Aggregation pheromones have been identified and tested in the field for Frankliniella occidentalis and Thrips palmi. These pheromones are produced by adult males and attract both males and females. They are likely to be widespread across the Thripidae and identification is in progress for several other pest species. Aggregation pheromones are used commercially for monitoring and activation. Field trials have shown they can be cost effective for mass trapping when used as part of an integrated pest management (IPM) programme. Use for other approaches, such as lure and kill and mating disruption have not yet been tested. A better understanding of the role of these pheromones in the mating behaviour of thrips is needed and this may suggest further ways of developing their potential for pest management.

Maruca vitrata (Fabricius, 1787) is a cryptic pantropical species of Lepidoptera that are comprised of two unique strains that inhabit the American continents (New World strain) and regions spanning from Africa through to Southeast Asia and Northern Australia (Old World strain). In this study, we de novo assembled the complete mitochondrial genome sequence of the New World legume pod borer, M. vitrata, from shotgun sequence data generated on an Illumina HiSeq 2000. Phylogenomic comparisons were made with other previously published mitochondrial genome sequences from crambid moths, including the Old World strain of M. vitrata. The 15,385 bp M. vitrata (New World) sequence has an 80.7% A+T content and encodes the 13 protein-coding, 2 ribosomal RNA and 22 transfer RNA genes in the typical orientation and arrangement of lepidopteran mitochondrial DNAs. Mitochondrial genome-wide comparison between the New and Old World strains of M. vitrata detected 476 polymorphic sites (4.23% nucleotide divergence) with an excess of synonymous substitution as a result of purifying selection. Furthermore, this level of sequence variation suggests that these strains diverged from ~1.83 to 2.12 million years ago, assuming a linear rate of short-term substitution. The de novo assemblies of mitochondrial genomes from next-generation sequencing (NGS) reads provide readily available data for similar comparative studies.

The US Food and Drug Administration (US-FDA) uses the presence of filth and extraneous materials as one of the criteria in implementing regulatory actions and assessing food adulteration of public health importance. So far, 22 common pest species (‘Dirty 22’ species) have been considered by this agency for the spreading of foodborne illness, and their presence is an indicator of unsanitary conditions in food processing and storage facilities. Recently, we classified the ‘Dirty 22’ species into four groups: Group I (four cockroach species), Group II (two ant species), Group III (12 fly species), and Group IV (four rodent species), and described two molecular diagnostic methods for group-specific identification. We developed a PCR-RFLP assay based on rRNA gene for the detection and differentiation of Group I ‘Dirty 22’ species. Later, we designed three Group II ‘Dirty 22’ species-specific nested PCR primer sets and sequence characterized the rRNA, elongation factor 1-alpha (EF-1a), and wingless (WNT-1) loci. In this follow-up study, we have evaluated the robustness of five unique sets of published primers targeting the mitochondrial cytochrome oxidase I (COI) gene for insect barcoding. With modified PCR conditions, we successfully used COI barcoding for 18 members of Group I, Group II, and Group III ‘Dirty 22’ species. Results of this study reveal that COI barcoding is an effective tool for rapid identification of insects of Groups I, II, and III ‘Dirty 22’ species known to contaminate food and spread foodborne pathogens.

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.

Apis mellifera jemenitica, the only indigenous honey bee race of Saudi Arabia, is well adapted to the harsh local environmental conditions. A large-scale field survey was conducted to screen major Saudi Arabian beekeeping locations for infection by Paenibacillus larvae. Paenibacillus larvae is one of the major bacterial pathogens of honey bee broods and is the causative agent of American foulbrood disease. Larvae from samples suspected of infection were collected from different apiaries and homogenized in phosphate-buffered saline. Bacteria were isolated on MYPGP agar medium. Two bacterial isolates, ksuPL3 and ksuPL5 (16S rRNA GenBank accession numbers, KR780760 and KR780761, respectively), were subjected to molecular identification using P. larvae-specific primers. A BLAST sequence analysis revealed that the two isolates were P. larvae with more than 98% sequence identity. This detection of P. larvae in the indigenous honey bee is the first recorded incidence of this pathogen in Saudi Arabia. This study emphasizes the need for the relevant authorities to take immediate steps towards treating and limiting the spread of this disease throughout the country.

In Senegal, damage caused by insect pests is a major obstacle to seasonal stability and an increase in cabbage production. Little is known about the spatial and temporal distribution of cabbage pests, which makes the design of management recommendations to small-scale farmers challenging. The objectives of this study were to: (i) evaluate the status of insect pests observed in cabbage farmers’ fields; (ii) give information on the spatial and temporal distribution of key pests and (iii) assess the effect of temperature, insecticide applications, and host crop abundance on their incidence. A total of 116 cabbage fields were monitored for insect pests and related damage over four crop cycles, from October 2012 to May 2014, in the main vegetable producing area of Senegal (Niayes). The diamondback moth Plutella xylostella (L.) was by far the most important pest present in all the fields and with high levels of incidence (37.1% infested plants), particularly in the latter part of the dry season in the South of Niayes (50% infested plants). The cabbage webworm Hellula undalis (F.) was mainly observed in the early dry season in the south of Niayes, with an incidence of up to 12.5% infested plants. More surprising was the detection of the tomato fruit worm Helicoverpa armigera (Hübner), with damage of up to 9.4% of cabbage heads. The incidence of sucking pests such as whiteflies Bemisia tabaci (Gennadius), or aphids (including Lipaphis pseudobrassicae (Davis, 1914), Myzus persicae (Sulzer) or Brevicoryne brassicae (L.)) was generally low. The incidence of P. xylostella increased significantly with the number of insecticide applications, indicating that control deployed by growers was ineffective. The incidence of H. undalis did not depend on the number of insecticide applications, but significantly increased with host crop abundance and decreased with temperature. This study is a first step towards developing alternative pest management strategies in the framework of sustainable vegetable production systems.

Dengue vector control programmes are mainly focused on insecticide fogging/space spraying to control adult Aedes mosquito vector populations. Due to the diurnal habit of the vectors, spraying is routinely conducted during the day when many other insect species are also active. This study reports the simultaneous effect of fogging on non-target insects by direct counting of knockdown in the insect population. Eight fogging treatments were conducted in two sites in Kurunegala District of Sri Lanka. Pesguard insecticide was sprayed in each treatment for 8 minutes according to the standard methodology and the ‘knockdown insects’ were collected on randomly spread polyethythene sheets (10 m2). A total of 3884 insects (24.3 insects per treatment per m2) belonging to 12 orders were collected and 12.44% of them recovered during a 24-hr recovery period. Diptera was the most affected insect order (36%) followed by Collembola (30%) and Thysanoptera (17%). Out of the 31 mosquitoes (<1%) collected, only two (<0.1%) belonged to the genus Aedes. Body length of 93% of the affected insects ranged from 0.35 mm to 1.8 mm. Positive controls using the WHO standard cage bioassays with the mosquito Ae. albopictus (n = 417) and the stingless bee Trigona iridipennis (n = 122) showed 100% initial knockdown, and 83.5% mosquito and 93.5% bee mortalities after the recovery period. The study shows that insecticide fogging does have a severe effect on non-target insects such as pollinators; therefore, fogging operations should be done in a controlled manner and indiscriminate fogging should be avoided.

Methyl isonicotinate is one of several patented 4-pyridyl carbonyl compounds being investigated for a variety of uses in thrips pest management. It is probably the most extensively studied thrips non-pheromone semiochemical, with field and glasshouse trapping experiments, and wind tunnel and Y-tube olfactometer studies in several countries demonstrating a behavioural response that results in increased trap capture of at least 12 thrips species, including the cosmopolitan virus vectors such as western flower thrips and onion thrips. Methyl isonicotinate has several of the characteristics that are required for an effective semiochemical tool and is being mainly used as a lure in combination with coloured sticky traps for enhanced monitoring of thrips in greenhouses. Research indicates that this non-pheromone semiochemical has the potential to be used for other thrips management strategies such as mass trapping, lure and kill, lure and infect, and as a behavioural synergist in conjunction with insecticides, in a range of indoor and outdoor crops.

Cosmopolites sordidus (Germar), commonly known as banana corm weevil, is an important economic pest in Asia that can cause severe yield loss depending upon the stage at which infestation occurs. In spite of its economic importance, little is known about the population structure of this pest in India. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) were used to characterize the population genetic structure of C. sordidus collected from five hot spot locations in India. Nineteen RAPD primers and five selective AFLP primer combinations generated 147 and 304 amplification products, respectively. UPGMA dendrograms generated with both marker systems failed to reveal populations clustered based on geographic distance, which was confirmed by the Mantel test, which did not show a strong correlation between genetic distance and geographic distance. Values of indices of genetic identity showed that the populations were closely related. Though the gene flow estimate (Nm) between the populations was 0.469, suggesting restricted gene flow, the populations are not genetically distinct. These observations suggest that the range expansion of this banana pest in India has taken place through transport of infested corms and plant material, resulting in genetically close populations that are geographically distinct. These results provide important information on the population structure of this pest in India, which will aid in designing suitable strategies for its control and management, especially with respect to insecticide resistance.

Phytosanitary measures are a major barrier to trade in papaya. We assessed the infestation of tephritid fruit flies on different stages of maturity of papaya, to determine its non-host stage of maturity, for market access. Papaya fruits were collected from Kilifi and Embu counties, Kenya from March 2013 to December 2014, to assess the level of infestation by fruit flies according to the degree of fruit ripening. In all locations, no fruit fly infestation was recorded on papaya when fruits were at the 0, 25 and 50% yellow fruit ripening stage. Bactrocera dorsalis (Hendel) was, however, observed attacking fruits when papaya fruits were at 75 and 100% all yellow (fully ripe fruit ripening stage) with infestations of 0.19−0.51 B. dorsalis/kg fruit and 0.24−1.24 B. dorsalis/kg fruit, respectively, in all locations. Field cage exposure of B. dorsalis to fruits of five papaya cultivars—‘Papino’, ‘Neo Essence’, ‘Sunrise Solo’, ‘Tainung No. 1’ and ‘Tainung No. 2’ in Manica Province, Mozambique—showed that B. dorsalis did not infest fruits at 0, 25 and 50% yellow ripening stages at the densities of 50 and 100 flies per cage. However, at 75% yellow ripening stage, up to 13.1 pupae/kg of fruits was recorded at a density of 150 flies per cage in Tainung No. 1, and infestation ranged from 4.5 to 136 pupae/kg fruits at 100% yellow ripening stage across all the cultivars and infestation densities. Laboratory evaluation of volatiles emanating from freshly crushed papaya pulp of four cultivars: ‘Sunrise Solo’, ‘Red Lady’, ‘Papayi’ and ‘Apoyo’ on egg viability of B. dorsalis showed that at 0, 25 and 50% yellow, egg hatchability was inhibited, suggesting that semiochemical compounds present in green tissues of papaya prevent egg development, although this effect was variable across the four cultivars and ripening stages. Export papaya is harvested at less than 40% yellow ripening stage. Our results, therefore, suggest that quarantine treatment for fruits at this ripening stage is inconsequential, as B. dorsalis does not infest papaya fruits at this stage; thus, authorities should permit entry of these papaya cultivars of less than 40% yellow ripening stage to quarantine-sensitive markets.

Laboratory and field studies were undertaken to establish the efficacy of some selected botanicals in the control of the tea red spider mite, Oligonychus coffeae Nietner, a major pest of tea. Bioassays were performed to evaluate the dose-mortality response of adults and eggs of O. coffeae to aqueous plant extracts. The order of adulticidal toxicity based on LC50 and slope values was Sapindus mukorossi L. > Nyctanthes arbor-tristis L. > Phlogacanthus thyrsiformis Nees. The order of ovicidal activity was reversed and was P. thyrsiformis > N. arbor-tristis > S. mukorossi. In addition, different concentrations of the aqueous extract of these plants exhibited repellent properties against adult mites and also significantly decreased the deposition of eggs by the mites on treated tea leaf surfaces. In field conditions, the extracts significantly reduced O. coffeae populations compared to propargite, a synthetic acaricide. There was no phytotoxic effect and the quality of tea was not adversely affected by the treatments. Further, the plant extracts caused no mortality or decrease in the predation efficacy of the adults and fourth instar larvae of Stethorus aptus Kapur, a natural predator of O. coffeae. Using the procedure adopted in this study, tea growers can easily formulate these low-cost eco-friendly botanicals for O. coffeae management in tea plantations.

Frankliniella schultzei Trybom is a polyphagous pest and vector of tospoviruses worldwide. It occurs in dark and pale colour forms that are morphologically similar but differ in vector competency and geographic spread. In Kenya and other tropical regions, mixed populations of both colour forms are observed in similar habitats, so are considered as one species. To ascertain the taxonomic status of the two colour forms, they were characterized using morphological, molecular, biological and ecological approaches. Morphological characterization revealed differences between the colour forms on eight features and they separated into distinct clusters through principal component analysis. Restriction fragment length polymorphism of the internal transcribed spacer region (ITS-RFLP) analysis revealed differences between the two colour forms and was confirmed by differences in ITS2 sequences. Virgin pale females had female offspring (thelytoky), while virgin dark females had male offspring (arrhenotoky). Interbreeding of dark males with pale females resulted in pale females, indicating absence of interbreeding between the two colour forms. Laboratory colonies of pale forms lacked males and further analysis of F. schultzei males from Ipomoea setosa flowers in the field indicated the presence of dark males and the absence of pale males. Field surveys in Kenya indicated differences in distribution and host plant preferences among the colour forms. Lack of interbreeding, distinct host preferences and distribution, and morphological and molecular differences indicate that the two colour forms of F. schultzei could be different species. The results highlight the need for combining morphological, biological, molecular and ecological characteristics for resolving taxonomic status of closely related insects.

Okra, Abelmoschus esculentus (L.) Moench, is an important vegetable crop grown throughout the tropical and temperate regions of the world. Spotted bollworm, Earias vittella (Fab.), is one of the most important insect pests of okra. The effects of insecticides (cypermethrin, imidacloprid, carbaryl and neem oil) were studied on the fitness of the F1 generation of E. vittella by a demographic method. Life table was constructed from the eggs obtained by the surviving individuals that had ingested insecticides. Survivorship and expectancy was highest with the commencement of age and gradually decreased with the progression of age in the treatment groups and control. However, it was reduced in the treatment groups in comparison to control groups. Highest numbers of unhatched eggs (17%) were recorded with imidacloprid and cypermethrin treatments, whereas all the eggs hatched in control groups. Larval mortality was high in the initial instars as compared to late instars. Potential fecundity was significantly reduced to 94 females/female/generation treated with cypermethrin as compared to 256 in the untreated females. Developmental time of pre-pupa and pupa was significantly decreased with cypermethrin treatment. The intrinsic rate of increase was reduced to 0.0201 females/female/day in cypermethrin groups as compared to 0.046 in the control groups. The generation time was 33.27 days in the control, which was reduced to 26.78 days with carbaryl treatment and was increased to 37.5 days with neem oil. Insecticides cause adverse effect on the surviving generation of E. vittella, and may be incorporated as a valuable component in the integrated management of E. vittella on okra.

Food losses caused by insects during postharvest storage are of paramount economic importance worldwide, especially in Africa. Laboratory bioassays were conducted in stored grains to determine the toxicity of powders of Eugenia aromatica and Moringa oleifera alone or combined with enhanced diatomaceous earth (Probe-A® DE, 89.0% SiO2 and 5% silica aerogel) to adult Sitophilus granarius, Tribolium castaneum and Acanthoscelides obtectus. Adult mortality was observed up to 7 days, while progeny production was recorded at 6–10 weeks. LD50 and LT50 values for adult test insects exposed to plant powders and DE, showed that A. obtectus was the most susceptible towards the botanicals (LD50 0.179% and 0.088% wt/wt for E. aromatica and M. oleifera, respectively), followed by S. granarius. Tribolium castaneum was most tolerant (LD50 1.42% wt/wt and 1.40% wt/wt for E. aromatica and M. oleifera, respectively). The combined mixture of plant powders and DE controlled the beetles faster compared to the plant powders alone. LT50 ranged from 55.7 h to 62.5 h for T. castaneum exposed to 1.0% M. oleifera and 1.0% DE, and 0.5% E. aromatica and 1.0% DE, respectively. Botanicals caused significant reduction of F1 adults compared to the control. Combined action of botanical insecticides with DE as a grain protectant in an integrated pest management approach is discussed.

Western flower thrips (WFT) (Frankliniella occidentalis) is an introduced pest that harms French bean production in Kenya and other countries. Since new WFT management approaches are being developed, a closer look at the genetic makeup of WFT populations can give new insights into source habitats, crop colonization patterns or host plant preferences, which are prerequisites for integrated pest management (IPM) strategies. For this purpose, we used six microsatellite loci to analyse the genetic structure, diversity and gene flow of WFT sampled on French beans, intercrops and weeds in Kenyan French bean production areas. The results of this preliminary study indicate that the available microsatellites are sufficiently polymorphic for more detailed analyses on local dispersal patterns of WFT in Kenya. Even with the limited data set, the results reveal that F. occidentalis populations show considerable genetic differentiation between host plant species but not between regions, which suggests reduced gene flow and a possible development of biotypes. Possible consequences of the results on IPM are discussed.

Cotesia vestalis was introduced into Kenya from South Africa in March 2003 for biological control of Plutella xylostella with initial release in 2004. To confirm establishment, the rate of spread beyond the release sites and parasitism rates by C. vestalis were assessed between October 2011 and April 2012 in eastern and southeastern Kenya (Kitui, Mwingi/Yatta and Loitokitok areas). Monthly observations on kale infestation by diamondback moth, damage scores, parasitism and parasitoid guild were undertaken on 20 randomly selected plants in farmer-managed kale farms. Sampled larval and pupal stages were placed in containers and taken to the laboratory for parasitoid emergence. The infestation levels ranged from 0.4 to 2.5 DBM per plant, while damage scores ranged from 1.2 to 1.6, which correlated with the infestation levels. Cotesia vestalis was not only the most abundant parasitoid, but it had also spread to new areas from the release sites. In December, the three sites recorded an average of 50% from C. vestalis. Excluding the exotic parasitoids C. vestalis and D. semiclausum, indigenous parasitoids accounted for less than 5% total parasitism. The parasitoid guild of the diamondback moth varied between months and study sites with January recording the highest species diversity and evenness of 1.15 and 0.63, 1.28 and 0.80, 1.08 and 0.47 in Loitokitok, Kitui and Mwingi/Matuu, respectively. Therefore, C. vestalis had an impact on the management of the DBM with parasitism rate of 35% to 88% and had spread beyond the release sites.

The Murshidabad District of West Bengal, India has practised traditional mulberry sericulture since time immemorial. One of the most important aspects for sustainable development of the sericulture industry is the control and prevention of silkworm diseases. The main objective of this study was to determine silkworm disease incidence over the period 1992–2011 in Murshidabad District and how environmental factors have contributed towards their occurrence. Data were collected from a crop-wise survey of silkworm diseases from 25 farmers (five farmers from five villages), who each had a separate rearing house, were progressive and had a capacity of rearing at least 100 disease free layings (dfls) in each crop. Disease incidence was expressed in percentage and calculated taking into consideration 40,000 larvae per 100 dfls. Crop-wise silkworm disease mortality data were correlated with meteorological data. Data collected from the continuous survey conducted in the district during 1992–2011 revealed that there was no set pattern of occurrence of silkworm diseases. However, maximum mortality (up to 30%) of silkworm due to diseases in all the seasons occurred mainly due to grasserie, as relative humidity remains high for most part of the year in this area. However, other than grasserie, for most of the period, disease incidence was below 10%. This observation of the dominance of grasserie over other diseases in causing silkworm mortality calls for renewed emphasis on the preventive measures and development of disease forecasting models, for disease control. Another observation was that since 1993, pebrine, the deadliest disease of the silkworm, has not been reported from the farmers’ fields.

The anthocorid bug Orius albidipennis Reuter is a generalist predator that feeds on the whitefly Bemisia tabaci Gennadius and the strawberry spider mite Tetranychus turkestani Ugarov & Nikolski in greenhouse crops. There are no previous studies on the potential efficacy of the predatory bug against these pests on greenhouse crops. We report on the efficacy and the prey preference of the predator to control these pests on different host plants under laboratory conditions. In a laboratory experiment, we estimated the predation rates of O. albidipennis at different densities of each prey after 24 h on cucumber and sweet pepper leaves. Predation rates of the predatory bug to T. turkestani and B. tabaci were significantly higher on sweet pepper leaf than on cucumber leaf. We studied the effect of plant species on prey preference and switching of O. albidipennis to B. tabaci and T. turkestani using Manly's α index values and Murdoch's no-switch line, respectively. Our results show that O. albidipennis prefers T. turkestani to B. tabaci on both host plants but its preference for T. turkestani on sweet pepper is significantly greater than on cucumber. Moreover, on sweet pepper, preference values are completely fitted by Murdoch's no-switch line. The findings suggest that morphological defence traits of plants, such as hairy leaves of cucumber, may effectively change prey preference and reduce predation success of O. albidipennis.

The short-range diurnal dispersal pattern of adult western flower thrips Frankliniella occidentalis (Pergande), in relation to spatial distribution of French beans, was determined in the field. A total of 1200 adult female F. occidentalis were released on 60 French bean plants with 20 adult thrips per plant at the central release point of 3.14 m2. Dispersal was determined in terms of the number of thrips recorded on French beans planted on concentric circles at 0.9, 1.8, 3.6, 7.2 and 14.4 m radii from a circular central release point for five days. Results indicated that there was a steady increase in the proportion of dispersing adult F. occidentalis from the first to the fourth day in the first planting season, and from the first to the third day in the second planting season. The peak hour for dispersal was 10.15 h in the first season while it was 13.15 h in the second season. Temperature and wind speed were positively associated with the dispersal activity of adult F. occidentalis. Minimal flight activity was at temperatures below 15 °C and peak flight activity was at 19 °C. The prevailing wind direction did not influence the dispersal pattern of adult F. occidentalis in both seasons. Adult F. occidentalis moved up to 7.2 m on French beans on the first day. In both seasons, the mean direction of thrips dispersal was mostly uniformly distributed (not oriented to a particular compass direction) around the central release point. The results provide an insight into developing integrated management strategies against the pest based on isolation of farm fields, management of alterative hosts around French bean fields and insecticide application.