Belongs within: Cryptocephalini.
The subgenus Burlinius of chrysomelid beetles is found widely in the Palaearctic. Burlinius species are generally polyphagous.
The Burlinius head-hiders
Published 11 February 2013
I may have to confess that, in direct opposition to the Deity, I am not overly fond of beetles. There are, quite simply, far too many of them, and even beetle families can be inordinately difficult to distinguish unless one is an expert (particularly the endless array of minute brown ones). Nevertheless, everything in beetles comes with an exception, and there are some groups that stand out: one of these is the leaf beetles of the Chrysomelidae. Chrysomelids are a highly diverse group, comparable to (though perhaps getting less press than) their close relatives the weevils and longicorns. They come in an enormous array of shapes and colours, and yet almost all (emphasis on almost) seem to carry an unmistakeable stamp saying, “I am a chrysomelid”.
The chrysomelid subgenus Burlinius of the genus Cryptocephalus includes over 120 species found across the Palaearctic region, with a single species known from the Simien Mountains of Ethiopia (Schöller 2002). The name Cryptocephalus means ‘hidden head’, and refers to how, when the beetle is viewed from above, the head is usually hidden underneath the pronotum. Species of Burlinius are relatively small with regular lines of punctures on the elytra, but are primarily distinguished from other Cryptocephalus species by the morphology of the male genitalia. The aedeagus (the intromittent organ) bears a dorsodistal appendage covering the dorsal opening, and two symmetrical ventral processes (Erber & Schöller 2006). The external appearance of many Burlinius species is known to be quite variable, and genital morphology is also the best way of distinguishing many species (Warchałowski 1999).
As you might have guessed from the vernacular name ‘leaf beetles’, chrysomelids are generally herbivorous. Host plant records for Burlinius species indicate that they are often polyphagous, feeding on a wide variety of hosts. Burlinius species have been recorded from legumes, composite-flowered plants, spurges, even pines (Erber & Schöller 2006). Cryptocephalus and related taxa belong to a subgroup of the chrysomelids called the Camptostomata, in which the females have an array of chitinous pads called the kotpresse in the rectum (Schöller 2008). The kotpresse is used to encase the eggs when they are laid in a covering made from faeces and other secretions; when the larvae hatches, it uses this covering for protection and adds to it itself as it grows.
Systematics of Cryptocephalus (Burlinius)
Characters (from Erber & Schöller 2006): Comparatively small species (1.9-4.5 mm) of Cryptocephalus, females somewhat larger than males, body shape cylindrical, colour predominantly creamy yellow. Basal segment of antennae long, laterally depressed; second segment small, only about twice as long as wide; following segments elongated and dilated from segment six onwards. Elytra with nine rows of punctures including a marginal row and scutellar row which is shortened and with punctures close. Part of rows near apex fused; punctation of apex sparse and confused. Humerus quite evident. Tarsi, especially fore tarsi, exhibiting sexual dimorphism: segments one and three more or less dilated in male. Claws divergent and simple, base of each slightly extended ventrally. Male: Aedeagus bearing distal dorsal process (appendix dorsalis) covering dorsal opening (orificium) and two symmetrical ventral processes. Weakly sclerotised area present at base of ventral processes, bearing short setae. Endophallus comprising dorsal guiding sclerite, bearing on dorsal side a fine tube which is elevated at its end, containing a thin filum. Tube elevated from guiding sclerite posteriorly, ending in round or slipper-shaped element. Anchoring sclerite present opposite guiding sclerite, resembling a mammal jaw, anterior ending prolonged into one or two tips, posterior ending into two wing-shaped apodemes corresponding with almost wing-shaped apodemes of guiding sclerite. Female: Spermatheca consisting of hook-formed vasculum and thread-like ductus. Part of ductus near vasculum spiralised, near vagina straight. Kotpresse consisting of two dorsal and one ventral sclerite. Dorsal sclerites bent as well anteriorly as in ventral direction; ventrally bent part following lateral fold of intestine; sclerites ending dorsally in sclerotised zone directed toward dorsal fold of intestine. Ventral sclerite a crosswise band ending in two apodemes which are wider than rectum. Sclerotised area near centre of ventral sclerite.
<==Cryptocephalus (Burlinius Lopatin 1965)ES06 |--C. (B.) biondii Sassi & Regalin 1998ES06 |--C. (B.) connexus Olivier 1807ES06 |--C. (B.) crenatus Wollaston 1864 (see below for synonymy)ES06 |--C. (B.) equisetiES06 |--C. (B.) fulvus (Goeze 1777)ES06 |--C. (B.) jocularisES06 |--C. (B.) macellus Suffrian 1860ES06 |--C. (B.) nitidicollis Wollaston 1864 [incl. C. validicornis Lindberg 1963]ES06 |--C. (B.) nubigena Franz 1982 [incl. C. nitidicollis var. gounellei Pic 1922, C. palmensis Franz 1982]ES06 |--C. (B.) pulchellusES06 |--C. (B.) puncticollis Wollaston 1864ES06 |--C. (B.) ragusanusES06 `--C. (B.) trapezicollis Lindberg 1953ES06
Cryptocephalus (Burlinius) crenatus Wollaston 1864 [incl. C. crenatus var. brunneobinotatus Pic 1938, C. crenatus var. madeirensis Pic 1938]ES06
*Type species of generic name indicated
References
[ES06] Erber, D., & M. Schöller. 2006. Revision of the Cryptocephalus-species of the Canary Islands and Madeira (Insecta, Coleoptera, Chrysomelidae, Cryptocephalinae). Senckenbergiana Biologica 86 (1): 85–107.
Schöller, M. 2002. The first representative of Cryptocephalus subgen. Burlinius Lopatin from tropical Africa (Chrysomelidae: Cryptocephalinae). Genus 13 (1): 33–37.
Schöller, M. 2008. Comparative morphology of sclerites used by camptosomatan leaf beetles for formation of the extrachorion (Chrysomelidae: Cryptocephalinae, Lamprosomatinae). In: Jolivet, P., J. Santiago-Blay & M. Schmitt (eds) Research on Chrysomelidae vol. 1 pp. 87–120. Brill: Leiden.
Warchałowski, A. 1999. Übersicht der westpaläarktischen Arten der Untergattung Burlinius Lopatin, 1965 (Coleoptera: Chrysomelidae: Cryptocephalus). Genus 10 (4): 529–627.