A basic study of the behavioural responses of the harvester termite, Hodotermes mossambicus (Hagen) to poison baits was undertaken. Laboratory trials revealed that the collected baits were not incorporated into the termite nest food stores. The baits were never eaten because the nest-bound larval caste selects the food to be consumed by the entire colony, from the material collected by the foraging caste. Moreover, field observations have shown that the commercial bait, Kamikaze®, bears no resemblance to the grass collected by the termite foragers. This study revealed that observations of foraging and feeding behaviour of the termites are necessary before designing control measures.

Larval dispersal and establishment of Chilo partellus (Swinhoe) was studied on different maize cultivar combinations at the whorl stage. Dispersal was increased 2-fold when the infested cultivar ICZ2-CM (resistant) was surrounded by the more susceptible Inbred A, and decreased when Inbred A plants were surrounded by ICZ2-CM. A negative relationship (r = 0.89) was found between the proportions of larvae establishing on infested plants and those unaccounted for. The influence of a cultivar on increased larval dispersal could be exploited in resistance breeding strategies. The possible role of such an effect in pest management strategies is discussed.

Flight activity in strain 16cSS of Anopheles gambiae (sensu stricto) has been investigated using an acoustic actograph. The peak activity was concentrated within the first hour after light off. After recording their activity, individual mosquitoes were examined for their chromosome inversion karyotype. No significant relationship was found of any of the karyotypes to total activity over the 2 hr after light off or the time at which 50% of their activity had been completed.

The results are discussed in relation to the possible widespread introduction of mosquito bednets and the possible selection of mosquitoes biting abnormally early before people go to bed.

The elegant grasshopper, Zonocerus elegans Thunberg, occurs in large numbers in Kilosa district during the dry season June to January and attacks a wide range of wild and crop plants. Its impact as a pest of crop plants becomes more noticeable from the middle of the dry season when the hoppers are well advanced and the only alternative food available are vegetables in backyard gardens and river valleys. The grasshopper damage continues throughout the vuli (short) rains until the end of the oviposition period in January, thus limiting the production of green vegetables in the district. A study on the biology and ecology of the pest in Kilosa district with emphasis on short term control strategies was started in 1987. Spot spraying with insecticides to kill the early instars was found to be effective, but area-wide implementation was necessary to prevent re-invasion of cleared areas.

In view of the losses of harvested grain incurred due to problems related to storage, marketing, transport, and handling, this paper reviews the situation on storage of food grains in developing countries. It lists the insect pests that frequently attack stored food grains in these countries and discusses strategies that would minimise the damage caused by the pests.

The induction of resistance in the urban pest mosquito, Culex quinquefasciatus, to chlorpyrifos and chlorfenvinphos and the cross-resistance spectra of these selected lines to propoxur and a number of organophosphate insecticides was studied. Distinct genetic factors governing intermediate (R1) and high (R2) levels of larval resistance to organophosphates were found to be allelic according to the single locus, multiple aliele hypothesis. Adults were less susceptible to malathion and fenitrothion after larval selection with chlorpyrifos, but the degree of resistance was found to be much less than that in the larvae. The implications of these results for the control of C. quinquefasciatus in Dar-es-Salaam, Tanzania, is discussed.

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 juvenoids fenoxycarb and methoprene were evaluated for morphogenetic activity on last-instar nymphs of the American bird grasshopper, Schistocerca americana (Drury) (Orthoptera: Acrididae). Topical application of fenoxycarb induced supernumerary nymphs, adultoids and adults with curled wings. Methoprene yielded similar morphogenetic effects although at reduced levels of activity. Of particular interest, however, is the discovery that, in addition to its morphogenetic activity, fenoxycarb causes significant mortality in developing fourth-, fifth- and sixth-instar nymphs.

A survey carried out over Western Kenya in order to determine the prevalence of microorganisms in cereal stem borers and legume pod borer showed the presence of a large number of insect pathogens in the dead larvae. Larval cadavers were recovered from all sampling sites. Bacterial and fungal microorganisms were highly prevalent. Other major groups of microorganisms were also recovered, although at a low level. Viruses (polyhedral inclusion bodies and granulosis viruses) occurred at 2.7% at the Mbita Point Field Station, and 1.1% in the field. Mermithids and rhabditids occurred at 0.4% in the station and 0.6% in the field, whereas the protozoans (microsporidia and gregarines) were more prevalent in the station than in the farmers' fields (9.4 and 1%, respectively).

The spotted stalk borer, Chilo partellus was the most common borer sampled, but Busseola fusca and legume pod borer, Maruca testulalis were sampled in most sites too. Sesamia calamistis and EIdana saccharina were recorded at a low level, and C. orichalcoceliellus was recorded only at the Kenya coast.

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.

Oecophylla spp. are used as biocontrol agents for many types of insect pests. A large and stable population is essential for effective control of pests. Colonies of Oecophylla spp. can be transplanted from wild habitats into orchards. Transplanted colonies can only survive in the presence of egg laying queens. It is difficult to locate nests with egg laying queens in large colonies that may sometimes contain more than 100 nests. Therefore, the need to explore and develop methods for rearing newly mated queens in nurseries may not be over emphasized, hence the current study. In the first experiment, we tested three rearing methods on queen survival and colony establishment. In the second experiment, we compared feeding techniques of different weaver ants on young colony growth. We observed that queens were best reared under continuous, indirect access to water. The first workers emerged earlier (32 days on average) in indirect and direct continuous access to water methods than on limited access to water (sprinkled) (38 days on average). Moreover, rearing mated queens under continuous indirect access and continuous direct access to water methods saved labour and time, because of limited attendance to the colonies. Availability of water, sugar solution and different sources of protein throughout improved the growth of young colonies. Likewise, the number of workers increased rapidly. Therefore rearing mated queens in nurseries is possible and would minimize hustles in hunting for the colonies and their queens in the wilderness.

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.

Plant resistance research requires many entomological and plant breeding techniques and methodologies of which some are critical to the success of the programme. The entomologist has the responsibility of developing techniques for: providing sufficient numbers of insects for screening and other plant resistance studies; creating uniform and controlled populations of the test insect for identifying and developing resistant germplasm; measuring resistance; and determining mechanisms and bases of resistance. A thorough knowledge of the insect-host plant relationship is essential for developing efficient techniques. Some of the considerations involved in developing these techniques are discussed with selected examples to illustrate various techniques employed in plant resistance to insects research.

Field and laboratory evidence now suggests that the African armyworm, Spodoptera exempta, is specifically adapted for survival at low population densities, providing a new basis for understanding the significance of its phase polyphenism and migratory strategy. This conclusion allows deductions to be made as to the expected extent of displacement of flying moths from low and, when they occur as a result of impeded or inadequate dispersal of parent moths, high density populations. The proposed migratory strategy which depends on the genetic determination of flight potential also provides a framework for interpreting observed patterns of armyworm outbreaks through the season and in relation to rainfall. Traits associated with a low-density, “armyworm” strategy are shared by other Noctuids which may have similar life histories.

Host location and feeding among ticks involves positioning for host findings, probing, attachment, imbibing blood and thereafter detachment. Different species of ticks fulfil this sequence of events in different ways. Behavioural differences are mainly due to sensory inputs obtained by a tick and the processing of that input by the central nervous system. Tick receptors responsible for perceiving stimuli originating in the general environment and the host in particular are located on the tarsi and mouthparts. This review gives a brief account of current knowledge on sensory receptors involved in the above behavioural patterns.

Increasing anthropogenic disturbance in tropical rainforests is a major challenge to biodiversity conservation. The responses of herbivorous insect communities to habitat changes are not well understood. In this study, we investigated the resilience of galling insect communities associated with Neoboutonia macrocalyx (Euphorbiaceae) trees to logging in Kibale National Park, Uganda. Resilience was measured by comparing the species density, abundance and community structure of gallers in nine differently aged successional forests with those in adjacent primary forests. Insect galls were sampled from the canopy of 10 randomly selected trees in each successional stage, five times in a 10-month period. A total of 7219 individuals representing five galler species were recorded. No significant differences were found in the species density and overall density of gallers between the regenerating and primary forests. The mean tree height was positively correlated with the overall density of gallers. The community structure of gallers differed significantly among the successional stages, but exhibited no clear directional recovery trend. In addition, remarkable seasonal variations were observed in galler communities, with peak abundance being found in the wettest months. The results of the preset study indicate that specialist galling insects whose hosts are pioneer trees can recolonize successional sites rapidly and are resilient to the effects of selective and clear-cut logging in case primary or secondary forests with an established population of Neoboutonia host trees (source populations) are close by. Thus, recovering tropical forests can provide important habitats for galling insect biodiversity, highlighting the need to include them in management and conservation priority plans.

This bibliography on diseases of insect pests of rice contains 287 references. Major groups of insect pathogens are briefly discussed. Available records on diseases, insect hosts and locations of collections are tabulated. Additionally, references are grouped by subject.