Chilocorini Mulsant 1846
Creators: name: POORANI, J.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Coccinellidae

description: Tribe Chilocorini Mulsant, 1846
Form circular, broadly oval, or distinctly elongate oval (Fig. 2); dorsum often dome-shaped and strongly convex or moderately convex, shiny and glabrous (at the most only head and anterolateral flanks of pronotum with hairs), or with sparse, short and suberect pubescence on elytral disc and more visibly on lateral margins, or with distinct dorsal pubescence (Fig. 2g, i). Head capsule with anterior clypeal margin laterally strongly expanded over eyes, medially emarginate, rounded or laterally truncate (Fig. 3a–c). Anterior margin of pronotum deeply and trapezoidally excavate, lateral margins strongly descending below; anterior angles usually strongly produced anteriorly. Elytra basally much broader than pronotum. Antennae short (7–10 segmented) (Fig. 3g –j), shorter than half the width of head; antennal insertions hidden and broadly separated. Terminal maxillary palpomere (Fig. 3d–f) parallel-sided and apically obliquely transverse or securiform or elongate, slender, subcylindrical to tapered with oblique apex, or somewhat swollen with subtruncate apex. Prosternal intercoxal process without carinae (Fig. 3k). Elytral epipleura broad, sometimes strongly descending externally with inner carina reaching elytral apex or not. Legs often with strongly angulate tibiae; tarsal formula 4–4–4 (Fig. 3o, p); tarsal claws simple (Fig. 3u) or appendiculate (Fig. 3v). Abdominal postcoxal line incomplete (Fig. 3l, n) or complete (Fig. 3m). Female genitalia with elongate triangular or transverse coxites (Fig. 3q, r); spermatheca with (Fig. 3t) or without (Fig. 3s, w) a membranous, beak-like projection at apex; sperm duct between bursa copulatrix and spermatheca most often composed of two or three parts of different diameters (Fig. 3w); infundibulum present (Fig. 3w) or absent.
Immature stages
Egg. Eggs elongate oval to somewhat cylindrical, chorion with distinct microsculpture in Chilocorus (Figs 4a, 5a), Brumoides (Fig. 4b), and Priscibrumus Kovář. Eggs laid singly or in small groups on or in the vicinity of prey. Chilocorus spp. have a characteristic and peculiar habit of laying eggs on sibling larvae, pupae, and exuviae besides the host colony (Fig. 4c–e).
Larva. Larvae of Chilocorini have a nearly cylindrical or broadly fusiform body with the dorsal and lateral surfaces covered with setose projections (“senti”) or prominent parascoli (Figs 4f, g; 5b–e). After completing their development, the mature larvae of Chilocorini, particularly armoured-scale feeders, pass 1–2 days in an immobile, prepupal stage (Fig. 5f).
Pupa. Pupae are exarate and enclosed in longitudinally and medially split open larval exuvium (Figs 4h, i; 5g). In many Chilocorus spp., larvae congregate in small or large clusters on the lower side of branches or on the tree trunk for pupation (Drea & Gordon 1990). It is common to see large congregations of pupae in Indian species such as Chilocorus circumdatus (Gyllenhal) (Fig. 6a, b), C. nigrita (Fig. 6c, d) and C. infernalis Mulsant on various host plants.
Biology. Members of the tribe Chilocorini are widely considered as specialized scale feeders but appear to have a broad range of prey associations not commonly known or studied. Species belonging to the genus Chilocorus are scale feeders, particularly on the families Diaspididae (hard or armoured scales) (Fig. 7a–c), Coccidae (soft scales) and also Pseudococcidae (mealybugs), and rarely on whiteflies (Fig. 7e, f) and aphids (Devi 1989). Indian Brumoides species, such as B. suturalis (Fabricius) and B. lineatus (Weise), appear to be more commonly associated with mealybugs (Fig. 7d), whiteflies and also aphids, rather than scale insects (personal observations, label data). Brumoides suturalis is known to feed on mites, psyllids, whitefly eggs and nymphs, aphids, scale insects, mealybugs and leafhopper eggs (Rahman & Nath 1940; Kapur 1942; Inayatullah 1984). Kapur (1942) also reported it as a pollen feeder on some grasses. Indian Priscibrumus spp. such as P. uropygialis (Mulsant) and P. lituratus (Gorham) widely feed on adelgids (Aphidoidea: Adelgidae) (Nagarkatti & Ghani 1972) and have been introduced in parts of North America for biological control of adelgids without success (Mitchell & Wright 1967; Clausen 1978; Schooley et al. 1984). Species of Parexochomus Barovsky feed on aphids, whiteflies, psyllids, mites, etc. (label data).
description: Published as part of POORANI, J., 2023, An illustrated guide to the lady beetles (Coleoptera: Coccinellidae) of the Indian Subcontinent. Part II. Tribe Chilocorini, pp. 1-108 in Zootaxa 5378 (1) on pages 6-7, DOI: 10.11646/zootaxa.5378.1.1, http://zenodo.org/record/10208917