The susceptibility of t'ef (Eragrostis abyssinica Schard.) to infestation by some insect pests of stored grain

Abstract

Abstract Insect-rearing experiments at 27°C and 70% r.h. on t'ef (the grain of Eragrostis abyssinica Schard.) showed that whole t'ef is unlikely to be infested by Sitophilus oryzae (L.) Rhyzopertha dominica (F.) or Sitotroga cerealella (Oliv.). Tribolium castaneum (Herbst) was the only insect, of eight species tested, able to multiply effectively on undamaged whole t'ef where it fed predominantly upon the grain embryo. T. destructor Uyttenb. and Ephestia cautella (Wlk.) showed some ability to produce surviving progeny on whole t'ef but are unlikely to be serious pests. Cryptolestes pusillus (Schon.) was able to infest t'ef in the presence of the other insect species and also multiplied effectively on milled t'ef, which suggests that it is the nature of the intact seed that prevents infestation in the absence of T. castaneum . It is likely that other insects with free-living larvae, including Oryzaephilus surinamensis (L.) which did not multiply on whole t'ef in these experiments, may be able to infest milled or damaged t'ef. However, none of the other species tested produced surviving larvae in the presence of T. castaneum (on whole t'ef). All eight species produced surviving progeny on whole wheat in separate cultures but in composite cultures O. surinamensis, E. cautella and S. cerealella were eliminated.