Since there is not any practice 
applied for the control of A. malacia up to 
know, control measures should be introduced 
in the studied area as soon as possible. 
REFERENCES 
CAB International, 2019. Available from: 
https://www.cabi.org/isc/datasheet/37808#
todistributionTable (accessed 16 
November 2019).  
Doganlar M., Hassan E., 2010. Review of 
Australian Species of Megastigmus 
(Hymenoptera: Torymidae) Associated 
with Eucalyptus, with Descriptions of 
New Species. Australian Journal of Basic 
and Applied Sciences, 4(10): 5059–5120. 
Han H. Y., Choi D. S., Ro K. E., 2017. 
Taxonomy of Korean Bactrocera (Diptera: 
Tephritidae: Dacinae) with review of their 
First record of Anselmella malacia  
13 
biology. Journal of Asia-Pacific 
Entomology, 20: 1321–1332.  
Juniper P. A., David R Britton D. R., 2010. 
Insects associated with the fruit of 
Syzygium paniculatum (Magenta 
Lillypilly) and Syzygium australe (Brush 
Cherry). Australian Journal of 
Entomology, 49(4): 296–303. 
https://doi.org/10.1111/j.1440-
6055.2010.00767.x 
Kapoor V. C., 2005. Taxonomy and Biology 
of Economically Important Fruit Flies of 
India. Isr. J. Entomol., 35(36): 459–475.  
Leblanc L., Doorenweerd C., Jose M. S., Pham 
H. T., Rubinoff D., 2018. Descriptions of 
four new species of Bactrocera and new 
country records highlight the high 
biodiversity of fruit flies in Vietnam 
(Diptera, Tephritidae, Dacinae). ZooKeys, 
797: 87–115. https://doi.org/10.3897/ 
zookeys.797.29138 
Le Duc Khanh, Nguyen Thi Thanh Hien, Tran 
Thanh Toan, Vu Thi Thuy Trang, Le 
Quang Khai, Vu Van Thanh, Dang Dinh 
Thang, Nguyen Thi Thuy Hang, 2010. 
Thanh phan ruoi hai qua ho Tephretidae 
va ky chu cua chung tai mot so vung sinh 
thai nong nghiep Vietnam. Tap chi Bao ve 
thuc vat, no. 3: 10–14 (in Vietnamese with 
English sumary).   
Leung W. T. W., Butrum R. R., Chang F. H., 
Rao M. N., Polacchi W., 1972. Food 
composition table for use in East Asia. 
FAO, Rome, 347 pp. 
Li X-Y., Achterberg C. van, Tan J-C., 2013. 
Revision of the subfamily Opiinae 
(Hymenoptera, Braconidae) from Hunan 
(China), including thirty-six new species 
and two new genera. ZooKeys, 268: 1–
168. https://doi.org/10.3897/zookeys. 
268.407 
Lim T. K., 2012. Edible Medicinal And Non-
Medicinal Plants: Volume 3, Fruits. 
Springer Science & Business Media B. V., 
pp. 778–786. 
Lin Y-C., Liao Y-C., Yang M-M., 2019. 
Biology of a Gall-inducing Species of 
Anselmella (Hymenoptera:Eulophidae) 
within the Fruits of Syzygium 
samarangense (Myrtaceae). Formosan 
Entomol., 38(Special Issue): 56–68. 
Roques A., Sun J-H, Pan Y-Zh, Zhang X-D, 
1995. Contribution to the knowledge of 
seed chalcids, Megastigmus spp. 
(Hymenoptera: Torymidae), in China, 
with the description of three new species. 
Journal of the Swiss Entomological 
Society, 68(1–2): 211–223. https://doi.org/ 
10.5169/seals-402594 
Roques A., Copeland R. S., Soldati L., Denux 
O., Auger-Rozenberg M. A., 2016. 
Megastigmus seed chalcids 
(Hymenoptera, Torymidae) radiated much 
more on Angiosperms than previously 
considered. I- Description of 8 new 
species from Kenya, with a key to the 
females of Eastern and Southern Africa. 
ZooKeys, 585: 51–124. https://doi.org/ 
10.3897/zookeys.585.7503  
Rosnah S., Wong W. K., Noraziah M. and 
Osman H., 2012. Chemical composition 
changes of two water apple (Syzygium 
samaragense). International Food 
Research Journal, 19(1): 167–174. 
Shu Z. H., Meon R., Tirtawinata, Thanarut C. 
2006. Wax apple production in selected 
tropical Asian countries, ISHS, Acta Hort, 
(ISHS), 773: 161–164. 
Turgeon J. J., Kamijo K., DeBarr G., 1997. A 
new species of Megastigmus Dalman 
(Hymenoptera: Torymidae) reared from 
seeds of Atlantic white cedar 
(Cupressaceae), with notes on infestation 
rates. Proceedings of the Entomological 
Society of Washington, 99(4): 608–613. 
Wharton R. A., 1997. Generic relationships of  
opiine Braconidae (Hymenoptera) 
parasitic in fruit-infesteing Tephritidae 
(Diptera). Contributions of the Americal 
Entomological Instite, 30(3): 1–53. 
Waterhouse D. F., 1993. The Major 
Arthropod Pests and Weeds of Agriculture 
in Southeast Asia. ACIAR Monograph 
Nguyen Thi Oanh et al. 
14 
No. 21. Canberra, Australia: Australian 
Centre for International Agricultural 
Research, 141 pp. 
Xiao H., Xu L-N., Huang D-W., Zhao Z-Y., 
2006. Anselmella malacia, A New Pest 
Wasp (Hymenoptera: Chalcidoidea: 
Eulophidae) reared from Syzygium 
samarangense in Malaysia. 
Phytoparasitica, 34(3): 261–264. 
Yang M-M., Lin Y-C., Wu Y., Fisher N., 
Saimanee T., Sangtongpraow B., Zhu C., 
Chiu W. C.-H. and Salle J. L., 2014. Two 
new Aprostocetus species (Hymenoptera: 
Eulophidae: Tetrastichinae), fortuitous 
parasitoids of invasive eulophid gall 
inducers (Tetrastichinae) on Eucalyptus 
and Erythrina. Zootaxa, 3846(2): 261–272. 
https://doi.org/10.11646/zootaxa.3846.2.6
 


First record of  Anselmella malacia  Xiao & Huang, 2006 (Hymenoptera: Eulophidae), a new insect pest of water apple (Syzygium samarangense)  and its associated parasitoid in Dong Thap Province, Vietnam

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First record of Anselmella malacia Xiao & Huang, 2006 (Hymenoptera: Eulophidae), a new insect pest of water apple (Syzygium samarangense) and its associated parasitoid in Dong Thap Province, Vietnam

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