Most dissected Nezara viridula (91.6%) from night catches had their stomach filled (half-full-full) with food, and females had a higher feeding activity than males. Females outweighed males at the ratio 1.3: 1, and an individual was heavier in October than in May. Ovarian development corresponded closely with decreasing fat body of females, and immature individuals had maximum fat in the abdomen. The spent individuals with empty stomach and fat thinly spread over the venter were relatively abundant in April and May, implicating the possibility of large-scale oviposition during these seasons.

Sounds produced in relation to the sexual behaviour of the tsetse, Glossina m. morsitans, were investigated. During mating, a receptive virgin female adopted a relatively passive role while the male produced sound and drummed her with the tarsi of the meso- and metathoracic legs upto about 4–5 min immediately after mounting. During the long cppulatory phase, the male only produced sound when the female became restless or the pair was disturbed. No sounds were produced during the ejaculatory phase after which the flies separated.

Immediately after separation, the females were often receptive for further short copulations, but were completely unreceptive 24 hr later and showed vigorous repellent behaviour. The post-copulatory behaviour patterns and the rejection behaviour of the female were also accompanied by sound production. Although males readily mated with freshly killed females with the usual mating behaviour, sound production was less intense than when the females were live.

Mating sounds were composed of frequencies up to 50 kHz with the exception of the sounds produced by males, while mating with freshly killed females which not only lacked any ultrasonic components, but were also of low intensity. The most dominant frequency was centered between 1.5 and 2.5 kHz. Peaks were also observed between 0.5 and 0.8 kHz, around 5 and 9 kHz. On the basis of intensity, it is suggested that the frequency components below 10 kHz carry the most important part of the acoustic signal.

Damage caused by the black bean aphid, Aphis fabae Scopoli, on the common bean, Phaseolus vulgaris L., was severest when the aphids were transferred onto bean plants during the preflowering stage. There were significant reductions in the average length of the central shoot, production of flowers, pods and seeds per plant. Seed weight per plant was also significantly reduced when aphid infestation occurred during the preflowering stage. Smaller, but significant reductions to the length of the central shoot, quantity of pods and weight of seeds produced per plant caused by A. fabae were also recorded when the aphids were transferred onto plants at anthesis. When aphid infestation occurred during the grain filling stage the damage caused was minimal and insignificant. The results obtained indicated that the preflowering stage was the vulnerable stage of bean development during which aphid attack is most harmful and, if unchecked, could lead to drastic yield losses.

Stripe (st+) is a dominant trait on chromosome 3R in region 33B on the cytological chromosome map of Anopheles albimanus. It is expressed as a white longitudinal stripe in fourth stage larvae and pupae, and marks a Y-autosome translocation stock T(Y; 3R)3. Pseudolinkage analysis of the available markers to the translocation breakpoint showed complete absence of recombinant progeny between T(Y;3R)3 and st+. The two loci most likely either overlap or are very closely linked. This translocation strain can be genetically sexed by selection of the stripe marker.

Some morphological characters of the rice plant were found to be associated with resistance to the African striped borer, Chilo zacconius Bleszynski. A very low, but negative correlation was recorded between percentages of bored stems and plant height. Positive correlations were recorded between percentages of bored stems and stem diameters, stem thickness, length and width of flag leaves and number of tillers per plant. High silica content in rice plants appeared to be a strong factor in resistance to the striped borer. Negative correlations were recorded between percentages of crude silica content of the plants and percentages of bored stems and number of living larvae per plant. Although each of these factors appeared to contribute to borer resistance, none by itself could be said to be the main cause of such resistance, as some varieties did not conform to some of the characters.

The consumption and digestion of two Ghanaian eggplant cultivars (Asesewa and Odwanhwoa) and two exotic cultivars (Black Beauty and Florida Market) by larval Selepa docilis were studied in the laboratory. Daily food consumption was highest on Asesewa and lowest on Florida Market. Total food consumption was significantly highest on Asesewa, followed by Odwanhwoa, Black Beauty and Florida Market. The dry weight of food consumed per unit of larval fresh weight per day was highest on Asesewa, followed by Odwanhwoa, Florida Market and Black Beauty. In general, food consumption was higher on the Ghanaian than on the exotic cultivars. The efficiency of food digestion was significantly higher on the Ghanaian than on the exotic cultivars. Growth of S. docilis larvae, recorded by the daily larval fresh weights, was highest on Asesewa, followed by Odwanhwoa, Black Beauty and Florida Market. The conclusion is made that S. docilis is best adapted to Asesewa, then Odwanhwoa, Black Beauty and Florida Market. Furthermore, S. docilis is better adapted to the Ghanaian than to the exotic cultivars.

Spatial dispersion of the nymphs of the jassid, Amrasca biguttula biguttula (Ishida), and the adults of the whitefly, Bemisia tabaci Genn. on F414, a Gossypium hirsutum variety, was systematic in Ludhiana (Punjab). Both the jassid and the whitefly displayed no definite pattern along the height of the plant, though a maximum number of whiteflies were recorded at middle canopy (21–40 cm from bottom). Sample sizes of 10–15 plants, selected in a statistically linear fashion represented populations of jassid nymphs and adult whitefly on all four varieties. Sampling jassid nymphs by visual counting and whitefly by split-cage were the most suitable sampling methods for local cotton growers among the various methods compared.

A tick assembly pheromone present in the excretory waste product of the soft tick, Ornithodoros porcinus porcinus (Walton), has been separated by high performance liquid chromatography (HPLC). It has been identified as guanine on the basis of absorption and mass spectral data, and bioassays using nymphs of Argas persicus (Oken). Guanine was active at a low concentration of 8 × 10 −12 M/cm2 of filter paper. Guanine was shown to induce assembly in Amblyomma cohaerens Donitz larvae and Rhipicephalus appendiculatus Neumann adults.

Various purines and ammonium salts tested in the assembly bioassay, and with exception of adenine, were shown to be active for A. persicus.

The treatment of different developmental stages and adults of Z. paravittiger with precoceneI failed to produce any precocious metamorphosis, but it definitely proved to be toxic at very low doses to eggs, first instar and second instar and showed an antigonadotrophic effect when adults were topically treated. The ID50 concentrations for emergence were 0.076, 0.005, 1.00, 1000 and 90 ppm for egg, first instar, second instar, third instar and pupae, respectively. The adult longevity and fecundity was reduced even when adults were treated with 0.1 ppm concentration of precoceneI in 1 μl of acetone.

Larval instars of Chilo partellus Swinhoe reared on sorghum plants were determined. The larvae were separable into five non-overlapping instars by analysis of variance and Duncan's multiple range test, frequency distribution and scatter diagram of the head capsule widths. Head capsule increment from one instar to the next conformed to Dyar's rule, while at the same time agreeing with Richards' hypothesis. The stadial periods for the five instars were 6, 4, 5, 3 and 7 days, respectively.

Early instars of Zonocerus variegatus fed on most weeds, but preferred those in the families Euphorbiaceae and Solanaceae. Plants that were accepted initially were lesser consumed than later chosen ones. Although there was no apparent difference between weights of nymphs fed on cassava and other plants in the first 9 weeks; thereafter, cassava fed insects excelled others. Somatic growth was not affected by feed type.

The amount of free amino acids increases during the larval development. The accumulation is greater during the later larval life followed by an abrupt decline in the defaecating larva and early prepupa. The overall decrease in the free amino acid content during the period of metamorphosis is more in case of drones in comparison to that in workers. However, the amount present in adult drones is less than that of workers. The changes in the free amino acid content during the post-embryonic development of workers and drones of Apis cerana indica seem to show sexual dimorphism.

Bruchidius atrolineatus (Pic) is present in crops of Vigna unguiculata towards the end of the dry season at the beginning of September when pods start to form. Females lay many eggs on most available green pods. However, this oviposition behaviour results in an important egg mortality. During September, pods gradually reach maturity whilst new pods are formed. Females therefore have at their disposal a growing number of differently mature pods. Confronted with such a situation, B. atrolineatus females show an opportunist behaviour and lay most of their eggs on the most abundant stage, i.e. the most easily discovered stage (ripening green pods in mid-September or dry pods towards the end of September). However, they also lay eggs on other phenological stages no matter how abundant they are. B. atrolineatus females therefore show a certain behavioural plasticity enabling them to reproduce on all stages of pods whose maturity, chemistry and texture may differ. Larvae can develop either in maturing or dry seeds. The number of eggs laid from mid September is lower and lower whatever the phenological stage attacked. This decrease would be due to a reduction of the first generation adult bruchids and of the reproductive potential of females.

Callosobruchus maculatus appears in crops at the same time as B. atrolineatus, but oviposits preferentially on dry pods. Eggs are observed during the whole period of study, but the numbers laid are always low. With the increase in pod number, eggs are dispersed among the different substrates available. However, the average number of eggs laid on the pods remains constant. Despite the high mortality due to the oviposition behaviour of B. atrolineatus and to other factors (impact of hymenopterous parasitoids), these two bruchids cause important losses to seeds of V. unguiculata. Control methods against these pests should be envisaged in the field before harvesting.

A survey of Heliothis spp. and their larval parasitoids was conducted in the states of Andhra Pradesh and Maharashtra, India during the period 1977–1983. H. armigera and H. peltigera were recorded on safflower. H. peltigera was found dominant on sole crop, while both the species were equally important on intercrop. In general, eight parasitoids: four Hymenoptera and four Diptera emerged from the larvae of Heliothis spp. Six parasitoids were recorded from H. armigera larvae on sole crop and eight on intercrop safflower. The level of parasitism in H. armigera was higher on sole crop.

Studies on damage by larvae of Eldana saccharina Walker, Chilo zacconius Bleszynski and Sesamia spp. to sugar-cane stands revealed a high degree of correlation between internode damage and stalk damage as well as between internode damage and sugar content of the canes. For every 1% increase in stalk damage there was a corresponding increase of 0.214% in the internode damage. The distribution of larvae inside the internodes was found to depend on the level of infestation. At low field infestation level (below 25 larvae per 100 canes) the distribution was random. As the level of infestation increases, the distribution becomes more aggregated. The distribution of damage in the sugar-cane field was found to depend on the overall stalk damage. The distribution tends to be more contagious when field level of stalk damage was less than 45%. The damage became evenly distributed when stalk damage rose above 60%. An estimation of average loss of sugar caused by stem-borers to the variety NCO 376 (at the field damage rate of 8.6, 10.6 and 3.1% damage for bottom, middle and top parts respectively of the cane) was U.S.S332.10 per ha of field.

Glossina pallidipes was sampled using biconical traps with stationary and revolving attachments in the form of blue and white flat screens. A modified biconical trap with attachment of four black strips captured the highest number of both female and male G. pallidipes Austen. However, all the stationary traps under-sampled teneral and young tsetse in post-teneral category. Biconical trap attached to a revolving component making 20 rev/min gave the best representative sample with regard to age category of females. Screens making faster revolutions resulted in larger proportions of males and hardly any old females. Flies that visited the trap with revolving screens were non-hungry, and probably mate-seeking. Those in stationary traps were mostly hungry and probably seeking blood meal.

A new character discovered on the superior claspers of male Glossina lonipalpis Wied. is described. This is a ciliated fold in the inner angle of the distal part of the claspers. It is absent in G. pallidipes Aust. The authors believe that this character will facilitate the study of the systematics of these species; and they propose to modify the key for the identification of Glossina.