Alfred Russel Wallace : Alfred Wallace : A. R. Wallace :
Russel Wallace : Alfred Russell Wallace (sic)

 
 
Note on the Sexual Differences in the
Genus Lomaptera (S56: 1860)

 
Editor Charles H. Smith's Note: Communicated to the 6 February 1860 meeting of the Entomological Society of London, then printed on page 107 of their Proceedings series for 1858-59. To link directly to this page connect with: http://people.wku.edu/charles.smith/wallace/S056.htm


    "Lacordaire says in his 'Genera' that the Lomapteræ offer no sexual distinctions, except slight variations in the legs; and in the generic character he adds 'the fore legs are three-toothed in both sexes or in the females only.' In four species of the genus which I have recently taken in the Gilolo group of islands, I have, however, observed very strongly marked sexual differences, and I have had the good fortune to confirm them by capturing pairs of two species in copulâ. These differences are as follows:

    "1st. The males have always a distinct longitudinal furrow or depression on the under side of the abdomen, which in the females is quite smooth or rounded.

    "2nd. The males have one tooth less than the females on the outside of the anterior tibiæ. In the two larger species the males have two and the females three teeth; in the two smaller species the males have but one (terminal) tooth, the females two teeth.

    "3rd. The pygidium in the males is simple, with the extremity somewhat obtuse. In the females it terminates in a sharp reflexed edge, and in the two smaller species is swollen and compressed above and very concave beneath, while in the males it is a simple ovate cone equally rounded above and below.

    "It is probable that these characters exist in all the species of the genus, and may enable persons possessing series of Lomapteræ to pair their specimens. I may here remark that the species of this genus are very closely allied, and at the same time very limited in their range. In Ternate and Gilolo, and in Kaiòa and Batchian,--islands only ten or fifteen miles apart,--are found distinct but closely allied species, differing so slightly (although constantly) that they would be infallibly considered as very trifling varieties, if single specimens of each only were examined. Differences of colour exist in specimens from the same locality; while minute differences of form and sculpture mark these representative species of adjoining islands."


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