Fungus gnats, which are also commonly known as mushroom fly, nuisance flies, black fungus gnats, and dark-winged fungus gnats, are small, dark-coloured flies that belong to the family Sciaridae. Although fungus gnats are principally mycophagous, they have also been described as opportunistic herbivores, making them important plant pests. They are primarily a problem in high moisture conditions. They cause direct damage on the plant through larval feeding and indirect damage through creation of entry points for plant pathogens. They also transfer fungal diseases between plants. The most important species that have been described as pests are Bradysia coprophila Lintner and Bradysia impatiens Johannsen. The latter is regarded as synonymous to Bradysia difformis, has a global distribution and has recently been identified in South African forest pine nursery beds. Control has mainly been achieved through the use of chemical insecticides, but also, to a considerable extent, the use of biocontrol agents such as entomopathogenic nematodes (EPNs). The use of EPNs is preferred, since fungus gnats are pests of such crops as mushrooms and vegetables that have a short lifecycle, or of houseplants that are in very close association with human beings. Control usingEPNshas mainly been achieved through the use of Steinernema feltiae.

False codling moth (FCM), Thaumatotibia leucotreta (Lepidoptera: Tortricidae) is an important pest of various fruit crops in South Africa. Current FCM control strategies include the use of chemical insecticides. However, FCM has developed resistance to some of the insecticides, and stringent chemical residue restrictions have been imposed by some foreign markets. Thus, the demand for high-quality fruit has translated into a need for new, efficient and effective integrated pest management (IPM) strategies. One such strategy is the control of the soil-dwelling life stages of FCM, using entomopathogenic nematodes (EPNs) and entomopathogenic fungi (EPF). Both of the biocontrol agents concerned have individually been shown to be effective against FCM. However, it is possible that, if they are applied simultaneously, a synergistic relationship might be observed between EPNs and EPF that could serve to enhance their efficacy against the target pest. In addition to reviewing previous and current control options against FCM in South African fruit crops, this study investigates the potential for using EPNs and EPF individually, and in combination, as biological control agents against FCM within an IPM system.

The polyandrous mating behaviour of the honeybee queen increases the genetic variability amongst her worker offspring and the genetic variability within the honeybee colony can affect their polyethism. In this study, we intend to understand whether there is genetic variability in the task of the queen retinue. Microsatellite DNA analyses revealed a total of 13 and 12 subfamilies in two colonies, respectively. It shows that the subfamily proportion of the queen retinue workers significantly deviated from random distribution, which suggests that they might have a genetic preference in the task of the queen retinue.

Trinervitermes trinervoides (Sjöstedt) (Termitidae: Nasutitermitinae) is principally a grass litterfeeding species common to the semi-arid and arid grasslands of southernAfrica. Abundance of sterile adult termites (workers and soldiers) at eight sites within an area of semi-arid grassland, northwest of Bloemfontein in the Free State Province, varied between 34 and 4871/m² (mean=2261/m²) with a live biomass of 0.2 to 27.8 g/m² (mean=12.9 g/m²). The numbers of live mounds in an area do not necessarily reflect termite abundance. At two sites at Bultfontein fewer termites and lower biomass were present on the site with 137 mounds/ha than that with 97 mounds/ha. Experimental studies on grass consumption of artificially fed field colonies of different sizes were used to estimate consumption by termites at the different sites. Consumption at the various experimental sites varied between 2.7 and 451.2 kg/ha/year (mean: 203.4 ± 175.1 kg/ha/year) and a marked seasonal periodicity in consumption was demonstrated. The impact of T. trinervoides within well-managed grassland ecosystems where the litter-feeding species forman important link in the food chain, is chiefly beneficial and far outweigh its harmful effects which tend to be associated with degraded, overgrazed grassland and drought.

Phylogenetic analyses based on the COI gene region, for 19 South African specimens of the fall armyworm (FAW), separated them into two well-supported clades. These clades indicated significant intraspecific variation and support the hypotheses that maize and rice strains of FAW are present in South Africa.

Lepidopteran stem borers are important pests of maize and sorghum in East and southern Africa. Except for Chilo partellus (Swinhoe), the other important lepidopteran pests of maize and sorghum, Busseola fusca (Fuller), and Sesamia calamistis Hampson, are indigenous to the African continent. As some stem borers became pest, some species remained in the natural habitats where they still infest non-cereal host plants. However, understanding the diversity of stem borer species that remained in uncultivated habitats and their role in pest dynamics received little attention in research. With the current changes in the natural habitats, some of the species in these habitats may switch to become pests. In addition to host switch, some of the unknown species currently restricted to natural habitats may disappear altogether. Several studies have been undertaken in Tanzania to assess stem borer species diversity. However, there are challenges in comparing diversity values among different zones due to differences in sampling protocols. In this study, a standardised sampling protocol was used and the paper presents a catalogue of stem borer species and their respective hosts in five different vegetation mosaics in Tanzania.

Water hyacinth is one of the five worst aquatic weeds that invades many SouthAfrican water bodies. It has been the target of at least eight biological control agents, including the water hyacinth weevil, Neochetina eichhorniae (Warner) (Coleoptera: Curculionidae). However, their success has been constrained by the high levels of eutrophication in South African water bodies, which promotes the plant's rapid compensation for feeding damage and growth. The aim of this research was to investigate the influence of water nutrients on the feeding and development of N. eichhorniae larvae.Water hyacinth plants were maintained at three different nutrient concentrations high (6 mg/l N; 0.83 mg/l P), medium (2.5 mg/l N; 0.4 mg/l P) and low (0.7 mg/l N; 0.01 mg/l P). The plants in each of these treatments were then inoculated with two larvae per plant, while the controls were kept free of larvae. Plant biomass and the number of leaves per plant were measured weekly for eight weeks. The results showed an increase in larval feeding rate as nutrient levels decreased. In contrast, larger larval size, greater numbers of survivors and shorter larval developmental time were recorded as nutrient concentrations increased from low to high levels. The findings of this study will therefore be helpful to understand how larval damage by N. eichhorniae affects water hyacinth populations and to predict the success of biocontrol under different nutrient levels.

Entomopathogenic fungi are increasingly gaining recognition as a viable alternative to synthetic insecticides for pest management; their efficacy is influenced by several biotic and abiotic factors. In this study, the effect of temperature on germination, growth and virulence of two isolates of Metarhizium anisopliae, ICIPE 18 and ICIPE 69, against first-instar larvae of Maruca vitrata at temperatures ranging from 15–35 °C, and mass-production potential of the isolates were assessed under laboratory conditions. Minimum, optimum and maximum threshold temperatures for efficacy of the best performing isolate, ICIPE 69, were estimated by the quadratic equation which emerged as the best model among the nonlinear mathematical expressions tested. Neither isolate germinated at 15 °C while germination was low at 35 °C for both. The optimum temperature for germination, radial growth and virulence of ICIPE 69 and ICIPE 18 ranged between 25–30 °C and 25–33 °C, respectively. Mortality of M. vitrata by both isolates ranged between 56.0 and 91.6�ross the different temperatures, with the highest mortality occurring at 25 and 30 °C for ICIPE 69 and ICIPE 18, respectively. The shortest LT50 values were 2.5 days for ICIPE 18 and 2.2 days for ICIPE 69 at 33 °C and 25 °C, respectively. The quadratic model predicted 25–30 °C as the optimum temperature range for maximum efficacy of M. anisopliae isolate ICIPE 69 against M. vitrata. Upper and lower threshold temperatures were predicted as 40 °C and 10 °C, respectively. Comparison of aerial conidia production on rice showed that ICIPE 69 yielded higher amounts of conidia (18.4 g conidia/kg rice) than ICIPE 18 (12.4 g conidia/kg rice). The results suggest that ICIPE 69 is a promising candidate for biocontrol of M. vitrata.

Management of Spodoptera littoralis infestation has been achieved by using chemical insecticides; however, the environment-friendly methods without unwanted side effects of these chemicals are becoming very important in modern pest management strategies. Natural products including plant extracts and oils are some of the alternative approaches in pest control. In the present work, insecticidal activities of oils from garlic cloves (Allium sativum), and ginger rhizomes (Zingiber officinale) were evaluated on S. littoralis by means of sublethal concentrations. The essential oils were extracted and their chemical composition was identified using a GC Ultra-ISQ mass spectrometer. The results showed that there were highly significant differences between all treatments and the control in some biological aspects. The larval and pupal duration was significantly prolonged, also pupal weight increased for all treatments when compared to the control. The percentage of hatchability of deposited eggs was significantly decreased, especially when using ginger both oil extracts at LC₅₀ concentration. On the other hand, the pupation percentage, rate of adult emergence, sex ratio and female fecundity were not significantly affected by all applications. The catalase enzyme (CAT) activity showed significant difference only at LC₅₀ of ginger oil.

Bruchus pisorum L., commonly known as the pea weevil, is a cosmopolitan insect pest of pea. Currently, its genetic diversity and population structure are still not well understood. Therefore, an examination of the pea weevil population diversity and evolutionary history will provide insight into efficient pest management strategies. In this study, we sequenced and analysed a 393 bp fragment of the mitochondrial Cytochrome C Oxidase subunit I (COI) gene from 29 samples of B. pisorum collected from the major pea-growing regions in northern Tunisia. Analysis of these sequences in addition to 18 supplementary sequences derived from six countries; Australia, China, Ethiopia, Germany, Italy and U.S.A.; led to the identification of 15 haplotypes among which nine were found in Tunisian samples, and among these, six were specific to Tunisia. The FST values reflected a weak population genetic diversity of B. pisorum in Tunisia. The haplotype network and phylogenetic analysis, including all sequences, supported the low genetic structuring of Tunisian B. pisorum and further revealed the presence of widely shared haplotypes. The presence of common haplotypes in geographically distant areas is mainly related to human intervention that facilitated the worldwide expansion of this pest, through the transportation of infested seeds, suggesting that local B. pisorum populations have different origins and may have resulted from multiple introductions.

Eucalyptus species are indigenous to Australia but arenowgrown worldwide due to their fast growth rate and various uses as timber and fuel wood. Insect pests of Eucalyptus have since followed their host and, in most cases, leaving behind the natural enemies which usually regulate them below economic injury. This is the case with Glycaspis brimblecombei and Leptocybe invasa which are now resident in most parts of the world including Zimbabwe. Damage as a result of the two pests currently poses a threat to reforestation efforts to provide alternative sources of firewood for curing tobacco. The objective of this study was to determine the distribution of the two pests as well as assess the possibility of managing L. invasa through biological control by releasing and recovering successive generations of the natural enemy Selitrichodes neseri in selected L. invasa-infested areas. Surveys were therefore carried out in Zimbabwe and GPS coordinates for pest presence recorded and used to determine the current distribution and future projections of the two pests using Maximum Entropy (maxent) ecological niche modelling. In preliminary studies to manage L. invasa, the natural wasp enemy S. neseri was released in Eucalyptus plantations and recovery studies done to establish their perpetuation in the field. Based on temperature and precipitation averages for Zimbabwe, the model predicted widespread distribution of the two pests especially in Mashonaland West, Bulawayo, Harare, Midlands province and parts of Manicaland province. This predicted range was projected to shrink due to climate change by the year 2055. In terms of relative contribution in predicting the distribution of the occurrence data, the three most important variables were mean annual temperature (39 %), mean temperature coolest month (18.3%)and annual moisture index (18 %). The performance of the model was high, with an AUC value of 0.884. Selitrichodes neseri wasps were recovered in infested Eucalyptus samples 4–6 generations after the initial release, indicating a high possibility of the natural enemy being able to establish in the future. Our findings are therefore important in understanding the current and projected distribution of both L. invasa and G. brimblecombei in Zimbabwe and formulating management measures for the two pests.

The biological parameters studies on Bemisia tabaci MED Q1 and Q3 genotypes in tropical areas are very scarce and could provide interesting insights for pest management programmes. The life history traits and demographic parameters of Q1 and Q3 genotypes of B. tabaci MED (Gennadius) were studied on Lantana camara (L.) and Solanum incanum (L.) plants under laboratory conditions (25 °C ± 2, 60 ± 5 % relative humidity (RH) and a photoperiod 12L:12D. In our study, L. camara and S. incanum were suitable forQ1whereasQ3 was able to develop on L. camara only. Q3 differs from Q1 by combination of several life history traits. Q3 has shorter developmental duration and higher fecundity than Q1 on L. camara. Sex ratio favouring Q1 genotype was observed. Longevity of females was more important than that of males for both genotypes. As for demographic parameters, values of intrinsic rates of natural increase (R_m) varied from 0.10 for Q1 to 0.18 for Q3 on L. camara and from 0.0 for Q3 to 0.13 for Q1 on S. incanum. The net reproductive rate of the Q3 genotype was twofold higher than that of genotype Q1 on L. camara (R₀ (Q3) = 20.30; R₀ (Q1) = 8.83). Generation times decreased from 21.3 to 19.86 days for Q1 genotype and 15.8 to 00.0 for Q3 genotype on L. camara and S. incanum, respectively. Results indicate that Q1 genotype adapted better to host plants than Q3 on the tested hosts, providing an hypothesis of increased invasive ability.

Here we present the first records and new data on the biology of flesh flies (Diptera: Sarcophagidae) emerging from terrestrial snails belonging to the families Cochlicellidae, Helicidae and Hygromiidae collected from eight sites on the Moroccan Atlantic coast over the period May 2015 to May 2016.We successfully identified 271 adults of these flies. Five of them represent new records for the Moroccan fauna.With these new records, the number of known species belonging to the family Sarcophagidae in Morocco has been increased from 51 to 56.

The predatory efficacy of phytoseiid mites, Neoseiulus barkeri was evaluated against onion thrips in controlled conditions. Different larval instars and adult thrips were provided as prey in different combinations (choice) or separately (no-choice). In choice test, no significant difference was observed in total thrips consumption per day. But in both observation hours (12 h or 24 h), a significant difference was observed between the feeding of immature and adult thrips. In a no-choice test,when we confined N. barkeri to feed on a specified diet of T. tabaci (first instar, second instar, or adults separately), a significant difference in total thrips consumption per day was observed in each prey group. In both tests, predatory mites fed more on first larval instar thrips compared to second larval instar and adults. However, consumption rate was rather higher during initial feeding hours (12 h) and slowed down later (24 h); this may be due to aggressive predation initially. The findings suggest that N. barkeri feed more on younger instars of T. tabaci and if these predators are released during early pest outbreak it will control the thrips population.

The Aphidiinae (Hymenoptera: Braconidae) are solitary endoparasitoids and koinobionts which are frequently used as biological control agents against aphids. Six aphidiine genera and 15 parasitoid species from 18 aphid taxa occurring on 42 plant taxa belonging to 18 botanic families were identified and 49 parasitoid-aphid associations are reported. In addition, this survey exhibits two species which are Aphidius platensis (Brethes, 1913) and Praon barbatum (Mackauer, 1967) and they are reported for the first time in Tunisia.

Biological assays were carried out to determine the effectiveness of powders of three locally available plants, Dennettia tripetala (G. Backer), Xylopia aethiopica (A. Rich) and Aframomum melegueta (K. Schum), for the control of Cylas puncticollis a sweet potato weevil. Powders of the leaves and fruits of each plant were separately applied at concentrations of 1, 3 and 5% (w/w for powders) for biological assays. This was laid out in a completely randomised design with each treatment replicated four times. Results revealed that 3 and 5%powders of the three test plants led to significantly (P < 0.05) higher mortality of C. puncticollis as compared to 1 % (powders) and the control (0.0 for powder). The fruit powders were more effective than leaves. The effectiveness of these plant products on C. puncticollis was directly proportional to concentration, with higher concentration providing greater protection of the tubers. Powders of A. melegueta and X. aethiopica fruits at 5 % applications caused the highest significant mortality of C. puncticollis after 96 h.Adult emergence was also significantly higher in the control than in treated tubers with A. melegueta giving the lowest number of emerged adults. Quantitative analysis of the plant products revealed the presence of the active phytochemicals (alkaloids, flavonoids, tannins, saponins, steroids, carotenoids and phenols) in various proportions, which may have caused the mortality of the pest in question on sweet potato in post-harvest storage at a small scale in Calabar, Nigeria.

Chaoborus ceratopogones (Theobald, 1903) is recorded for the first time from Réunion Island and C. fryeri Verbeke, 1958 for the first time from Ghana. Both species are briefly rediagnosed to account for differences with previously described populations. Additional new material of C. ceratopogones from Ghana and C. pallidipes (Theobald, 1911) from Uganda is presented.

The present study aimed to evaluate the genotoxic effect of insect growth regulators (IGRs) pyriproxyfen and novaluron on the fully grown larvae and 1-day-old pupae of Bactrocera zonata. The genotoxic investigations occurred on the whole body cells of adults that emerged from the fully grown larvae in sand treated with lethal concentrations (LC₅₀ = 0.96, 11.4ppm of pyriproxyfen and novaluron, respectively) and those emerged from the 1-day-old pupae in sand treated with lethal concentrations (LC₅₀ = 4.5, 6200 ppm of pyriproxyfen and novaluron, respectively). Comet assay is the technique used in this study. The comet assay (SCGE - single-cell gel electrophoresis) is often used in measurements of the level of DNA strand breaks in individual eukaryotic cells as a rapid, sensitive and inexpensive method. However, the IGR is considered to have little human toxicity because humans do not make chitin and do not make or use the hormones that insects use in moulting, but it was noticed that IGR-treated insects resulted a significant increase in DNA damage values expressed as tail length (TL), tail moment (TM) and DNA tail%in the body cells compared to the control insects. These results mean that workers should be careful when using IGRs in the field due to the conservation of genes and pathways affecting key biological processes between flies and humans.

The use of family variation of aquatic insects in assessing freshwater quality in ecosystems has only recently been applied in the northern parts of Africa. The current study along with El Husseiny et al. (2015) and Bream et al. (2017) can be considered the first of such studies in Egypt. The survey was conducted during the period April 2015 to February 2016, in the permanent stream, El-Mansouriya, in Dakahlia province, Egypt. The water quality and health status of water for human use of this stream was determined using different aquatic invertebrate family biotic indices formulations (BMWP, SWRC and EPT indexes) along with the physical and chemical properties. Water samples were analysed and the water quality parameters were compared to the WHO (2004) standards. Most of the parameters were found to be within permissible limits, except for turbidity and nutrient salts. Aquatic insects were collected and identified to order and family levels. A total of seven orders and 19 families were collected, including a few intolerant insects (EPT orders) and insects more tolerant to pollution (chironomid larvae). The values of the water quality parameters sampled showed significant correlations with aquatic insect diversity. The canonical correspondence analysis clarified that the electrical conductivity of the water was the most significant variable affecting the variation in taxa. From these results it can be seen that the water quality of this stream is moderately impacted, and could therefore be considered harmful, since this stream is the main supply to the Water Central Station in Aga. Water quality degradation is generally due to impacts associated with population growth, industrialisation and agricultural activities. These results can be used to assist in conservation planning and decision-making in Egypt.

Agronomic trials were conducted in central SouthAfrica to establish Amaranthus cruentus as a commercial grain crop. Knowledge of potential pest- and pathogen-related problems that might arise during cultivation is essential for future industry development. Previous studies linked fungi belonging to the genera Fusarium and Alternaria with weevil damage of leafy amaranth (A. hybridus). The aim of the present study was to conduct a disease survey to identify possible fungal association with weevils (Coleoptera: Curculionidae) and weevil damage in A. cruentus fields at Potchefstroom and Taung in the North-West Province, South Africa. Isolations were made from lesion margins, larval galleries of the weevil Hypolixus haerens, and stem lesions associated with the weevils Athesapeuta dodonis and Baris amaranthi. Weevil larvae associated with lesions as well as adults collected from plants in amaranth plots were euthanased and plated out onto fungal growth media. Fungi arising from the weevils were purified and identified to genus level based on morphology. Alternaria was predominantly isolated from leaf spots in contrast to Fusarium species that were isolated from root rot, cankered roots and stems. Fusarium species were by a considerable margin the dominant group associated with weevil damage and stem lesions, as well as larval tunnels, larval bodies and free living adults. Species of Cladosporium and Alternaria were also isolated from adult weevils with significant consistency. Other less dominant fungi isolated from adult weevils and larval tunnels included species of Aspergillus, Epicoccum, Humicola, Mucor, Penicillium, Rhizopus and Trichoderma. It is evident that Fusarium and Alternaria are the genera that host the most important and potentially dominant fungal pathogen taxa linked with grain amaranth disease symptoms and associated weevil pests. As such they will have to be investigated further in future.

The insecticidal action of two insect growth disruptors (IGDs): the chitin synthesis inhibitor, diflubenzuron, and the ecdysone agonist, chromafenozide, were evaluated against the house fly, Musca domestica, larvae. The LC₂₅, LC₅₀, and LC₇₅ were used for each IGD. The total carbohydrate, protein and lipid contents were estimated, and the effects of these compounds on native protein, glycoprotein and lipoprotein patterns were investigated in third instar larvae (treated as second instars). Results of susceptibility tests demonstrated that chromafenozide is more toxic to the larvae than diflubenzuron. Application of the three lethal concentrations of diflubenzuron and chromafenozide to second instar larvae increased the total protein, carbohydrate and lipid contents in treated third instar larvae as compared to the control. The electrophoretic study revealed a reduction in native protein bands, as well as the appearance of new lipoprotein and glycoprotein bands in treated larvae. Results showed that both diflubenzuron and chromafenozide cause physiological disorders, biochemical changes as well as death of treated M. domestica larvae.

Markets importing citrus fruit including lemons, Citrus limon (L.) Burman f., from South Africa require that the fruit be free of fruit fly pests (Diptera: Tephritidae). Historically there has been no fruit fly infestation recorded on lemons destined for export from South Africa. In this study, we assessed the host status of commercial export grade Eureka lemons, Citrus limon (L.) Burmanf. cv. Eureka, for four fruit fly pest species of economic importance in South Africa: Ceratitis capitata (Wiedemann), Ceratitis rosa Karsch, Ceratitis quilicii De Meyer, Mwatawala & Virgilio, and Bactrocera dorsalis (Hendel). Trapping was conducted in 10 Eureka lemon orchards in two major citrus production regions over two citrus seasons between 2016 and 2017 to determine the level of fruit fly abundance in the sampled orchards. Lemons were collected at harvest over the two seasons in the same orchards where trapping was conducted. Fruit fly infestation of the sampled lemons was determined by dissection. Additionally, infestation of lemons was determined under forced exposure to mature mated females of C. capitata and B. dorsalis. Trapping data showed the presence of adults of all four fruit fly species in the sampled lemon orchards. No fruit fly infestation was detected in 43 222 Eureka lemons sampled at harvest. There was also no infestation of lemons under forced exposure conditions. The results of this study provide evidence with 99.99 % efficacy and a 99%confidence level that SouthAfrican commercial export grade Eureka lemon fruit is not a host for C. capitata, C. rosa, C. quilicii or B. dorsalis.

The Arabian species of the rare ant genus Parasyscia Emery, 1882 are reviewed. Two species are treated, P. rifati sp. n. and P. wittmeri (Collingwood, 1985). Parasyscia rifati sp. n. is described from the Asir Mountains, Saudi Arabia based on the worker and ergatoid gyne castes. A key to both species is presented. New locality records with a distribution map and biological notes are presented.

The aim of this survey was to evaluate three field termite sampling methods to investigate whether there is a method for the evaluation of termite diversity which does not require experienced personnel. The sampling methods included the cattle dung method, toilet paper roll method and the visual searching (scouting) method. The methods were evaluated in a transect of 2 × 100 m in cattle grazing lands during the dry and wet seasons. Thirteen species from eight genera and three subfamilies were recorded with all three methods. The results for the number of species detected revealed differences between the three methods with 57%of the termite species found using the transect search method, 29%of the species were attracted to the cattle dung bait and 14%attracted to the toilet roll bait. The most abundant species, based on the number of encounters, was for individuals in the Odontotermes genus 15 (33 %), followed by Microtermes 12 (27 %). A higher Shannon diversity index (1.80) was recorded with the transect search method, followed by the cattle dung bait method (1.54), while the toilet roll bait method recorded the lowest diversity index (0.95). Results of the Chao2 and Jackknife estimators showed that all the methods underestimated the taxa present. A combination of the transect search method and the cattle dung bait method is recommended for monitoring termite diversity.