The shootfly, Atherigona soccata Rondani, is a major seedling pest of sorghum in many areas of tropical Asia, Africa and Mediterranean Europe. A chronological review of the progress made in various programmes on the screening techniques (natural and artificial) with artificial diets, sources, stability and mechanisms of resistance, bases (physico-morphological and biochemical factors) of resistance, inheritance and breeding for resistance is made. Many resistant varieties have been identified and sources of resistance utilized in breeding programmes to transfer resistance in high yielding background are listed. In addition, the glossy and trichome traits identified is sorghum cultivars are also reported. Glossy leaf surface and trichomes are frequently associated with shootfly resistance.

A laboratory study of the biology of Corcyra cephalonica (Staint.) was made at 30°C and 70% r.h. on sorghum. The number of eggs laid per female, oviposition period, development time and survival from egg to adult were determined. The data were used to estimate the finite rate of increase and the intrinsic rate of natural increase of the moth. For the finite rate of increase (λ) the estimated value was 18 per lunar month, corresponding to an intrinsic rate of natural increase (r) of 2.9. The results are compared with published data and it is concluded that the pest potential of C. cephalonica has been, hitherto, underestimated.

Nightly catches of Scirpophaga nivella (F.) in light traps in rice plots in West Bengal, India, showed two discrete peaks of abundance in each trap-year corresponding to congenial weather and abundance of summer (mid-March-mid-June) and autumn (mid-July-mid-November) rice plants. Estimated generation times showed many overlapping generations in each trap a year. Variations in summer catches were significantly correlated (P < 0.01–0.05) with maximum temperature and minimum relative humidity of the day, and minimum temperature and wind speed of the night; whereas those in autumn catches were significantly associated with maximum temperature and minimum relative humidity of the night (P < 0.01–0.05). Autumn crops had more infestations, and sustained greater larval density than summer ones. Females were twice as heavy as males (2.1:1) and adults were heavier in October than in May. Catches of immature and mature females were consistently maximum at full moon and new moon, respectively.

Polyacrylamide disc gel electrophoresis (PAGE) was performed on soluble proteins from the fat body, haemolymph (male and female), and ovary of the adult fresh water-bug, Laccotrephes rubra, in order to determine their protein patterns. The electrophoresis resulted in the separation of 16 and 17 protein components in male and female haemolymph respectively. In female fat body extracts 15 protein bands could be detected; whereas ovary extracts resolved into 11 protein bands only. Comparison of the electropherograms of protein pattern of fat body (FBPP), haemolymph (HPP) and ovary (OPP) revealed that the extra band present in the female haemolymph is common to both female fat body and ovary, which is suggestive of it being the female specific protein, i.e. vitellogenin. A careful examination of the various electropherograms further revealed that the majority of the protein bands of haemolymph and ovary are common to its corresponding fat body protein bands. This might suggest that the ovary derives most of its protein components from the surrounding haemolymph, which have presumably been synthesized and secreted by the fat body.

The histochemical analyses demonstrated that the female-specific protein band is a glycolipoprotein; and most of the haemolymph protein zones stain as glycoprotein, lipoprotein or ribonucleoprotein. ‘Stains-all’ technique however, revealed the presence of four possible RNA bands in fat body extracts.

Diaeretiella rapae (M'cintosh) was the only parasitoid of the cabbage aphid, Brevicoryne brassicae L., during studies reported here.

Percentage parasitism of B. brassicae ranged from 27.1 to 76.1% in studies carried out around Nairobi area during 1978/79. It was highest during the month of September, when the aphid population density had reached maximum, and lowest in May when aphid numbers were low. High parasitism coincided with a decline in aphid population.

Because of these high levels of parasitism and other attributes of the parasitoid, it was concluded that D. rapae played a significant role in suppressing populations of B. brassicae and should be taken into consideration in any control programme aimed at protecting brassica crops against aphid pests in Kenya.

Studies conducted on the spatial pattern of Leucinodes orbonalis Guen. larvae at the Experimental Farm, Barapani of ICAR Research Complex for NEH Region, Shillong revealed that they follow positive binomial distribution within plant, shoot and fruit. The larvae were distributed as negative binomial (contagious) within plot (2 × 2 m) at all stages of sampling except during initial and last stages of crop where they follow positive binomial distribution. The possible reason for this change in distribution may be due to comparatively lower larval densities at initial and last stages of crop.

At room temperature (diurnal range 23–28°C), Sarcophaga haemorrhoidalis (Fallen) developed from egg to adult in approx. 32 days. Survival ( ± SE%) was generally high (76.63 ± 5.67 for the egg, 80.69 ± 3.20 for the larval and 89.83 ± 3.80 for the pupal stages). Adults emerged over a 4-day period between 07.00 and 13.00 hr local time, with daily peak emergence occurring between 07.00 and 10.00 hr. Their immediate post-emergence period was characterized by a highly active and mobile phase lasting 10–15 min followed by an immobile phase lasting about 1.5 hr. Copulation commenced 4.35 ± 0.43 days after adults emerged and was not preceded by elaborate courtship. After a pre-oviposition period of 12.96 ± 0.47 days, females deposited eggs in batches (1.57 ± 0.23 egg-batches/female) each containing a mean of about 37 ± 4 eggs. Fecundity was 52 ± 6 eggs/female during a mean adult life span of 18.68 ± 1.76 days. Although the foregoing life history parameters are strongly suggestive of K-selected ecological strategy, S. haemorrhoidalis may in fact be adopting an opportunistic r−selected ecological strategy since it habitually breeds in unstable environments.

The effect of temperature and relative humidity on mating and commencement of oviposition in Plodia interpunctella (Hubner) was studied in the laboratory. Mating was most successful at 20 and 30°C and was less so at temperatures of 15 and 35°C. Increased relative humidity appeared to have favoured mating at higher temperatures investigated which were 30 and 35°C.

The onset time for mating was higher at 30 and 35°C than at 15 and 20°C. Mating started earlier at the lower temperatures than at higher temperatures. The mean duration of mating was higher at 15 and 20°C than at 30 and 35°C at which high relative humidity favoured increase in mating time.

At 20 and 30°C oviposition started within the first 2 days of mating whereas at 15°C oviposition started about 8 days after mating. At 35°C oviposition commenced within 4 days. Low relative humidity caused early commencement of oviposition at 15 and 35°C.

The human body louse aggregates on filter paper impregnated with an aqueous extract of louse faeces. Chemical analysis of the faeces revealed the presence of haemoglobin, xanthine, hypoxanthine, uric acid and ammonium salts. Of all these compounds, only ammonium salts caused marked aggregation of lice. Excretory products of other insects and ticks also failed to induce aggregation. Total faecal material was more attractive than ammonium, and led to greater aggregation of females than of males. Antennectomized lice reacted neither to faeces extract nor to ammonium carbonate solution.

Bacillus thuringiensis H-14 (Alex), originally isolated from moribund and dead larvae of the casuarina stem borer, Stromatium fulvum, was tested in the laboratory against the second and fourth-instar larvae of both mosquito species, Aedes aegypti and Culex pipiens. The pathogenicity of this bacillus was established when both insects were found to be susceptible to infection over the whole range of test concentrations (0.005–0.35 mg/1). However, A. aegypti showed a higher degree of susceptibility to B. thuringiensis H-14 (Alex) than C. pipiens. A mortality of 100% was achieved within 24 hr with concentrations of 0.09 and 0.25 mg/1 for second- and fourth-instar larvae of A. aegypti, respectively. Also, younger larvae of both test mosquito strains were more susceptible than mature ones.

Effects of pheromone trap design and trap placement methods were tested for catching males of the peach twig borer Anarsia lineatella (Zeller), in Iraq. Zoecon's pherocon lc trap captured more moths than corrugated plastic delta trap.

Significantly more moths were caught in traps hung at a height of 3.0 m above ground (surface) than at any other level of traps. Although more males were caught in the traps placed in south quadrant of the trees than other quadrants, the analyses showed that there was no significant difference between quadrants at P = 0.05. Response to traps at the interior of the orchard was significantly higher than that to the traps in perimeter orchard.

The paper analyses the extent to which ticks and tick-borne diseases, particularly East Coast Fever (ECF), are an economic problem in Kenya. It qualitatively argues that several socio-economic factors, viz. inadequate information, indivisibility of the main tick control facilities, externalities, and risk make individual farmers undertake less control efforts than is optimal for the society. This fact is used to justify a more active role for the state in tick control efforts. A simple regression model that tests the impact of ECF on the cattle breed portfolio in the country is presented.

In the field and laboratory, Gossypium arboreum varieties G 27, LD 133 and LD 230 were less preferred by the jassid, Amrasca biguttula biguttula, and the aphid, Aphis gossypii, than G. hirsutum variety, F 414. The arboreum varieties also supported fewer numbers of the two sucking pests than the hirsutum cotton. These varieties proved potentially susceptible to bollworms Earias spp and Pectinophora gossypiella damage in laboratory tests. Interestingly the varieties exhibited considerable degrees of field resistance. In the field, Earias moths showed no preference for any plant part for oviposition among the four cotton varieties. Of the reproductive parts of the cotton plant offered, first and last instar Earias vittella larvae orientated maximally to bud. Nonetheless, the larvae showed no definite pattern of preference for the fruiting structures of the cotton plant. In the laboratory, the four varieties showed non-significant differences in supporting the growth of Earias and Pectinophora larvae. The number of Earias eggs on the four varieties did not vary significantly. The number of fruiting bodies per plant and Earias incidence were unrelated in the four varieties.

Four goats, which had been previously bitten on two different occasions by Glossina morsitans centralis infected with Trypanosoma congolense and subsequently treated on each occasion with the trypanocidal drug diminazene aceturate were each fed upon by six uninfected tsetse. Hypersensitivity reactions developed in the skin of two of the goats within 1 hr after the bite, and reached a maximum intensity over the next 24 hr. In order to determine whether hypersensitive skin reactions could be induced by tsetse saliva alone, six different goats were bitten by uninfected tsetse up to eight times. Only a few small nodular skin reactions were noticed. However, following infection and treatment and another sequence of uninfected tsetse bites, hypersensitive skin reactions did occur in two animals, although the reactions were not as severe as anticipated. The hypersensitivity reactions usually precede but sometimes overlap the chancre reaction elicited by metacyclic trypanosomes transmitted by tsetse.

The development of Dysdercus voelkeri on three dwarf and short-season varieties of sorghum: BES, HP3 and HP8 and its damage to the grains were studied in the laboratory and greenhouse, respectively. An average development period of 27 days was recorded on the three varieties. The fecundity, fertility, live-weight and dorsal surface area were significantly higher in insects that developed on HP8 than in those that developed on BES and HP3. There were, however, no significant differences in these parameters except fertility between the insects that developed on BES and HP3.

The highest grain damage of 56.6% was recorded for HP8, while 51 and 27.6% grain damage were recorded for BES and HP3, respectively. The potential pest status of D. voelkeri on these new and improved sorghum varieties in the southern Guinea and derived savanna zones of Nigeria is confirmed in these studies. Effective control of this bug and other sucking insects at the milky stage of grains' development is suggested for high yield and good quality grains.

Chlordimeform (CDM), tested by topical application, was found to be toxic to both male and female tsetse with the maximum effect some 72 hr after treatment. Median lethal doses were approx. 0.4 μg/fly for unfed adult tsetse of both sexes, 100% mortality at 72 hr was achieved with 2 μg/fly. Mature fed females were less susceptible to chlordimeform, the median lethal dose for 72 hr being 12.5 μg/fly. High doses of chlordimeform depressed the weight of puparia from survivors, but had no effect upon fecundity. Sublethal doses caused a significant depression of feeding activity, but did not cause hyperactivity or disrupt fat body lipid reserves.

Field evaluation showed oxydemeton methyl 25% E.C. at 0.6 kg a.i./ha and dimethoate 40% E.C. at 0.74 kg a.i./ha to be more effective than cypermethrin 40% E.C. at 0.25 kg a.i./ha, decamethrin 2.5% E.C. at 0.03 kg a.i./ha, endosulphan 35% E.C. at 0.8 kg a.i./ha and profenofos 50% E.C. at 0.74 a.i./ha in the control of apterae on potatoes. Disulfoton 10G at 1.6 k0g a.i./ha and carbofuran 10G at 5.2 kg a.i./ha were superior to oxamyl 10G at 5.2 kg a.i./ha and terbufos 5G at 2.6 kg a.i./ha applied in the furrow at planting for the control of aphids. Although these insecticides gave good control of apterae, the alate population in the treated plots varied from significant reduction to no reduction. All the insecticides tested did not significantly increase potato yield, although mean yields were increased.

Eight potato cultivars, viz, Anett, Desiree, Feldeslohn, Kerr's Pink, Kenya Baraka, Roslin Eburu, Roslin Gucha and Roslin Tana were tested in the field to compare their susceptibility to aphids. Despite the variation in results, Anett, Kerr's Pink and Desiree were identified as the most susceptible cultivars. The experiments revealed that Roslin Tana was a comparatively resistant cultivar useful for reference in further work.

There were no significant correlations between leaf area, glandular hairs and alate aphids with the number of apterae aphids on the eight potato cultivars. Resistance of Roslin Tana to aphids was, therefore, not due to the morphological characteristics of the cultivar, but probably to some physiological factor(s).

Amylase, sucrase and cellulase were detected in the alimentary canals of workers and soldiers of Amitermes evuncifer Silvestri, but only sucrase and cellulase were found in the alimentary canal of the alates. Enzyme activities varied in different parts of the alimentary canal. That high enzyme activities were observed in the guts of the workers (than those of the soldiers) is due to the fact that the workers forage for food which they digest partially before feeding other members of the colony through trophallaxis. The presence of enzymes in the alimentary canals of alates and soldiers indicates that the partially digested food, from the workers, undergoes further digestion in their systems.