The study sought to confirm reports by farmers and agricultural extension personnel of Prostephanus truncatus (Horn) attacking harvested maize in Mashonaland West and Mashonaland Central provinces of Zimbabwe and to map out, using pheromone trap catch data, the distribution of the pest in the country. A survey of 296 respondents confirmed the presence of P. truncatus in five districts of the provinces. Some respondents reported that the first few sightings of the pest were in 2005 or earlier, while the majority mentioned the 2006/2007 storage season. The map showed a more concentrated distribution of P. truncatus in the northern part of the country moving further inland towards the central and eastern parts of Zimbabwe, indicating possible spread of the pest from the neighbouring countries Zambia and Mozambique. The results of the study indicate legitimate concerns over food security with respect to stored maize grain and seed. The occurrence of P. truncatus in the country has serious implications on training of extension agents and packaging of extension messages that need to be disseminated to the farming community to reduce the impact of the pest. This is the first evidence-based and official documented report of P. truncatus occurrence in Zimbabwe.

Control methods used to limit field losses caused by Bruchus rufimanus Boheman, 1833 consist of synthetic insecticides that pose health risks to farmers, consumers and the environment. In an attempt to find safer alternatives, we screened essential oils from the leaves of Rosmarinus officinalis collected in the Middle Atlas and Loukkos regions of Morocco in the laboratory as natural fumigants against B. rufimanus. These essential oils were extracted by steam distillation using a Clevenger distiller, characterised chemically by coupled gas chromatography–mass spectrometry (GC/MS) and tested at five concentrations (0, 10, 20, 40, 80 µl/l air). The essential oils of R. officinalis mainly comprised oxygenated monoterpenes (Middle Atlas: 79.4%; Loukkos: 48.78%) and terpenes (Middle Atlas: 14.71%; Loukkos: 32.33%). The lethal concentrations (LC50) of Middle Atlas and Loukkos essential oils against male beetles ranged from, respectively, 46.53 to 1.19 µl/l air and 58.85 to 11.57 µl/l air. Similarly, doses of R. officinalis essential oils from Middle Atlas and Loukkos lethal to females, ranged from 44.6 to 2.08 µl/l air and from 53.00 to 5.38 µl/l air, respectively. Additionally, the lethal time (LT50 and LT99) of exposed adults ranged from 1–8 and from 2–13 days for different concentrations of R. officinalis essential oils from Middle Atlas and Loukkos, respectively. With no mortality recorded in the control groups, these findings demonstrate the fumigant potential of these oils against this bruchid under the storage conditions.

The present study was undertaken to determine the nutritional value of the fifth instar larva of Bombyx mori, locally referred to as ‘Niang ryndai’, which is a popular edible silkworm among the local inhabitants of East and West Khasi Hills and Ri-Bhoi district. Larvae were collected from the Iewduh market of Shillong in the months of October and November as these larvae are available during these months. The composition of lipids, amino acids and the fat-soluble vitamins A and E in the frozen and oven-dried samples of B. mori was estimated and compared with that of conventional food items. The detection of the fatty acids eicosapentaenoic acid and docosahexaenoic acid in the larva indicates its potential to support a healthy cardiovascular function. Because of their use for the production of silk yarn, silkworms have economic potential for the people of the State and north-eastern region of India. Increased appreciation of this insect as an alternative and cheap source of nutrition would contribute to the socio-economic development of the indigenous people.

Feeding of the adult parasite of Trichogramma evanescens Westwood on a honey solution containing 500 μg of Bacillus thuringiensis var. galleriae HD-129 for 4–5 days had no effect on their longevity, productivity or their capability to parasitize the host eggs of Spodoptera littoralis (Boisdüvalle) or Anagasta kuehniella Zeller. After spraying the freshly laid host eggs with B. thuringiensis at the same concentration, a significant decrease was observed in the percentage of parasitism. No deleterious effects were observed in the development of the immature stages of the parasite and the percentage of its emergence, as affected by B. thuringiensis, when applied to the host eggs before or after parasitism.

About 20 species of borers are rice pests. Of these, five—yellow borer, striped borer, white borer, dark-headed borer, and pink borer—are of economic importance. Yellow borer and striped borer occur most widely in Asia and cause serious yield losses.

Varietal resistance to these two species has been investigated during the last 30 years. Field and greenhouse screening techniques have been developed and numerous germplasm entries have been evaluated for resistance. Several hundred varieties with low to moderate levels of resistance have been identified. Except for several wild species of Oryza, germplasm with a high level of resistance has not been found.

Information available to date indicates that the resistance is under polygenic control. Moderate levels of resistance from several donor parents have been incorporated into improved varieties. Some of these moderately resistant varieties, for example, IR20, IR36, IR50, Ratna and Chandina, are widely grown and play an important role in integrated pest management programs for stem-borer control. Efforts to develop cultivars with levels of resistance higher than presently grown varieties are under way using the diallel selective mating system and the male sterile facilitated recurrent selection schemes.

Mutualistic bacterial endosymbionts provide many benefits to their insect hosts, but their role in mating has not been studied in the past. In this study, we examined copulatory success and mating latency as two parameters of mating success to assess the influence of Candidatus Erwinia dacicola on mating between a laboratory population of olive flies (Bactrocera oleae Rossi) of Israel origin and a wild population of olive flies from Israel. Previous studies have shown that in many species of tephritid flies, laboratory-reared males have lower fitness and achieve fewer matings than wild males. Our research has shown that this Israeli population of olive flies reared in the laboratory on an artificial diet lacked an endosymbiont, Ca. E. dacicola, found in wild-caught insects from Israel. We hypothesized that decreased fitness and mating ability in laboratory-reared flies could be due to the absence of this endosymbiont. Mating assays between both sexes of these two Israeli populations revealed matings to occur primarily between laboratory-reared females and wild males. Laboratory-reared males achieved only 22% of the total matings. Candidatus Erwinia dacicola was found in significantly fewer insects from the laboratory population than in the wild population; within populations, male and female olive flies were equally likely to have the endosymbiont. However, differences in readiness to mate between the two populations, and not the presence of the endosymbiont, explained mating latency.

Biotypes refer to the infraspecific category of insect populations with similar genotypes for biological attributes. They have been encountered mostly in association with cultivation of resistant crop cultivars and in well-studied cases a gene-for-gene relationship between pest virulence and host plant resistance has been documented. To date, biotypes have been reported to occur in 36 crop pest species belonging to 17 arthropod families in six Orders. Almost 50% of these pest species with known biotypes are aphids. Knowledge of occurrence of insect biotypes is crucial to the success of crop improvement programmes aiming to incorporate pest resistance. Biotypes represent evolutionary transients in the process of speciation and develop through natural selection acting upon genetic variations within the pest populations. To slow down the process of biotype selection, crop cultivars with broad genetic bases are needed.

The spotted pod borer Maruca vitrata (Geyer) is known for its economic importance throughout its geographical distribution because of its destructive nature to reproductive parts of several grain legume crops including pigeonpea. In view of the importance of the pest, the present study was carried out on the association of different morpho-chemical traits with resistance/susceptibility to M. vitrata at the International Crops Research Institute for the Semi-Arid Tropics, Patancheru, India. Trichome length and density, sugars, proteins and phenols were found to be associated with resistance to M. vitrata in short-duration pigeonpea genotypes. Pod damage by M. vitrata on different short-duration pigeonpea genotypes in the field ranged from 5.8 to 68%. Laboratory studies showed less consumption of food and reduced larval and pupal weights of M. vitrata when reared on the resistant genotypes ICPL 98003 and ICPL 98008 indicating antibiosis effects of the genotypes. Trichome density on upper and lower surfaces of the leaf (390 and 452/9 mm2), and length (3.5 mm) and trichome density (442/9 mm2) and length (5.9 mm) on pods were found positively correlated with the resistant genotype ICPL 98003. High sugar content in flowers (22%) and pods (10.6%) was responsible for the susceptibility of ICPL 88034, while high phenol concentration in flowers (6.5%) and pods (9.3%) in ICPL 98003 was responsible for resistance. Protein content in pods was significantly higher (25.5%) in susceptible ICPL 88034 when compared with resistant ICPL 98003 (16.5%). Based on these results, ICPL 98003 and ICPL 98008 were categorized as highly resistant and ICPL 98012 as moderately resistant. This paper discusses the physico-chemical traits associated with resistance to M. vitrata in short-duration pigeonpea genotypes.

The termite Macrotermes subhyalinus (Rambur) builds large earthen mounds of many different types, two of which are described in detail here. As far as is known at present, the two types occur in different areas. The main difference is in the ventilation system. In one, the Bissel type, there are many holes connected up inside the mound in such a way that external air is drawn through the passages and cools the interior of the mound. The other, the Marigat type, has only one large opening raised to a considerable height above the ground so that air is drawn out at the top, and drawn in from the surrounding soil through underground foraging passages.

Biotic factors (including insect pests) constrain field-grown tomato production in Senegal. However, little information is available on the identity and life system of key pests. The objectives of this study were to: (i) update key pest records of field-grown tomato in the central vegetable-producing area along the northern coast of Senegal, known as the Niayes area; (ii) map their spatial and temporal incidence and (iii) understand insecticide use by growers to control the pests. A total of 98 tomato fields distributed in three zones along a north–south transect in the Niayes area were monitored over four crop cycles from 2012 to 2014. As expected, the tomato fruitworm Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) was the most destructive pest with an occurrence of 92% in sampled fields (90/98) and up to 38% damaged fruits in one field at the time of sampling. The proportion of damaged fruits did not differ among zones, but was significantly higher in the early dry season compared to the late dry season. The invasive tomato leafminer Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) was detected in 53% of sampled fields (52/98), mainly in the south of the Niayes area in the late dry season. Because of their ability to adapt to unstable environment and insecticides, this insect pest assemblage is a new challenge that farmers have to deal with while decreasing their use of broad-spectrum insecticides.

Cacao mirids (Sahlbergella singularis, Distantiella theobroma and Bryocoropsis laticollis) were captured in pheromone traps releasing a 2:1 blend of the sex pheromone components of the two first named species in a series of five experiments on cacao (Theobroma cacao) plantations in Ghana. A total of 835 cacao mirids were caught, all male, 95% of which were S. singularis, 3% D. theobroma and 2% B. laticollis. Two sticky trap and two water trap designs made from locally available materials were as effective for capturing S. singularis and total mirids as the best sticky trap from previously reported studies. Coating the outer surface of a large water trap with sticker increased the catch 4.4×, and 2.7× for a cylindrical sticky trap. Sticker on the outside of the water trap also increased the inside catch of S. singularis by 76% and total mirids by 71%. The numbers of S. singularis and D. theobroma trapped increased with increasing trap elevation and were highest around canopy level. Those traps caught an average 12× more mirids than traps at 1.8 m, the height recommended currently. Therefore, large water traps coated with sticker and aligned with the cacao canopy should raise the current capture rates of pheromone traps for cacao mirids about 50×, which may be sufficient for effective pest management by mass trapping without synthetic insecticides.

Rather than a true adaptive process, laboratory colonization is proposed to depend on the plasticity of the tolerance limits in insect species. Insects will establish successfully in captivity if the magnitude of environmental variables are within the insects' ranges of colonization. Optimum physiological and behavioural responses are obtained when the variables are within the smaller preferred range of colonization. Other concomitant processes at colonization are selection, acclimatization and domestication. Definition of the terms “adaptation”, “acclimatization” and “domestication”, commonly misused in describing processes during laboratory colonization are proposed.

Adparaproba gabrieli Carvalho is a phytophagous neotropical bug with a restricted distribution to southeast Brazil. The histology of the digestive system and that of the male and female reproductive tracts of A. gabrieli was studied. We found that the male had a pair of testes with two follicles per testis, two short vasa defentia that joined in a muscular ejaculatory duct with two pairs of well-developed accessory glands. The female has a meroistic telotrophic ovary with three ovarioles per ovary. There is a pair of sac-like salivary glands. The digestive tract, after the pharynx, has a long, thin oesophagus ending in a muscular proventriculus. The transition fore-midgut is marked by a stomodeal valve, and the midgut is the main organ with an anterior portion with columnar cells and an posterior one with flattened cells. The hindgut is short and differentiated in the ileum and rectum. The Malpighian tubules are also described and the phytophagous feeding habit of A. gabrieli is discussed.

The application of the sterile insect technique to fruit flies involves the mass-production of the pest insects using an artificial diet, irradiation during a narrow time window at the late pupal or early imaginal stage to inhibit reproduction without affecting reproductive capacity, and then release into the target area where the sterile insects compete reproductively with their wild counterparts. The timing of irradiation is important to enable the release of males that are sterile but of good quality and exhibit an acceptable sexual performance. In this study, we examined the pupal development of 12 tephritid (Diptera: Tephritidae) species: Anastrepha fraterculus (Wiedemann), A. ludens (Loew), A. obliqua (Macquart), A. serpentina (Wiedemann), Bactrocera cucurbitae (Coquillett), B. dorsalis (Hendel), B. invadens (Drew, Tsuruta & White), B. oleae (Rossi), B. philippinensis (Drew & Hancock), B. tryoni (Froggatt), B. zonata (Saunders) and Ceratitis capitata (Wiedemann). The insects were reared at various temperatures, in the laboratory (15–28 °C) and under fluctuating natural conditions (20–35 °C). The gradual colour changes of the insect eyes during metamorphosis were observed and photographed, measuring the specific eye colour parameters of each species and matching them with the colour scale of the Munsell Soil Color Charts. The duration of pupal development and the time to emergence in Anastrepha species were longer than those in C. capitata and Bactrocera species at all the holding temperatures. The data obtained can be used by mass-rearing facilities to manage pupal holding conditions and as indicators for optimizing the timing of irradiation.

Investigations were conducted to establish the magnitude and pattern of differential expression of proteins due to generational selection of third instar Anopheles gambiae s.s. Giles larvae by cadmium, copper and lead heavy metals, the three possible common urban pollutants.

A susceptible strain of A. gambiae s.s. third instar larvae was separately placed under selection pressure with cadmium, copper and lead at LC30 and controls through five generations. First, third and fifth generation selection survivors were screened for differentially expressed proteins relative to non-exposed control by two-dimensional gel electrophoresis. Distribution patterns of the spots were analyzed by χ2 or Fishers' exact test and variations in expressions between and within generations by ANOVA. Most differentially expressed spots were acidic and of low molecular weight among all metals and generations. Type of heavy metal and generation were the main indicators of variations in differential expressions. Variation between generations was most significant among cadmium-selected populations of which the most number of spots were induced in the fifth generation. Most spots were induced in the copper-selected population in the third generation. The induced protein spots may be the products from respective genes that respond to heavy metals and counter their toxicity, thus building A. gambiae s.s. tolerance to these pollutants. The differential pattern and magnitude of expressed spots have potential application as molecular markers for assessment of anopheline adaptation status to heavy metals, and provide insight into the extent of environmental pollution.

Five natural compounds possessing antiparasitic activity were isolated from East African plants and tested, together with some semisynthetic derivatives, against micro-organisms and arthropods of agricultural interest. Anonaine (1), from Annona squamosa, canthin-6-one(8) and 5-methoxycanthin-6-one (9), from Fagaropsis angolensis, showed fungicidal activity. E,Z-matricarianol (4), from Hoehnelia vernonioides was fungicidal, Insecticidal and acarlcldal. Caryophyllene oxide (12), isolated from Uvaria sp., turned out to be insecticidal and antifeedant. Canthin-6-one (8) and its dihydroderivative 11 were the most effective antimicrobial compounds tested. The possibility ofusing some of the isolated compounds as leads for new synthetic chemicals is discussed.

The influence of larval diet, body weight at imago, size of blood-meal and age on the fecundity of Culex quinquefasciatus was investigated. The mean weights of mosquitoes at adult emergence varied significantly with larval diet. Larvae reared on liver diet grew into heavier adults, and produced more eggs than those reared on milk. The volume of blood engorged by the female mosquitoes apparently remains constant during each gonotrophic cycle. However, the number of eggs produced is a function of both the blood-meal size and age of the mosquitoes. These results were discussed in relation to the need for full knowledge of the reproductive potential of this species of filaria vectors.

The spatial distribution of Bactrocera fruit flies in the Goa region (west coast of India) was studied using several dispersion parameters between April 2006 and March 2008 in three ecological zones, viz. coastal, midland and upland. These zones are 10, 25 and 50 km to the east from the coastline of the Arabian Sea at an elevation of 15, 70 and 100 m above mean sea level, respectively. The dispersion parameters revealed that the population of all the fruit fly species attracted to methyl eugenol-baited traps, viz. Bactrocera dorsalis, Bactrocera caryeae, Bactrocera zonata, Bactrocera affinis and Bactrocera correcta, followed the negative binomial distribution pattern and was highly aggregated or clumped.

A study was conducted at Mtwapa in the northern coastal area of Kenya during the long and short rainy seasons of 1999 and 2000 to assess the benefits of agroecosystem diversification—through agroforestry and intercropping—on the activity of natural enemies of maize stemborers. Treatments consisted of maize and cowpea intercrops or maize monocrops planted within hedgerows of Leucaena leucocephala and Gliricidia sepium. The plots were mulched or unmulched and insecticide-treated or not. The maize stemborers encountered, in order of abundance, were Chilo partellus, Chilo orichalcociliellus and Sesamia calamistis. The egg parasitoids Trichogramma spp. and Telenomus spp. were recovered from stemborer eggs. Ants, ladybird beetles, earwigs and crab spiders were found predating on the eggs. The larval parasitoids recovered included Cotesia sesamiae, Cotesia flavipes and Goniozus indicus, and the pupal parasitoid was Pediobius furvus. Mean rates of stemborer egg parasitism were generally high (>70%) while larval and pupal parasitism rates were low (<10%) for all the treatments. The observed rates of parasitism did not support the natural enemies hypothesis, which predicts that natural enemy activity increases with increasing agroecosystem diversity. Predation, larval and pupal mortality rates were generally low in all the treatments (<10%), with no significant differences between treatments.

Little is known about phase polymorphism in the red locust, Nomadacris septemfasciata (Serville) in Madagascar, despite its economic importance. Only solitary and transiens forms have been reported from the island earlier, but not the gregarious form. Important recent outbreaks have allowed for the studying of the phase polymorphism under experimental and field conditions. Morphometric differences (pronotum size and shape, and F/C and E/F ratios) were noted among hoppers and adults caged for several generations and at various densities, in a field laboratory. These criteria were later used to study adults collected in different areas between 1996 and 2002, from populations with various densities (<1000 to >25,000 imagos/ha). Morphometric measurements revealed that gregarious red locust populations have existed naturally in Madagascar and that these were erroneously classified as transiens forms. The upper threshold density for the solitary phase was estimated at 5000 adults/ha; beyond this limit, locusts develop either into transiens or into highly gregarious forms. The southern part of the island, known as a red locust outbreak area, has harboured gregarious phases despite previous reports that prevailing ecological conditions are not suitable for its complete phase transformation. Deforestation in the northern part of the island has probably led to new favourable biotopes for serious outbreaks and gregarious populations development.