Surveys for population densities of the maize borer Sesamia eretica Led. (Lepidoptera: Noctuidae) were conducted for three consecutive years (1997–1999) in several localities of the Nile delta in Egypt, in order to get a better insight into the population dynamics of the pest and to propose rational basis for its biocontrol using a recently isolated granulovirus. High population densities (more than one borer per plant) were observed only in the first plantings after winter (first fortnight of April). After this peak, populations almost vanished until the end of the crop season (September-October) when a slight increase was observed (0.1 borer per plant). The drastic decrease in population densities in plantings from the end of April occurs because most final instars of the borer leave the plant to pupate in the soil. This behaviour, uncommon in maize borers, results in a very high mortality rate due mainly to pupal parasitism. Only the few larvae pupating in the stem, which are much less parasitised, give rise to adults. Spatial distribution was studied using Taylor's power laws which enabled the elaboration of enumerative sampling plans for eggs, small larvae (1st and 2nd instars) and older ones. Fixed optimal sample size and sequential sampling plans for different precision levels were developed. The precision of the estimated sample size was checked using resampling of some of the data that were not used to build the models. The validation study showed that the plans were suitable for the entire Nile delta region.

As a background to an IPM project, this paper describes pesticide treatment of cotton in Sudan Gezira, starting in 1945/46. Until the end of the 1950's, one treatment per season was sufficient to control the only important pest, the jassid, Empoasca lybica, but the number of treatments increased during the 1960's (from 3 to 5) and has since the early 1970's been 6–9.

The continuous use of pesticides has resulted in changes of the pest complex, ultimately creating “hyper” pests such as the whitefly (Bemisia tabaci), cotton bollworm (Heliothis armigera) and aphids (Aphis gossypii). The increase in number of applications of pesticide is coupled with the rising costs of pest control and a stagnant yield. The stickiness problem created by the honey dew of whitefly and aphids increased with the rising number of sprays. The exclusive use of chemical control not only failed to improve the quality or quantity of the yield, but put a great strain on the national economy as well.

The Sudan therefore requested the FAO to initiate an IPM project starting in 1979, with financial support from the Netherlands. During the past 2 years support has also been given by the World Bank. The IPM approach has given very valuable results during the last two seasons when large (more than 100 acres) plots in the Gezira and Rahad Schemes were left unsprayed with the objective of investigating the potential of the natural enemies in the absence of pesticides, and to compare findings with population trends of pest and beneficial organisms in the fields subjected to conventional chemical control.

The first significant finding was that Bemisia tabaci and Aphis gossypii can be managed at desirable levels by their indigenous natural enemies, and that their outbreaks are attributed to the decimation of these natural enemies by chemical treatment. Populations of beneficial arthropods were consistently much lower in the fields which received regular pesticide applications.

The result of the large-scale experiments indicate that Empoasca lybica is the only really damaging pest (“key pest”) in the Gezira because of the absence of natural enemies to regulate its population. Control of E. lybica in the 1940's and 1950's resulted in the creation of Heliothis armigera as a major pest. This situation necessitated early season applications of pesticides to suppress H. armigera, which further reduced the role of the natural enemies of B. tabaci and A. gossypii. Both have developed into major pests of regular occurrence.

Cotton farmers in Gezira are now faced with a complex of very serious pests. In order to solve this problem, we will have to make drastic changes in pest control strategies and to adopt an IPM approach as soon as possible. The biological control H. armigera is considered as first priority in order to avoid the early season application of pesticides. Trichogramma pretiosum was introduced from the USA and released in the Rahad Scheme in 1988/89. The preliminary results are very promising.

Cultural and biological control of E. lybica will be attempted in order to further reduce pesticide applications. The control of this pest by the use of “milder” pesticides is also included in the programme.

The presently used threshold levels for all major pests are very low, and are under revision through properly conducted large-scale experiments.

Twenty-three insecticide formulations were bioassayed for toxicity against the eggs and larvae of H. hampei in maturing and ripe berries of C. arabica L. Var. typica. The infested berries were dipped in different concentrations of individual formulations, dissected 24 hr later for recording larval mortality and transferring the eggs to wet filter papers where larval hatching was recorded for the next 4 days. The order of toxicity and LC50 (% a.i. × 103) values for the eggs in maturing and ripe (figures in parenthesis) berries were: thiodan EC 35, 5.1 (6.2) > perfekthion, 5.9 (8.1) > decis, 7.2 (9.4) > carbicron, 7.3 (9.8) > actellic, 10.6(12.9) > thiodan EC 3, 14.7 (17.4); > folimat > aldicarb > dursban > tiovel > supona > dimilin > methomyl > kelthane > phosdrin > sevin > methoxychlor > dieldrin > azordrin > fenitrothion > bimarit > chlorpyrifos > gardona, 39.7−1043.7 (44.3−2642.2). The order of toxicity remained almost the same for the larvae, the LC50 values being 2.1−12.7 (2.9−21.8) for the top six and 14.8−1920.4 (47.1−2738.6) for the remaining 17 formulations. Generally, the formulations were 1.1−2.7-fold more toxic to larvae than to eggs infesting the maturing berries but 0.47−3.57 more toxic to eggs than larvae in the ripe berries.

The influence of banana weevil, Cosmopolites sordidus (Germar)(Coleoptera: Curculionidae), population density on oviposition rates and larval survivorship was studied in the laboratory at the Kawanda Agricultural Research Institute in Uganda. This study was undertaken to elucidate the relationship between density-dependent factors and rates of banana weevil increase in the field. Oviposition substrates (corm pieces) were offered to a range of densities of weevils maintained in buckets. Mean oviposition rates per female at densities of 10, 20 and 40 females per bucket were 29, 37 and 53%, respectively, lower than that at a density of 5 females. Nevertheless, total oviposition for the same groups was 1.4, 2.5 and 3.7 times higher than that of the 5-female group. Providing fresh corms daily instead of every five days did not increase oviposition. Larval survivorship was slightly higher at lower densities of immatures following insertion of different densities of eggs or first instars into banana corms. The results suggest that density-dependent factors can influence oviposition rates of individual weevils and survivorship of immatures, but appear to exert only modest influence in reducing banana weevil population growth. More likely, high mortality of weevil immatures under field conditions and/or higher rates of adult mortality and emigration than previously postulated contribute to the slow population build-up of this pest.

Studies on aspects of the biology of the kola weevil Balanogastris kolae on Cola acuminata and C. verticillata were made in the laboratory at temperatures of 28–30°C. Mated females of B. kolae oviposited a significantly higher number of eggs (238) in C. acuminata than in C. verticillata (205) when confined separately with the nuts. But when the weevil was offered the choice of three Cola species as oviposition media, significantly more eggs were oviposited in both C. nitida and C. verticillata than in C. acuminata. However, there was no significant difference between the number of eggs oviposited in C. verticillata and C. nitida.

The average total incubation, larval and pupal developmental periods of B. kolae in both C. nitida and C. verticillata were 6, 16.2 and 6.1 days, respectively. The average total developmental period in C. acuminata was 28.8 days, and 26.5 days in C. verticillata. Although the total developmental periods overlap, there was a significant difference between the periods of development of B. kolae in the two Cola species. Oviposition and development of B. kolae in the wild species, C. verticillata, coupled with its wide distribution show that it may be ecologically important in the survival of the weevils, especially when the cultivated Cola species are not available in the field.

Studies of cocoa tree genetic resistance to attack by Scihlbergella singularis (Haglund.) (Hemiptera: Miridae), have so far been based on field observations of cultivar performance. Although this approach was useful in guiding breeding programmes, observations on tree crops are time-consuming (3–4 years) and labour-intensive. Thus a standard laboratory microassay method based on a study of the mirids’ dietary preferences was developed to quantify the attractiveness of cocoa trees to mirids under controlled conditions, with reproducible results.

A dual approach was taken to establish relations between laboratory data and field observations: preliminary cultivar sorting of both clones and hybrids in the laboratory, by microassays was combined with an eight-year observation programme in two different ecological zones in Ivory Coast: on the shores of a lagoon (Bingerville) and under thinned forest in Basse Côte (Divo). In Cameroun only clones from IRA field station at Nkoemvone were tested by microassays.

After three successive sets of field observations, a comparative analysis of the results revealed close correlations between cultivar responses in microassays and those observed in the field.

Cultivar responses to mirids revealed that there are two performance groups within the planting material selected, viz., in increasing order of attractiveness, Forasteros (upper and lower Amazon cultivars) and Trinitarios.

In Cameroon, microassays revealed behavioural polymorphism amongst the cultivars tested: plants of the same origin can react very differently to mirids as it was the case for the local trinitarios SNK group.

The microassay technique is quick and easy to use, and is effective for the early selection of mirid-tolerant plant material.

Focal species are valuable tools for evaluating management practices for biodiversity conservation. Butterfly gardening through the creation of appropriate habitats can be a primary conservation tool to increase species abundance and richness and gene flow among the populations in fragmented landscapes. In this context, the role of butterfly gardens in the conservation of butterfly populations and the seasonal population trends of swallowtail butterflies (family Papilionidae) sighted in the Butterfly Safari Park at Thenmala were studied. A total of 4760 sightings of 15 species of swallowtails belonging to five genera were recorded, of which six were endemic species, three species had protected status and two were rare species. It is worth noting that of the 19 species of the papilionids recorded in Kerala, as many as 15 species were recorded in Thenmala. Of the various species recorded, Troides minos, Pachliopta pandiyana, Pachliopta aristolochiae, Graphium agamemnon, Graphium sarpedon, Papilio polytes, Papilio clytia, Papilio demoleus and Papilio polymnestor comprised the resident populations, while species such as Atrophaneura hector, Papilio helenus, Papilio dravidarum, Papilio paris, Papilio liomedon and Graphium nomius were found only during certain seasons. The overall butterfly abundance was high from August to November. The butterfly populations exhibited a gradual decline in numbers from December onwards with the onset of dry seasons. The abundance of butterfly populations was low during March–April. The abundance of T. minos, P. pandiyana, P. polymnestor, P. paris, P. dravidarum, P. helenus, P. polytes and P. liomedon showed a significant negative correlation with monthly average temperature and a significant positive correlation with humidity.

The banana weevil, Cosmopolites sordidus (Germar), is a nocturnal insect that is not readily observed in banana fields. Knowledge on its distribution is essential for the design of management strategies that target the adult stage. Marked weevils were released into seven-year-old banana plots. Ten days later the plots were systematically sampled for adult weevils by first removing the banana leaf mulch and residues, searching subsections of the soil to depths of 3 and 25 cm and, finally, removal and dissection of the banana mats. Of the marked weevils, 62, 56 and 82% respectively, were recovered in three trials. Most weevils were found in close association with either the banana mat (46–66%) or with cut residues lying on the ground between the mats (24–31%). Lesser numbers were found in the leaf mulch and in the top 3 cm of soil away from the mat. The distribution of weevils is likely to be influenced by crop management practices and the availability of residues and by the presence of mulch. Implications for banana weevil IPM are discussed.

A core reality in wildland conservation is “Use it or lose it”. And when you use it, something has to restore it. Footprints must mostly erase, or the use is not sustainable. The Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica is a 3-decade old and long-term pilot project in tropical wildland biodiversity development and tropical wildland ecosystem development. In summary, it is environmental services development. Some conclusions are already evident:

• Restoring complex tropical wildlands is first and foremost a social endeavor; the technical issues are far less challenging.

• Survival of a large complex wildland, whatever its origin, in the face of humanity's genes and domesticated genomic extensions, requires a major paradigm shift—we cannot afford to perceive the conserved area as “wild”, otherwise known as “up for grabs”.

• Sustainability of a large wildland will only be achieved by bestowing garden status to it, with all the planning, care, investment and harvest that implies.

• All use is impact, all gardens are impacted—restoration is footprint absorption by the garden and occurs at all scales.

• Planning, care, investment and harvest within the wildland garden is achieved through detailed understanding of biodiversity and its ecosystems, AND in simultaneous incorporation of a specific garden's social milieu at local, national and international scales.

• The “achievable” is an ever-shifting and ever-negotiating n-dimensional hyperspace produced by the intrinsic traits of a specific wildland interwoven with the mosaic of social energies and agendas brought to bear on it.

A wide variety of Hemiptera species are found on the leaves of palms in humid tropical zones. Many of them are highly polyphagous, and generally once adult, only accidentally end up on palm leaves, on which they can nevertheless feed. Other hemipterans spend the whole of their developmental cycle on palms, and some seem to live on palms alone. Most of the Hemiptera have no economic impact on their hosts, since their population levels are rarely high enough to cause significant damage. However, some Heteroptera: Coreoidea and Homoptera: Coccoidea species can be very damaging primary pests. Others amongst the Homoptera: Fulgoroidea, Cicadelloidea and Heteroptera: Pentatomoidea transmit serious diseases that have decimated oil palm and coconut plantations, for example coconut lethal yellowing in Africa and the Caribbean, and oil palm and coconut trypanosome diseases in Latin America. Lastly, some Heteroptera: Pentatomoidea and Reduvioidea species are natural enemies of lepidopteran caterpillars.

The leaf-eating caterpillar, Opisina arenosella Walker, is the most destructive pest of coconut palm in India and Southeast Asia. The management practices employed against O. arenosella so far have been unsuccessful in many instances in India, due to the pest behaviour and coconut palm phenology. The life cycle, incidence and behaviour of O. arenosella are rather interesting and useful for the intervention of pheromone trapping technique for its management. We conducted the present study with the intention of identifying the female sex pheromone of O. arenosella and testing its efficacy under field conditions. Gas chromatography coupled electroantennographic detection (GC–EAD) and gas chromatography–mass spectrometry (GC–MS) analysis of female pheromone glands extract of one-day-old O. arenosella females confirmed the presence of (Z,Z,Z)-3,6,9-tricosatriene (Z3Z6Z9-23Hy) as the dominant sex pheromone component. The male antennal response to female pheromone gland extract and synthetic Z3Z6Z9-23Hy was recorded using GC–EAD, and the results revealed that antennal response was positive to both the treatments at 0.13 mV and 0.14 mV respectively, compared to control (air), which was 0.016 mV. It was also evident from wind-tunnel experiments that the male moth response was high (80%) with the female gland extract, compared to 60% with synthetic pheromone and 0% for control (air). Male moths caught in the traps with and without lure were assessed in two field sites and recorded 69.26% and 54.25% more moth catches in the traps with the lure. We also observed a similar result in the cage experiment in which male moths caught in the traps with and without lure were 64.50% and 12.40%, respectively. The study also confirmed that 93.20% moths caught in the pheromone-baited traps were male. From the study, it is evident that the presence of (Z,Z,Z)-3,6,9-tricosatriene, which is the sex pheromone compound from the female gland extract of O. arenosella, is an effective attractant in pheromone traps for the male moth under field conditions.

Factors regulating activity of adult Rhipicephalus appendiculatus ticks were investigated. Observations were made on ticks treated to 100% hydration, 85% hydration and 65% hydration during the hot dry, hot wet (rainy) and cool dry seasons. Two-months old and 6-months old ticks of each sex were released in two different habitats in 25 × 25 cm enclosures.

Comparisons were made between the number of ticks in each group seen on the upper part of the vegetation at intervals of 2 hr during daylight hours only. Although temperature changes seemed to be the cue to tick activity, the immediate activity shown by the 100% hydrated ticks and the delayed activity of the dehydrated groups after release, suggested that only fully hydrated ticks were responsive to temperature changes.

The most commonly recorded temperatures were within the range at which tick activity appeared to be at its maximum. During the daily temperature cycle, reduced activity was observed when the temperature was outside these limits. Activity increased again as soon as the temperature returned to the optimum range.

The effect of solar radiation, rainfall and cannibalism on the disappearance of eggs and larvae of the cereal stemborer Chilo partellus (Swinhoe) were studied. Disappearance and nonviability of egg batches was higher on plants exposed to solar radiation than on shaded plants. Significantly fewer small larvae were recovered from plants exposed to rainfall than from shielded plants. Cannibalism among larvae of the same size was not common except at high larval densities. Contrary to the common belief that disappearance is the result of predation, these studies show that solar radiation and rainfall might also play an important role in the disappearance of stemborer eggs and small larvae.

The effect of pod angle on the resistance of cowpea, Vigna unguiculata (L.) Walp. to the legume pod borer, Maruca testulalis Geyer, was investigated under field conditions at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, using two cowpea cultivars: IT82D-716 (susceptible to borer damage) and TVu 946 (resistant to borer damage). Three different pod angles were used In the study — a normal angle, a decreased angle and an increased angle. Negative and highly significant (P < 0.01) relationships were found between pod angle and per cent pod damage, as well as the seed damage Index In the two cowpea cultivars. Pods with wide angles (≥ 89°) were damaged on only one and rarely on both pods. Apart from biochemical and other bio-physical factors, selection and breeding for wide pod angle is suggested as a strategy for reducing M. testulalis damage to cowpea pods.

We studied host discrimination in flight morph of Callosobruchus maculatus (F.) among the legume plants Ife-brown (IB) and black-eyed (BE) cowpea, Vigna unguiculata (L. Walp), soybean (SB), and Glycine max (L.) and analysed legume volatiles towards developing an attractant for C. maculatus. Olfactometry studies were conducted to investigate attraction of mated 3–4-day-old female C. maculatus to legume plants with the green pod (PGP), green pods (GP), plant with the ripened pod (PRP), ripened pod (RP), and plant without pod (PWP). We also assessed the response of beetles to phenological stages of the most attractive legume. In Y-tube bioassays, C. maculatus showed greater attraction to individual legumes at three phenological stages: PGP (73–93%), PRP (80–100%), and RP (63–93%) compared with PWP (6–36%). In four-choice bioassays, C. maculatus preferred IB at all stages to other legumes. SB had an insignificant attraction on the beetle. The RP of IB was the most attractive part of the plant. Gas chromatography (GC) and GC–mass spectrometry (GC–MS) analyses of volatiles emitted by RP of the legumes revealed a variation in the compositions of odour blends. Benzaldehyde was found in the volatiles of IB and BE with a higher emission in IB. Octanone was detected only in IB. The two compounds were undetected in SB volatiles. These results reveal that in addition to infesting cowpea plants at RP stage as reported in previous studies, C. maculatus could also infest cowpea plants at the GP stage.

Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) is an indigenous, gregarious, larval endo/parasitoid which is widely distributed in Africa and attacks mid- to late instars of stemborers. There is renewed interest in using Co. sesamiae for biological control to reduce the problems caused by stemborers. However, Wolbachia sp., a bacterial symbiont of some populations of Co. sesamiae, poses some threat to the successful use of the parasitoid for stemborer control. This bacterium's common effect is cytoplasmic incompatibility between infected males and uninfected females. Polymerase chain reaction (PCR) tests were carried out on parasitoid samples collected from 5 locations in Kenya and 8 other countries in eastern Africa. Wolbachia presence was detected in Co. sesamiae populations from Coast and Machakos in Kenya, and from samples collected from 6 other eastern and southern African countries. No infection was detected from western Kenya, Uganda and Malawi. Cross mating among 3 infected populations (North Coast, South Coast and Machakos) and 2 uninfected populations (Kitale and Kuja) was done to establish which populations were reproductively compatible. Biological parameters, such as brood size and percent females were compared among the different crosses. One-way incompatibility, indicative of Wolbachia infection, was observed from the crosses between males of either Mombasa or Machakos arid females from Kitale. Selection of compatible Co. sesamiae populations is critical to successful augmentation biological control programmes.

The design and construction of the Nitse trap are described. The materials required are: royal blue cotton, black cotton, mosquito netting, brass pipe, metal rods and galvanised wire. The cutting and joining of the various parts to produce the trap and the method of placement are also described. Finally a rough estimate of the cost of the trap is given.

The effects of sowing date, host plant and insecticidal control of the stemborer Busseola fusca Fuller were studied in the highlands of Eritrea at Halhal Begos in 2003–2005. Sowing date had a significant effect on stemborer incidence and damage levels. Early sowing dates (April 1 and 15) had significantly lower numbers of larvae, percent infestation and deadhearts, and produced higher yields compared with later sowing dates. In the host preference experiment, Sudangrass (Sorghum× drummondii (Steud.) Millsp. & Chase) had the highest infestation (91%), and it was the most preferred host for oviposition among the tested plants. All the chemical treatments significantly reduced stemborer infestation and damage levels compared with untreated plots. Furadan and Cymbush significantly lowered infestation and larval damage. There were significant differences in days to heading, maturity, plant height and yield. In general, the study showed that early planting coupled with host preference and insecticides reduced the infestation of stemborers and significantly increased the yield of sorghum in the highlands of Eritrea.

A preliminary survey was conducted in coastal Kenya to assess the hosts of economically important tick species (Acari: Ixodidae) of domestic animals, as part of a training course for tick scientists from African research institutions. Ticks were collected from domestic animals in Kilifi and Kwale districts.

Eight tick species, namely Amblyomma variegatum, Boophilus decoloratus, B. microplus, R. appendiculatiis, R. evertsi evertsi, R. pulchellus, R. simus and A. gemma were identified. Further, more comprehensive surveys on the hosts, distribution and ecology of ticks of economic importance are recommended.

Two new cost-effective trap designs for capturing arthropod flower visitors are described. Small flower visitors such as Thysanoptera and Diptera, hardly noticeable during direct flower observations, were dominant in trap catches. These trapping techniques combined with direct observations allow a more comprehensive picture of the flower visitors.