Vespula germanica (Fabricius) and Polistes dominula (Christ) are known to represent a significant threat to the biodiversity of ecosystems that they invade. Following their discovery in South Africa, there has been a lag in investigations into the presence and spread of both invasive wasp species in South Africa with limited action taken to address their expansion. Recent research indicated that populations of both species are still restricted to the Western Cape Region, where the Cape Fold Mountain Belt seems to serve as a barrier to further spread to the rest of South Africa. The limited distribution range creates a favourable scenario for management efforts and, if acted on rapidly, increases the possibility of successful control. Various control methods, including mechanical, chemical and biological control have been developed and implemented internationally in an effort to curb population expansion of social wasps. These methods, together with a summary of the initiatives that have been launched locally to control these wasp species, are discussed in this review.

The fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae), is the most important noctuid pest in the Americas and has recently become an invasive pest in Africa. A detailed record of S. frugiperda's host plants is essential to better understand the biology and ecology of this pest, conduct future studies, and develop Integrated Pest Management programmes. In this study, we collected and systematically arranged the fragmented bibliographic information on S. frugiperda feeding records. Furthermore, we registered new records of host plants for S. frugiperda based on eight years of surveys in Brazil. The literature review and surveys resulted in a total of 353 S. frugiperda larval host plant records belonging to 76 plant families, principally Poaceae (106), Asteraceae (31) and Fabaceae (31). The literature search revealed 274 (77 % of total) bibliographic records, while 82 (23 %) are new records from surveys in Brazil. The new comprehensive and updated host plant list will improve our understanding of pest biology and management, as well as facilitate future studies on this pest.

This study evaluated the potential of mass trapping to reduce Prostephanus truncatus population numbers in granaries and hence its possible utilisation as pest management tool. Universal moth traps (Uni-traps) were used to trap the pest and its predator, Teretrius nigrescens Lewis (Coleoptera: Histeridae), in granaries of small-scale farmers in three villages of the Gaza Province of Mozambique during the maize storage period of August 2013 to January 2014. Five granaries were selected in each village. Two baited pheromone traps were set up adjacent to each of three of these granaries. The other two granaries were used as controls, without traps. Numbers of both the pest and its predator were monitored in these traps as well as in stored maize ears inside the granaries for a 6-month period. Mean numbers and densities of P. truncatus, the percentage damaged maize kernels and maize kernel weight loss in granaries with and without traps were compared by means of t-tests. The Cohen's standard of effect size was applied to measure the magnitude of differences between studied variables. An average of 1272 individuals of P. truncatus was caught per trap. Mean densities of P. truncatus recorded per maize ear in granaries with traps were lower (27 individuals/ear) than of those without traps (129 individuals/ear). Mean numbers of T. nigrescens per trap followed similar patterns between granaries with and without traps. The percentage of damaged maize kernels was higher (62 %) in granaries without traps than in those with traps (22 %). Highly significant negative correlations were found between mean numbers of P. truncatus caught in traps and mean infestation in maize ears inside granaries. These findings indicate that mass trapping holds potential for control of P. truncatus in granaries of small-scale farmers.

Cucurbits are among the most valuable food crops in various developing countries of sub-Saharan Africa. The development of integrated strategies in their pest management is limited by lack of information on fruit losses, especially by tephritids and their pest status on crops. Thus, based on fruit damage rates and infestation rates, cucurbits' susceptibility to tephritids was assessed in Yaoundé and Koutaba, two localities situated in different agroecological zones in Southern Cameroon. From systematic samplings in trap plots, 6009 damaged fruits from nine cucurbit species were collected weekly and bimonthly and incubated during 2009–2011. Fruit losses, which were evaluated at 36.73±1.90%atYaoundé and 37.08 ± 3.22 % at Koutaba, did not vary in relation to locality. Losses due to tephritids were more important on Sechium edule and Cucurbita moschata at Yaoundé and on S. edule, Citrullus lanatus (watermelon), Cucumis melo (sweet melon), Cucumis sativus and Cucurbita moschata at Koutaba. At each site, Cucumis melo var. agrestis was the less susceptible species. With the exception of S. edule, developing fruits were more susceptible to tephritids as 80% of positive fruits weighed less than 100 g. Moreover, four tephritids emerged from fruits; Dacus bivittatus and Dacus ciliatus appeared to be the major pests and Dacus vertebratus a minor pest. Pest status of Dacus punctatifrons depends on border plants. Also, D. ciliatus exhibited preference for Cucurbita moschata and D. bivittatus for S. edule and Cucumeropsis mannii. Our findings provide useful data for the conception of Integrated Pest Management (IPM) strategies against tephritids.

European red mite (ERM), Panonychus ulmi (Koch) is a major pest of fruit crops (apple and almond) in Kashmir Valley, India. Investigations were carried out at ICAR-Central Institute of Temperate Horticulture, Srinagar,Jammuand Kashmir to study the population dynamics, biology and efficacy of acaricides against P. ulmi on almond and apple. In both the crops highest population (31.56 and 6.46 mites/leaf), respectively, was observed in the 29th standard week (SW) and significantly correlated with the temperature. Biology of ERM was also studied on almond: eggs hatched in 6.50 ± 0.29 days; larval development took 2.00 ± 0.00 days; protonymphal and deutonymphal stages lasted for 1.75±0.25 days each. Longevity of adult males and females was 4.25 ± 0.25 and 8.25 ± 0.48 days, respectively. The efficacies of some of the acaricides were evaluated against ERM on almond. Among these, fenazaquin 10 EC (0.004 %) was found to be excellent with 94.92 % mortality of ERM on almond.

Bradysia spp. are major pests of undercover crops, to which they can cause considerable economic loss. The use of entomopathogenic nematodes (EPNs) for the control of Bradysia spp. has proven to be relatively advantageous, since sciarids are mostly pests of undercover crops that have a short lifecycle, or for which the application of pesticides is unsuitable. In this study, eight South African local EPN species and a non-native EPN species, namely Steinernema feltiae, were tested for their ability to kill Bradysia impatiens larvae at different temperatures. The results showed four local EPN species, Steinernema yirgalemense, Heterorhabditis noenieputensis, Heterorhabditis indica and Heterorhabditis zealandica, achieving higher than 80 % mortality, at 25 °C and 30 °C, from the different bioassays performed. Heterorhabditis zealandica had the lowest LD50 of 2.60 infective juveniles (IJs) per larva and LD90 of 18.68 IJs/larva. Steinernema yirgalemense had an LD50 of 8.98 and an LD90 of 64.16, which were similar to those of H. indica. Steinernema yirgalemense, H. indica and H. zealandica were all able to reproduce inside the fourth-instar larvae of B. impatiens, and to produce IJs. The relatively larger nematodes, Steinernema jeffreyense, Steinernema khoisanae, and Steinernema litchii were unable to infect the fourth-instar larvae of B. impatiens, which indicated that the size of the EPNs affected their ability to infect fungus gnat larvae. This study demonstrated the high potential for the use of locally isolated EPNs for the control of fungus gnats in South Africa.

The tropical ichneumonid wasps are poorly sampled, particularly in the Old World, despite their ecological importance and high species richness. Existing inventories also tend to have had a taxonomic focus, with trap placement reflecting the need for maximal sample size rather than rigorous ecological comparisons. Here, we report the results of an intensive sampling effort at Kibale National Park, Uganda, carried out with randomised trap locations. We sampled ichneumonid faunas for a year (2011–2012) with Malaise traps, in eight successional sites ranging from clear-cut exotic plantations to primary rainforest. The traps were situated in 10 random locations at each site and were moved between locations once a week. The total sampling effort encompassed 231 trap months (using traps smaller than the standard size), one of the largest we know of from a single Afrotropical location.We sorted the collected ichneumonids into subfamilies and investigated whether their community composition differed between the sites. Ichneumonid faunas differed between forest and former plantation sites, with both the overall difference and that of four subfamilies significant. Our sample size was unexpectedly small (1212 individuals), but we estimate that the model-based analyses we used could still have given a significant result with a smaller (954 individuals) sample. Overall, randomly placed Malaise traps detected ecological patterns in Afrotropical ichneumonid distributions. Our data also showed that there is a rich and at least partly undescribed ichneumonid fauna still awaiting discovery in the Afrotropical rainforests. Future inventories of this fauna may, however, have to compromise on objective random trap placement in order to get a large sample size.

Among insects, the melanisation immune response is an important part of their innate immunity. Current research has provided evidence that insects regulate their melanisation immune response via the activities of inhibitors, such as the serine protease inhibitors. However, as the key substrate of the melanisation process, it is plausible that dopamine may also play a role in regulating the strength of the melanisation immune response. To address this hypothesis, a novel transgenic RNAi-inhibited gene system was developed to suppress dopamine catabolism in the model lepidopteran insect, the silkworm Bombyx mori, and later challenged the resulting transgenic insects with the bacterium Escherichia coli. Furthermore, comparisons were made on the expression levels of dopamine related genes amongst the transgenic and wild type silkworms in two of the major insect immune tissues, fat body and haemolymph, using real-time PCR and Semi-quantitative PCR. Results from this study showed that when E. coli germsolution was injected into the silkworms, the concentration of dopamine was markedly increased in the transgenic compared with the wild type group. The expression of genes BmTH and BmDDC, which are involved in the anabolism of dopamine was suppressed while the expression of genes BmEbony and Bm-iAANATs, which are involved in dopamine catabolism was elevated in transgenic silkworms injected with E. coli. These findings suggest that dopamine may play an important role in regulating the strength of the melanisation immune response. Therefore this study contributes to the current knowledge of melanisation immune response in insects.

Our study examined the repellent and toxic effects of ethanolic extracts from Mentha haplocalyx and Allium ascalonicum against adult and larval forms of maize weevil, Sitophilus zeamais, at 25 ± 2 °C with 50±5% relative humidity (RH) and 14L:10D h light-dark cycles in the laboratory. Filter paper discs, 9 cm diameter, were used for area preference testing to determine repellency. One-half of the filter paper was treated with 0.1 ml of essential oil, while the other half was treated with a control solution. Twenty weevil adults were released into each Petri dish on the filter paper and covered with a lid. The experiment was repeated with weevil larvae. Repellency was recorded at 6, 12, 24, and 48 h of exposure. Mentha haplocalyx repellency to adults (67.50 %) and larvae (67.50 %) was higher than A. ascalonicum repellency to adults (66.25 %) and larvae (63.75 %). For toxicity testing, 0.1 ml of essential oil was applied on filter paper discs, 6-cm diameter, and papers were placed inside the lids of 100-ml jars. The lids were placed on jars after weevil adults were added. The test was repeated with weevil larvae. Fumigant toxicity was recorded at 4, 8, 12, and 16 h of exposure. Mentha haplocalyx toxicity to adults (37.34 %) was higher than A. ascalonicum toxicity to adults (26.35 %), whereas A. ascalonicum toxicity to larvae (50.29 %) was higher than M. haplocalyx toxicity to larvae (46.36 %). The chemical components of the essential oils were identified using gas chromatography–mass spectrometry (GC-MS). Bioactivity was higher for M. haplocalyx than A. ascalonicum. Further study is recommended on the bioactivity of individual chemical components of essential oils on S. zeamais and other insect and non-insect pests of stored grains.

Damage incidence and interactions between native and invasive vegetable-infesting fruit flies (Diptera: Tephritidae) on high-value crops have rarely been studied, despite their threats to the horticultural industries in Africa and quarantine implications.We established the composition and host range of tephritid flies in the field and carried out comparative host suitability studies of major fruit flies: Dacus bivittatus (Bigot), Dacus ciliatus Loew and Zeugodacus cucurbitae (Coquillet) on watermelon [Citrullus lanatus (Thunb.)], cucumber (Cucumis sativus L.), courgette (Cucurbita pepo L.) and butternut (Cucurbita moschata Duchesne) in the laboratory. Five new host species were recorded. Zeugodacus cucurbitae was the most destructive fruit fly, infesting 17 hosts from five families, followed by D. ciliatus and D. bivittatus. Direct field damage inflicted on immature to mature crops on the plants ranged from 2.1%on eggplant (Solanum melongena L.) to 66.8%on bitter gourd (Momordica charantia L.). The most preferred hosts of Z. cucurbitae were bitter gourd, watermelon and tomato (Solanum lycopersicum L.) (16.2, 13.3 and 12.1 flies/kg fruit, respectively). Mango (Mangifera indica L.) (24.1 flies/kg fruit) and guava (Psidium guajava L.) (14.7 flies/kg fruit) were recorded for the first time as hosts of D. ciliatus. The relative abundance index showed high variation among host species, suggesting a differential use of these hosts by the different fruit fly species. Choice versus no-choice experiments revealed a significant variation in pupal recovery, pupal size, adult emergence, percentage females, adult wing deformity and body size. These results are significant for the decision-making process for effective monitoring and management of fruit fly species on cucurbitaceous vegetable crops.

The Ga-Selati River has been systemically impaired by increasing human activities in its catchment, resulting in contamination by mining, industrial and agricultural effluents and domestic waste, and as a result significantly impacting the water quality of the river. The study aimed at investigating the ecological state of the Ga-Selati River and the impact of water quality on the aquatic macroinvertebrate communities was conducted in 2014 and 2015. Five sites along the Ga-Selati River were selected for sampling macroinvertebrates. The family composition, based on abundance and diversity, was evaluated in relation to environmental variables. The levels of dissolved oxygen, conductivity, total dissolved solids, turbidity and nutrients affected the distribution of tolerant taxa. The number and diversity of macroinvertebrates were found to be higher at less degraded upstream sites compared to more degraded downstream sites. A canonical analysis clearly grouped the various macroinvertebrates with the physico-chemical parameters having an influence on their distribution. The relatively high influence of environmental factors in the abundance and distribution of the sensitive taxa highlights the importance of environmental variation on macroinvertebrate assemblages.

Aphids are major pests of African indigenous vegetables. Information on the genetic diversity and the role of host crop and environmental differentiation in their diversity in East Africa is scanty. The knowledge on genetic diversity is a critical component in the development of sound and sustainable integrated pest management strategy, from detection to control. A portion of the mitochondrial cytochrome c oxidase subunit I (COI) gene was used to characterise the species of aphids on amaranth and nightshades at different agro-ecological zones of Kenya and Tanzania. Aphid samples were collected in localities growing the vegetables in low, mid and high altitude agro-ecological zones. Total DNA was isolated and amplified using universal barcoding primers targeting the 5′ end of the COI barcode region. Nucleotide sequences of the COI barcode, using the Basic Local Alignment Search Tool model, found high homology to four species of aphids: Myzus persicae, Aphis fabae, Aphis craccivora and Macrosiphum euphorbiae. Three subspecies of the A. fabae were also detected. Intraspecific diversity depicted M. euphorbiae having the lowest value, while A. fabae showed the highest diversity. Interspecific diversity between A. fabae and A. craccivora was the lowest while between A. craccivora and M. persicae it was the highest. The phylogenetic tree showed each species clustering together irrespective of the host crop or site where collected. Principal component analysis and haplotype network analyses confirmed these results. Low genetic diversity revealed by COI suggests that the environment or host crop contribute less to the genetic diversity of aphids in both countries.

Inoculation by means of injection has become a prominent bio-manipulation technique. This physical delivery system offers an advantage over other techniques by introducing precise quantities of inoculate into any life stage of an organism. However, this technique is intricate, laborious and requires extensive optimisation. Factors such as the location of injection, age of the organism, injection volume, and nutritional status of the organism prior to injection are variables that will likely differ between species. Bio-manipulation studies have been performed on the major African malaria vector mosquito species, Anopheles gambiae s.s., yet they are still lacking for the closely related vector An. arabiensis. This study established a method of nano-injection procedure for An. arabiensis mosquitoes and found that the highest rate of survival was achieved when 1-day-old mosquitoes, fed on a 10 % sucrose solution prior to injection, were intra-thoracically injected using an inoculation volume of 69 nl.

Mass use of insecticide-treated mosquito nets impregnated with permethrin or its derivatives is likely to result in a decline in vector density and transmission of malaria. The present study shows, on the contrary, higher mosquito aggressiveness and an increase in malaria transmission in a district of Douala where alpha-cypermethrin impregnated mosquito nets were recently distributed.Asurvey of the coverage and utilisation of insecticide-treated nets (ITNs) was conducted in February 2016 in the Youpwé district. Night catches of adult mosquitoes on human volunteers were carried out prior to (January 2016) and after (March 2016) alpha-cypermethrin impregnated mosquito nets distribution, in and outside eight randomly selected houses in the Youpwé district. Mosquitoes were identified according to morphological and molecular criteria. The physiological age of mosquitoes was determined according to the Detinova method. Vectors' infectivity was determined by the ELISA CSP test. Long-lasting insecticidal nets coverage and utilisation rates in the Youpwé district were 95.2%and 90 %, respectively. Overall, 3923 mosquitoes were collected within 32 man-night catches. Anopheles coluzzii (24.8 %, n=973) and Culex quinquefasciatus (75.2 %; n=2950) were the only species aggressive to humans. The biting rate was significantly higher after ITN distribution (P=0.024). The aggressiveness cycles were similar during the two phases of the study with a peak of activity between 22:00 and 00:00. The physiological age and infectivity of An. coluzzii were significantly lower before the distribution of ITNs (P<0.004). Poor effectiveness of alpha-cypermethrin impregnated mosquito nets at a dose of 200 mg/m², added to first rainfalls, are the likely causes of the significant increase in aggressiveness and malaria transmission.

The new Afrotropical nemognathine genus Zoltanzonitis is described. Species herein assigned have until now been placed in the Palaeotropical genus Zonitoschema based on their elongate, filiformantennae and greatly enlarged eyes, but are distinguished by the distinctly shorter antennomere II (0.5 or less the length of III), the absence of sclerotised rings in the male ejaculatory ductus and the emarginate ventrite V in males. Thenewgenus includes five sub-Saharan species belonging to two distinct phenetic groups. New combinations for all species are proposed as well as the following new synonymies: alluaudi, burgeoni elongaticeps var. surcoufi and posticalis = natala; elongaticeps and jansei = testaceiventris.

The mitochondrial antioxidant manganese superoxide dismutase (Mn-SOD) plays a vital role in defence against reactive oxygen species (ROS) in eukaryotic mitochondria. This study was conducted to characterise SOD as an antioxidant gene from haemolymph of third larval instar of the flesh fly, Sarcophaga argyrostoma after challenging with hydrogen peroxide. Mn-SaSOD of S. argyrostoma has a single open reading frame (orf ) of 765 nucleotides that encode a polypeptide of 254 amino acids. Subsequent analyses of Mn-SOD gene sequences revealed that the identified Mn-SaSOD gene in this study shared homology with similar genes from other insect species. In addition, four manganese ion-binding sites (metalbinding sites) and Mn-Fe SOD signature were identified within the orf of Mn-SaSOD. One putative transcription factor-binding site (TATT) within the 5′-flanking region was predicted. This finding suggests that Mn-SaSOD might be involved in environmental stress responses and could be used in the production of novel antioxidants to compensate for the increasing demand of natural antioxidants instead of the chemical synthetic ones.

Lepidopteran stem borers are among the most important pests of maize in East Africa. Understanding the factors that influence maize stem borers' distribution is crucial in predicting their response to future climate change. The hypothesis of this study was that the potential distribution of the maize stem borers Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) and Busseola fusca (Fuller) (Lepidoptera: Noctuidae) at small scale along altitudinal gradients at Mount Kilimanjaro and Taita Hills in Tanzania and Kenya, respectively, depends on other climatic and edaphic factors besides temperature. The species distribution was studied using the maximum entropy (Maxent) application with three climatic (temperature, rainfall and relative humidity) and five soil variables [soil silicon (Si), potassium (K), phosphorus (P), nitrogen (N) concentrations and water-holding capacity (WHc)]. The model accuracy was evaluated using area under the curve (AUC) values based on 25%independent test data set. The results revealed that in addition to temperature, rainfall, and relative humidity, soil characteristics were affecting the geographical distribution of C. partellus and B. fusca at both the Mount Kilimanjaro and Taita Hills study sites. The relative importance of all studied variables varied between the two study sites. At Mount Kilimanjaro, WHc exhibited the greatest influence on C. partellus distribution while at Taita Hills it was relative humidity. For B. fusca distribution, the temperature was found more crucial at both Mount Kilimanjaro and Taita Hills.

Chromolaena odorata (L.) R.M. King and H. Robinson (Asteraceae: Eupatorieae) is one of the worst invasive weeds in West Africa, and a serious biotic threat to food security. The stem-galling fly, Cecidochares connexa (Macquart) (Diptera: Tephritidae), a biological control agent for C. odorata, was released in the Ivory Coast in 2003 and first detected in Ghana in 2014. The spatiotemporal distribution and abundance of C. connexa in Ghana was determined by country-wide surveys from 2015 to 2016. Galls were found in varying densities across Ghana but gall densities were consistently low east of Lake Volta. A limited survey conducted in the extreme west of Togo in 2016, found the gall fly also in low numbers. There was a significant correlation between C. connexa gall densities and the distance from the release sites in the Ivory Coast. The distribution and abundance of the gall fly in Ghana could be explained by its spread from the original release sites over time and/or the much drier conditions east of Lake Volta. Cecidochares connexa has dispersed a distance of about 1000 km over a 10-year period and, while there is some evidence that the gall fly is still dispersing towards the east, its range and population size could be limited by the dry climatic conditions in the east of Ghana and in Togo.Actively redistributing the agent over this dry corridor to the more humid and higher rainfall areas of Nigeria, may result in the spread of this agent through the rest of West and Central Africa, thereby aiding the control of C. odorata in the region.

Previous studies on Culex pipiens pipiens mosquitoes collected from Tunisia between 1990 and 1996 revealed an alarming resistance to organophosphate insecticides. However, since then very few studies have assessed the evolution of insecticides resistance in this species of mosquitoes. Three populations of Cx. pipiens pipiens mosquitoes were collected in three districts across the country between 2003 and 2005 and subjected to evaluation of their fenitrothion resistance/susceptibility status and associated mechanisms. Studied populations showed moderate resistance to the used insecticide which ranged from 7.59 to 11.8. The use of synergists revealed the lack of detoxification enzymes as metabolic resistance. However, starch gel electrophoresis indicated that resistance at the Ester locus was attributed to different Ester alleles. On the other hand, the positive cross-resistance to organophosphate fenitrothion and carbamate propoxur insecticides indicating a high prevalence of insensitive AChE1 mechanism in field populations. AChE activity showed that all populations exhibited a significant excess of heterozygotes ([RS]) compared to other detected genotypes ([SS] and [RR]) in the studied samples. Our analysis suggests that the heterozygotes often have a fitness advantage over the homozygotes.

Three species of non-biting midges, Microchironomus deribae, Cricotopus (Isocladius) ornatus and Synendotendipes impar, are reported for the first time from the current fauna of Tunisia. All three species were collected close to a lake in a semi-desert area in Gasfa Governorate, Tunisia. Their diagnostic morphological characteristics are illustrated and their current geographical distribution in North Africa is discussed.

Insects react to temperature variation, chemical and physical stressors by synthesis of a set of proteins known as heat shock proteins (HSPs). In this study, a cDNA gene coding a heat shock protein70 (HSP70) from Tribolium castaneum has been sequenced and characterised from adult beetles. The deduced peptide sequence ORF (Open Reading Frame) of HSP70 had 220 amino acid residues, had a calculated molecular mass of 24.30 kDa and an isoelectric point (Ip) of 6.85. T. castaneum HSP70 showed high identities with other coleopteran HSP70 by BLAST search in NCBI. Multiple sequence alignment at both nucleotide and amino acid levels were performed showing conserved regions between HSP70 and other heat shock proteins isolated from insects. Phylogenetic analysis was constructed by neighbour-joining distance analysis showing that HSP70 putative peptide was clustered with other heat shock protein from the same species. 3-D structure modelling of HSP70 was employed. Transcriptional profiles of HSP70 were determined by quantitative RT-PCR analysis after adult beetles were exposed to 45 °C, 4 °C and novaluron (insect growth regulator) for 60 min as physical and chemical stressors. HSP70 transcript was up-regulated at the highest level when adults were exposed to 45 °C for 60 min. In contrast, HSP70 transcript was down-regulated when adults were exposed to 4 °C and novaluron for 60 min.

The Sarcophaga spp. available whether through the field collections from different Egyptian localities and/or through the material preserved in the main Egyptian insect collections are keyed in the present study. One new species, S. mennae sp. n., is described, and two new species records for Egypt, S. parkeri (Rohdendorf, 1937) and S. marshalli Parker, 1923 are discovered. A key to nine subgenera and 21 out of 27 species representing the genus Sarcophaga in Egypt is provided based primarily on male genitalia. Photographs and illustrations of treated species are included.

Insect growth disruptors of the aryl terpenoid ether type including 185 compounds derived from 10 basic olefinic, epoxidised and alkoxidised type-structures were tested against the prepupae of the Mediterranean brocade, Spodoptera littoralis. The potent decenyl compounds are mainly derivatives of 4,8-dimethyl-3,7-decadiene and the epoxides of its external olefinic bond. The potent nonenyl compounds are mainly derivatives of either 4,8-dimethyl-3,7-nonadiene and the epoxides of its external olefinic bond or 3,7-dimethyl 6,7-epoxy-2-nonene. The phenyl group of the potent compounds have either methylenedioxy (3,4-), ethyl or methyl groups (4- or 3-). The presence of an alkoxy group on the terpenoid side chain, and/or the phenyl group does not lead to formation of a potent compound. The addition of one terminal carbon atom to some nonenyl derivatives leads to activity in the resulting decenyl compound. Continuing studies on synthetic juvenile hormone analogues may provide novel potent compounds for more benign insect control strategies.

Protection of local agriculture from invasive pest insects is critical for adequate and sustainable crop production. Important to this objective is the ability to accurately distinguish foreign from closely related domestic species, a process that has traditionally required identification using diagnostic morphological keys that can be both subtle and labour-intensive. This is the case for the mealybugs that include several important agricultural pests with cryptic morphological characters.ADNAbarcoding methodology was used to identify a destructive mealybug species recently reported from cotton and vegetables in different regions of Swaziland. A fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene was sequenced for specimens of mealybug collected from wild and cultivated host plants in Highveld, Lowveld and Lubombo regions. The sequences obtained were aligned and comparisons were made within the group and with GenBank sequences of morphologically identified species collected from Turkey, Japan and Israel. Mealybug specimens from five crops and seven wild host plants belonging to six families in the Highveld, Lowveld and Lubambo regions of Swaziland were identified to be the cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae). This is the first record of the invasive mealybug in southern Africa. The study has validated the efficacy of sequence diversity in the COI gene for identifying mealybugs. The risks this pest poses to crop production in Swaziland and neighbouring countries are discussed.

The relative abundance of all heteropterans recovered during this survey was influenced by the phenological development of the host plant (macadamia). Bathycoelia distincta Distant (Hemiptera: Pentatomidae) was the dominant heteropteran and occurred during all four phenological stages of the host plant that were monitored. However, abundance levels of this pest decreased during winter when fewer nuts were available. This decrease was immediately accompanied by a concomitant increase in the relative abundance levels of lesser important heteropterans. B. distincta, Pseudatelus raptorius (Germar) (Hemiptera: Pentatomidae) and Pseudotheraptus wayi Brown (Hemiptera: Coreidae) were the only heteropterans able to reproduce in macadamias which further strengthened the hypothesis of seasonal resource-based competition by the dominant species. All heteropterans recovered from these surveys can be categorised into two major groups namely: a group with a fairly large body size and long mouthparts which is able to reproduce successfully in macadamias and which occur mainly when nuts are available, as well as a group with smaller body size, shorter mouthparts, which cannot reproduce in this crop and which is only abundant when there are no or few nuts available on the trees.