Research Article |
Corresponding author: Xiaohua Dai ( leafminer@vip.qq.com ) Academic editor: Astrid Eben
© 2018 Chengqing Liao, Zhilin Zhang, Jiasheng Xu, Charles L. Staines, Xiaohua Dai.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Liao C, Zhang Z, Xu J, Staines CL, Dai X (2018) Description of immature stages and biological notes of Cassidispa relicta Medvedev, 1957, a newly recorded species from China (Coleoptera, Chrysomelidae, Cassidinae, Hispini). ZooKeys 780: 71-88. https://doi.org/10.3897/zookeys.780.23280
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The first instar and mature larva and pupa of Cassidispa relicta Medvedev, 1957, a newly recorded species from China, are described and figured. The chaetotaxy of the head, mouthparts, legs, and dorsal and ventral surfaces of the body is described. This is the first detailed description of immatures in the genus Cassidispa. Diagnostic characters of this species are compared with other described immatures of some Hispini genera. Biological notes on C. relicta, such as host plants, feeding patterns of adults, structure of larval mines and life history, are also presented.
Cassidinae , Cassidispa , chaetotaxy, Hispini , immature stages, leaf-mining insects, morphology
Cassidispa Gestro, 1899 is a leaf beetle genus belonging to the tribe Hispini Gyllenhal, 1813 (Chrysomelidae: Cassidinae), with eight species occurring in China, Russia, Angola, Democratic Republic of Congo and Zimbabwe (
There is little published biological information on Cassidispa species.
In this publication, we describe the larvae and pupa of C. relicta and provide the first detailed report on immature morphology and biological information for the genus Cassidispa.
All immatures and adults were observed and collected at Shanggaotai Forest Farm (Zhuozi County, Inner Mongolia) from March 2016 to October 2017. Immatures and adults of C. relicta were collected on wild plants and some of them were preserved in anhydrous ethanol. Some adults were pinned in the laboratory (Figs
The photos of adults were taken using a Cannon EOS 7D camera with macro lenses; the dissection of heads and mouthparts was made with a Motic SMZ-140 and Olympus SZX2-ILLT stereomicroscope; figures and examination were performed using an Optika B-292 microscope and Cannon EOS 70D camera. Our descriptions of immature stages follow
(Figs
Body distinctly flattened dorso-ventrally. Pronotum of first instar larvae slightly wider than abdominal segments; mature larvae widest across abdominal segments IV–V (Figs
Body with eight pairs of lateral scoli on abdominal segments (Figs
Granulation of body distinct in all examined specimens including both first instar and mature larvae. Each tergite and sternite (except for sternite VIII) with minute setae on anterior margin; tergites and sternites covered with short pointed setae. Tergites of meso- and metathorax, abdominal segments I–VI and sternites I–VII of abdomen with transverse grooves (Figs
Pronotum with four setae on each lateral margin, five setae on each lateral side, and three setae close to posterior margin (Figs
Prosternum with one seta in each anterior angle; one seta laterally at base of leg; and two setae close to posterior margin (Figs
Nine pairs of distinct spiracles (Figs
Head well sclerotized, prognathous, partially retracted into pronotum (Figs
Five stemmata laterally: four dorsal-laterally, one ventrally (Figs
Labrum approximately three times wider than long, anterior margin slightly emarginate (Figs
Mandibles heavily sclerotized, with two prominent teeth (Figure
Maxillae and labium connate (Figure
Legs oblong, consisting of three segments: coxa, femur, and tibiotarsus (Figure
Cassidispa relicta, larva. 8 Dorsal view of head: cs – campaniform sensilla 9 Ventral view of head 10 Dorsal view of labrum 11 Ventral view of labrum 12 Mandible 13 Leg 14 Antenna 15 Maxillae and labium, ventral. Abbreviations: hyp – hypopharynx; mal – mala; mp – maxillary palp; pp – palpifer; lp – labial palp; pre – prementum; post – postmentum; st – stipes.
(Figs
Body flattened dorso-ventrally, elongate-oval. Color of live as well as alcohol-preserved pupa brownish yellow, mesothorax with two dark markings at base of wings, apex of abdomen dark brown (Figs
Body, especially abdomen, distinctly granulate (Figs
Head visible in dorsal view (Figs
Head with three pairs of setae laterally and four setae anteriorly (Figure
In ventral view (Figure
Abdominal segments each with one pair of spiracles (Figure
The biology of the genus Cassidispa is poorly known. There is only one species having confirmed host plant record.
The larvae of C. relicta were found mainly mining in the leaves of Betula platyphylla (Figs
The life cycle of C. relicta is univoltine based on our field observations throughout 2016–2017. C. relicta overwinters as a mature larva until the temperature rises and the soil thaws in the spring. The mature larvae break dormancy and pupate in the fallen leaves in early April (Figs
General morphology of the larva and pupa of C. relicta is typical for species of leaf-mining Hispini. The immature stages of Hispini beetles have been reported on some species, such as Acmenychus inermis (Zubkoff, 1833) (
Comparisons of diagnostic characters of immature stages among C. relicta and some species in the genera of Dactylispa, Dicladispa, and Platypria.
Diagnostic characters | Larva | Pupa | References | ||||
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Lateral scoli on meso- and metathorax | Shape of abdominal scoli | Lateral branches of abdominal scoli | Processes on pronotum | Processes on abdominal apex | Spiracles of fifth abdominal segment | ||
C. relicta | absent | rounded | segments VI–VII | absent | 2 flattened | short, thick | This paper |
D. setifera | absent | triangular | absent | absent | 2 flattened | short, pointed |
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D. rufiventris | absent | diminutive | absent | absent | 2 spinulose | short, pointed |
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D. chapuisi | absent | rounded | absent | absent | 2 spinulose | spiniform |
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D. javaensis | present | triangular | absent | absent | 2 small | long conical | Maulik 1931 |
D. higoniae | present | triangular | absent | absent | 2 small triangular | long conical |
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D. insulicola | present | triangular | absent | absent | 2 flattened | long conical | Lee and Cheng 2007 |
D. latipennis | present | triangular | absent | absent | 2 flattened | long conical |
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D. doriae | present | triangular | absent | absent | 2 pointed | upward-hooked |
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D. xanthopus | present | triangular | absent | absent | 2 short | upward-hooked |
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D. haturanga | present | triangular | segments VI–VII | absent | 2 branched | long conical |
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Di. armigera | absent | triangular | absent | present | 6 small spinous | long pointed |
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Di. testacea | absent | short, fine | absent | absent | 2 flattened | elongate-horned |
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P. andrewesi | present | triangular | absent | present | 2 flattened | long conical |
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P. melli | present | triangular | absent | present | 2 flattened | long conical | Kimoto et al. 1997 (larva); |
The larva of C. relicta is very similar to that of some Dactylispa species and can be distinguished by the lateral branches of abdominal scoli on segments VI–VII (very small and with a rounded apex), although this character also presented on D. haturanga but distinctly slender and with a pointed apex (
The larvae, especially younger larvae, usually returned to the resting place (Figure
Life stages of Cassidispa relicta on host plants (all on Betula platyphylla except Fig.
Life stages of Cassidispa relicta on host plants Betula platyphylla. 28 Eggs 29 A leaf with new mines of hatching larvae and larval resting places focusing on their egg points: r – resting place of larva 30 Shared large mine of three older larvae in a same leaf 31–32 Mature larva leaves its original mine and builds a new one for overwintering and pupation, in Fig.
We thank every member of Leafminer Group of Gannan Normal University and Ulanqab Forestry Pest Control and Quarantine Station for collection, laboratorial rearing, observations, and recording of leaf-mining hispines. We also acknowledge the great comments from the three reviewers (Drs. Jolanta Świętojańska, Jesus Gomez-Zurita and Lukáš Sekerka), which soundly improve our first manuscript. Special thanks to Dr. Lukáš Sekerka for correct identification of the species. This study was funded by the National Natural Science Foundation of China (31760173, 41361009, 31260116), Natural Science Foundation of Jiangxi, China (20171BAB204023) and Innovation Team Project of Gannan Normal University.