Research Article |
Corresponding author: Xiaohua Dai ( leafminer@vip.qq.com ) Academic editor: Astrid Eben
© 2018 Chengqing Liao, Peng Liu, 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, Liu P, Xu J, Staines CL, Dai X (2018) Description of the last-instar larva and pupa of a leaf-mining hispine – Prionispa champaka Maulik, 1919 (Coleoptera, Chrysomelidae, Cassidinae, Oncocephalini). ZooKeys 729: 47-60. https://doi.org/10.3897/zookeys.729.21041
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The last-instar larva and pupa of Prionispa champaka Maulik, 1919 are described and figured in detail. The chaetotaxy of the head, mouthparts, legs, and dorsal and ventral surfaces of the body are given. The larva of P. champaka mine in the leaves of Pollia japonica Thunb. (Commelinaceae) and pupate in the base of the mid-ribs. The adults were also observed feeding on the leaves of Pollia siamensis (Carib.) Faden ex D. Y. Hong. The prominent diagnostic characters of immature stages of other species of the three genera of Oncocephalini (Prionispa, Chaeridiona, and Oncocephala) are discussed.
Cassidinae , chaetotaxy, immature stages, leaf-mining hispines, morphology, Oncocephalini , Pollia , Prionispa
The genus Prionispa Chapuis, 1875 is a member of the tribe Oncocephalini, Chapuis 1875 (Chrysomelidae: Cassidinae) and consists of 29 described species occurring in the oriental tropics (
So far only five Prionispa species have been recorded with host plants: P. champaka feeding on the leaves of an unidentified Zingiberaceae (
Immatures of Prionispa champaka were collected on wild plants (natural host plants) that were placed in plastic zip-lock bags. Then larvae and pupae were reared and observed in the laboratory. Field-collected and laboratory-emerged adults were preserved as pinned specimens (Figs
All immatures were collected at Anjishan Provincial Forest Park (Longnan County, Jiangxi Prov.) from 2015 to 2017, on Pollia japonica Thunb. (Commelinaceae). One adult was collected at Jiulianshan National Nature Reserve (Longnan County, Jiangxi Prov.) in July 2016 (without host plant note), and one adult was collected at Bawangling National Forest Park (Changjiang County, Hainan Prov.) in August 2016, on Pollia siamensis with feeding channels of adults.
Three mature larvae, three pupae, and three pupal exuviae were examined morphologically. Larvae and pupae were preserved in anhydrous ethanol. For microscopic study, heads of the larvae were separated from the rest of body and then the mouthparts were dissected. The photos of adults were made using a Cannon EOS 7D camera and macro lenses; dissection of heads and mouthparts were done using a Motic SMZ-140 and Olympus SZX2-ILLT stereomicroscope; figures and examination were obtained using an Optika B-292 microscope and Cannon EOS 70D camera. Descriptions of immature stages follows
All studied material (mature larvae, pupae and exuviae) and adults were deposited at the Leafminer Group, School of Life and Environmental Science, Gannan Normal University, China.
Mature larva (Figs
Length of mature larva 6.5–6.6 mm without head, width of body 1.8–1.9 mm across pronotum and 2.9–3.0 mm across abdominal segment IV. Body distinctly flattened dorso-ventrally, mature larvae are widest across abdominal segments IV-V (Figs
Body with four pairs of lateral scoli placed on abdominal segments V-VIII (Figs
Pronotum on each side with 14 setae arranged in a constant pattern (Fig.
Prosternum with two rows of setae medially (anterior with two setae, posterior with four setae) and four setae on each side at base of leg (Fig.
Nine pairs of distinct spiracles (Figs
Head well sclerotized, prognathous, partially retracted into pronotum (Figs
Six stemmata on each side of head (Figs
Prionispa champaka, 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 Antenna 13 Leg 14 Mandible 15 Dorsum of palpiger and maxillary palp 16 Ventral views of maxillae and labium. Abbreviations: hyp - hypopharynx; lp - labial palp; mal - mala; mpI - first segment of maxillary palp; mpII - second segment of maxillary palp; post - postmentum; pp - palpifer; pre - prementum; st - stipes.
Labrum approximately two times wider than long, anterior margin emarginate (Figs
Mandibles heavily sclerotized, with four prominent teeth, followed by some tiny teeth (Fig.
Maxillae and labium connate. Each stipes (st) with three short pointed setae laterally (Figs
Legs stout, consist of three segments: coxa, femur, and tibiotarsus (Fig.
Pupa (Figs
Length of pupa 6.5 mm, width of body 2.0 mm across the base of pronotum and 3.0 mm across abdominal segment IV without lateral scoli. Body flattened dorso-ventrally, elongate-oval, color when alive as well as alcohol preserved pupa yellowish-brown (Figs
Head with two distinct long and one short triangular processes on anterior margin (Figs
Pronotum with one pair of setae laterally and five setae on each side medially (Fig.
In ventral view (Fig.
Abdominal segments each with a pair of spiracles (Fig.
There is little biological information known on P. champaka. It was reported to feed an unidentified host plant of the family Zingiberaceae from China (
Life stages of Prionispa champaka. 21 Pollia japonica, the host plant for P. champaka 22 Adult of P. champaka and its feeding channel 23-24 An egg sheath of P. champaka which laid and located on the mid-rib of upper surface of a leaf 25 A leaf with new mine of hatching larvae of P. champaka and some linear feeding channels of adults 26 Large larval mine of mature larvae 27 Two pupal mines of P. champaka located at the base of petiole on the upper surface 28 Freshly emerged adult.
The female of P. champaka bites a narrow line across the mid-rib of the lower canopy leaves on the plant, and then extends it along each side of the mid-rib in the same direction. The biting channel results in two short vertical lines and forms an elongate “U” shape. Subsequently, the female lays a single long egg sheath (usually comprising 5–8 eggs) at the base of the biting channel. Finally, the female covers this portion of the biting channel with feces (Figs
Immature stages of only four species in the tribe Oncocephalini have been described in detail.
In the present study, a prominent diagnostic character of the larva of P. champaka was found: the lateral scoli on abdominal segments V–VIII. However, the lateral scoli of P. houjayi are present on all abdominal segments, as well as the meso- and metathorax (
The pupa of P. champaka is most similar to that of P. houjayi. These two species have a pair of prominent processes on the head and pronotum which is probably a constant character within the genus. The lateral scoli of the abdominal segments and the fifth abdominal spiracles also look very similar, but the opening of the fifth abdominal spiracle extends to the base of the spiracle. The most prominent difference from other species of these three genera is that the abdominal apex of P. champaka has 14 long flattened processes, whereas P. houjayi has only two wide flattened processes, O. quadrilobata has four flattened processes, and C. thailandica and C. picea respectively have two and three slender processes (
It can be seen from above that the lateral scoli and abdominal apex of larva and pupa are the most important diagnostic characters between different species in these three genera as well as other Old World genera of leaf-mining hispines, such as Dactylispa Weise, 1897 (
The habits of immature stages of P. champaka are similar to other leaf-mining chrysomelids especially hispines. The mature larvae move to another location and build a new mine (called “pupal mine” or “pupal chamber”) for pupation (
We thank every member of the Leafminer Group of Gannan Normal University for collection, laboratorial rearing, observation, and recording of leaf-mining hispines. We also thank Prof. Renlin Liu and his postgraduate Chao Fu (Gannan Normal University, China), and Dr. Xiaoya Yu (Qiannan Normal University for Nationalities) for identifying of the host plants. 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.