The suitability of Chilo partellus (Swinh.) larvae reared on gram (Cicer arietinum) flour diet, for rearing of the parasite, Apanteles flavipes (Cam.), was determined. The successful parasitism on diet fed or control larvae (reared on maize stems) was almost equal. There was also no significant difference in the mean egg-larval period of the parasite developed on both kinds of the hosts. However, on diet reared larvae, significantly more parasite grubs (20.3/host) failed to pupate as compared with control larvae (3.5/host). Consequently, the parasite cocoon production/host on them declined significantly but not drastically as they supported more number of parasite grubs/host as compared to control larvae.

Reasons of the failure of parasite grubs to pupate in diet are not certain but considering all the biological attributes of the parasite developed on diet reared larvae, the diet is recommended for its mass multiplication.

The mandarin orange or portugal, Citrus reticulata (Blanco), is unattractive as a forage material for the leaf-cutting ant, Acromyrmex octospinosus (Reich) while pineapple orange, Citrus sinensis (L.), is quite attractive. Lipid and non-lipid components were separated from portugal whole leaf extracts. Bioassays revealed the lipid fraction to be less attractive to the ants. This fraction was further separated using preparative layer chromatography into polar and non-polar lipid constituents. Two non-polar lipid fractions, Rf 0.5–0.7 and Rf 0.7–1.0, were shown to be the most deterrent constituents of portugal leaves to A. octospinosus.

A laboratory study was carried out in Egypt to determine the effect of combining treatments of gamma radiation and methyl bromide fumigation applied to adults of Tribolium confusum (Duv.). An interaction between irradiation and insecticidal treatment was obvious, with additive effects noted at most combination treatments. When the irradiation treatments were applied first and fumigation were accomplished within 24 hr., the intermediate dosage of irradiation (6 krad) afforded the insects some protection against marginally effective dosages of methyl bromide after 14 days. On the contrary, it is evident that a possible synergistic effect of irradiation pretreatment followed by chemical exposure, after 21 days, where all of irradiation dosages used (2-10 krad) enhanced the fumigant effectiveness. On the other hand, when the irradiation dosages were increased from 5-50 krad and followed by fumigant treatments after 7 days, the trend did continue where all combination treatments killed more insects than did either treatment applied alone. Conversely, when fumigation preceded treatment with irradiation the sublethal methyl bromide fumigation also apparently leaves the surviving insects in a debilitated state and became more radiosensitive.

In general, the effects from combination of irradiation and fumigation were more effective than were the effects of either treatment given singly, whether irradiation preceded insecticidal treatment or vice versa.

The larvicidal activity of two entomopathogenic bacteria Bacillus thuringiensis H-14 and B. sphaericus 1593 against mosquito larvae of Culex pipiens has been evaluated. According to LC50 values obtained, B. thuringiensis (4.6 x 105 spores/ml) proved to be highly pathogenic to fourth instar larvae than fi. sphaericus (4.2 x 106 spores/ml).

Larval treatment with LC50 levels of both pathogens affected the reproductive potential of surviving adults during two successive gonotrophic cycles. These treatments caused insignificant changes in some basic morphometric characteristics of mosquito females that developed from surviving larvae.

In tomato, infestation by the natural population of the fruit borer, Heliothis armigera (Hubner), on number basis was positively correlated with infestation on weight basis. Infestation was negatively correlated with the number of flowers per inflorescence. Surface texture of calyx also affected the susceptibility of the genotype. Reducing sugars in fruits were positively correlated, while zinc and iron content in foliage and ascorbic acid contents in fruits were negatively correlated with degree of infestation. Coefficient of determination revealed that 87% variability in borer infestation was due to zinc, iron, ascorbic acid and reducing sugar content.

The seasonal distribution and abundance of adult Temnoschoita quadrimaculata Gly., a pest of oil palm in Ghana was studied. The weevil occurred throughout the year with a peak of abundance from March to June. It preferred breeding in cut fronds which result from harvesting or pruning and was more abundant in 3–6 days old cut fronds.

Adult weevils preferred the upper third portion in comparison to the lower and middle third portion of the palm tree. Their incidence and abundance in pruned plantations was statistically greater (P < 0.05) than in unpruned plantations. Older palm trees were relatively more susceptible to attack than younger ones. Adult weevils preferred feeding on the fresh frond tissues than on leaflets.

The queen's fresh weight can be deduced from her external dimensions, or less accurately from the size of the royal cell in the case of single queens. Cell shapes and methods of enlarging the cell are described.