A taxonomic study of the species of Antestiopsis (Hemipteea, Pentatomidae) associated with Coffea arabica in Africa

Abstract

The taxonomy of African species of Antestiopsis, some of which are important pests of coffee, has hitherto been in confusion owing to the difficulty of finding decisive morphological characters. In the present study an attempt is made to clarify the relationships of the coffee pest species and some of their close allies by the use of both biological and morphological characters.The species of Antestia and Antestiopsis occurring on coffee in Africa are differentiated in a key, and descriptions are given of the following: Antestiopsis orbitalis (Westw.), with three clearly distinguishable subspecies, orbitalis, bech-uana (Kirkaldy) and ghesquierei Carayon, several local colour forms of these, and a few variable populations that cannot be referred definitely to any one of the subspecies; A. intricata (Ghesq. & Carayon); A. facetoides sp.n. for the species hitherto known as “ faceta ” in eastern Kenya and Tanzania; A. crypta, sp.n. confined to Katanga; A. falsa (Schout.), a rare and imperfectly known species; A. lepelleyi sp.n., which does not feed on coffee; and A. littoralis sp.n., from the Kenya coast, known to the writer only from museum specimens.Evidence for the arrangement adopted is discussed, and the taxonomic value of certain morphological characters is assessed. The distributions presented on maps are discussed, and it is concluded that the activities of man are unlikely to have obscured the natural patterns. A list is given of known host-plants, which, except for those of A. orbitalis orbitalis and form facetus, are with only a single other exception members of the Eubiaceae. The distribution on a local scale and recent changes of abundance of species in competition are discussed, and it is shown that A. orbitalis ghesquierei and A. o. bechuana appear to be spreading at the expense of A. intricata in Uganda and A. facetoides in Tanzania, respectively. Kesults of crossing East African species and forms show that those here regarded as species will not cross but that the subspecies of A. orbitalis will do so, producing intermediates that, when allowed to interbreed, are not as viable as pure strains. Finally an attempt to find morphometrical characters is discussed, and the results are given of a calculation of discriminant functions based on two characters. These, while, not conclusive, support the conclusions drawn from other evidence.