Bruchus dentipes Baudi was found to have four larval instars, and the sex ratio was very close to 1:1. Both sexes fed on pollen and nectar of faba beans (Vicia faba) for seven days before and throughout the oviposition period of the females, which was about 33 (range 26–40) days. The beginning and peak of oviposition were influenced by the phenology of the crop, particularly flowering and pod-setting dates, but also temperature. Females laid an average of 123 (range 28–310) eggs, and the end of the adult life in the field came in May when the pods had matured. In different years, peak oviposition occurred on different dates in April when the pods were still all green. During the quiescence period in the winter, females obtained from wetted seeds were fed with different diets in the laboratory, but only those supplied with faba bean flowers laid eggs. No major adult mortality occurred in seeds harvested in May and stored until the end of March of the following year, after which mortality rose steeply till all adults had died by early June. Therefore, storing seeds and delaying their planting till the following year will ensure 100% adult mortality. As the seeds remain viable, such storage is one method for reducing infestation in the field. Mortality of larvae in the stored seeds was from cannibalism when two larvae met at the same tunnel (10%), from the mite Pyemotes tritici (Lagrèze-Fossat & Montagné) (11%), from the braconid larval parasite Triaspis thoracicus (Curtis) (2%) and from unknown reasons (5%).

The use of six cowpea varieties highly resistant to Aphis craccivora Koch in grafts (as resistant scion and rootstock) with the susceptible variety Prima indicated the presence of a graft-transmissible chemical involved in the resistance. Wrapping the resistant part in light-proof foil indicated that photosynthesis is involved in the production of the chemical. In a third test, intergrafting is involved in the production of the chemical. In a third test, intergrafting the resistant part with and without leaves confirmed the importance of photosynthesis in the transfer of resistance. Finally, covering the resistance intergrafts with foil showed that the accumulation of the chemical in the stem before the foil was applied was the major source of the graft-transmissible resistance.

Female Aphidius rhopalosiphi De Stefani Perez reared on Rhopalosiphum padi (Linnaeus) made equal numbers of encounters with another suitable host aphid (Sitobion avenae (Fabricius (both Homoptera: Aphididae))) in arenas where the aphids were on either pieces of wheat leaf or moist filter paper. However, the number of oviposition stabs made in arenas with wheat was far higher than with filter paper, demonstrating the importance of host-plant cues in the acceptance of the aphids by the parasitoid. Diet reared aphids (even if subsequently fed on wheat) appeared to be accepted more readily than totally wheat reared individuals. In another arena experiment, there were more encounters with and more stabs made into both S. avenae and a non-host aphid (Myzus persicae (Sulzer)) on wheat than on Brussels sprouts (a host plant of M. persicae), again showing the over-riding importance of host-plant cues.

Significant differences in nymphal development period and fecundity were observed between five populations of Cicadulina mbila (Naudé) and C. triangula Ruppel from three climatic zones in Nigeria: rain forest (Ibadan), southern part of Sudan savanna (Kadawa, Kano) and the Jos Plateau. The C. triangula population that is used in mass rearing for resistance screening at the International Institute of Tropical Agriculture (IITA), Ibadan, developed much more rapidly than the wild C. triangula population from Ibadan. Similarly, the C. mbila population from the Kadawa Irrigation Scheme, Kano, developed more rapidly than the population from the Jos Plateau. All Cicadulina populations were 3–4 times as prolific on pearl millet as on maize, sorghum or the grass Digitaria exilis. The IITA colony of C. triangula was significantly more fecund than C. mbila. It is clear that Cicadulina species and populations with high reproductive potential would be most suitable for mass rearing for resistance screening to the maize streak virus disease.

Field screening experiments for resistance of faba bean (Vicia faba) to Bruchus dentipes Baudi in Syria between 1982 and 1985 involved about 1000 accessions and indicated that only phenological resistance was present. Two accessions were chosen, on the basis of seed infestation with larvae, for further study. The two accessions (BPL33 and ILB1814) were tested against natural infestations as well as under four levels of bruchid infestation and at two different times of release of adults. BPL 33 maintained its resistance (about 50%) in relation to ILB1814 under these different conditions, except when adults were released at a time when both accessions carried pods simultaneously. This confirms that the resistance of BPL33 was phenological, related to late flowering and late pod setting. An intergrated control approach is there fore suggested.