Scirtothrips dorsalis Hood is a polyphagous species and an important sucking pest of tea (Camellia sinensis) (Theaceae). The fitness traits of S. dorsalis on two alternative host plants: Capsicum annuum L. (chilli) (Solanaceae) and Ricinus communis (castor oil plant) (Euphorbiaceae) and on C. sinensis and corresponding levels of defence enzymes was studied. The study revealed that C. sinensis is the more suitable host of S. dorsalis based on faster development (13.6 days) compared to the alternative hosts, C. annuum (15.5 days) and R. communis (16.7 days), a higher fecundity (C. sinensis: 11.4 eggs; C. annuum: 9.7 eggs; R. communis: 8.6 eggs), and superior egg hatchability (C. sinensis, 92.6%; C. annuum: 82.5%; and R. communis: 74.6%). The host-based variation in the fitness traits of S. dorsalis corroborated in light of differential activity of three major detoxifying enzymes, such as the general esterases (GEs), glutathione S-transferases (GSTs), and cytochrome P450 mediated monooxygenases (CYPs). Densitometric analysis of GEs showed five esterase isozymes (EST I–V) with retardation factor (Rf) values of 0.17, 0.22, 0.27, 0.35 and 0.52, respectively. The pixel density, and accordingly the profile height, varied in different host-specific S. dorsalis. A significant variation of the quantity of these enzymes was also apparent in the insect when reared on the three hosts. A 2.4 and 2.7, 1.6 and 2.0, and 2.0 and 2.3-fold higher GEs, GSTs and CYPs activity on the two non-tea hosts possibly signify a predisposition of the species for higher tolerance to insecticides, enabling the pest to switch to tea where synthetic insecticides are routinely used.

Recognition of Anopheles mid-gut molecules interacting with the malaria parasite is important as they can potentially be targeted to interrupt the life cycle of the parasite in the mosquito's body. The mid-gut of mosquitoes is covered with the glycocalyx, which is composed of various glycoproteins. Pieces of evidence show that mucin proteins are one of the most frequent ingredients of the glycocalyx. In the present study, we isolated and identified the sequence of mucin from the mid-gut of Anopheles stephensi, Liston and Kazerun strains. Anopheles stephensi mucin (AsMuc) has two central core repeats with the consensus sequence TTTTVAP flanked with a hydrophobic N-terminus and a C-terminus which it seems are both necessary for cell surface expression. To show if this molecule is expressed on the surface of the cell, we cloned AsMuc in a baculovirus vector and tracked the expression of the protein in Sf9 insect cells. Immune assays showed the surface localization of the recombinant mucin. AsMuc expression on the surface of the cell suggests it could be a potential ligand for Plasmodium spp. attachment to the Anopheles mid-gut.

Understanding the impact of altitude and ecological heterogeneity at a fine scale on the populations of malaria vectors is essential to better understand and anticipate eventual epidemiological changes. It could help to evaluate the spread of alleles conferring resistance to insecticides and also determine any increased entomological risk of transmission in highlands due to global warming. We used microsatellite markers to measure the effect of altitude and distance on the population genetic structure of Anopheles funestus and Anopheles gambiae s.s. in the Muheza area in the north-eastern part of Tanzania (seven loci for each species). Our analysis reveals strong gene flow between the different populations of An. funestus from lowland and highland areas, as well as between populations of An. gambiae sampled in the lowland area. These results highlight for An. funestus the absence of a significant spatial subpopulation structuring at small-scale, despite a steep ecological and altitudinal cline. Our findings are important in the understanding of the possible spread of alleles conferring insecticide resistance through mosquito populations. Such information is essential for vector control programmes to avoid the rapid spread and fixation of resistance in mosquito populations.

Sustainable pest management requires the use of ecosystem-friendly control options (e.g. entomopathogens) coupled with target-specific application methods. Here we investigate the susceptibility of the sorghum chafer (Pachnoda interrupta, Olivier) to Metarhizium sp., isolated from dead P. interrupta under field conditions over several years. Target-specific trapping was achieved using Japanese beetle traps or locally made autoinoculation devices, with methyl salicylate or banana as an attractant. Of the attracted and infected beetles, 49% mortality was achieved during October 2005 and 71% during July 2006, while the corresponding mortality in control treatments was 13 and 5%, respectively. We further confirmed that the mortality of the beetles was due to the fungal treatment as 50 and 80% of the dead beetles showed mycosis, respectively. The performance of the pathogen was also investigated in an autodissemination device in 2008 and 2009, where the beetles that were attracted passed through an inoculation chamber. Of the attracted and infected beetles in the autodissemination device, 58.5% (October) and 90.9% (July) were dead within 15 days after treatment. Control mortality was only 3 and 2%, respectively. The potential for horizontal transmission was investigated, where 47% (October) and 59% (July) of the beetles exposed to the pathogen through horizontal transmission were killed. The pathogen was found to be viable for more than 3 days in the field. Our results show that Metarhizium sp. has potential as a biological control agent, and for achieving autodissemination using the target pest as the vector.

The antestia bug Antestiopsis thunbergii (Gmelin 1790) is a major coffee pest in East Africa. Nymphs and adults feed on all vegetative and fruiting parts of the coffee tree leading to yield reduction and poor quality of coffee beans. Our study aimed to characterize the developmental biology and provide life table parameters for A. thunbergii reared in the laboratory. The biology of A. thunbergii was studied at four constant temperatures of 20, 25, 30 and 35°C with 80±5% RH and a photoperiod of L:D 12:12. Complete development of A. thunbergii from egg to adult occurred between 20 and 30°C, while eggs did not hatch at 35°C. Immature stage development time decreased significantly with an increase in temperature, with the exception of fifth nymphal stage, duration of which was similar for all temperatures. The fecundity was maximal at 20°C with an average of 132.8 eggs per female and 1.7 egg per female per day. The gross reproductive rate (GRR) was the highest at 20°C with 75.79 daughters per female compared to 19.56 and 2.69 daughters per female at 25 and 30°C, respectively. The intrinsic rate of increase r was maximal at 20°C with 0.013 and negative at 30°C. The time required for the reared population to double (doubling time Td) was shorter at 20°C with 53.31 days compared to 115.52 days at 25°C. Our study provides basic information on A. thunbergii biology that will contribute to a better understanding of the pest distribution and dynamics on arabica coffee in East Africa.

We assessed the host stage preference and performance of the aphid parasitoid Diaeretiella rapae (McIntosh) on two aphid species, Brevicoryne brassicae (L.) and Lipaphis pseudobrassicae (Davis). Although the parasitoid parasitized all nymphal instars of both aphid species, it showed a higher oviposition preference for 2nd (48.2 ± 7.74%) and 3rd (41.0 ± 7.82%) instars of L. pseudobrassicae, and for the 3rd (40.0 ± 4.59%) instar of B. brassicae. Across the host species, there was no significant difference in parasitoid preference between the 3rd and 4th instars, while 1st and 2nd instars of L. pseudobrassicae were significantly more preferred than their counterparts (B. brassicae). Days to mummification among different instars of the same host was not significantly different when the parasitoid was reared on B. brassicae, whereas this was highest on the 2nd, 3rd and 4th instars of L. pseudobrassicae. Number of mummies was also significantly different among the nymphal instars of both host species and between the two host species for the 1st and 2nd instars. In terms of body size, female D. rapae reared on L. pseudobrassicae were significantly larger than those reared on B. brassicae. We discuss the findings in the context of laboratory mass rearing of D. rapae and its potential as a biological control agent for both aphid pest species.

Diversity amongst the different populations is one of the problems in the control of medically important mosquitoes. Wing morphometry was used to identify within-species variation amongst some populations of Aedes aegypti in three areas of Lagos State, Nigeria. Ten landmarks on the right wing of adult female Ae. aegypti mosquitoes were digitized using TPSdig software. Relative distances of the veins and interpoints were calculated as well as the Euclidean distances based on these relative distances. In three (50%) of the interpoints, the relative distances were significant (P<0.05) to both the Brown–Forsythe F ratio and Welch ANOVA. The highest Euclidean distance of 7.738 was between Ebute Metta 2 and Badagry; the lowest of 4.426 was between Ikorodu and Ebute Metta 2. The distance between Ebute Metta 1 and Ebute Metta 2 was 5.867, which is more than the distance between Ebute Metta 2 and Ikorodu. Three groups of Ae. aegypti were identified, and the differences in lengths and interpoints observed on the wing veins suggest a possible morphological divergence amongst populations.

Aulacophora foveicollis Lucas causes economic losses to creeping cucumber [Solena amplexicaulis (Lam.) Gandhi] growers in India and Bangladesh because adults feed on the leaves and flowers causing death of the plant. The insect is a generalist herbivore as it also causes damage to pumpkin, bottle gourd, sponge-gourd and gac fruit production by feeding on leaves and flowers of these plants. At present, insects are controlled with insecticides, which are harmful to human health and the environment. We studied the behavioural responses of adult A. foveicollis to flower surface waxes and synthetic compounds mimicking flower surface waxes to determine their potential for monitoring this pest. The gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) analyses of S. amplexicaulis flower (50 g) surface waxes indicated presence of 17.9 and 3.1 mg alkanes and free fatty acids, respectively. Seventeen n-alkanes from n-C15 to n-C34 and 16 free fatty acids from C10:0 to C22:0 were detected in the flower surface waxes. Heptacosane was predominant among n-alkanes representing 2748.1 µg; whereas, pentadecanoic acid was the major fatty acid accounting for 466.6 µg. Aulacophora foveicollis were attracted to the flower surface waxes at concentrations of 4 to 8 μg/ml, as demonstrated by a Y-tube olfactometer bioassay. Using a dose response bioassay, the insect was shown to be attracted to individual synthetic pentadecane, heptacosane, nonacosane, undecanoic acid and nonadecanoic acid at 0.70, 0.70, 1.20, 1.60 and 1.40 µg/ml, respectively. The insect displayed highest attraction to a synthetic mixture of 0.70, 1.23, 0.77, 0.84, 0.94 and 0.74 µg/ml of pentadecane, heptacosane, nonacosane, undecanoic acid, lauric acid and nonadecanoic acid, respectively, and hence, this combination might be used for insect pest management such as in baited traps.

Annual losses of cocoa in Ghana from mirids are significant; therefore, accurate timing of insecticide application is critical to enhance yields. However, cocoa farmers often lack information on the expected mirid population for each season to enable them to optimize pesticide use. This study assessed farmers' knowledge and perceptions of mirid control and their willingness to use forecasting systems informing them of the expected mirid peaks and the time of pesticide application. A total of 280 farmers were interviewed in the Eastern and Ashanti regions of Ghana with a structured open- and closed-ended questionnaire. Most farmers (87%) considered mirids the most important insect pest on cocoa, with 47% of them attributing 30–40% of annual crop losses to mirid damage. There was a wide variation in the timing of insecticide application as a result of farmers using different sources of information to guide the start of application. The majority of farmers (56%) did not have access to information about the type, frequency and timing of insecticide use. However, respondents who were members of farmer groups had better access to such information. Extension officers were the preferred channel for information transfer to farmers, with 72% of farmers preferring them to other available methods of communication. Almost all the respondents (99%) saw the need for a comprehensive forecasting system to help farmers manage cocoa mirids. The importance of the accurate timing of mirid control based on forecasted information to farmer groups and extension officers is discussed.

We evaluated an aqueous extract of Duranta repens L. in the laboratory against the tea red spider mite, Oligonychus coffeae Nietner, to determine its effect on adult mortality, viability of eggs, oviposition deterrence and repellent properties. We also evaluated the same extract in the field to determine its effect on mite populations. The direct spray method was used in the laboratory at concentrations of 2, 4, 6, 8 and 10 g/l. Mortality of O. coffeae was dependent on both concentration and time after application. Deposition of eggs by adult mites on treated leaf surfaces decreased and the viability of eggs was also reduced. Its bioefficacy was comparable to that of the commonly used commercial neem oil formulation (azadirachtin 0.03EC). In addition, different concentrations of the aqueous extract of D. repens also exhibited repellent properties against adult mites. In the field, the application of the aqueous extract of D. repens reduced the mite population and its bioefficacy was comparable to that of the synthetic pesticide Propargite 57 EC. No phytotoxic effect was observed when tea bushes were sprayed with different concentrations of D. repens. Tea samples were taint free. Treatment of plants with the extract did not affect the quality (appearance of liquor, flavour, taint and taste) of made tea. Availability and distribution of this plant in and around tea growing areas of Assam, along with its processing, and the possibility of including D. repens extracts in the current IPM programme are discussed.

The Asian tiger mosquito, Aedes albopictus (Skuse) and the yellow fever mosquito, Aedes aegypti (Linnaeus) are medically important species that vector several arboviruses. Globally, populations of both species experience (and are sensitive to) photoperiodic variations. The present study aims to test if photoperiod regimes affect the population performance of Ae. albopictus and Ae. aegypti. Since mosquitoes have sex-specific strategies to maximize fitness, we also tested the hypothesis that Ae. albopictus and Ae. aegypti would exhibit differences in the male and female response (sexually dimorphic response) to various photoperiod treatments. We reared cohorts of first instar larvae to adulthood in three photoperiod treatments: short day (10 h light), control (12 h light) and long day (14 h light). We measured and compared survival to adulthood, population growth, development time of males and females, and wing length across treatments. Although we detected no effects of photoperiod on the population performance of both species, we found evidence of a sexual dimorphic response to photoperiod in Ae. albopictus, but not in Ae. aegypti, with Ae. albopictus females being more sensitive to variations in photoperiod. The observed differences between sexes of Ae. albopictus are consistent with sex-specific developmental constraints. The absence of a sexually dimorphic response to photoperiod in Ae. aegypti can be attributed to different strategies evolved in this species to prepare for unfavourable conditions associated with shorter day length. We discuss the ecological and medical implications of our findings.

Termites are an important component of savannah ecosystems throughout Africa. Despite their importance in the ecosystem, they can be serious pests of structures, houses, rangelands, tropical forestry, and agriculture. For many decades, chemical insecticides have remained popular for termite management worldwide. However, with the growing environmental concerns over pesticides, biological control using entomopathogenic fungi such as Metarhizium anisopliae (Metschnikoff) Sorokin has become an often-considered alternative. Metarhizium anisopliae is an ubiquitous, naturally occurring pathogen, which has been reported infecting over 200 insect species; therefore, there is concern that use of M. anisopliae may affect non-target organisms. The effects of M. anisopliae isolate ICIPE 30 were experimentally tested on the ants which associate with Odontotermes spp. termite mounds. Laboratory bioassays were carried out to assess the effects of direct exposure to M. anisopliae on Crematogaster mimosae and Camponotus spp. In addition, ant diversity was monitored over 18 months from termite mounds treated with M. anisopliae in situ near the Mpala Research Centre in Laikipia District of central Kenya. Results obtained revealed no effects of direct exposure to M. anisopliae isolate ICIPE 30 on the mortality of C. mimosae (F1 = 7.29, P = 0.0072) or Camponotus spp. (F1 = 13.01, P = 0.0004) in the laboratory. No significant difference in Shannon indices of ant diversity from treated and untreated mounds (F1 = 0.016, P = 0.8989) was found. It is evident that M. anisopliae has no negative effects on ants that are associated with Odontotermes spp. termites.

Glossina pallidipes, a widely but discontinuously distributed African savanna species, is one of the economically important tsetse flies because it is a vector of trypanosomiasis, a lethal disease of cattle and other domestic animals. DNA sequences of ribosomal (r16S2, 249 bp) and cytochrome oxidase I (COI, 421 bp) concatenated mitochondrial genes were analysed in 23 geographically diverse samples of G. pallidipes from Ethiopia, Kenya, Tanzania, Zambia and Zimbabwe. Among 873 flies, we detected 181 composite haplotypes and found that their spatial diversities and frequency distributions were heterogeneous. Haplotype and nucleotide diversities were greatest in Ethiopia and least in southern Africa. We observed little haplotype and nucleotide diversity among regions, and detected severely limited maternal gene flow among the sampled populations (ΦST= 0.42). Tests for demographic stability and analysis of mismatch distributions revealed regionally contrasting demographic histories. The Ethiopian populations were phylogenetically the oldest and genetically the most diverse, and exhibited successive waves of contraction and expansion. The southern African populations were phylogenetically the youngest and genetically the least diverse, and showed only a single, recent expansion. Likely ecological correlates of historical tsetse fly demography include population suppression trials in East Africa and recurring rinderpest epizootics in southern Africa, beginning in the late nineteenth century that reduced host mammalian populations.

An invasive pest, Tuta absoluta (Meyrick) has been observed infesting tomato Solanum lycopersicum L. (Solanales: Solanaceae) in Central Uganda. The affected farmer made the report, and upon visiting the farm, we observed tiny larvae, green to cream in colour with a black head feeding on tomato leaves, fruit, as well as tender stems. Also, we saw several tiny moths resting on screen house linings. Delta traps baited with TUA-Optima® (Russell IPM) were set in and around the affected farm. Dozens of moths were attracted and trapped on the sticky surface of the traps. The team tentatively identified the insect as T. absoluta. Scientists at the International Centre of Insect Physiology and Ecology (icipe) in Nairobi, Kenya identified the insect using morphological features and molecular techniques.

This study on predispersal seed predation of the leguminous species Vachellia abyssinica (Hochst. Ex. Benth.) Kyal & Boatwr., Senegalia senegal (L.) Britton, Vachellia seyal (Del.) P.J.H. Hurter, and Vachellia tortilis (Forssk.) Galasso & Banfi was conducted around Lake Langano and Menagesha Forest in Ethiopia to identify the associated seed predators and determine their impact on seed germination. Eight seed beetles Bruchidius albosparsus (Fåhraeus, 1839), B. aurivillii (Blanc, 1889), B. djemensis Decelle 1971, B. discoidalis (Fåhraeus, 1839), B. sinaitus (K. Daniel, 1907), B. silaceus (Fåhraeus, 1839), B. sp 411, B. simulans (Anton and Delobel, 2003), and one unidentified species of Cerambycidae were found associated with seeds of these Acacia species. These predators damaged less than 9% of seeds of these species, which exhibited lower germination. This study provides unrecorded lists of predispersal seed predators associated with seeds of Vachellia and Senegalia species in Ethiopia, and some associations are new. There is need to assess the distribution, abundance and effects of predispersal seed predators on other Vachellia, as well as other tree species.

New data on bat ectoparasites from Mindoro Island, Philippines are reported. Eighty-three individuals of ectoparasitic insects representing seven species of Nycteribiidae and five species of Streblidae (both Diptera), and one species of Ischnopsyllidae (Siphonaptera) were recorded from 11 bat species captured in Naujan Lake National Park, Mindoro Oriental Province, Philippines. Raymondia pagodarum is a new record for the country. Eight species are also newly recorded for Mindoro Island, including Cyclopodia garrula, Leptocyclopodia ferrarii mabuhai, Megastrebla parvior, Brachytarsina amboinensis, B. werneri, R. pagodarum, R. pseudopagodarum and Thaumapsylla longiforceps. Five species are newly documented on various hosts: C. horsfieldi on Pteropus pumilus, M. parvior on Macroglossus minimus, B. amboinensis on Hipposideros diadema, B. werneri on Rhinolophus arcuatus and R. pagodarum on Hipposideros bicolor.

The influence of young, mature and senescent leaves of bitter gourd Momordica charantia L. (Cucurbitaceae) on the feeding, growth and reproduction of Epilachna dodecastigma (Weid.) (Coleoptera: Coccinellidae) were studied under laboratory conditions (27 ± 0.5 °C, 12 h light: 12 h dark photoperiod, 65 ± 5% RH). Larval developmental time of E. dodecastigma was longest on senescent leaves followed by young and mature leaves, whereas the pupal period was shortest on young and mature leaves. The longevity of females was generally higher than males. Male and female longevity were highest on mature leaves and lowest on senescent leaves. Fecundity was highest on mature leaves followed by young and senescent leaves. The growth and development of E. dodecastigma were related with nutrient and phenol content of three types of bitter gourd leaves. Carbohydrate content was higher in young and mature leaves, whereas protein, nitrogen, amino acid and lipid content were in greater quantities in mature leaves followed by young and senescent leaves. Phenol content was greatest in senescent leaves and least in mature leaves. Higher level of carbohydrates, proteins, lipids, nitrogen and amino acids including water content and lower phenol content of mature leaves had influenced higher growth rate and fecundity of E. dodecastigma.

A total of 39 strains of Anopheles stephensi, an important urban malaria vector, were collected from various parts of India and maintained in the insectary for this study. Based on the egg-float ridge number, 19 strains were classified into ecological variants and 32 strains were exposed to chlorpyrifos and propoxur to investigate their resistance status. Filter paper containing freshly laid eggs was taken, the ridge numbers on the floats were counted under the microscope, and strains were classified into ecological variants. Of the 19 strains, 18 were of ‘type form’, with ridge numbers ranging from 15 to 21. The Papareddipalya (PRP) strain belonged to the ‘intermediate form’, with 14 to 17 ridge numbers. Larval bioassays were carried out according to the procedure of the WHO. For chlorpyrifos, the lowest LC50 value was 0.00107 mg/l (Padmanabhanagar strain) and the highest value was 0.0403 mg/l (GOA-A strain). Furthermore, the lowest LC90 value was 0.00368 mg/l (Delhi strain) and the highest was 0.1746 mg/l (GOA-A strain). For propoxur, the lowest LC50 value was 0.00029 mg/l (Goraguntepalya strain) and the highest value was 0.0037 mg/l (JP Nagar strain). Moreover, the lowest LC90 value was 0.00094 mg/l (Goraguntepalya strain) and the highest value was 0.0115 mg/l (JP Nagar strain). The tolerance values ranged from 1.26 to 37.68 for chlorpyrifos and from 1.34 to 12.77 for propoxur. All the type forms were from urban and semi-urban locations, and the intermediate strain was from a semi-urban location. The bioassay results indicated that the strains of An. stephensi were more susceptible to propoxur than to chlorpyrifos.

Herbivory by insects and mites on physic nut (Jatropha curcas L.) seedlings was investigated and compared with irrigation in the semi-arid Sahelian Niger, utilizing a randomized complete block design experiment. Three water treatment protocols were applied and the types of damage were recorded. Less than 5% of the seedlings died during the 10-month trial period with sap suckers causing the most damage on the surviving plants. Plants with high production of biomass and leaf cover (foliage) were most strongly positively correlated with irrigation and were also the plants that endured the highest degree of herbivory. The low dieback may indicate that defence mechanisms counteract seedling herbivory and that drought-stressed plants invest more in their defence mechanism system than vital plants.

We studied the food and habitat preferences of beetles of the subfamily Scarabaeinae in a protected tropical monsoon forest, the Wasgomuwa National Park in Sri Lanka. While gaining an insight into the capacity of different resources to support dung beetles, we tested the hypothesis that, in a landscape with a mosaic of habitat types and a diversity of large mammals, specialization facilitates coexistence of the scarabs. Pitfall traps were laid in five distinct habitat types (forest, riverine, sandy banks, scrub and grassland), and baited with five dung types (leopard, cervid, elephant, bear and buffalo). Four hundred and fifty seven beetles of 22 species in seven genera were recorded. Significant differences were seen in the species richness and abundance of dung beetles between different habitats and dung types, indicating habitat and food preferences. The highest richness of scarabs was in the riverine habitat and in leopard dung. Niche breath values of the individual species indicated differences in the degrees of specialization, while niche overlap values indicated a greater sharing of dung beetle species between similar habitats and dung types than between dissimilar ones. These findings provide evidence that selectivity of habitat, and dung, may be important in promoting coexistence among the scarabs in a tropical environment.