Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae) is a newly discovered species alien to Benin (West Africa) and the dominating aphid primary parasitoid in vegetable agroecosystems. A study on the preference of this parasitic hymenopteran for three key aphid pests of vegetables (Aphis craccivora Koch, Aphis gossypii Glover and Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae)) was carried out under choice and no-choice conditions at 26 ± 1 °C in both Petri dishes and cages. The aphidiine rejected L. erysimi and did not oviposit in this aphid species in any of the trials. In all tests, A. gossypii proved to be the aphid host preferred most frequently by L. testaceipes. This study contributes to the fundamental knowledge on the oviposition behaviour of L. testaceipes and provides information for use in the development of sustainable aphid pest management strategies in Benin.

The success or not of ladybirds as biological control agents is dependent on both their foraging behaviour and their individual survival rates. The former is a function of the habitats they utilise; the latter, a consequence of their reproductive strategy. Egg clustering was investigated in two ladybird species, Aphidecta obliterata, a conifer specialist, and Adalia bipunctata, an arboreal woodland generalist. The effect of oviposition substrate (filter papers vs. spruce needles) on clutch size and oviposition preference was also tested. Adalia bipunctata laid significantly more eggs than A. obliterata. The size of egg clusters laid by the two coccinellids varied between species and substrate types. Adalia bipunctata laid larger egg clusters than A. obliterata, with batches reaching a maximum size of 32 eggs on spruce and 41 eggs on paper, while those of A. obliterata contained a maximum of 5 eggs on spruce and 9 eggs on paper. Of the clusters laid by A. obliterata, 18.6% of those on paper and 21.4% of those on spruce contained only a single egg, whereas a minimum of two eggs per cluster were laid by A. bipunctata. Smaller clusters were laid on the spruce cuttings by both species when compared with those laid on the filter paper, but A. obliterata laid significantly more eggs on spruce than on the filter paper (77% vs. 23%), whilst A. bipunctata laid significantly more eggs on the filter paper (91%). It is suggested that coccinellid eggs are more likely to be washed off spruce needles than broad leaves and that, by laying smaller egg clusters on spruce, A. obliterata reduces this risk. Adalia bipunctata usually lays its eggs on the underside of broad leaved trees and thus does not face this risk and thus can lay larger egg clusters. No differences in cannibalism rates were found between the two species. These findings have implications for the use of ladybirds as biological control agents in spruce forests.

Host searching, slit making, egg deposition and protection are distinct sequences of one event, which lead to oviposition on the lower surface of rice leaves by the rice hispa Dicladispa armigera (Olivier). Females spent an average of 8.05±1.35 min in selecting an oviposition site, 6.40±0.25 min in preparing a triangular slit, and 1.17±0.07 min in laying and protecting a single egg. An egg measuring 0.85×0.42 mm in size was partially inserted inside a slit of 1.95×0.84 mm. The female exhibited ovipositional preference among the leaves of a rice plant, as 67.5% of eggs were deposited in the first leaf. On the first, second and third leaf, the female deposited her eggs mostly in the middle part of the leaf blade, avoiding the area between 4.15–4.89 cm from the tip and 12.72–14.25 cm from the base of the leaf.

Observations on the reproductive behaviour of the armoured ground cricket, Acanthoplus speiseri Brancsik were made in the laboratory and field. In the field a male ready to mate attracted both receptive females and mature “silent males” by stridulating. A receptive female moved to the stridulating male and upon reaching it courtship begun. Silent males also moved towards the stridulating male, but stopped at a mean distance of 1.07 ± 0.14 m from him and either seduced females that passed their way to the stridulating male, to copulate with them, or joined the stridulating male singing. Chorusing of the calling song involving more than two males was not uncommon in both the field and laboratory.

Due to stiff competition for mates in the environmental chamber in the laboratory male A. speiseri combined acoustic and substrate signals to attract receptive females. The male ground crickets vibrated their appendages, while they stridulated. Substrate signalling through body/appendage vibration or tremulation is here being reported for the first time in the tettigoniid subfamily Hetrodinae, to which A. speiseri belongs. The courtship behaviour, orientations of members of a copulating pair relative to each other, copulation, spermatophore transfer from the male to the female during copulation and oviposition and postoviposition behaviours of the species are described. Finally, the differences in the reproductive behaviour of A. speiseri in the field and laboratory are discussed.

The oviposition behaviour of spotted bollworm, Earias vittella Fab. was studied on 23 cotton genotypes under field and laboratory conditions. There were substantial differences in the number of eggs laid on different genotypes. More eggs were deposited on the bolls compared to leaves and squares. The relative oviposition preference differed under the field and laboratory conditions in the case of some genotypes. Leaf hairiness was significantly and positively correlated with number of eggs laid both under field and laboratory conditions. The effect of oviposition on varietal susceptibility appeared to be modified through other factors, such as gossypol and tannins. However, oviposition non-preference was one of the important resistance mechanisms in some cotton genotypes.