Henosepilachna implicata (Mulsant)

Poorani, J., Booth, R. G., Gracy, R. Gandhi, Anuradha, C., Thanigairaj, R. & Swathi, R. S., 2021, Immature stages, host plants and natural enemies of Henosepilachna implicata (Mulsant) (Coleoptera: Coccinellidae) with DNA sequence data and a new synonym and notes on some Indian species of Epilachnini, Zootaxa 4970 (3), pp. 533-546 : 535-543

publication ID	https://doi.org/ 10.11646/zootaxa.4970.3.5
publication LSID	lsid:zoobank.org:pub:55507B4C-7669-40BA-94E8-22C0A95A3B44
DOI	https://doi.org/10.5281/zenodo.4912413
persistent identifier	https://treatment.plazi.org/id/03F58798-4C6E-FFEA-DC80-7F1ABB66221D
treatment provided by	Plazi
scientific name	Henosepilachna implicata (Mulsant)
status

Treatment

Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 , 5 View FIGURE 5 , 6 View FIGURE 6

Epilachna implicata Mulsant, 1850: 837 .- Kapur, 1959: 657 (redescription).

Henosepilachna implicata: Jadwiszczak & Węgrzynowicz, 2003: 154 .

Epilachna circularis Korschefsky, 1933: 3 . New synonym.

Henosepilachna circularis: Jadwiszczak & Węgrzynowicz, 2003: 141 .

Diagnosis: Length: 4.40–5.17 mm; width: 3.75–4.36 mm. Henosepilachna implicata outwardly resembles other 28-spotted species of Henosepilachna such as H. vigintioctopunctata and H. septima , and also H. pusillanima (occasionally 28-spotted). Henosepilachna pusillanima (Length: 4.64–4.90 mm; width: 3.86–4.17 mm) and H. vigintioctopunctata (Length: 3.96–4.95 mm; width: 3.21–3.91 mm) are usually smaller but fall within the overall size range of H. implicata and only H. septima (Length: 4.07–5.65 mm; width: 3.46–4.49 mm) is occasionally slightly larger in size than H. implicata . Henosepilachna implicata is highly variable and can be reliably distinguished from these other species only by the male genitalia.

Description: Body broad oblong oval to elongate oval, usually larger in size; male ( Fig. 1b View FIGURE 1 ) with a robust body, more rounded and convex than female, female ( Fig. 1a View FIGURE 1 ) elongate oval, broadest around shoulders, more distinctly narrowed towards apex; dorsum densely pubescent. Head and pronotum reddish brown; ground colour of elytra generally dull reddish with a pinkish tinge or testaceous brown or much darker, greyish black to almost blackish with a dark greenish tinge. Pronotum with 5–7 black spots, elytra with 26–28 black spots, elytral spots usually ringed with yellowish-orange or reddish halos ( Figs. 1a–b View FIGURE 1 , 2a–b View FIGURE 2 , 3a–f View FIGURE 3 ); rarely spots larger, darkly pigmented ( Figs. 3e, f View FIGURE 3 ) and / or lacking distinct halos ( Fig. 3b View FIGURE 3 ). Ventral side yellowish brown with a pair of dark maculae on lateral sides of metaventrite, abdominal ventrites 2–4 laterally distinctly spotted in male ( Fig. 1c View FIGURE 1 ), with paler spots in female ( Fig. 1d View FIGURE 1 ). Abdominal postcoxal line ( Fig. 1c–e View FIGURE 1 ) apically incomplete; ventrite 5 apically broadly emarginate and ventrite 6 emarginate in male; ventrite 5 subtruncate and ventrite 6 medially split in female ( Fig. 1d View FIGURE 1 ). Apical angles of elytra rounded. Male genitalia ( Figs. 1f–i View FIGURE 1 , 2h–o View FIGURE 2 ) as illustrated, penis guide in lateral view ( Figs. 1f View FIGURE 1 , 2h–l View FIGURE 2 ) broadest basally, progressively narrowed and apically inwardly produced, in ventral view ( Fig. 1g View FIGURE 1 ) cylindrical and subparallel up to two-thirds of its length, gradually narrowed and triangular in apical third, apex blunt; penis ( Fig. 1h View FIGURE 1 ) with a characteristic apical emargination ( Fig. 1i View FIGURE 1 ), penis capsule well developed, variable as illustrated ( Figs. 1h View FIGURE 1 , 2m –o View FIGURE 2 ). Female genitalia: Coxites ( Fig. 1j View FIGURE 1 ) as illustrated.

Notes: Mulsant (1850) considered H. implicata as related to H. vigintioctopunctata and described the differences in the position and size of elytral spots by which these two species can be separated. Crotch (1874: 87) listed this species as a variety of H. vigintioctopunctata (Fabricius) . Dieke’s (1947) monograph on Epilachninae s.l. did not provide any detail of H. implicata .

Henosepilachna implicata appears to be close to H. pusillanima ( Figs. 4c, d View FIGURE 4 ) in having similar female genital coxites, but it differs from H. pusillanima “by having the elytra more rounded and less produced apically, the sutural angles are less broadly rounded and the sides of the elytra are straight declivous, without the weak lateral explanation or ‘gutter’” ( Booth & Pope 1989). It also looks similar to H. septima ( Figs. 4e–h View FIGURE 4 ), which is occasionally much darker with distinct halos around elytral spots ( Figs. 4f–h View FIGURE 4 ), but with different female genital coxites. Kapur (1959) redescribed the lectotype of H. implicata and illustrated the genitalia with a detailed account of the differences between H. implicata and H. vigintioctopunctata .

The male genitalia of the specimens of H. circularis ( Korschefsky, 1933) ( Figs. 2d–g View FIGURE 2 ) collected from Pune, Maharashtra, were found to fall within the overall range of intraspecific variations found in H. implicata ( Figs. 2h–o View FIGURE 2 ) collected from Karnataka and Tamil Nadu, confirming that they are conspecific. The Indian material was also compared with the reference collections at BMNH and ZSIK for further confirmation. Based on these, H. circularis is here reduced to a junior synonym of H. implicata (new synonym). The male genitalia of H. diekei Jadwiszczak & Węgrzynowicz (2003) are similar to those of H. implicata , but the former is mainly a southeast Asian species and also known from Sri Lanka and its host plants belong to Asteraceae and Acanthaceae ( Matsubayashi et al. 2016) .

Henosepilachna circularis , originally described from South India ( Korschefsky, 1933), is much darker with greyish black elytra having black spots ringed with orange-yellow halos in live specimens and these halos are usually more prominent than those in H. implicata . The only major difference in H. circularis ( Figs. 2a, b View FIGURE 2 ) is that the nonpersistent spots ‘a’, ‘b’ and ‘c’ (as defined by Dieke 1947) are almost fully orange and lack the usually fully developed black spots with halos found in H. implicata . Occasionally, nonpersistent spots ‘a’ and ‘c’ are orange with a pale black median speck or a small spot, but nonpersistent spot ‘b’ is nearly always fully orange or yellow in H. circularis . In H. implicata , usually all the elytral spots present are black with reddish or orange or yellowish halos and only the size of the spots is variable and very rarely some spots are absent or reduced ( Fig. 3a View FIGURE 3 ).

Korschefsky (1933) did not mention the type depository of E. circularis and only listed the localities from where his study material was collected and all these places, namely Coorg ( Fraserpet ) (in the state of Karnataka) and Jawalagiri and Aiyur (North Salem) (in the state of Tamil Nadu), are in South India .

Specimens examined: “ INDIA; Madurai 1982 Sp. A/ on Luffa aegyptiaca / female, genitalia on coverslip/ Henosepilachna sp. , det. T.G. Vazirani, 1982/ Pres. By Comm. Inst. Ent. B.M. 1982-1/ Epilachna implicata Muls. , det. R.G. Booth, 1988, comp. with type in OUM” (BMNH); “ INDIA: T. Nadu, Coimbatore 1988/ on Cucurbita sp. CIEA 20142/ E. implicata Muls. , det. R.G. Booth 1989 / Pres. By Comm. Inst. Ent. BM 1989-1” (BMNH); “ INDIA: Katrain, 10.viii.72, on brinjal, C.I. Veg. Res. Stn, CIEA 6150/? Epilachna implicata Muls. , det. R.G. Booth, 1988” (BMNH); Tamil Nadu: Tiruchirappalli: Ex. Coccinia sp. , Coll. R. Thanigairaj, several laboratory reared specimens (NRCB).

Distribution: India: Karnataka; Maharashtra; Tamil Nadu ( Fig. 5 View FIGURE 5 ).

Host plants: Korschefsky (1933) described E. circularis from material collected on the leaves of sandal ( Santalum album L.). Chatterjee and Bose (1933) reported that it was collected on healthy and spike disease affected sandal and Ziziphus oenoplia (L.) Miller ( Rhamnaceae ). The recorded host plants of H. implicata include members of Solanaceae (potato, eggplant, tomato) and Cucurbitaceae ( Momordica charantia , ivy gourd) ( Kapur 1959; Schaefer 1983). In Tamil Nadu, South India, all stages are commonly collected on Coccinia grandis (= Coccinia indica ) and wild Coccinia sp. It was also observed to breed on sponge gourd ( Luffa cylindrica M. Roem. = L. aegyptiaca Mill. ) during winter months (November–February) (unpublished data). Few specimens collected on Cucurbita sp. and eggplant ( Solanum melongena ) (label data) were also examined. One male and one female were collected on mango ( Mangifera indica L., Anacardiaceae ) on separate occasions from Trichy, Tamil Nadu, and it is not clear if it is a host plant because immature stages were not observed.

Immature stages: Eggs of H. implicata ( Figs. 6a, b View FIGURE 6 ) are laid in large groups of 25–80 on the leaves of Coccinia sp. , which appears to be the most preferred host plant. Early instar larvae ( Figs. 6c–e View FIGURE 6 ) are yellow with dark brown spiny processes on the dorsal and lateral sides and gradually turn darker. Fully developed larva ( Figs. 6f–i View FIGURE 6 ) is pale yellowish grey with dark brown to almost black dorsal and lateral processes with spiny projections, which are much longer than those found in H. vigintioctopunctata , H. pusillanima and H. septima and is medially much wider. The pupa ( Figs. 6k–l View FIGURE 6 ) is pale creamy yellow with dark brown to black markings, that are occasionally paler or much darker than usual. Both larvae and adults make a characteristic, semicircular to circular laceration on the leaves adjacent to their feeding territory, which appears to be unique to this species among South Indian Epilachnini .

Natural enemies: One egg parasitoid, Quadrastichus ovulorum (Ferrière, 1930) ( Figs. 7a–d View FIGURE 7 ) and one larvalpupal parasitoid Pediobius ? foveolatus (Crawford, 1912) ( Fig. 7f View FIGURE 7 ) ( Hymenoptera : Eulophidae ) were commonly observed to parasitize H. implicata . Pediobius foveolatus is “so variable as to be difficult to characterize” ( Kerrich 1973) and the specimens reared in this study are not identified unequivocally as P. foveolatus because though they largely agree with the description given by Kerrich (1973), there are some subtle differences. These two parasitoids have been recorded in association with several pestiferous Epilachnini such as H. vigintioctopunctata , H. pusillanima , H. ocellata , and H. septima in India ( Schaefer, 1983; Noyes 2019; label data) and exert some degree of control on their populations.

COI barcode: Mitochondrial COI partial gene sequence of H. implicata was obtained from the progeny of field collected and subsequently laboratory reared specimens. At present, DNA sequence data is not available for H. implicata and we found no comparable sequences in GenBank. In the phylogenetic tree constructed for COI sequences by using the Maximum Likelihood method ( Fig. 8 View FIGURE 8 ), H. implicata (GenBank MT985166 View Materials ) was embedded in the same subclade as a sister taxon to H. pusillanima with supporting value of 91, confirming they are close relatives.