Eight desi chickpea genotypes of mid-maturity group were screened by using an open-field screening technique. The genotypes ICC-3137, K-850 and ICC-1403 were found to be more susceptible than the others. More eggs were laid and more larvae were recorded on more susceptible genotypes. A low amount of acidity in the leaf extracts of genotypes was found to be associated with susceptibility to gram pod borer, Heliothis armigera (Hubner).

Isolation of vitellin from mature eggs of the palo verde beetle, Derobracus geminatus, was achieved by a combination of gel permeation and anion-exchange chromatography. It is a phosphoglycolipoprotein (Mr ˜250,000) that contains 8% lipids, 4% carbohydrates and 0.2% protein-bound phosphorus. The vitellin is composed of three apoproteins designated I (Mr ˜160,000), II (Mr ˜140,000) and III (Mr ˜50,000). The carbohydrate moiety is composed exclusively of mannose and N-acetylglucosamine. All three apoproteins are glycosylated as shown by flourescein isothiocyanate-conjugated concanavalin A and periodate-Schiff (PAS) staining suggesting the presence of a high mannose structure. Further evidence for the high mannose structure was obtained by the ability of endo-β-N-acetylglucosaminidase H treatment to remove the carbohydrate moieties on the apoproteins.

Key mortality factors of sugar-cane top borer, Scirpophaga excerptalis Wlk. during the third brood were quantified on a susceptible sugar-cane variety, Co 1148 during 1981 and on susceptible CoJ 64, resistant CoJ 67 and collateral hoste, Sorghum halepense Peru, and Saccharum spontaneum L., during 1982 in Haryana (sub-tropical India). As artificial rearing of this borer is not possible, a methodology to have uniform age group at the beginning of the study by tagging the egg masses and the freshly attacked plants was developed. Results showed that parasitization of various stages and failure of neonate larvae to enter the midribs were the key mortality factors common to all the hosts. In S. halepense there was negative trend index (0.104) due to high mortality of larvae in all the instars. This revealed that it is not a suitable host for top borer. No predators were found to feed on any of the sub-imaginal stages of the borer due to the unique habits of the borer.

A total of 17 species of Hemiptera were collected from sorghum with compact panicles during the 1982 and 1983 cropping seasons at Samaru and Kano, Nigeria. The most important species based on time of appearance and abundance were Eurystyhis rufocunealis, Campylomma angustior and C. subflava. Paramixia suturalisand Taylorilygus vosseleri occurred in high numbers only at Samaru in 1982. Significantly more Orius spp. were collected at Kano. These species represented 95 % of all hemipterans collected.

The number of spiders per panicle were significantly lower at Samaru, up to three per panicle, than at Kano, up to 10 per panicle, in 1983. There was no relationship between the number of spiders and the number of hemipterans at Samaru, but at Kano a significant positive relationship was observed between the number of spiders and the number of immature hemipterans. The spider families Dysderidae, Thomisidae and Salticidae represented 80% of the spiders collected.

We studied the distribution of wild Mediterranean fruit flies, Ceratias capitata (Diptera: Tephritidae) in different environments of trimedlure-baited Jackson traps during high fall season populations in Southern Egypt. We found that 98% of females attracted to within aim radius of standard trimedlure (TML)-baited Jackson traps remained on the surrounding foliage without approaching the trap. Also about 30 % of males aggregated there, calling and competing for matings with approaching females. The closest mating occurred 25 cm from a standard trap. The nearest lek formation away from a trap was observed at a distance of 2 m on the same trap tree. The highest captures of males were recorded in the morning after male calling on the foliage reached its daily peak. Jackson traps baited with both protein hydrolyzate and TML on cotton wicks caught as many males, but significantly more females than traps with TML only.

Apanteles flavipes is a gregarious endoparasitoid of Porthesia scintillans. A new method for the estimation of energy available to the parasitoid is presented and used to prepare an individual energy budget for A. flavipes. A. flavipes consumes 13.9 J of the host tissue and assimilates 13.4 J. Production amounted to 10.1 J. Efficiencies of assimilation and production are 96.2 and 753 % respectively. Metamorphic metabolic rate was 0.555 kJ/g/day.

Limonoids such as deoxylimonin, obacunone and pedoniti are known to have antifeedant effects against some lepidopteran pests. However, there is no electrophysiological data showing the effect these compounds have on taste receptor cells. This information gap is due to the fact that limonoids are insoluble in water and this makes it difficult to apply the tip-recording technique in an electrophysiological bioassay of limonoids. This problem was solved by dissolving the limonoids in a mixture of 50 % tetrahydrof uran and 50 % aqueous NaCl. Limonoids and sucrose so dissolved were used to investigate responses of Eldana saccharina maxillary styloconic sensilla. The solvent mixture did not appear to damage the taste receptor cells and the taste receptor responses to solutes dissolved in that solvent were reproducible. Sucrose stimulated a cell in the medial as well as in the lateral styloconic sensilla. Deoxylimonin alone stimulated a cell in the medial sensillum but not in the lateral sensillum. When presented with sucrose, deoxylimonin inhibited the sugar receptor cell and this was also true for obacunone.

We studied the behaviour of three Anastrepha spp. (Diptera: Tephritidae) that were attracted to protein hydrolysate in glass McPhail traps, hung on an 8 m tall wild mango tree, Mangifera indica at three different heights. Out of 665 flies that landed on the exterior of the trap only 31 % were caught. Females represented 60.2 % of all flies trapped. The intermediate trap hung at 5m caught the most flies (57.5%). We observed a great deal of feeding activity (on trap, leaves, branches and fruit) including régurgitation and reingestion of liquid food droplets. When not on the trap surface, flies were more commonly seen on leaves than on branches and fruits. Inter- and intraspecific encounters between all Anastrepha spp. and both sexes were commonly recorded. Males were observed calling alone or in leks. All leks were formed on leaves and on two occasions included individuals of two species. Our observations suggested that the McPhail traps attracted different Anastrepha spp. with varying degrees of intensity.

Nerve cord sectioning in the early fifth instar larva of Papilio demoleus inhibited or delayed pupation depending on the site of sectioning. This seems to be due to interruption in the feeding leading to interruption in the proprioceptive input reaching the brain. Sectioning of the peripheral nerves N5 and N8 prevented shortening (condensation) of the thoracic segment of the ventral nerve cord in the adult. Sectioning of these and other nerves, however, had no effect on the developmental events.

Petroleum ether extract of Eichhornia crassipes (Mart) Solm. was evaluated for its biological activity against Tribolium castaneum (Herbst), Sitophilus oryzae (L.), Callosobruchus maculatiti (F.) and Corcyra cephalonica (Stainton). The crude extract included in the diet of insects retarded development and caused mortality in the fourth instar larvae of T. castaneum and C. cephalonica. Cuticle melanization in patches were observable in C. cephalonica larvae. High mortality of adult C. maculatus occurred in insects confined to the treated diet as well as in insects exposed to treated surfaces. The extract did not show any toxicity to adult S. oryzae.

Studies on critical time of insecticidal protection in relation to damage by aphid, Aphis gossipii Glover and leafhopper, Amrasca biguttula biguttula Ishida on plant growth and yield of okra revealed that 21–42 days after germination, was the most critical time prior to fruiting. Application of carbofuran at the time of sowing was redundant. Effective plant protection 21–42 days after germination resulted in lowest leafhopper and aphid infestation and subsequently the highest benefit to cost ratio.

Immune haemolymphs from the giant silkmoth, Hyalophora cecropia and, to a lesser extent, from the tsetse, Glossina morsitans morsitans possess antibacterial activities against several species of bacteria known to be pathogenic to man, animals and poultry, as demonstrated by in vitro bacterial growth inhibition assays. Cecropia immune haemolymph possesses a broader antibacterial spectrum and was found to be active against several Gram-positive and Gram-negative pathogenic bacteria. Mice injected with pre-determined lethal doses of Enterobacter cloacae, Klebsiella pneumoniae and Corynebacterium pseudotuberculosis and then treated with single intraperitoneal or subcutaneous injections of Cecropia immune haemolymph had much lower mortality than untreated controls. A possibility of developing a broad-spectrum antibiotic modelled on insect immune factors is discussed.

Studies conducted using laboratory and field bioassays showed that cypermethrin (b = −1.691) had a significantly (P < 0.05) higher and longer residual action at 7,14,21 and 28 days after application than did fenvalerate (b = −2.28) and permethrin (b = −1.871) against Dysdercus fasciatus Sign, and D. nigrofasciatus Stal. when coefficient regression analyses were performed. Residual action of fenvalerate and permethrin was regarded as being identical over the same experimental period in the field since their regression coefficients were not significantly (P > 0.05) different from each other.

It was also shown by these studies that the effective interval between applications was 21 days for cypermethrin and 14 days when fenvalerate and permethrin were applied. This finding has important practical implications in the adoption of an integrated approach aimed at minimizing damage to cotton by D. nigrofasciatus.

Adults of the Caribbean fruit fly, Anastrepha suspensa (Loew) were fed on three diets in order to identify one that was optimal for adult longevity, fecundity and egg viability. The diets were a dry mixture of Brewer's (hydrolysed) yeast and sugar (Diet A); Brewer's yeast, sugar, agar, and water (Diet B); and a dry commercial diet (BioServ) with Brewer's yeast, sugar and casein (Diet C). There were no significant differences in per cent adult mortality among the three diets. However, the longevity of females in Diet C was significantly reduced in comparison to that of females fed the other two diets. Diet C was also suboptimal for fecundity and egg viability. Diets A and B were optimal for and had similar effects on all parameters evaluated in this study. However, Diet A appeared to be the best if preparation time and ingredient costs are considered along with biological effects.

Qualitative assessment of nine promising mulberry varieties with two check cultivars was evaluated with silkworm, Bombyx mori (L.). The feeding experiment revealed that ACC-143 and ACC-203 (S-135) varieties were superior to other varieties and check cultivars in all the economic characters of cocoon. The variety x season interaction was highly significant. ACC-143 and ACC-203 showed significantly better results over other varieties.

Various components of the neem tree, Azadirachta indica A. Juss were tested for their insecticidal effects on Sitophilus zeamais Motsen in stored maize. Seed kernel, leaf, flower and bark from the tree in powdered and extract (80% ethanol) form were used at the rate of 2.5g and 2ml respectively per 50g of grain, infested with 20 insects. Pirimiphos methyl and ethanol applied at 25mg and 2ml served as comparative treatment, and control neem products were efficient where used as a preventive measure. The degree of infestation was 3.2 as compared with 53 recorded in curative assay. Ethanolic extracts showed higher toxicity to S. zeamais than the powdered form. Insects after being confined 72 hr to treated grains had a mortality ranging between 29 and 96.4% (powder) and 32.5 to 100% (extract). The index of susceptibility varied from 0.45 (kernel) to 3.87 (bark) in powdered and 0 (kernel or leaf) to 1.76 (bark) for extracts. When leaf or kernel powder was used to protect grain over a 60 day storage period in aerated and non-aerated environment, insect mortality was 100% (kernel), whereas the leaf powder did not show complete insect control in aerated environment (88.1 %). A very high rate of population increase of S. zeamais was observed in the control.

A schedule of insecticide spray combining two insecticides: Decis®(deltamethrin) and Systoate® (dimethoate) with four times of spray: 35, 45, 55 and 65 days after planting (DAP) was investigated in order to search for the most effective treatment against Maruca testulalis (Geyer) population on cowpea (Vigna unguiculata (L.) Walp). The local cowpea cultivar “Kpodjiguegue” was used to study the onset and fluctuation of M. testulalis larvae infestation on cowpea terminal shoots, flowers and pods. The trial was carried out during the 1985 early cropping season at Abomey-Cala vi. The treatments' effect on M. testulalis in the terminal shoots was not significant at the 5% level of probability because of the very low infestation of this part of the plant. In the flowers and pods, Decis® was better than Systoate® which failed in controlling this borer satisfactorily. In the unsprayed plots (i.e. control), the peak of the natural infestation occurred in the flowers towards 50 DAP and 65% of the flowers were injured. In the pods, up to 89% of infestation by M. testulalis larvae were observed 60 DAP. The lowest yield was recorded from the unprotected plots (322 kg/ha) whereas the treatment 0-Decis®Systoate®Decis® provided the highest yield (1367 kg/ha) and the highest returns.

At present there are nine species of tephritid fruit flies in Mauritius and together they plague a wide range of hosts, from wild guavas to cultivated fruits and vegetables. The most destructive among them are: the natal fruit fly, Pterandrus rosa Karsh; the medfly Ceratìtis capitata Wiedemann and the melon fruit fly Dacus cucurbitae Coquillet. Studies with parapheromones indicate that trap colour has little if any effect on the efficiency of fly capture, the olfactory component completely dominating any visual effect. The efficiency of the traps with respect to height varies from species to species and with the vegetation. A height of 120 to 180 cm from the ground was found to be optimal for the natal fruit fly in wild guava zones. Traps placed at ground level on creeping plants were found to capture the highest number of the melon fruit fly. The response of the medfly in fruit tree orchards with height of traps was erratic, showing inconsistent trends with more than one peak.

Oviposition behaviour of the cotton bollworm, Heliothis armigera, and its relation to day-night cycle was examined under laboratory conditions. Eggs were laid both in large quantities of clumped eggs at one place, and singly distributed in the oviposition cage, always glued on the substrate. The maximum individual life time fecundity recorded was 3080, and the highest number of eggs delivered in 1 day was 949. The mean pre-oviposition period was 2.9 days. Peak fecundity occurred between days 5–9 and the highest mating frequency from days 4–6 after emergence. Maximum age for egg laying was 29 days, average life expectancy was 22 days, with longest individual survival of 32 days. Male longevity did not vary from that of females. There was a significant difference in the longevity of mated and virgin females; the mated females lived for a shorter time but produced a significantly higher number of eggs. Also, mating induced a sudden surge in oviposition. Almost 90% of the total eggs were laid in the darkness. Out of them, 60% were from the first and 30% from the second half of the dark period.

During investigations on the malaria parasites of lizards in the West Pokot district of Kenya, haemoproteids, haemogregarines, pirhemocyton-like and anaplasma-like organisms were found in the blood. Microscopic examination showed that some of these are new species and they are described in this paper. The new described species are Haemoproteus mungutii (haemoproteid), Karyolysus poleensis, Schellakia mabuyai (haemogregarines), Pirhemocyton kongelai, Haematractidium omogoi, Sauroplasma kachelibaensis (Pirhemocyton-like organisms), Eperythrozoon ngokai and Aegyptianella elgonensis (anaplasma-like organisms). K. poleensis and S. mabuyai are regarded as the first report of the genera in lizards in Africa while A. elgonensis is regarded as the first report of the genus Aegyptianella in lizards.