Effective biodiversity monitoring and rehabilitation relies on a good understanding of the factors that influence species distributions and assemblage composition. Here we investigated the influence of plant community characteristics on arthropod diversity, abundance and community composition at the radioactive waste-disposal facility of the South African Nuclear Energy Corporation (NECSA), Northern Cape Province. Plant alpha-diversity and cover was similar between all five plant communities surveyed. Similarly, total arthropod alpha-diversity did not differ between these plant communities. In contrast, arthropod abundance differed between the different plant communities and was negatively correlated with plant alpha-diversity and positively correlated to vegetation cover. Also, more beta-diverse plant communities did not necessarily support greater beta-diversity of arthropods. However, different plant communities generally had different arthropod communities. This highlights the importance of maintaining a mosaic of different plant communities for the effective conservation of arthropod biodiversity in this semi-arid region.

Since 2000, the groundnut leaf miner has increasingly become a pest of groundnut and soya bean on the African continent. The origin of the pest in Africa is uncertain. Early reports in South Africa assumed it was an invasion of Aproaerema modicella (Deventer) from the Asian continent, but subsequent mitochondrial DNA COI gene (mtDNA COI) fingerprinting matched it to Aproaerema simplexella (Walker, 1864) from Australia. Prior to this, reports in the 1950s recorded it in Africa under the name Stomopteryx subsecivella (Zeller, 1852). Furthermore, it was found that A. simplexella responded to the species-specific lure developed from the sex pheromone of A. modicella. As a result of these apparent anomalies, we examined the genetic relatedness of the above species fromAfrica, India andAustralia.mtDNACOI analysis was performedon 44 specimens collected from SouthAfrica, four from Mozambique, and three each from single locations in India and Australia. In the BOLD gene bank, 70 % of the specimens analysed matched with A. simplexella sequences from Australia (99–100 %), including all three specimens from both India and Australia, and two from Mozambique. In the remaining specimens, the match was 98–99 %. Two specimens, later to be identified as parasitoids, did not match with any sequences in the BOLD gene bank. In the NCBI gene bank, 81 % of the sequences matched 99–100 %, and a further 15 % matched 92–98 % with A. simplexella sequences. Based on these mtDNA COI analyses, and the similarities of the behavioural responses originally noted between the species, we thus suggest the re-examination of the taxonomy and synonymisation of the three populations of the two species.

A cytotaxonomic study was carried out to determine the species composition and dynamics of Simulium damnosum sensu lato in Oyan River, an onchocerciasis mesoendemic area in southwest Nigeria. Simulium larvae were collected fortnightly from different attachments between March and November 2012 fixed in Carnoy's solution for laboratory identification using cytotaxonomic keys. A total of 255 Simulium larvae were obtained and identified from their polytene chromosomes. Simulium soubrense Beffa (56.5 %) and Simulium damnosum sensu stricto (43.5 %) were the two cytospecies observed. No new inversions were found in the larvae. Statistical analysis revealed a significant difference (P<0.05) in the abundance of S. damnosum s.s. and S. soubrense in relation to rainfall pattern. The sympatric breeding of both species in the area may suggest their involvement in the transmission of onchocerciasis in the area, as S. damnosum s.s. and S. soubrense Beffa are known vectors of Onchocerca volvulus in West Africa.

The role of juvenile hormone (JH) and corazonin in the maternal regulation of progeny characteristics was examined in the migratory locust, Locusta migratoria (Orthoptera: Acrididae). Crowded female adults are known to produce large eggs, heavier and darker hatchlings than solitarious female adults which produce smaller eggs, smaller hatchlings with brighter cuticular colour. Implantation of corpora allata (CA) taken from gregarious sexually mature females caused crowded females to deposit smaller eggs and smaller, lighter hatchlings. The neuropeptide [His⁷]-corazonin, present in the central nervous system and corpus cardiacum, is known to induce darkening of body colouration when injected into locusts reared in isolation. To examine whether this neuropeptide is responsible for the maternal regulation of progeny phase characteristics, 1 nmol [His⁷]-corazonin mixed with 2 µl of sunflower oil were injected twice into solitarious female adults. No effect of corazonin on egg size, the weight of the hatchlings and brightness of their cuticular colour changes was found.

Phosphine-resistant populations of lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) were reported in Oklahoma, U.S.A. in 2012. Knowledge of the fitness effects associated with phosphine resistance is important for the development of resistance management strategies. Therefore, the goal of our study was to determine if there were fitness effects associated with phosphine resistance in populations of R. dominica and T. castaneum from Oklahoma. We measured population growth and developmental rates of phosphine-resistant and -susceptible populations of these two species in a phosphine-free environment. Three resistant R. dominica populations exhibited lower population growth and developmental rates compared to the susceptible population, whereas the only resistant T. castaneum population tested exhibited higher population growth and developmental rates compared to the susceptible population. Our data indicate that there is a fitness cost and possibly a fitness benefit, respectively, associated with phosphine resistance genes in these two species. In conclusion, phosphine resistance development in susceptible R. dominica populations can presumably be slowed by infrequent use of phosphine, whereas it can be mitigated by suspending phosphine use for extended periods of time in resistant populations. However, withholding phosphine use for long periods of time may not mitigate phosphine resistance in T. castaneum.

Ethanolic extracts obtained from the seed coat of Chenopodium quinoaWilld. were evaluated for their acaricidal effect on different stages of the carmine spider mite Tetranychus urticae Koch. At 72 h after application of the extracts directly on the adult females, mortalities ranged from 30%to 93%, with concentrations of 6.11, 7.61 and 9.11%w/v producing the best results. The lethal effect of the extracts on the nymphs of T. urticae manifested at 24 h after inoculation, with mortality rates ranging between 50 % and 99 %. The extracts of C. quinoa had no lethal effect on the eggs of T. urticae. At 120 h post-application, between 76%and 89%of the larvae had hatched. The extracts showed a repellent effect on adult females of T. urticae. Oviposition by femaleT. urticae was not affected by application of sublethal concentrations of the extract. The survival of juveniles whose mothers were sprayed with the extracts ranged between 17 % and 48 %, showing a sublethal effect of the extracts on the offspring. Lethal concentrations of the extract of C. quinoa for adult females of T. urticae were determined as 1.24 % w/v (LC₅₀) and 4.34 % w/v (LC₉₀).

In South Africa, after harvest and prior to the winter months, when the entire codling moth population enters diapause, no control measures are applied in apple and pear orchards. The biocontrol potential of three imported entomopathogenic nematode (EPN) isolates, being Steinernema feltiae and two isolates of Heterorhabditis bacteriophora (Hb1, Hb2), as well as a local isolate, S. yirgalemense, were evaluated for the control of codling moth under local conditions. All concentrations of S. yirgalemense, applied by immersion in a suspension of nematodes, gave >98 % control. The in vivo-produced S. yirgalemense resulted in codling moth control of >90 %, compared to 54 % and 31 % control by the H. bacteriophora Hb1 and Hb2 isolates, respectively. In follow-up field trials, S. feltiae resulted in ³80 % control, and was more effective than both the S. yirgalemense and the H. bacteriophora (Hb1) isolates. To validate the data obtained from the field trials, subsequent laboratory bioassays were conducted evaluating temperature regimes, following the same cycle as under natural conditions, with a constant humidity of 100 %. Steinernema feltiae proved to be most effective, causing >90 % mortality, followed by S. yirgalemense, with 78 % mortality. The two H. bacteriophora isolates (Hb1, Hb2) under the above-mentioned laboratory conditions, resulted in 73 % and 59 % control, respectively. Humidity, thus, seems to be the most important factor affecting EPN efficacy during above-ground applications. From the results obtained, it can be concluded that H. bacteriophora will not be suitable for the control of codling moth, with S. feltiae proving to be a better candidate than S. yirgalemense for such control purposes.

Black beetles (Heteronychus spp., Coleoptera: Dynastidae) are significant pests of upland rice in the Central Highlands of Madagascar, particularly in some conservation agriculture (CA) systems. On the other hand, certain species of cover crops used in CA systems may have a suppressive effect on black beetle populations or reduce the damage they cause to rice plants. Between 2009 and 2011, we conducted a laboratory study on the possible effects of adding dried ground plant parts (hereafter ‘residues’) to the soil on larvae (white grubs) and adults (black beetles) of Heteronychus bituberculatus. Ten cover crop species were tested: Cajanus cajan, Crotalaria grahamiana, Desmodium intortum and Vicia villosa (Fabaceae); Brachiaria ruziziensis and Eleusine coracana (Poaceae); Cosmos caudatus and Tagetes minuta (Asteraceae); Cleome hirta (Capparaceae); and Raphanus sativus (Brassicaceae). Adding residues of C. grahamiana, E. coracana and C. caudatus resulted in significantly higher larval mortality than in the control treatments, while residues of R. sativus had a marginally significant effect. Adding residues of C. grahamiana, C. caudatus, C. hirta, T. minuta and R. sativus significantly reduced damage caused by adult black beetles.

False codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is indigenous to sub-Saharan Africa. It infests a large number of wild plants and can be a pest of commercial concern in cultivated fruit and nuts. A limited number of insecticides, as well as biological control and mating disruption can be applied as control measures in citrus, but they often do not reduce pre- and post-harvest crop loss adequately. The potential of the sterile insect technique (SIT) for the control of T. leucotreta was investigated between 2002 and 2006 in Citrusdal, Western Cape Province, South Africa, and entailed studies on radiation biology and F1 sterility, compatibility with the egg parasitoid Trichogrammatoidea Nagaraja (Hymenoptera: Trichogrammatidae), and field cage experiments to determine sterile:fertile moth overflooding ratios. Promising results justified a pilot experiment conducted on semi-commercial scale in citrus orchards in Citrusdal during 2005–06. One thousand mixed sex moths were treated with 150 Gy ionising radiation and released in 35 ha of Washington navel oranges twice a week for 28 weeks during the production season. The moths were released by hand from an all-terrain vehicle, with release rows 40mapart and the numbers of released and feral moths monitored weekly with pheromone traps. Released moths dispersed well and fully overlapped between release rows. The target overflooding ratio of released to feral males (10:1) was exceeded by wide margins and ameanoverflooding ratio of 41:1 was maintained during the experiment. Fruit drop assessments were conducted once a week in the SIT-treated and control orchards. Crop loss due to T. leucotreta infestation was reduced by 95.2 % in the SIT-treated area compared to the control orchard. The project resulted in the commercialisation of the SIT for T. leucotreta on citrus.

Food quality has a profound impact on various life history traits, including life span, development time and resistance to infections. In the current study, we used isofemale lines originated from African and European populations that cover a broad range of performances regarding different life history traits. These isofemale lines showed very different survival rates even on standard medium, which is indicative of a significant impact of the genotype on their overall performance. It was hypothesised that different nutritive yeast species influence life history traits. Thus, we used two different yeast species that are usually associated with Drosophila and that may function as major food sources under natural conditions. Adding either yeast species Pichia toletana or Metschnikowia pulcherrima as a food source, increased survival rate and decreased development time; P. toletana was more effective than M. pulcherrima. This difference was also reflected in a behavioural choice assay showing that P. toletana was more attractive than M. pulcherrima. Pichia toletana had not only positive effects on the different life history traits under control conditions, but it also increased the resistance to infection with the pathogenic bacterium Pseudomonas stutzeri. Confrontation with either yeast species induced expression of the antimicrobial peptide gene drosomycin. The expression pattern of this antimicrobial peptide was similar to what is observed after stress-induced activation of the immune system rather than that observed after conventional infection with a pathogen. The results presented in this study support the hypothesis that different nutritive yeast species affect Drosophila survival rate, decrease development time and increase resistance to infection. This study provides evidence that the fitness of Drosophila critically depends on the fly's genotype as well as the nutritive yeasts.

A taxonomic revision of the South African mealybug genus Octococcus Hall is presented. Most species of this genus feed on plants in the Asteraceae. Six species are treated, namely, O. barbarae, O. gullanae. and O. warniae which are described as new. The three previously described species are: Octococcus africanus (Brain), O. minor De Lotto, and O. pentziae Hall. Octococcus salsolicola (Priensner & Hosny), which was described originally as Ripersia salsolicola, is treated as a nomen dubium. Adult females of all species are described and illustrated and a key for their identification is presented. Illustrations and descriptions are also presented of first-instar nymphs of Octococcus africanus, O. minor, and O. warniae and a key for their identification is presented. Descriptions and illustrations are also given for a second-instar nymph of O. africanus and a third-instar nymph of O. warniae.

In the first study of its kind, ants (Hymenoptera: Formicidae) were sampled near a unique natural environment, a large saline lake, Chott El Hodna, a Ramsar ConservationWetland in eastern Algeria. The species of ants were determined at two sites, Medbah and Birkraa in spring (March–April) 2011 using pitfall trapping and hand collecting.We provide a checklist and some observations on 24 species belonging to 14 genera and four subfamilies (Dolichoderinae, Dorylinae, Formicinae and Myrmicinae). To evaluate the ant diversity, we used data from pitfall traps for calculating ecological indexes.

Agathis bishopi (Nixon) (Hymenoptera: Braconidae) is a koinobiont larval endoparasitoid of false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a pest of economic importance on citrus in South Africa. In the field Agathis bishopi was found to parasitise up to 34 % of FCM larvae in fruit, reflecting reasonable biocontrol potential. Improving the rearing of A. bishopi would therefore complement the existing biocontrol strategies for FCM. In several parasitic wasps, sugar concentration and feeding duration has been shown to influence parasitism and longevity. However, their effect on parasitism and longevity of A. bishopi is unknown. In the present study a rearing protocol for A. bishopi is described, including evaluation of the effects of honey concentration on parasitoid longevity. On average, 18.2%of FCM larvae in rearing containers were parasitised under the rearing protocol described. Cotton wool, instead of paper towelling, as honey carrier for feeding parasitoids in rearing containers significantly increased parasitism and yield of offspring. Furthermore, longevity significantly increased with higher concentrations of honey. Maximum lifespan duration for male and female parasitoids was achieved when parasitoids were fed on 36 % (w/v) honey. Results from this study indicate that A. bishopi requires a sufficient concentration of sugar, coupled with frequent and prolonged feeding on a cotton wool substrate, in order to achieve maximum parasitism and longevity. Such information provides a basis for optimising mass-rearing and longevity of A. bishopi and parasitism of FCM in orchards.

Plant cultivars that negatively influence fitness of target phytophagous insects can be an important component of integrated pest management when they substantially restrict population growth of the target pest. In this study, the effects of seven cabbage (Brassica oleracea var. capitata L.) cultivars on survival and development of immature stages, pupal weights, moth longevity and oviposition rates of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), were evaluated in the laboratory. Under the no choice test, overall survival of P. xylostella immature stages was highest on Karabo (67.26 %) and lowest on Megaton (44.92 %). The larval and pupal developmental period, and thus generation time took longer on Empowa (18.48 d), Karabo (14.64 d) and Beverly Hills (17.48 d), while development on Hollywood F1 (13.79 d) was the fastest. Male and female P. xylostella pupal weights were lower in larvae that fed on Megaton (4.13 and 4.65 mg), Menzania (4.53 and 4.91 mg), and Hollywood F1 (4.11 and 5.08 mg), whereas pupal weights from Karabo (6.0 and 6.82 mg) were the heaviest. Unfed female moths reared on Beverly Hills lived the longest (5.05 d), whereas those reared on Leano (3.54 d) and Megaton (3.89 d) lived for a shortest period. Under the choice-test, P. xylostella laid significantly more eggs on Empowa (48.8 %) and Hollywood F1 (45.6 %) and least on Menzania (11.8 %) and Leano (10.6 %). Although these results show differential impact of the cultivars on the fitness parameters studied, low survival rate of offspring on a crop is the primary target for using plant resistance as a pest management tactic. As survival rates of immature P. xylostella were lower on Megaton together with lower pupal weights and moth longevity, which together negatively impacts fecundity, and thus overall fitness of the pest was lower when developing on it. Megaton was more resistant to P. xylostella. The results of this study show that Megaton can play a major role in restricting population growth of this pest and generational number of eggs deposited on it.

There is a paucity of knowledge of whitegrub pest species in black wattle (Acacia mearnsii) plantations, which hampers the development of integrated pest management programmes. This study determined the composition and community structure of the various whitegrub morphospecies that attacked seedlings during their re-establishment on 10 previous wattle sites in KwaZulu-Natal, South Africa. Whitegrub specimens collected from these trials were examined in the laboratory to determine which morphospecies were present and their abundance. Morphospecies were separated on the basis of their species-specific raster patterns. Multivariate analyses were done using PRIMER (Plymouth Routines in Multivariate Ecological Research) as statistical package. The proportions of morphospecies at the different sites were evaluated by using the non-metric multi-dimensional scaling (MDS). Thirteen whitegrub pest morphospecies were found attacking A. mearnsii seedlings. About 98%of the total whitegrub abundance was represented by seven morphospecies and the remaining about 2%was represented by six whitegrub morphospecies. Three different whitegrub pest community structure patterns were found. The black wattle silvicultural weeding and plantation residue management practices of the South African forestry industry explained the resultant three whitegrub pest community assemblages. These practices were windrowed-burnt-weeded or with closer spacing, weeded fallow sites and windrowed-burnt-ripped or planted in an old arable land. The greatest species richness (13 morphospecies) and abundance (95 %) of whitegrubs was the community assemblage under the windrowed and burnt silvicultural practices. The whitegrub pest community was less abundant (3% and 2%) and diverse (six and five morphospecies) in sites that were left fallow before planting and where the silvicultural practices were windrowing, burning and ripping or planting in an old arable site, respectively.

Most ponerine ants have flying queens that monopolise sexual reproduction, but in a minority of species, workers can also mate and lay fertilised eggs. Such ‘gamergates' reproduce in addition to queens in some species but have replaced queens entirely in other species. The occurrence of a functional spermatheca in workers often appears associated with a slight difference in body size relative to winged queens, as is the case in Euponera sikorae (Forel) studied here. Eight colonies (19.9±8.7 workers and 0–2 dealate queens) were collected in humid forests of Madagascar. A mated queen reproduced in most colonies, but ovarian dissections indicated that 1–3 workers were also inseminated, and one of these laid eggs if the original founding queen was missing or no longer fecund. Exoskeleton remains (including 29 heads) of a staphylinid beetle were found in one nest of E. sikorae, pointing to specialised predation. We review the occurrence of non-flying reproductives (gamergates and ergatoid queens) in Odontomachus genus-group.

The developmental and reproductive biology of the two-spotted spider mite, Tetranychus urticae (Koch), a devastating polyphagous pest, were studied on five vegetables in summer (27–36 °C, RH 81–85 %) and winter (5–19 °C, RH 70–75 %) under prevailing laboratory conditions. Immature developmental time and adult longevity were inversely related to seasons. The results indicated that the development of the mite increased more rapidly on bean in summer than on the other tested hosts. The longest developmental period was 41.94 and 41.07 days for females and males, respectively, in winter when T. urticae was fed on cowpea. In contrast, it was the shortest (11.25 and 10.39 days) in summer while reared on bean. Lifetime fecundity (62.71) and daily fecundity (5.48) was the highest on bean in summer. The sex ratio (female:male) was the highest (0.76) on cowpea and the lowest (0.66) on brinjal in winter. Survivorship during immature development varied from 82.14 to 95.65 %, with the lowest rate in summer when reared on bean. Life table parameters were analysed and the generation time (T) was found the lowest (20.37) in summer when fed on bean, net reproductive rate (R₀) was the highest (36.29) in summer on cowpea and both intrinsic rate of natural increase, r_m (0.17), and finite rate of increase, l (1.19), were the highest in summer when fed on bean.

One antimicrobial peptide was isolated and purified to 5.50-fold from the crude lysate of immunised Aedes caspius larvae by (NH₄)₂SO₄ fractionation, ion-exchange chromatography, and reverse-phase high performance liquid chromatography (HPLC). The peptide, named ACAm, was found to be heat stable below 80 °C and exhibited strong antimicrobial activities against Gram-positive and Gram-negative bacteria as well as against peptidoglycans and lipopolysaccharides of bacterial cell walls. The estimated molecular weight of ACAm by sodium dodecyl sulphate polyacrylamide gel (SDS-PAGE), under non-reducing conditions, was 4 kDa. Using isoelectric focusing (IEF), ACAmexhibited pI in basic pH (8.4) belonging to cationic peptides.

Postharvest disinfestation of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) in citrus fruit can be achieved through cold treatment, but chilling injury becomes increasingly problematic with lower temperature and longer exposure to the treatment. Ionising radiation is an alternative treatment, but also has a dose dependent negative effect on fruit quality. The potential of including both a reduced radiation dose and a less detrimental cold treatment in a combination treatment was assessed. The effects of 40 to 70 Gy radiation and cold treatments of 0.6 °C to 7.0 °C for periods of 10 to 22 days by themselves and in combination, were investigated on mature larvae in artificial rearing diet. It was demonstrated that various combinations of the two methods can act together to potentially provide adequate control, with the prospect of moderated fruit quality effects due to the reduced intensity of the component treatments. A combination treatment consisting of 60 Gy followed by 16 days at 2.5 °C was identified for further evaluation as a combination treatment that could potentially be validated at the probit-9 level of efficacy.

To overcome constraints on ionising radiation and cold treatment as stand-alone disinfestation treatments for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) in citrus fruit, the efficacy of a combination treatment consisting of ionising radiation and cold, both at reduced doses, was tested at the probit-9 level. Earlier research indicated that combination treatments involving ionising radiation and cold suppressed larvae and their successive development stages more effectively than the individual treatments. The probit-9 level efficacy (at least 93 613 insects) of a treatment combination comprising 60Gyof ionising radiation followed by cold exposure for 16 days at 2.5 °C was evaluated. A total of 104 617 mature, fifth instars was treated. Larval mortality was 99.7%and 50.2%of the subsequent pupae died. A total of 143 moths with a sex ratio of one female to 7.9 males eclosed. Only 4.8%of the moths were able to fly. No eggs were produced by the moths in mating studies. The probit-9 level efficacy of the combination treatment was validated, indicating that it meets the efficacy requirements for utilisation as a phytosanitary disinfestation treatment for T. leucotreta in citrus fruit in international trade.

The Diptera family Ulidiidae or picture-winged flies known from the Kingdom of Saudi Arabia are reviewed. Six species in three genera are recognised, Ceroxys confusa (Becker), C. urticae (Linnaeus), Melieria nigritarsis Becker, M. omissa (Meigen) [Otitinae], Physiphora alceae (Preyssler), and P. smaragdina (Loew) [Ulidiinae]. Only M. nigritarsis and P. alceae were previously recorded from the Kingdom. The other four species, C. confusa, C. urticae, M. omissa, and P. smaragdina represent new country records. Additionally, the above records of Ceroxys are new for the Arabian Peninsula. Physiphora smaragdina (Loew) is known for most of Africa except SouthAfrica. This is the third time this species is recorded outsideAfrica in addition to Israel and the United Arab Emirates. The Saudi Arabian genera and species are keyed and images are provided to facilitate identification.

In the short communication ‘New records of the parasitic wasp Dinocampus coccinellae (Hymenoptera: Braconidae) and its hosts in South Africa’ by I.A. Minnaar, R. Shinner, S.Van Noort & S. Clusella-Trullas that appeared in African Entomology 22(1): 226–229 (March 2014), the species named ‘Adalia flavomaculata De Geer’ should have read ‘Lioadalia flavomaculata (DeGeer)’ and the authority names for all species should have been listed as follows: ‘Dinocampus coccinellae (Schrank)’, ‘Cheilomenes lunata (Fabricius)’, ‘Exochomus flavipes (Thunberg)’, ‘Hippodamia variegata (Goeze)’, ‘Harmonia axyridis (Pallas)’ and ‘Cheilomenes propinqua (Mulsant)’.