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The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama (Hemiptera: Liviidae) is a destructive, invasive species that poses a serious threat to the citrus industry wherever it occurs. The psyllid vectors the phloem-limited bacteria 'Candidatus Liberibacter americanus' and 'Ca. L. asiaticus', causal agents of the incurable citrus greening disease or huanglongbing (HLB). It is essential to understand which regions and areas are suitable for colonization by ACP to formulate appropriate policy and preventive measures. Considering its biology and ecology, we used a machine learning algorithm based on the MaxEnt (Maximum Entropy) principle, to predict the potential global distribution of ACP using bioclimatic variables and elevation.The model predictions are consistent with the known distribution of ACP and also highlight the potential occurrence outside its current ecological range, that is, primarily in Africa, Asia and the Americas. The most important abiotic variables driving the global distribution of ACP were annual mean temperature, seasonality of temperature and annual precipitation.Our findings highlight the need for international collaboration in slowing the spread of invasive pests like D. citri. © 2022 Society of Chemical Industry.

False codling moth, Thaumatotibia leucotreta is among the key constraints of the agricultural industry. Little is known about the population dynamics and genetic diversity of this pest in East Africa. The spatial–temporal population dynamics and genetic diversity of false codling moth were evaluated in citrus orchards in Kenya and Tanzania between May 2017 and August 2018 covering two fruiting seasons. The diversity of false codling moth sampled in these orchards and from solanaceous hosts, as well as from specimens received from Uganda, Sudan, and South Africa were assayed using the mitochondrial cytochrome oxidase I gene. A similar spatial–temporal pattern of false codling moth was found in both Kenya and Tanzania, with the most male moths in August 2017 and 2018. In Tanzania, the number of male moths caught at high and mid altitudes did not differ but were significantly higher than those caught at low altitude. A relatively low false codling moth genetic diversity was recorded at the sites where sampling was done in the respective countries as well as between specimens sampled from different host plants. The low false codling moth genetic diversity determined in this trial can be exploited in the management of the pest in the studied countries.

Spoladea recurvalis (Fbr.) (Lepidoptera: Crambidae) larvae can cause up to 100% foliage loss on amaranths during severe outbreaks. The Bacillus thuringiensis Subsp. kurstaki product Halt® is a biologically safe biopesticide recommended for the management of Spodoptera exigua (Hübner) and Plutella xylostella (Linnaeus). Spoladea recurvalis larvae are less susceptible to the product. Thirteen chemical additives to improve the efficacy of a Bt spray for control of S. recurvalis were evaluated in laboratory bioassays against second‐instar larvae. All the additives except calcium chloride caused an increase in mortality when applied in mixtures with Bt. Among the seven inorganic salts, boric acid was the only inorganic acid that caused more than 50% larval mortality. Boric acid at a concentration of 0.05% increased the activity of B. thuringiensis by 2.9‐fold. Boric acid had the shortest LT50 values of 5.3 days compared with all other combinations. Two nitrogenous compounds, peptone and sodium nitrate, caused 54 and 51% larval mortalities; however, this increase in efficacy was not significantly different from the mortalities caused by Bt applied without any additive. Urea increased larval mortality from 40% to 51%, although the increase was not significant from a Bt spray application only. Citric acid had no significant effect on the efficacy of Bt spray against S. recurvalis larvae. Overall, among the additives evaluated, the efficacy of Bt spray was most enhanced by boric acid and could be further evaluated under field conditions for validation, and integration into an Integrated Pest Management (IPM) strategy for S. recurvalis management

Bactrocera zonata is an alien fruit fly which was introduced into Sudan in 2012 and spread throughout the country, severely hampering the production and export of fruit and vegetable crops. Cataloguing indigenous natural enemies of pests, especially parasitoids, is key to successful biological control programmes, to mitigate damage and decrease reliance on insecticides. This study was conducted to determine the parasitoids of B. zonata in two orchards in Gezira State, Sudan from November 2015 to May 2016 and from February to December, 2016 and to determine their role in natural control of the pest. Three parasitoids emerged from puparia of B. zonata, these were: Tetrastichus giffardianus Silvestri (Eulophidae), an Aganaspis sp. (Figitidae: Eucoilinae) and a Psyttalia sp. (Braconidae Opiinae). Tetrastichus giffardianus was the most numerous parasitoid throughout the study period. The mean percentages of B. zonata from guava fruits that were parasitized by T. giffardianus for the whole study period were 13.7% and 13.2% with 3.1 ± 0.3 and 2.8 ± 2.4 parasitoids per puparium at Fadasi and Gazirat Elfil sites respectively. Data on the temporal abundance of T. giffardianus is presented. Strenuous efforts should be considered to involve the reported natural enemies of B. zonata in integrated management programmes for fruit flies in Sudan.

The African citrus triozid (ACT), Trioza erytreae Del Guercio, is a destructive pest particularly on citrus, and vectors, “Candidatus” Liberibacter africanus (CLaf), which is the causal agent of the African citrus greening disease. Our study seeks to establish the distribution and host‐plant relationship of ACT across citrus production areas in Kenya. We also modelled the risk of spread using the maximum entropy modelling algorithm with known occurrence data. Our results infer that ACT is widely distributed and causes severe damage to four alternative host plants belonging to the family Rutaceae. The adults, immature stages (eggs and nymphs), galls and the percentage of infested leaves were significantly higher in shaded than unshaded trees. However, adult ACTs preferred Kenyan highlands to Victoria Lake and coastal regions. The average area under the curve of the model predictions was 0.97, indicating an optimal model performance. The environmental variables that most influenced the prediction were the precipitation of wettest quarter, precipitation of wettest month, mean diurnal range, temperature seasonality and mean temperature of the coldest quarter. The current prediction of ACT exceeded its existing range, especially in the Western, Nyanza, Central, Rift valley and Eastern regions of Kenya. The model predicted a contraction of suitable habitats for a potential spread in 2040 with an inland shift to higher altitudes in the cooler regions. The potential for further expansion to climatically suitable areas was more pronounced for the 2080 forecast. These findings provide relevant information to improve monitoring/surveillance and designing IPM strategies to limit its spread and damage.

Maize is a major staple food for over 300 million people in sub‐Saharan Africa. Sustainable productivity of this primary crop has been recently threatened by Fall armyworm (FAW), Spodoptera frugiperda invasion. Due to lack of environmentally safe management strategies, immediate responses by growers and governments to tackle FAW are based on rampant use of pesticides. Looking for efficient biopesticides, twenty entomopathogenic fungal isolates (14 Metarhizium anisopliae and 6 Beauveria bassiana) were screened for their efficacy against eggs and second instar larvae of FAW. A single discriminating concentration of 1 × 10⁸ conidia ml⁻¹ and four replicates per treatment were used in all experiments. Isolates were assessed for their ability to cause mortality of FAW second instar larvae, eggs and the neonate larvae that emerged from treated eggs. Among the isolates tested, only B. bassiana ICIPE 676 caused moderate mortality of 30% to second instar larvae. Metarhizium anisopliae ICIPE 78, ICIPE 40 and ICIPE 20 caused egg mortalities of 87.0%, 83.0% and 79.5%, respectively, and M. anisopliae ICIPE 41 and ICIPE 7 outperformed all the others by causing 96.5% and 93.7% mortality to the neonate larvae, respectively. The cumulated mortality of eggs and neonates was highest with M. anisopliae ICIPE 41 (97.5%), followed by M. anisopliae ICIPE 7, 655, 40, 20 and 78 with total mortality of 96.0%, 95.0%, 93.5%, 93.0% and 92.0%, respectively. These isolates with high cumulated mortality (≥92%), especially ICIPE 78 and 7, which are already commercialized for spider mites and ticks control respectively, would be good candidates for development as biopesticides for management of FAW in Africa if further evidence of their efficacy is obtained in the field.

African citrus greening (ACGD) and huanglongbing (HLB) diseases are the most damaging diseases of citrus worldwide. Currently, the disease has no cure and has been attributed to the collapse of the citrus industry in several countries. In Africa, the causative agent “Candidatus” Liberibacter africanus is vectored by African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae). African citrus triozid is native to Africa but has been recently reported in Asia and Europe. Apart from citrus, Murraya koenigii (L.) and Clausena anisata (Willd) Hook. F. ex Benth. are also considered as preferred host plants. At present, there is scant information on host plant suitability and preference of T. erytreae. Also, there are contradictory reports on its reproduction and survival on rutaceous and non‐rutaceous host plants. In the present study, we tested the suitability and preference of rutaceous and non‐rutaceous trees and shrubs as potential ACT host plants in choice and no‐choice bioassays. The development from egg to the adult stage was longest on Calodendrum capense (Wright & Arn.) Engl. Host plants of superior quality accordingly to several ACT's biological parameters measured also revealed significantly higher morphometric characteristics. Our findings on the host status of the five rutaceous plants imply that these plants can greatly influence the population dynamics of ACT as well as the epidemiology of ACGD, and these can be a useful guide in the area‐wide management of the pest in Kenya.

BACKGROUND: The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae) is one of the most devastating pests of citrus with a well‐known role as a vector of the phloem‐limited bacteria (Candidatus Liberibacter africanus) associated with huanglongbing (citrus greening disease), currently considered the world's most serious disease of citrus. Although the pest can successfully develop and reproduce on non‐citrus host plants, there is no documented information on the geometric morphometry of ACT. We determine the effect of host plants on ACT morphometry under controlled laboratory conditions using traditional and geometric analysis. RESULTS: ACT reared on C. limon and Citroncirus spp. was significantly larger than when reared on the other host plant species. ACT reared on C. anisata and C. tangelo was consistently smaller than that reared on M. koenigii and C. sinensis. Based on warped outline drawings, ACT reared on Citroncirus spp. and Murraya koenigii had narrower wings than when reared on C. anisata, C. limon, and C. sinensis with slightly broader wing patterns. CONCLUSION: This study clearly demonstrates that host plant species affect morphometric variation in ACT, which might have a direct impact on fitness parameters of the pest as well as its potential for dispersion. Wing shape and size appear to be useful in separating populations of ACT into different groups. © 2018 Society of Chemical Industry

We estimate the impacts of a bundle of integrated pest management (IPM) practices on mango yield, mango net income, insecticide use, human health and the environment, using recent household survey data of mango growers in Kenya. We employ a multinomial endogenous switching treatment regression model with an ordered probit selection rule to establish counterfactual outcomes. Our results indicate that IPM‐adopting farmers have higher mango yields and mango net income, and also use lower quantities of insecticide and cause less damage to the environment and to human health. In addition, switching from one IPM to multiple IPM practices generates greater economic, environmental and human health benefits. These results suggest intensification of IPM‐adoption efforts and encouragement of the use of multiple IPM practices. These positive outcomes could be achieved through greater provision of technical support and extension services to farmers.

Phthorimaea operculella granulovirus (PhopGV) is infectious for larvae of different Gelechiidae insect species, including Tuta absoluta and Phthorimaea operculella. As these are major economic pests in North and sub‐Saharan Africa as well as in the Mediterranean area, the development of locally suitable biocontrol agents is essential. We have studied five isolates of PhopGV from Tunisia (Tns16, Tu1.11 and Tu2.11), Kenya (Ken13) and Yemen (Ym14) for their biological activity and the sequence polymorphism of their granulin and ecdysteroid UDP‐glucosyltransferase (egt) genes and allocated the isolates to two different egt types. Infection experiments with neonate larvae of T. absoluta and P. operculella demonstrated their pathogenicity to both host species. The isolate PhopGV Tu1.11 was the most virulent one for T. absoluta but had a relatively low infectivity to two P. operculella populations originating from Italy and Tunisia.

The horticulture industry in Benin is under threat due to fruit fly infestation on important crops such as cucurbits and mango. Given the economic losses due to fruit fly infestations, population dynamics of fruit flies on these crops were monitored over 6 years (2004–2010) using three parapheromones—cuelure, methyl eugenol and terpinyl acetate. A total of 2,714,186 specimens belonging to 14 species in four genera (Bactrocera, Ceratitis, Dacus and Zeugodacus) were collected. Bactrocera dorsalis was the dominant species that accounted for 89%, 89.6% and 77.2% of captures in the Forest Savannah Mosaic (FSM), Southern Guinea Savannah (SGS) and Northern Guinea Savannah (NGS) agro-ecosystems, respectively. Shannon index values of species diversity differed significantly among agro-ecosystems, with highest diversity in FSM followed by SGS and NGS. Temperature, rainfall and relative humidity (RH) positively influenced the abundance of Dacus species and Zeugodacus cucurbitae across the three agro-ecosystems. Monthly mean temperatures were in a range suitable for development and reproduction of fruit flies, although minimum temperatures could be below such range, which may explain the lower abundance of fruit fly populations during this period of the year. The abundance of B. dorsalis was negatively correlated with maximum temperature and positively correlated with RH and rainfall. Ceratitis species assemblages were significantly affected by minimum temperatures, rainfall and agro-ecosystem. Populations of B. dorsalis and Ceratitis cosyra dropped drastically in August, while those of Z. cucurbitae and Dacus punctatifrons increased sharply from August. Results of this study provide a platform for developing a comprehensive and sustainable management strategy for B. dorsalis and other fruit flies in the three agro-ecosystems to protect the horticulture industry in Benin.

Mango, Mangifera indica L. (Anacardiaceae), is one of the most important fruits in Africa, providing household nutrition and economic development opportunities for millions of growers across the continent. In Kenya, over 80% of mango production is carried out by smallholders who produce this crop for both the domestic and the export markets. Despite its importance, mango production is hampered by several constraints, including infestation by fruit flies, especially the exotic Bactrocera dorsalis. In addition to its direct damage to fruits, the high quarantine status of the pest restricts the export of fruits and limits access to lucrative markets, impacting negatively on export earnings. To facilitate access to export markets, post-harvest management measures such as hot-water treatment are required to ensure quarantine security. Internationally, this level has been set as either 99.99% (Probit 8.7) or 99.9968% (Probit 9). In developing a protocol, the development of immature life stages of B. dorsalis in ‘Apple’ mango was established. Using this information, infested mangoes harbouring the different immature life stages were subjected to a hot-water treatment of 46.1°C for four different times, and the egg mortality and larval mortality were determined. The third-instar life stage was the most heat tolerant, followed by second- and first-instar larvae and the egg stage, respectively. The immersion time of 81.47 min (95% CL 75.77–87.18) was established as the time required to achieve 99.99% security level. In the validation experiment, there were no survivors from the 51,101 third-instar individuals treated in ‘Apple’ mango weighing 400–500 g. Furthermore, there were no survivors from the 44,651 third instars exposed to 46.1°C for 68 min. These results provide sound evidence that the shorter treatment duration is an effective post-harvest disinfestations treatment against B. dorsalis, and should facilitate access to export markets for mango fruits from Africa.

Democratic Republic of the Congo (DR Congo) has a wide diversity of edible insects making it one of the most important biodiversity hot spots in Africa. The aim of this study was to give the first insight into the food plant range, seasonal availability of edible insects, community preference and willingness to consume them. The study revealed a list of eleven edible insect species belonging to four families. Twenty-six plant species were recorded as food plants of nine edible caterpillar species. Seasonal availability of these insects coincided with the rainy season and was strongly linked to relatively high level of consumption. The caterpillars Elaphrodes lactea Gaede, Lobobunaea saturnus Fabricius and Cinabra hyperbius (Westwood) as well as the termites Macrotermes falciger Gerstacker were the most dominant species of edible insects preferred and consumed among the different communities. Our study demonstrates that entomophagy is a common practice among the ethnic populations with married, tertiary and university-level individuals recording significantly higher consumption of edible caterpillars. Populations between the ages of 18 and 45 years as well as the Bemba tribe were also more actively involved in entomophagy. Further research would be necessary to exploit edible insect biodiversity and ethno-entomophagy and initiate actions for food plant conservation in DR Congo.

Vegetables are one of the important crops which could alleviate poverty and malnutrition among the smallholder farmers in tropical Asia and Africa. However, a plethora of pests limit the productivity of these crops, leading to economic losses. Vegetable producers overwhelmingly rely on chemical pesticides in order to reduce pest-caused economic losses. However, over-reliance on chemical pesticides poses serious threats to human and environmental health. Hence, biopesticides offer a viable alternative to chemical pesticides in sustainable pest management programs. Baculoviruses such as nucleopolyhedrovirus (NPV) and granulovirus (GV) have been exploited as successful biological pesticides in agriculture, horticulture and forestry. Maruca vitrata multiple nucleocapsid NPV (MaviMNPV) was found to be a unique baculovirus specifically infecting pod borer on food legumes, and it has been successfully developed as a biopesticide in Asia and Africa. Entomopathogenic fungi also offer sustainable pest management options. Several strains of Metarhizium anisopliae and Beauveria bassiana have been tested and developed as biopesticides in Asia and Africa. This review specifically focuses on the discovery and development of entomopathogenic virus and fungi-based biopesticides against major pests of vegetable legumes and brassicas in Asia and Africa. © 2019 Society of Chemical Industry.

Leaf extracts of Capurnia aurea (Fabaceae) have been reported to attract ticks and can be considered for use in combination with entomopathogenic fungus in an autodissemination approach, whereby ticks that are attracted to baited traps are infected with the inoculum. Bioassays were undertaken to assess the compatibility of aqueous, methanol and acetone extracts of C. aurea with conidia of Metarhizium anisopliae sensu stricto (ss) (Hypocreales: Clavicipitaceae) isolate ICIPE 7 in terms of mycelial growth, conidial production and spore viability. Aqueous extract of C. aurea was compatible with the fungus at all the concentrations tested whereas methanol and acetone extracts inhibited all the fungal growth parameters. The virulence of M. anisopliae formulated in different extracts of C. aurea was also tested against different developmental stages of Rhipicephalus pulchellus in laboratory bioassays. No significant differences in virulence were observed between M. anisopliae applied alone and M. anisopliae formulated in different concentrations of extracts of C. aurea among the larvae, nymphs and adults. However, mortality varied according to the developmental stage, with larval stage being the most susceptible. Aqueous extract was compatible with M. anisopliae and could be therefore mixed together for ‘spot-spray’ treatments as low cost and environmentally friendly technology for tick control in grazing pasture.

This work was supported by the European Union (SANTE 2007 147–790). The Hlabisa HIV Treatment and Care Programme has received support through the United States Agency for International Development (USAID) and the President’s Emergency Plan (PEPFAR) under the terms of Award No. 674-A-00-08-00001-00.

Male sexual aggregations are a common territorial, mating-related or resource-based, behaviour observed in diverse organisms, including insects such as thrips. The influence of factors such as plant substrate, time of day, and geographic location on aggregation of thrips is uncertain, therefore we monitored the dispersion of male and female bean flower thrips (BFT), Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), on cowpea, Vigna unguiculata (L.) Walp. (Fabaceae), over three cowpea growth stages and across three cowpea-growing areas of Kenya. Our results indicated that for all the crop growth stages, the density of BFTs varied over the time of day, with higher densities at 10:00, 13:00, and 16:00 hours than at 07:00 hours. Thrips densities did not differ among blocks at the budding stage, but they did at peak flowering and podding stages. Dispersion indices suggested that both male and female BFTs were aggregated. Active male aggregation occurred only on green plant parts and it varied across blocks, crop stages, and locations. Similarly, active female aggregation was observed in peak flowering and podding stages. Such active aggregation indicates a semiochemical or behaviour-mediated aggregation. Identification of such a semiochemical may offer new opportunities for refining monitoring and management strategies for BFT on cowpea, the most important grain legume in sub-Saharan Africa.

This paper presents the results from a survey that was carried out to determine the host plants of tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in five States in Sudan. This survey was carried out in greenhouses and open-field vegetable production areas between the years 2011 and 2014 using pheromone traps. The survey showed that the main host plant of T. absoluta is tomato (Lycopersicon esculentum), but it also attacks potato (Solanum tuberosum), eggplant (S. melongena) Jimson weed (Datura stramonium) and S. dubium in the family Solanaceae, and broad bean (Vicia faba) and alfalfa plant (Medicago sativa) in the family Fabaceae. This paper is the first record of the following plans being hosts for T. absoluta: Watermelon (Citrullus lanatus) in the family Cucurbitaceae, Physic nut (Jatropha curcas) in the family Euphorbiaceae, spiny amaranth (Amaranthus spinosus) in the family Amaranthaceae, Ramtouk (Xanthium brasilicum) in the family Asteraceae and S. dubium. The study showed that the leafminer male numbers and the symptoms were significantly increased in S. melongena and S. dubium after severe damage and complete loss of the main host, the tomato crop and these two species may be the preferred alternative host plants. Signalements de plantes-hotes pour la mineuse de la tomate Tuta absoluta (Meyrick) au Soudan Le present article presente les resultats d'une prospection visant a determiner les plantes hotes de la mineuse de la tomate Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) dans cinq etats du Soudan. Cette prospection a ete realisee dans des serres et des zones de production de legumes en plein champ entre 2011 et 2014, a l'aide de pieges a pheromones. La prospection a montre que la principale plante-hote de T. absoluta est la tomate (Lycopersicon esculentum), mais qu'elle attaque aussi la pomme de terre (Solanum tuberosum), l'aubergine (S. melongena), Datura stramonium et S. dubium dans la famille des Solanaceae, ainsi que la feve (Vicia faba) et la luzerne (Medicago sativa) dans la famille des Fabaceae. Le present article constitue le premier signalement des plantes suivantes en tant qu'hotes de T. absoluta: pasteque (Citrullus lanatus) dans la famille des Cucurbitaceae, Jatropha curcas dans la famille des Euphorbiaceae, Amaranthus spinosus dans la famille des Amaranthaceae et Xanthium brasilicum dans la famille des Asteraceaeet S. dubium. L'etude a montre que le nombre de mâles de la mineuse et les symptomes avaient augmente de maniere significative sur S. melongena et S. dubium apres des degâts importants et la destruction totale de l'hote principal, la culture de tomates, et ces deux especes pourraient donc etre les plantes-hotes alternatives preferees. Peгиcтpaция pacтeний-xoзяeв лиcтoвoгo минepa тoмaтa Tuta absoluta (Meyrick) в Cyдaнe Дaннaя paбoтa пpeдcтaвляeт peзyльтaты oбcлeдoвaния, пpoвeдeннoгo для oпpeдeлeния pacтeний-xoзяeв лиcтoвoгo минepa тoмaтa, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) в пяти штaтax Cyдaнa. Oбcлeдoвaниe пpoвoдилocь в тeплицax и в oткpытыx зoнax выpaщивaния oвoщeй в пepиoд 2011-2014 гг. c иcпoльзoвaниeм фepoмoнныx лoвyшeк. Oбcлeдoвaниe пoкaзaлo, чтo ocнoвнoe pacтeниe-xoзяин T. absoluta – тoмaт (Lycopersicon esculentum), нo этoт минep aтaкyeт и кapтoфeль (Solanum tuberosum), и бaклaжaн (S. melongena), и дypмaн вoнючий (Datura stramonium L) и Solanum dubium из ceмeйcтвa пacлeнoвыx, a тaкжe фacoль (Vicia faba) и люцepнy (Medicago sativa) из ceмeйcтвa бoбoвыx. Дaннaя cтaтья пpeдcтaвляeт coбoй пepвyю peгиcтpaцию cлeдyющиx pacтeний в кaчecтвe xoзяeв T.absoluta: apбyз (Citrullus lanatus) из ceмeйcтвa тыквeнныx, ятpoфa aптeчнaя (Jatropha curcas) из ceмeйcтвa мaлoчaйныx, кoлючий aмapaнт (Amaranthus spinosus) из ceмeйcтвa aмapaнтoвыx, бpaзильcкий дypнишник (Xanthium brasilicum) из ceмeйcтвa acтpoвыx и S.dubium. Иccлeдoвaниe пoкaзaлo, чтo чиcлeннocть caмцoв лиcтoвoгo минepa и cимптoмы yщepбa знaчитeльнo пoвыcилиcь нa S. melongena и S. dubium пocлe нaнeceния yщepбa и пoлнoй yтpaты ocнoвнoгo xoзяинa, тoмaтa, эти двa видa мoгyт cлyжить пpeдпoчитaeмыми aльтepнaтивными pacтeниями-xoзяeвaми.

Bactrocera papayae Drew & Hancock, Bactrocera philippinensis Drew & Hancock, Bactrocera carambolae Drew & Hancock, and Bactrocera invadens Drew, Tsuruta & White are four horticultural pest tephritid fruit fly species that are highly similar, morphologically and genetically, to the destructive pest, the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). This similarity has rendered the discovery of reliable diagnostic characters problematic, which, in view of the economic importance of these taxa and the international trade implications, has resulted in ongoing difficulties for many areas of plant protection and food security. Consequently, a major international collaborative and integrated multidisciplinary research effort was initiated in 2009 to build upon existing literature with the specific aim of resolving biological species limits among B. papayae, B. philippinensis, B. carambolae, B. invadens and B. dorsalis to overcome constraints to pest management and international trade. Bactrocera philippinensis has recently been synonymized with B. papayae as a result of this initiative and this review corroborates that finding; however, the other names remain in use. While consistent characters have been found to reliably distinguish B. carambolae from B. dorsalis, B. invadens and B. papayae, no such characters have been found to differentiate the latter three putative species. We conclude that B. carambolae is a valid species and that the remaining taxa, B. dorsalis, B. invadens and B. papayae, represent the same species. Thus, we consider B. dorsalis (Hendel) as the senior synonym of B. papayae Drew and Hancock syn.n. and B. invadens Drew, Tsuruta & White syn.n. A redescription of B. dorsalis is provided. Given the agricultural importance of B. dorsalis, this taxonomic decision will have significant global plant biosecurity implications, affecting pest management, quarantine, international trade, postharvest treatment and basic research. Throughout the paper, we emphasize the value of independent and multidisciplinary tools in delimiting species, particularly in complicated cases involving morphologically cryptic taxa.

The efficacy of aqueous and emulsifiable formulations of the fungus Metarhizium anisopliae isolate ICIPE78 was evaluated on the population density of Tetranychus urticae infesting common bean plants under screenhouse and field conditions. Synthetic acaricide abamectin was included as a check. Bean plants were artificially infested with T. urticae and allowed to multiply. Three treatments were applied in the screenhouse and 1 treatment in field trials. Mite density was recorded 2 d before spraying and weekly postspraying. The number of pods per plant, number of seeds per pod, and the dry weight of seeds per plant were recorded only in the screenhouse trials. In both screenhouse and field trials, fungal formulations applied at the concentration of 10(8) conidia/mL and the acaricide reduced the population density of mites as compared to the controls. There were significant differences in T. urticae population densities between the treatments at the various post-spraying sampling dates. In the screenhouse, the mite densities were near zero from 3-week postspraying in the treated leaves. At 4-week postspraying, there were no more leaves in the untreated control (T1) and in the control water + Silwet-L77 (T2). Fungal formulations were as effective as abamectin in reducing mite densities in both screenhouse and field experiments. There were significant differences in the production parameters during the 2 screenhouse trials, with fungal and abamectin treatments generally having the highest yield. Results of this study underline the potential of the M. anisopliae isolate ICIPE78 as an alternative to acaricides for T. urticae management.

A composite blend consisting of sunflower cake, maize germ, wheat bran, fresh water shrimps and cassava flour was extruded using a single‐screw extruder to produce expanded fish feed pellets. The effects of temperature (80–120 °C), die diameter (2–4 mm), and feed pre‐conditioning time (50–150 s; steam 400 kPa) on properties of the pellets (expansion ratio, bulk density, floatability, durability, water absorption, water solubility, water stability, and in‐vitro protein digestibility) were investigated using response surface methodology. Regression equations describing the effect of each variable on the product responses were obtained. The pellets extruded using a factor combination of 120 °C extruder barrel temperature, 2 mm die diameter, and 100 s of feed pre‐conditioning time gave most desirable pellet floatability (100%), durability index (99%), expansion ratio (2.64), water absorption index (4.12), water solubility index (9.31), water stability (87%), bulk density (479 g/L), and in vitro protein digestibility (69.97%) with a composite desirability of 0.88. Practical applications Extrusion is a modern feed processing method whose use is fast gaining popularity among small feed processors in developing countries. However, extrusion is a process that involves many parameters that need to be optimized for desirable end properties. These findings guide fish feed manufacturers on the optimum conditions for single screw extruders for production of feeds with desirable properties especially for the fish types that are top feeders. In addition, the results offer important insights on how temperature, die diameter, and feed pre‐conditioning, may be manipulated to influence properties of extruded aquafeed when using simple low‐cost small‐scale extruders.

Cashew (Anacardium occidentale) is an economically important cash crop for many rural households in Tanzania. However, its production is constrained by some insect pests and diseases. As a prerequisite for the development of a more sustainable integrated insect pest and disease management strategy for cashew, information on the biology and ecology of the key insect pests and diseases in a changing environment, and on influencing biotic and abiotic factors, is needed. Surveys were conducted in the major cashew nut-producing areas of Tanzania for two seasons: August to December, 2009, and August to December, 2010. Data on number of infested and infected shoots by key insect pests and diseases, natural enemies and associated farmer practices, namely synthetic pesticide use and intercropping systems, were collected from different subzones within agroecological zones. Our data showed that abundance and diversity of key cashew insect pests and diseases were influenced by agroecological zones and subzones. Intercropping was more commonly practised in the northern than in the southern zone. Agrochemicals were most frequently used in the southern agroecological zone and affected the occurrence of natural enemies, notably the weaver ant that was more abundant in the northern zone. Furthermore, our findings revealed that Helopeltis sp. and the powdery mildew remained the major constraints to cashew nut production in Tanzania.

Field cage tests were carried out to determine the mating compatibility of sterile and wild melon fly, Bactrocera cucurbitae (Coquillett), males that were treated or not treated with entomopathogenic fungi. The melon flies were irradiated at 70 Gy, and the adults were treated with dry conidia of either Beauveria bassiana (Balsamo) or Metarhizium anisopliae (Metchnikoff) Sorokin 1 day before the mating test. Our results demonstrate that sterile melon flies treated with either B. bassiana or M. anisopliae showed mating compatibility with the wild flies. Inoculation of the flies with the fungi did not significantly affect the mean time of copulation (323–567 min) as compared to mating involving only wild flies (407–518 min). Treatment of the flies with either B. bassiana or M. anisopliae did not significantly affect the propensity of mating. Wild females mated indiscriminately with sterile, sterile B. bassiana-treated or sterile M. anisopliae-treated males. Irrespective of the treatment combinations, mean percentage remating was significantly higher for sterile females with sterile males (7.72–27.12%) as compared to wild females with sterile males (0.76–14.90%). The possibility of using sterile melon flies as vectors of the entomopathogenic fungi to enhance an SIT programme is discussed.

We assessed the infestation of Bactrocera invadens Drew Tsuruta & White on field-collected Cavendish dwarf bananas of different ripening stages in Kenya and Mozambique. Of 5085 fruits collected in Kenya, B. invadens was reared from all ripening stages except bananas at the mature green stage. The highest level of fruit fly infestation was recorded from the ‘all yellow’ fruit ripening stage at 17% of which 401 B. invadens was recovered. In Mozambique, no fruit flies were recovered from a total of 169 fruits of different ripening stages sampled. Of 1349 culled Cavendish dwarf bananas sample, the highest number of fruit flies (518 B. invadens) was recovered from fruits that were precociously ripened. In field cage experiments conducted in Kenya and Mozambique, although oviposition wounds (101–587) were observed on green bananas after artificial infestation with 100–1000 gravid B. invadens females, no flies were recovered from fruits at the green stage of harvest maturity. Based on the results of these findings, mature green bananas of the Cavendish dwarf cultivar should be considered as a non-host stage of maturity for B. invadens. However, bunches with precociously ripened fingers and with other damages such as cracks and splits, ant burns, abrasions, point bruise, tip rot or general decay should be carefully inspected before export and discarded because such damages can permit attack by B. invadens and pose the risk of inadvertent translocation of the insect during export.

In frugivorous insects, the physiological state of the female (e.g. age, egg load) as well as environmental parameters like fruit availability and characteristics may affect oviposition decision, host choice and the resulting clutch size. We studied host acceptance and clutch size decision as a function of fly egg load as physiological state and mango variety and ripeness stage as the environmental parameter in two major mango pests in sub-Saharan Africa, Bactrocera invadens and Ceratitis cosyra, under laboratory conditions. In addiction, egg maturation dynamics were investigated because for both species, egg production had never been explored before. Female egg load was the most important factor influencing host acceptance in both species. With respect to fruit characteristics, ripeness stage was significant for oviposition decisions only in C. cosyra. In particular, ripe and fully ripe fruits had more probability of oviposition than unripe ones. In contrast, fruit variety affected clutch size in B. invadens, with, respectively, the local variety Ngowe receiving the biggest clutches and the export Kent the smallest. Moreover, the invasive species showed a significantly higher egg production compared with the native species. Implications in terms of competitive displacement between the two species are also discussed.

Temperature-dependent development, parasitism and longevity of the braconid parasitoids, Fopius arisanus Sonan and Diachasmimorpha longicaudata Ashmed on Bactorcera invadens Drew Tsuruta & White, was evaluated across five constant temperatures (15, 20, 25, 30 and 35°C). Developmental rate decreased linearly with increasing temperature for both the parasitoid species. Linear and Briere-2 nonlinear models were used to determine the lower temperature threshold at which the developmental rate (1/D) approached zero. For F. arisanus, lower thresholds to complete development estimated with the linear and nonlinear models were 10.1 and 6.9°C, respectively. The total degree-days (DD) required to complete the development estimated by the linear model for F. arisanus was 360. In D. longicaudata, the linear and nonlinear models estimated lower thresholds of 10.4 and 7.3°C, respectively, and the total DD estimated was 282. In F. arisanus, percentage parasitism differed significantly across all temperatures tested and was highest at 25°C (71.1 ± 2.5) and lowest at 15°C (46.4 ± 1.4). Parasitoid progeny sex ratio was female biased at all temperatures except at 20°C. In D. longicaudata, percentage parasitism was highest at 20°C (52.2 ± 4.0) and lowest at 15°C (27.7 ± 2.5). Parasitoid progeny sex ratio was female biased and similar for all temperatures. Adult longevity of both parasitoids was shortest at 35°C and longest at 15°C, and females lived significantly longer than males at all temperatures tested. Our findings provide some guidance for future mass rearing and field releases of the two parasitoids for the management of B. invadens in Africa.

The performance of an autoinoculation device was evaluated in field cage experiments for control of Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), in French bean, Phaseolus vulgaris L. var. Samantha (Fabaceae). Treatments consisted of a fungus-treated device with and without semiochemical (Lurem-TR), and a fungus-free device as control; the fungus used was Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae). The overall mean number of conidia acquired by a single insect was higher in the fungus-treated semiochemical-baited device than in the device without semiochemical: 5.0 ± 0.6 × 104 vs. 2.2 ± 0.4 × 104 conidia per insect. The overall thrips mortality was also higher in the semiochemical-baited device than in the device without the semiochemical: 59.3 ± 3.9 vs. 41.7 ± 3.5%. Conidial viability was not affected in the M. anisopliae-treated device without semiochemicals, 7 days after treatment, whereas it was considerably decreased – from 81.0 ± 1.3 to 6.5 ± 1.1%, 2 and 7 days post-inoculation – in the M. anisopliae-treated semiochemical-baited device. Thrips mortality was positively correlated with M. anisopliae conidial viability, and conidial viability was negatively correlated with conidial acquisition. This suggests that the semiochemical volatiles reduced the conidial viability, which in turn resulted in significant reduction in thrips mortality, despite the highest conidial acquisition in the semiochemical-baited fungus-treated device. Thrips density per plant was significantly reduced in both fungus-treated treatments (with semiochemical: 8.7 ± 1.7 adults per plant; without semiochemical: 6.6 ± 1.4 adults per plant) compared with the fungus-free control (19.8 ± 2.6 adults per plant). These results demonstrate the potential for an autoinoculation device strategy for the control of thrips, particularly in screenhouses.

We investigated the influence of temperature and infestation sequence on interspecific competition between two fruit flies: an invasive (Bactrocera invadens Drew, Tsuruta '' White, (B) and a native (Ceratitis cosyra Walker, C) (both Diptera: Tephritidae) species. Mango fruits [Mangifera indica L. (Anacardiaceae)] were co-infested with larvae at different constant temperatures (15, 20, 25, and 30 °C) and relative humidity of 50 ± 8%, using different infestation sequences at each temperature (BC together; BC/CB 1, 2, and 3 days apart). There were significant effects of competition in most experimental treatments, resulting in reduced larval survival, pupal mass, and adult emergence for both species. At most of the infestation/temperature combinations, C. cosyra was clearly the inferior competitor. The only exception was at 20 °C when the outcome depended on the sequence of infestation: no C. cosyra survived when the sequence was BC, but more C. cosyra than B. invadens survived when it was CB. At 15 °C, all C. cosyra larvae died, while the development of B. invadens was prolonged and adult emergence reduced. We conclude that resource pre-emption and fluctuations in temperature in mango agroecosystems help to explain observed shifts in dominance between B. invadens and C. cosyra on mango in many parts of Africa. The small window of competitive superiority for C. cosyra at 20 °C and CB infestation sequence, together with other factors such as fecundity and alternative hosts, may allow for co-existence in some environments.

The development and survival of immature stages of Bactrocera invadens Drew, Tsuruta and White (Dipt.: Tephritidae), a new invasive fruit fly pest in Africa, was studied in the laboratory at five constant temperatures of 15°C, 20°C, 25°C, 30°C and 35°C and photoperiod of L12:D12. The developmental time of eggs was 5.71 days at 15°C, decreasing to 1.24 days at 35°C. Larval development periods decreased from 35.95 days at 15°C to 6.64 days at 35°C. Pupal development at 15°C took 34.08 days while no adults emerged at 35°C, this being the most lethal temperature. The longest total development period occurred at 15°C (75.74 days) and was shortest at 30°C (17.76 days). The linear model provided a reliable fit of development rates vs. temperature for the immature stages. Lower developmental thresholds that were estimated from linear regression equations for the egg, larva and pupal stages were 8.8, 9.4 and 8.7, respectively. Total degree-day (DD) accumulation was estimated at 376 DD for development from egg to adult emergence. The highest adult survival given as the mean of emergence from a cohort of 50 eggs occurred at 20–30°C. At the egg stage, survivorship was highest at 20–30°C and at the larva and pupa stages, it was at 25°C. The practical implication of the findings is discussed in relation to mass rearing of B. invadens and understanding its biology and ecology.

Diachasmimorpha longicaudata (Ashmead), a solitary koinobiont larval–prepupal endoparasitoid of fruit flies, was introduced into Kenya for testing and final release against the recently discovered invasive species, Bactrocera invadens Drew, Tsuruta and White in Africa. Laboratory experiments were conducted to determine host preference, host acceptability for oviposition and physiological suitability of B. invadens and five other indigenous tephritid fruit fly species –Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi) and Ceratitis anonae Graham – for the development of D. longicaudata. Females of D. longicaudata visited all host-larval patches, and were also attracted to these hosts at comparable levels. Acceptability, successful development of parasitoid progenies and their sex ratio varied widely across hosts. C. capitata yielded the highest parasitoid numbers whereas B. invadens was the only host that yielded a female-biased sex ratio. Larvae of B. invadens, C. rosa, C. fasciventris and C. anonae mounted differential immune reaction towards D. longicaudata eggs. Although, the parasitoid performed poorly on the target host B. invadens, it was able to form new association with C. cosyra and C. capitata. The prospect of using this parasitoid in biological control of African indigenous fruit flies is discussed.

The susceptibility of immature stages of the legume flower thrips, Megalurothrips sjostedti, to the entomopathogenic fungus Metarhizium anisopliae, was investigated under laboratory conditions. The adult stage was found to be more susceptible to infection than the larval and pupal stages. Mortality at all stages was dose-dependent, with the highest concentration of 1 10 8 conidia ml 1 producing the highest mortality (26, 46 and 100% for larvae, pupae and adults, respectively) at 8 days post-inoculation. At the same concentration, daily pollen consumption was significantly reduced at 2 days after treatment in infected adults but more slowly in infected larvae. Fecundity, egg fertility and longevity in adults surviving infection as larvae were significantly reduced compared to the control.

Megalurothrips sjostedti is an economic pest of cowpea in tropical Africa. There are no reports of the effect of temperature on the development of the pest and no diapause has been detected. The developmental rate and reproduction of M. sjostedti was studied under six constant temperatures (14, 17, 20, 23, 26 and 29 degrees C) and a photoperiod of L12:D12 in the laboratory. Total developmental time ranged from 33.1 days at 14 degrees C to 19.2 days at 26 degrees C. At 29 degrees C, all larvae died during hatching. Egg, larval and pupal stages required 94.3, 97.1 and 105.3 deg-days (DD) above a threshold of 8.2, 9.1 and 10.4 degrees C, respectively, to complete development. Total developmental cycle was completed at 163.9 DD above a threshold of 12.6 degrees C. Adult longevity was lowest (11.1 days) at 29 degrees C and highest (28.7 days) at 14 degrees C. At constant temperatures, the highest pre-oviposition period was observed at 29 degrees C under a photoperiod of L16:D8. Egg production also ceased at this temperature/photoperiod combination. Total fecundity was highest at 26 degrees C under L10:D14. At cyclical temperatures, pre-oviposition period was longest (12.4 days) at 20/29 degrees C under L16:D8. Total fecundity was highest (168.4 eggs) at 14/26 degrees C under L10:D14, and lowest (8.2 eggs) at 20/29 degrees C under L16:D8. The significance of these findings in the management of M. sjostedti is discussed.

Twenty-two strains of entomopathogenic fungi were tested in the laboratory to determine their pathogenicity to adult Megalurothrips sjostedti. All the fungal strains were pathogenic to the insect. Beauveria bassiana and Metarhizium anisopliae strains caused mortality ranging between 29 and 100% and 54 to 100%, respectively. In contrast, Verticillium lecanii and Paecilomyces fumosoroseus were less virulent, causing mortality ranging between 29 to 68 and 13%, respectively. The LT 50 of the most virulent B. bassiana and M. anisopliae strains was 2.7 and 2.4 days, respectively. The LC 50 for the most active B. bassiana strain was 7.9 × 10 6 conidia/ml. The LC 50 for the most active strain of M. anisopliae was 1.3 × 10 6 conidia/ml. Two strains of B. bassiana and four strains of M. anisopliae were found to be highly pathogenic to M. sjostedti, which suggests a potential for their use in the biological control of the pest.

1 Pandora neoaphidis is an important aphid-specific fungal pathogen in temperate agroecosystems. Laboratory studies were carried out to obtain baseline data on factors that may affect its performance in conservation biological control. 2 Virulence of P. neoaphidis was assessed in dose–response bioassays against Microlophium carnosum on nettle, Uroleucon jaceae on knapweed, Acyrthosiphon pisum on bean and bird's-foot trefoil Lotus corniculatus, and Metopolophium dirhodum on barley and Yorkshire fog Holcus lanatus. The most susceptible aphid was A. pisum feeding on bean with an LD50 of 19 conidia per mm2, whereas U. jaceae had an LD50 of 104 conidia per mm2 and was least susceptible to infection. 3 The presence of foraging adult ladybirds, Coccinella septempunctata, increased transmission of P. neoaphidis from infected cadavers to apterae of M. carnosum, U. jacea, and A. pisum by 7–30% at the largest cadaver density tested. Adult coccinellids that had previously foraged on nettle, knapweed, bean or bird's-foot trefoil transfered conidia to A. pisum on bean and induced infections in 2–13% of aphids. 4 Conidia of P. neoaphidis dispersed passively in the airstream from sporulating M. carnosum cadavers on nettle plants and initiated infections in A. pisum colonies feeding on bean (4–33%) or M. dirhodum on barley (3%) located within 1.0 m of the nettle source. 5 The results suggest that M. carnosum and A. pisum may be more useful as reservoirs for P. neoaphidis in noncrop and crop areas than U. jaceae or M. dirhodum, and infection and dispersal between habitats could be enhanced in the presence of coccinellids.