A surprising finding concerning the noctuid moth Phlogophora meticulosa (Linnaeus, 1758) (Lepidoptera Noctuidae)

The Angle Shades moth, Phlogophora meticulosa (Linnaeus, 1758) (Noctuidae), is a migratory species which is widespread in Europe, western and central Asia and north Africa; it is known throughout Italy, including on the two major islands. Sometimes it is also a crop pest. This contribution points out a very singular finding regarding this insect. On the evening of 20.05.2013, at Piacenza (northern Italy) on the campus of the Università Cattolica del Sacro Cuore, on the outside surface of a building, a specimen of Ph. meticulosa resting on the wall near an artificial light was collected by the author. The specimen at first sight had, at the tip of its abdomen, a rather showy, pendulous extension of an unclear nature. Examination in the laboratory showed that it was a male whose genital armature was holding another similar male armature, almost devoid of the typical covering of hairs and scales and, so to speak, ‘torn’ from another male abdomen. Also the tip of the abdomen of the specimen with this singular abdominal appendix was partially devoid of the covering of hairs and scales which normally characterizes the males of this species including on genital armature, so that all these structures were well in evidence. The specimen at the time of capture appeared hardly or not at all reactive: it was probably dying if not already dead but if the latter, it had died recently, because it was clinging to the wall with its legs and resting near an attractive light source, and under laboratory examination and subsequent preparation still retained some elasticity in the joints. A microscopic preparation and examination of the tip of the abdomen was set up. The two male genital armatures were similar and conspecific. The coupling between them was by means of the uncus of the male specimen collected, which was holding the right valve of the other armature tightly; this torn armature was therefore placed almost transversely with respect to the other and did not show other kinds of connections with the abdomen of the entire specimen, connections which would have suggested a teratological case. In all likelihood it belonged to another male specimen, from which it had been torn. How should this curious finding be interpreted? A teratological case is to be excluded (the duplication of ectodermal genital structures in a single specimen - male or female - is a known but very rare monstrosity among insects of some orders; in these cases the two 'twin' structures are generally close together, side by side with each other, and, obviously, both connected with the abdomen). By way of hypothesis, the phenomenon may be the consequence of an attempt to mate with a female by two males attracted almost simultaneously by the same female pheromone, with subsequent 'conflict' and accidental mechanical coupling of the uncus of the first to a valva of the second, which then attempting to free itself from the grip and fly away may have ‘lost’ its armature. It is not to be excluded that predation e.g. by an insectivorous bird on one of the two hooked males is the real cause of this strange situation. The author would be interested in hearing any other opinions on this matter. Is anyone aware of similar observations? Does the hypothesis formulated here seem likely? Thanks to anyone who might kindly provide some comments.