Investigations have been made to evaluate the development of Spodoptera littoralis as affected by feeding on a standard artificial diet containing powder of some plant species known to be resistant to the infestation of this insect. Trials were also made to find out whether the effect of these plants facilitate the potency of Bacillus thuringiensis var entomocidus HD-635 vs. the target insect. The results revealed that powders of pomegranate peel, guava leaves and lemon grass, greatly affected the insect development in terms of larval duration, larval and pupal weights, deformities in pupae and moths, percentage of emergence, egg production and hatching. This may be correlated to the chemical constituents of these plants. A marked increase was observed in the potency of B. thuringiensis endotoxin preparation vs. S. littoralis when combined with some of the tested powdered plants or its extracts but in varying degrees.

The biology of Chilo partellus (Swinhoe) was studied on two resistant, IS 2205, IS 5469 and two susceptible, HC 136, ICSV1 sorghum genotypes. Significant differences were observed between resistant and susceptible genotypes in regards to larval mortality in whorl, larval period, larval weight, larval length, per cent pupation, pupal weight, fecundity per female and total life span of this pest. Growth index was also influenced by the resistant genotypes. It has been concluded that high mortality of larvae on resistant lines is due to antibiosis.

The correlations between the characters of the pest biology have been worked out and larval stage was the most important parameter influencing the total pest survival and population build-up in the succeeding generations.

Seedlings of apple variety, Yarlington mill, were sprayed with different sprays containing 0.1% cypermethrin, and were subjected for 15 min to 65.3 mm artificial rainfall. The effectiveness of deposits after rainfall were tested in the laboratory with neonate codling moth larvae.

Cypermethrin formulations sprayed with each nozzle were more persistent after artificial rain, when small droplets of volume median diameter (VMD = 30–70 μm) were applied by spinning discs (charged or uncharged) compared with larger droplets (VMD* = 90–160 μm) produced by air shear nozzle. No significant difference in effects was obtained between droplets by either charged or uncharged disc.

The spatial distribution of the eggs and larvae of Anaphe venata Butler within canopies of its host, Triplochiton scleroxylon K. Schum situated at Araromi Village northeast of Ibadan was determined. Sampling branches of T. scleroxylon once in a spiral from base of canopy upwards was sufficient in determining the distribution of eggs and larvae of A. venata. Although the differences in the mean count of egg masses and larval groups in the lower, middle and upper canopy levels were not significant, the highest percentage of egg masses and larvae occurred on the tips of branches in the lower canopy. Sampling studies on the developmental stages of A. venata may therefore be done at the lower canopy level for best precision. Eggs and larvae are aggregated while the larval dispersion on the host suggest photo-positivity. The use of mounted, motorised elevators is proposed in order to enhance efficiency of sampling and avoid destructive sampling.

A study of several populations of the cassava green mites from eleven African countries representing wide ranging ecological zones were studied using a Principal Component Analysis. This study revealed that there is only one species of the Mononychellus present on cassava in Africa and is here designated M. tanajoa.

Field trials of various neem formulations were conducted to determine their effectiveness for the control of some major pests of eggplant, Solanum melogena (L), okra, Hibiscus esculentus (L) and cowpea, Vigna unguiculata (L), Walp. Various concentrations of neem emulsion reduced incidence of Selepa docilis (Butler), Urentius sp. and Zonocerus variegatus (L), on eggplant. Damage caused by Sylepta derogata (F), defoliator of okra, was less in plots treated with 5, 10 and 20% aqueous-methanol extracts of defatted neem cake. Moreover, neem seed cake applied as dust enhanced cowpea yield.

A low cost artificial diet was formulated from materials which are locally available in Africa. The diet utilized cowpea, sorghum and corn instead of pinto bean and wheat which are widely used in the USA. The new diet was as satisfactory as the pinto bean diet for all the biological criteria tested. On a pinto bean diet, pupation and eclosion required 14.3 ± 1 and 26.3 ± 1 days, respectively. On the cowpea diet, 14.6 ± 1 and 26.9 ± 1 days were required, respectively. Ninety-eight per cent of adults eclosing on each diet were viable. Females eclosing on the cowpea diet laid 739 ± 53 eggs of which 59 ± 2% hatched. On the pinto bean diet, 774 ± 62 eggs were laid per female with 61 ± 2% hatching. Pupal weights were 526 ± 22 and 537 ± 28 mg when larvae were reared on the pinto bean and cowpea diets, respectively. Food consumption and utilization by larvae reared on the new diet were comparable with those of larvae reared on the popular pinto bean diet.

The effect of topical application and oral administration of diflubenzuron on the feeding budget in the fifth instar larva of Papilio demoleus has been studied. The LD50 and LC50 values of diflubenzuron were 13.50 and 9.00 μg/larva/48 hr respectively. Topical application was found more efficacious in producing 50% mortality at a comparatively minimum dose of 9.00 μg. The growth efficiency was reduced by 44.54% in oral administration and 38.19% in topical application at the highest sublethal dose over that of control larvae. Not only the growth of the larvae of P. demoleus was inhibited, but the adults showed morphological deformities.

Assessment of damage to apparently good quality palm kernels by test insect species under laboratory conditions revealed that all the cultures had other pest species due to hidden infestation. The total damage caused by the insects to palm kernels in the experimental jars ranged from 17.5 to 30.9% at the end of a 1-yr storage period. With the exception of test species, Oryzaephilus mercator (Fauv.) and Tribolium castaneum (Herbst) which were predominant in cultures in which they were formally introduced, the other cultures were found to be dominated by O. mercator, T. castaneum, Lasioderma serricorne (F.) and Cryptolestes ferrugineus (Steph.). Thus the damage reported above was principally due to these four species. Symptoms of damage to palm kernels by O. mercator; T. castaneum and L. serricorne have been given for the first time and the pest status of the beetle pests associated with stored palm kernel assessed relative to damage caused.

The influence of soil moisture and temperature on hatchling weight during the solitary phase of Locusta migratoria migratorioides (Reiche and Fairmaire) was studied. Soil moisture is an important weight determining factor; heavier hatchlings are produced in relatively wetter soils. Temperature has no apparent influence on hatchling weight. Hatchling weight and hatchling survival to the second instar showed a positive significant correlation.

Spray distribution in an apple tree canopy using an adapted knapsack mistblower fitted with a spinning disc, with the provision of an induced electrostatic charge on the droplets was studied.

Droplets were sampled using uvitex fluorescent tracer on Kromekote cards positioned in different areas of the canopy.

Droplets were highest on the outer surface and decreased sharply into the canopy. Uncharged spray droplets gave the poorer deposition with better distribution, but by adding an electrostatic charge, droplet deposition was significantly improved in the outer parts of the canopy. An average of 3 ml/tree of spray liquid was used in all applications. The larger variety (Red Victoria) required about 50% more spray liquid, but distribution was still lower than that achieved by the smaller Keswick variety.

The male accessory reproductive glands (ARGs) of the tobacco caterpillar, Spodoptera litura begin development on 6th day of the pupal stage. The synthetic activity of the gland begins from the eighth day pupal stage as shown by 3H-leucine incorporation studies. There is a significant increase (2.4-fold) in the specific activity of 3H-leucine incorporation into TCA precipitable proteins in 10 hr old males when compared to newly emerged males (0 hr), and this synthesis is partially blocked (60%) by cycloheximide (5μg/insect) treatment.

Several insects attack the groundnut, which is a major crop in Senegal. Sporadic attacks of Heliothis ( = Helicoverpa) armigera Hbn. and other insects have been recently noted. In order to reduce the pest attack, neem cake extract (1 and 3%) was compared with cypermethrin and a mixture of dimethoate and deltamethrin and gave satisfactory results. However, yield was not significantly increased.

The effects of cyanocobalamin on the protein, RNA and DNA contents of ovary of silkworms, Bombyx mori L., were investigated. Two sets of experiments were performed, one set dealing with the changes on some selected days in protein, RNA and DNA contents after a single injection of different doses of cyanocobalamin (0.25, 0.5, 1, 2 and 5 μg/g of body weight), given on 2nd day of fifth larval instar (day 0), and the other dealing with the day-to-day variations of these cellular constituents and the effect of a particular dose (2 μg/g) of cyanocobalamin on the daily changes of the substances. In the first set of experiments, the enhanced protein content of ovary over the control value was found on day 8 (2nd day of pupa) and day 13 (adult stage) with 1, 2 and 5 μg of cyanocobalamin/g. Cyanocobalamin at the dose of 0.25 and 0.5 μg/g was ineffective in causing any change in protein content. Increased RNA content was noted in comparison to the control on days 3 (5th day of fifth instar), 8 and 13. In case of DNA content of ovary, the enhancement was observed on days 8 and 13 with 1, 2 and 5 μg/g doses. It was further evident from day-to-day changes that protein, RNA and DNA in ovary followed a specific individual pattern of changes during the developmental period under study. Cyanocobalamin at the dose of 2 μg/g increased protein content of ovary from day 5 to day 13, RNA content from day 3 to day 13 and DNA content from day 4 to day 13 without altering the specific pattern of variation of these cellular constituents. It was further observed that ovarian weight and egg number increased with different doses (0.5–5 μg/g) of the vitamin.

In southern India, the principal tea pests such as the mites, Acaphylla theae, Calacarus carinatus and Oligonychus coffeae; the thrips, Scirtothrips bispinosus; the aphid, Toxoptera aurantii; and the caterpillars, Caloptilia theivora, Homona coffearia and Cydia leucostoma are attacked by many natural enemies. H. coffearia is efficiently controlled by the ichneumonid, Phytodietus sp., and the tachinid, Palexorista solennis, whilst the eulophid, Sympiesis dolichogaster, affords excellent regulation of C. theivora. The braconid, Apanteles aristaeus, is the chief parasitoid of C. leucostoma, but the efficiency of this species is rather low. The aphiidids, Aphidius colemani, Lipolexis scuttellaris and Trioxys indicus, and several species of coccinellids and syrphids exert tremendous influence on the populations of T. aurantii. No natural enemies of the scolytid stem borer, Xyleborus fornicatus, could be recorded. For the management of mites, pesticides are applied regularly and the widespread usage of broad spectrum acaricides such as dicofol and sulphur is an important reason for the low incidence of predatory mites in tea fields.

Trials for cold storage of the mummies of Aphis craccivora Koch parasitized by Trioxys indicus Subba Rao & Sharma were made. Newly formed mummies having fourth instar larvae of the parasitoid were put either at 20–25°C or at 12–15°C, 10 hr photoperiod for 24–72 hr before storage inside the refrigerators (4–8°C) for 10–40 days. A higher proportion of adult emergence was usually associated with the group of mummies passed at 12–15°C before storage and practically good emergence was recorded even if the mummies were stored for a month at 4°C if kept at 12–15°C for 72 hr prior to storage.

This paper describes the immature stages of the striped caterpillar Epicerura pulverulenta Hampson, a notodontid defoliator of combretaceous trees, viz., Terminalia ivorensis, T. superba, T. catappa and Anogeissus leiocarpus. The structure and chaetotaxy of the mature (fifth stage) larva is described in detail with illustrations to aid easy field identification of the moth.

Combining ability analysis for three stem borer resistance parameters, i.e. “dead hearts”, leaf injury and stem tunnelling, revealed that both additive and non-additive types of gene effects were involved in the inheritance of these attributes. The specific combining ability (sca)/general combining ability (gca) variance ratios further indicated predominance of additive gene effects for stem tunnelling and non-additive effects for “dead hearts” and leaf injury. The genotypes, IS 2123 and IS 5469 are good general combiners for all the three parameters. Among F1 hybrids, IS 1054 × IS 5469 and IS 18551 × IS 2123 expressed good sca for all the parameters of stem borer resistance. The use of IS 2123 and IS 5469 parental genotypes in the future breeding programmes is suggested.