Common bean (Phaseolus vulgaris L.) is amongst the most important grain legume crops in Africa in general, and Ethiopia in particular. The Mexican been weevil (Zabrotes subfasciatus Boheman) heavily attacks the grain of common bean. A total of 300 common bean entries were subjected to a ‘no-choice’ test at Melkassa Agricultural Research Centre, Ethiopia, using a randomized complete block design with three replications, to evaluate for resistance to the Mexican bean weevil. Data on insect and seed traits were collected and a significant level (P<0.01) of variation in all parameters measured was observed amongst genotypes. Relative resistance was recorded in landraces, improved genotypes and breeding lines, but the resistant genotypes, RAZ-11, RAZ-36, RAZ-2, RAZ-44, RAZ-120, RAZ-40 and MAZ-203, showed consistently complete resistance, with zero index of susceptibility value. Two other promising entries were also identified from the breeding lines (SCR-11) and landrace collections (NC-16) of Ethiopia. Stratified ranking diagrams showed that accessions from different eco-geographical origins in Ethiopia and those with different colours showed different patterns of response to infestation. The Ethiopian bean breeding programme should take up the resistant genotypes for a comprehensive yield trial at the national level and direct release them as commercial varieties. The incorporation of bean weevil resistance genes into adapted varieties through backcross breeding techniques, supported with marker assisted selection, seems to be the best strategy not only in terms of time saving but also in terms of effectiveness and efficiency.

Chitinases are found in species from all kingdoms, including Kingdom Animalia. We purified chitinase, poly [1,4-(N-acetyl-β-d-glucosaminide)] glycanohydrolase, by cation exchange chromatography on SP-Sepharose from the integument of a lepidopteran, the Mediterranean flour moth, Ephestia kuehniella Zeller, and further characterized it. Ephestia kuehniella chitinase has similar properties to other insect chitinases, with respect to the molecular mass. Its molecular mass was 79.7 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature for activity were 6 and 40 °C, respectively. The purified enzyme exhibited stability at a pH range from 4.5 to 8.0 and showed high sensitivity to Co2+, Mn2+, Ca2+, Hg2+ and Ag+. The Km and Vmax values of E. kuehniella chitinase were, respectively, 3.98 mg/mL and 7.11 μmol/min/mg for colloidal chitin. In comparison to the values determined for the substrate affinity, the enzyme had a 2.36-fold higher affinity for Carboxymethyl–Chitin–Remazol Brilliant Violet (CM–Chitin–RBV) as a soluble substrate. We examined the antibacterial effect of E. kuehniella chitinase on the growth of both Gram-positive and Gram-negative bacteria. The enzyme inhibited the growth of Bacillus subtilis, Bacillus thuringiensis and Escherichia coli, where the average diameter of inhibition zone was 20, 23 and 19 mm, respectively. The antimicrobial effect and chitinase activity strengthen the hypothesis that the enzyme could be used in biological control against plant pests.

Vegetable and grain amaranths represent a vital source of micronutrients and protein in Asia and Africa. However, various foliar lepidopteran pests and stem-mining weevils hinder amaranth production. Insect-resistant cultivars can enhance the productivity of this crop. Here, we report on the performances of amaranth varieties screened for their resistance to insect pests under the field conditions at The World Vegetable Center stations in Asia and sub-Saharan Africa. We conducted two preliminary screening trials with a total of 263 entries from around the world in Taiwan and a third preliminary screening trial with 49 African-indigenous entries in Tanzania. Promising entries from these preliminary trials were collectively evaluated in an advanced screening trial in Tanzania, to identify lines resistant to foliar and stem-boring pests in East Africa. Four entries exhibited moderate resistance to foliar pests: TZ51 and TZ53 (Amaranthus cruentus), TZ34 (A. dubius) and TZ39 (Amaranthus sp.). Five entries showed moderate resistance to stem weevils: TZ06 and TZ27 (A. cruentus), TZ52 (A. graecizans), TZ59 (A. palmeri) and TZ07 (Amaranthus sp.). Lepidopteran pests affecting leaves were reared to adulthood and identified as Spoladea recurvalis (Crambidae), Spodoptera exigua (Noctuidae) and Spodoptera littoralis (Noctuidae). Stem weevil larvae were also reared and identified as: Neocleonus sannio Herbst, Gasteroclisus pr. rhomboidalis Boheman, Hypolixus pr. haerens Boheman and Baradine sp. (Curculionidae). These results highlight key amaranth pests in East Africa and identify insect-resistant entries that will be useful in breeding programmes and resistance studies.

The springtail Megalothorax laevis Denis, 1948 is redescribed from a broad sampling in the intertropical zone: Vietnam (including type locality), Ivory Coast, Gabon, Réunion island and French Guiana. Pseudopore-like elements are for the first time reported on the trunk and legs of Megalothorax species. New molecular data for M. laevis (16S rDNA, 28S rDNA d1 and d2 and COI Barcode) are provided. The phylogenetic position of the species within the Megalothorax genus is analysed. Megalothorax laevis belongs to the incertus group but shares similitudes with the minimus group acquired through evolutionary convergences (such as smooth lamellae of the mucro). Those similitudes might have created confusion between M. minimus and M. laevis. While M. minimus used to be regarded cosmopolitan, M. laevis has been overlooked since its original discovery. However, the present sampling led us to believe that M. laevis replace M. minimus as the commonest edaphic Megalothorax species in the intertropical zone. A key to the Megalothorax species with smooth mucro lamellae is provided.

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.

Storage pests cause considerable damage to stored grains in Eritrea. A study on storage pest control was conducted at room temperature (25 °C) and 57% relative humidity, to evaluate the efficacy of botanicals and sodium chloride (table salt) against Zabrotes subfasciatus Boheman on field pea (Pisum sativum L.). The experiment was conducted in a completely randomized design (CRD) in three replications. The treatments used were: neem (Azadirachta indica), red pepper (Capsicum frutescens L.), sesame (Sesamum indicum L.) oil, datura (Datura stramonium L.), eucalyptus (Eucalyptus globulus Labill), table salt (sodium chloride) and a control without pesticide. Data collected were weight loss, damage percent and germination percent of field pea grain, and also adult mortality of Z. subfasciatus. Rates of application for all the treatments were 3% w/w and an untreated control. Results of the study showed that E. globulus leaf powder caused 88.89% mortality of Z. subfasciatus and sesame oil caused 100% mortality, three days after treatment. The other treatments were less effective in causing mortality of the insect. After five months of storage, the lowest weight loss was observed in grain treated with sesame oil (1.81%) and neem (4.02%) compared with the control that had 16.68% loss. Grain weight loss was 7.45% for treatment with table salt, 8.11% for eucalyptus, 9.62% for red pepper and 15.29% for datura. Grain damage and weight loss increased as storage time increased. Moreover, these plant materials and table salt had no effect on the germination capacity of field pea. In general, the results obtained indicate that these plant materials and table salt can be used for the control of Z. subfasciatus.

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

Outbreaks of three orthopteran species—Tropidacris collaris (Stoll), Cornops frenatum frenatum (Marschall) and Parascopas obesus (Giglio-Tos)—occurred in three different regions of Brazil during the summers of 2012 and 2013. Insects were observed causing severe damage in commercial crops and subsistence farming areas. In this study, the three species were shown to be susceptible to infection with an oil-based formulation of the fungus Metarhizium acridum under laboratory conditions. In this article, we briefly discuss insect mortality levels for each species and behavioural response to infection. This is the first report of the pathogenicity of the entomopathogenic fungus M. acridum to P. obesus, C. f. frenatum and T. collaris.

The citrus leafminer (CLM), Phyllocnistis citrella Stainton causes injury to citrus and related species in the Rutaceae family. The damage that the CLM larvae can cause is significant in citrus plantations. We tested two citrus cultivars — ‘Kinnow’ (Citrus reticulata Blanco) and ‘Fairchild’ (a hybrid of Citrus reticulata Clementine x Orlando Tangelo) — to quantify CLM larvae infestation and effect on the physiology of the citrus cultivars. We then compared the CLM larval weight with its associated damage. To calculate infestation level, mine area and total leaf area, we used the image analysis technique. The infestation level of CLM was higher in ‘Fairchild’ than in ‘Kinnow’ cultivar of citrus. For both cultivars, larval weight of CLM was directly proportional to the amount of mines generated. Taken together, the results of this study suggest that the mines that CLM larvae generate pose significant effect on the net photosynthetic rates and water use efficiency of citrus nursery plants. These results will help improve our understanding of the interaction between CLM and citrus nursery plants and effect of the pest on the yield potential of the crop.

An inventory of arthropods was carried out at locations in the desert area of Touggourt, southeast Algeria. Samples were collected from two diverse habitats, a palm grove (agricultural habitat) and dunes (natural habitat). Using the Barber pitfall trap, 1100 specimens, divided into four classes, 15 orders, 44 families and 99 species were obtained. In the palm grove, 660 arthropods were trapped, belonging to four classes and 12 orders. Of these four classes, Insecta dominated followed by Crustacea, Arachnida and Entognata. Insecta accounted for 59.49% of the total capture and was dominated by two orders: Hymenoptera (41.81%) and Amphipoda (34.55%). In the Hymenoptera, Cataglyphis sp. was the most abundant (38.2%), followed by Pheidole pallidula (2.3%). In the dunes, 440 individuals were trapped. Insecta was the most abundant (90.69%), and Crustacea and Arachnida were scarce. Of the dominance by insects, Hymenoptera was most abundant (68.15%), and within that order, Cataglyphis bombycina (35.5%) was the most abundant followed by Monomorium subopacum (8.9%). In the palm grove, 42 species were recorded, compared to 57 in the dunes. The Shannon–Weaver index and equitability varied in both stations. In the palm grove, the diversity was 2.6, and the equitability was 0.5. By contrast in the dunes, the diversity was equal to 4 and the Equitability equal to 0.7. The differences in vegetation between the two sites reflect the differences in species diversity.

Mexican bean weevil, Zabrotes subfasciatus Boheman, is a significant pest of stored beans (Phaseolus vulgaris L.) that causes considerable loss in the quality and quantity of bean grain in Africa. In the past two to three decades, researchers have attempted to identify botanicals with better insecticidal potential against storage pests. However, there is a lack of information on the potency of botanical combinations, their toxicology, and optimal application rates. This study was conducted to examine the bioefficacy of unitary and binary botanical combinations of Jatropha curcas (L.), Datura stramonium (L.), Chenopodium ambrosioides (L.), Schinus molle (L.), and Azadirachta indica (A. Juss) against Z. subfasciatus at 1% and 2% w/w dosages. The insecticidal activities of the botanicals were measured based on their effect on adult mortality of Z. subfasciatus and progeny reduction, grain weight loss, and weevil perforation index. Among botanical admixtures, binary combinations of C. ambrosioides + D. stramonium, J. curcas + C. ambrosioides, and S. molle + C. ambrosioides were the most potent. They resulted in the highest mortality of Z. subfasciatus, low weevil perforation index or none, and grain weight loss at the most moderate test dosage (1% w/w). Treatment with C. ambrosioides resulted in the highest efficacy when applied individually. We failed to observe any notable difference in toxicity between dosage levels among the binary botanical combinations. However, the effectiveness of unitary formulations improved with the increase in dosage rate. Application of botanicals did not adversely affect bean seed germination. Our study suggests that botanicals in binary mixtures may enhance the potency of constituent components for effective control of Z. subfasciatus.

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.

In this study, we investigate the spatio-temporal fluctuations of the cashew leafminer Eteoryctis gemoniella Stainton, which was recently reported as one of the most devastating cashew pests in Benin. Eteoryctis gemoniella causes serious damage, especially to the young tender leaves, thus reducing the photosynthetic capacity of trees and hence their productivity. This study was carried out in three different cashew orchards in Northern Benin, West Africa, where we monitored the fluctuations of the infestation rates and population changes of E. gemoniella during a one-year cycle, from September 2010 to August 2011. In addition, we collected cashew leaves with mines to check for emergence of hymenopteran parasitoids. Our results show that infestation rates (as well as population densities of E. gemoniella) varied through time and among orchards. The most infested orchard was at Korou, whereas, the least infested was at Okoutaossé. In general, infestation rates and number of mines per leaf passed through two peaks, the first in July–August and the second in November, whereas no infestations were observed from January to June. Spatial distribution pattern of E. gemoniella within the orchards showed that this moth almost has a random distribution. Parasitoids attacking the leafminer were recovered from the samples. These were Apanteles sp., Chelonus (Microchelonus) nr. curvimaculatus Cameron (Hymenoptera: Braconidae) and Trathala sp. (Hymenoptera: Ichneumonidae). Further detailed studies on these natural enemies will be needed for evaluating their potential in controlling E. gemoniella in cashew orchards.

Attempts have been made in recent years to reduce the use of synthetic pesticides and seek alternative and innovative methods for pest control. We conducted a study on the chemical composition of Eucalyptus occidentalis essential oil and investigated the fumigant, contact and repellent effects against Tribolium castaneum (Herbst) (Col: Tenebrionidae) and Rhyzopertha dominica (F.) (Col: Bostrichidae). The major components were τ-cadinol (17.20), 1,8-cineol (15.5%), α-cadinol (14%) and α-pinene (9.21%). The contact toxicity experiment showed that the oil was more toxic to R. dominica (LD50 value 0.82 μL/cm) than to T. castaneum (LD50 value 0.99 μL/cm) and showed the same fumigant toxicity for both insects according to the 95% confidence limit of LC50. The repellency against T. castaneum was more than for R. dominica and increased from 14 to 75% for R. dominica and 22 to 78% for T. castaneum after 2 h. These results suggest that E. occidentalis essential oil is a potential candidate for use as a natural repellent and insecticide for stored-product insect pests.

Jatropha curcas L. is a stem-succulent shrub that produces high concentrations of seed oils that are convertible into biodiesel. In this study, the incidence of four insect pests on Jatropha, Strabala rufa, Gnathamitermes tubiformans, Pempelia morosalis, and Acanthoplus discoidalis was recorded over three years in a semi-arid climate in Gaborone, Botswana. The occurrence of these insects was concentrated in the summer season from October to April, while lower numbers of all species were found in May as the temperature began to reduce towards the winter season, suggesting that insect pests of Jatropha exhibit a unique temporal pattern in this region. A considerable variation was observed among Jatropha accessions regarding the insect pest occurrence, indicating a vast difference in the susceptibility to insect pests among Jatropha accessions.

Rove beetles (Coleoptera: Staphilinidae) are a group of diverse insects occurring in a range of different ecosystems, from the plains to the mountaintops. However, there are no reports in the literature of their presence in the tidal zone of the seashore. This is the first report of the presence of Paederus fuscipes Curtis on the coastal sands of the Caspian Sea, northern Iran. In all 14 counties of Mazandaran Province on the southern coast of the Caspian Sea, systematic monthly sampling of the beetles took place from May 2012 to April 2013. Samplings (30-min-person) were performed and specimens collected from the sandy seashore by gloved bare hands and identified using appropriate keys. To our surprise, all 1012 specimens collected were exclusively P. fuscipes Curtis, but with significant seasonal and geographical variations among the numbers of specimens collected. The distribution and activity of P. fuscipes were outstanding in Mahmoodabad and Fereidonkenar counties, with the highest abundance and frequency in September, posing a serious health threat to tourists and residents of these areas.

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), is one of the most destructive pests of date palm in United Arab Emirates. We conducted field trials in Abu Dhabi from May 2010 to April 2011, to evaluate the effect of weekly stirring of water and dates in the RPW pheromone trap on adults captured in brown and white traps, using a randomized complete block design with four treatments and five replications. Each trap contained: (1) a dispenser of the RPW male aggregation pheromone (Ferrolure™) containing 700 mg of the active ingredient (4-methyl-5-nonanol (90%) + 4-methyl-5-nonanone (10%)) at 95% purity; (2) an ethyl acetate (EA) dispenser (Weevil Magnet™) containing 40 ml of the active ingredient of EA at 98% purity; (3) 350 g of fodder date fruits; and (4) 4 L of water. Mean adults captured in white traps was 22.5 ± 0.50 and 16.8 ± 0.41 adults/trap/month with and without stirring, respectively, while in brown traps the mean was 39.9 ± 1.31 and 28.3 ± 0.51, respectively. The overall mean of adults captured was 31.2 ± 6.21 and 22.6 ± 4.81 adults/trap/month with and without stirring, respectively. The highest number of weevils caught was in the brown traps with stirring, while the lowest was in the white traps without stirring. The results of these trials suggest the use of brown traps containing aggregation pheromone, 350 g of date fruits, EA and water. It is necessary to stir the water with dates in the traps to increase their efficacy.

Nauclea diderrichii (De Wild and Th. Dür.) (common name Kusia and trade name, Opepe) is an evergreen tree found throughout the tropical rainforests of West Africa. It is heavily exploited for its timber and listed as vulnerable on the IUCN Red List of Threatened Species. The shoot borer Orygmophora mediofoveata Hamps, which attacks the nursery stage, has hampered attempts to establish N. diderrichii plantations in Ghana. This study examined the potential of four insecticides to protect N. diderrichii seedlings from O. mediofoveata attack and damage. Four insecticides–Pyrinex (chlorpyrifos), Dursban (chlorpyrifos), Cerox (dimethoate) and Golan (acetamiprid)–were applied to four-month-old N. diderrichii seedlings growing in full sunlight and under shade (80% of normal light), to evaluate their effects on incidence of attack, survival, severity of damage and growth. Insecticide treatment and light conditions had variable effects on the damage and growth of the seedlings after six months of evaluation. Seedling survival was not significantly influenced by the insecticide treatment. Percent survival of insecticide-treated seedlings did not differ significantly from that of control seedlings in full sun; however, under shade survival of treated seedlings was significantly higher than control seedlings. Nonetheless, control seedlings in full sun had higher survival (92.5%) than those under shade (62.5%). Insecticide-treated seedlings in full sun had lower incidence of shoot borer attack than those under shade. In full sun, dieback incidence following shoot borer attack was significantly lower for insecticide-treated than control seedlings. Growth in height and girth of seedlings was influenced positively by both insecticide and light, with girth especially being significantly lower under shade conditions. Currently, N. diderrichii seedlings are typically raised under shade; however, this study shows that raising seedlings in full sun with insecticide application could result in faster and better growth.

Millipede diversity in tropical regions, and in Mexico in particular, is still mostly unknown. A modest but recurrent source of new Mexican species is the colonization of exotic species, due to human activity. The invasive species Cylindrodesmus hirsutus Pocock, 1889 has spread from its area of origin in Indonesia or Melanesia and become a virtually pantropical species. Although long known from South and Central America, reports from the Caribbean are sparse and limited to some eastern islands and southern Central America. On 9 March 2016, two adult specimens were found on Cozumel Island, Quintana Roo, in an area of medium semideciduous tropical forest. This paper comprises the first record of this species from Mexico and the northern Caribbean. Given the intense commercial activity in the region, the presence of more populations both in Cozumel Island and in the mainland coast is highly probable.

Zygogramma bicolorata Pallister is a potential biocontrol agent of Parthenium hysterophorus L. (Asteraceae). This study was carried out to understand the effect of abiotic (temperature and moisture) and biotic factors (age and reproductive status) on the induction and termination of diapause in Z. bicolorata. We also evaluated the effect of diapause on longevity and fecundity of Z. bicolorata. In Z. bicolorata the induction of diapause occurred between the months of July and December. No diapause was observed in May and June, which coincided with the commencement of the monsoon rains. The percentage of diapause induction in Z. bicolorata was found to increase from one generation to another as well as with the age of adults. Diapause significantly increased the fecundity of females as compared to the fecundity in pre-diapause conditions. Soil moisture (80% RH) played an important role in providing the conditions for initiation and termination of diapause. Similarly, 18.4 and 12.5% of diapause adults resumed their activity in 6 and 5 days when exposed to temperatures of 40° and 45° C for 2 h every day, respectively. Exposure of adults to low temperatures, i.e. 5° and 10° C induced 94.3 and 92.5% diapause, respectively, with no adult mortality. Thus, our findings reveal suitable conditions for preventing and inducing diapause in Z. bicolorata, which is of great importance in the suppression of P. hysterophorus. We discuss the implications of these findings in the control of P. hysterophorus.