Harlequin Beetle

Cerambycidae, Lamiinae, Acrocinini, Acrocinus longimanus. Spanish: Escarabajo arlequín. Portuguese: Arlequim da mata (Brazil). French: Mouche bagasse. Jak tree borer (Trinidad).

The gaudy, harlequin pattern of black, olive, and coral crescents and bars and the outlandishly long forelegs of the males im

Figure 9.14 LONG-HORNED BEETLES (CERAMBYCIDAE). (a) Metallic longhorn (Psalidogna-thus friend!). (b) Three-lined fig tree borer (Neoptychodes trilineatus). (c) Harlequin beetle (Acrocinus longimanus), male, (d) Longhorn beetle (Taeniotes scalaris). (e) Metallic longhorn (Plinthocoelium sp.).

mediately identify this large longhorn (BL 4.5-7.5 cm) (fig. 9.14c, pi. 2a). This pattern, although conspicuous on a neutral background, affords the beetle consider-i able camouflage on the lichen-covered or mottled tree trunks that are its favored rest-' ing places. It is also a very strong, spiny crea ture and difficult to hold. Some early authors have said that the large lateral spines of the prothorax can rotate as if on ball bearings, but this is erroneous (Bates 1861).

Individuals are strongly attracted to exudates or the sap seeping from wounded I trees, especially the bagasse tree (Bagassa j guianensis, Moraceae), a fact well known to i collectors in the past who deliberately scored the trees to attract large numbers of the beetles (Wood 1883: 244). The species is widespread throughout the forested portions of the Neotropics. (A specimen once turned up in Portugal in 1977 where it was believed to have strayed without human assistance [Lemos Pereira 1978]).

Females often select trees infested with bracket fungi for oviposition (Chemsak 1983). Some say that the very long forelegs of the adults are used to brachiate among the branches of vegetation, much like a spider monkey, but this is doubtful (Duffy 1960: 231), their normal function probably being concerned with mating. The beetle is || active both day and night, but apparently it Jk fl'es after dark and is occasionally observed U around electric lights. JHl The larvae bore under the bark of dead HI trun'is many hardwoods, such as Ficus, which seems to be preferred, Chorisia, Enterolobium, and jak fruit (Artocarpus) (Duffy 1960: 228). Live trees are seldom attacked, so the species should be considered a reducer of dead wood rather than a forest pest. Little else is recorded regarding its natural history (Tippmann 1951).

Pseudoscorpions of the family Cherneti-dae (Cordylochernes and Lustrochernes) are almost invariably found riding under the wing covers of the harlequin beetle. They utilize the beetle host not only for transportation but to prey on phoretic or parasitic mites also living on it. Cordylochernes scor-pioides assumes a special posture and makes "beckoning" movements with its pedipalps when encountering the beetle and quickly tries to grasp it and hide under the elytra (Beck 1968).

One author (Reitter 1961: 33) thinks the hieroglyphlike pattern on the elytra might be copied on the shields of South American Indians.

References

Bates, H. W. 1861. Contributions to an insect fauna of the Amazon Valley. Coleoptera: Longicornes. Ann. Mag. Nat. Hist. (3)8: 40-52.

Beck, L. 1968. Aus den Regenwaldern am

Amazonas. I. Natur. Mus. 98(1): 24-32. Chemsak, J. A. 1983. Acrocinus longimanus (Arlequin, harlequin beetle). In D. H. Janzen, ed., Costa Rican natural history. Univ. Chicago Press, Chicago. Pp. 678—679. Duffy, E. A. J. 1960. A monograph of the immature stages of Neotropical timber bee-

ties (Cerambycidae). Brit. Mus. Nat. Hist., London.

Lemos Pereira, A. B. 1978. Sobre o apareci-mento em Portugal de um Coleóptero longicórnio exótico, do género Acrocinus. Inst. Zool. "Dr. Augusto Nobre." Publ. 138: 11-16.

Reitter, E. 1961. Beetles. Putnam's Sons, New York.

Tippmann, F. F. 1951. Eine Harlekinade am Rio Tulumayo. Entomol. Zeit. 61: 137-142, 147-152, 155-157.

Wood, J. G. 1883. Insects abroad. Routledge Sons, London.

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