African Entomology - Volume 23, Issue 2, 2015
Volumes & issues
Volume 23, Issue 2, 2015
Description of a new species of Attagenus Latreille, 1802 from South Africa (Coleoptera : Dermestidae : Attageninae)Source: African Entomology 23, pp 439 –442 (2015)More Less
Efficacy of Bacillus thuringiensis and indigenous Trichogramma turkistanica for controlling lepidopterous pests on Taify pomegranate fruitsSource: African Entomology 23, pp 443 –450 (2015)More Less
The impact of Bacillus thuringiensis and native Trichogramma turkistanica on the infestation rates of two lepidopterous pests, Virachola livia and Ectomyelois ceratoniae, was assessed in field experiments conducted in four pomegranate farms distributed in the Taif region of Saudi Arabia. Pomegranate trees were sprayed with B. thuringiensis spores, and indigenous T. turkistanica was inundatively released during the pomegranate fruiting season from April to September of 2014. The highest infestation rates with E. ceratoniae and V. livia in control and treated trees gradually increased until the end of the season, reaching 79, 54 and 22 % for E. ceratoniae, and 22, 16 and 7% for V. livia in control, Bacillus-treated trees, and Trichogramma-treated trees, respectively. The mean percentages of fruits infested with E. ceratoniae or V. livia were significantly different between the untreated trees and both the trees treated withTrichogramma and those treated with Bacillus. Moreover, the trees treated with Trichogrammahad a lower infestation rate by both E. ceratoniae and V. livia compared to the trees treated with Bacillus. The number of larvae collected from infested fruits varied from one to two larvae per fruit for both E. ceratoniae and V. livia. Use of Bacillus or native Trichogramma to control these pests can achieve high yields of Taify pomegranate of better quality.
House dust mites : studies on the occurrence, identification and control in rural houses of Shebin El-Kom locality, EgyptAuthor H.M. HeikalSource: African Entomology 23, pp 451 –457 (2015)More Less
The present study was conducted in Elkom Elakhdar village, Shebin El-Kom, Menoufia Governorate, during 2012 to determine the species composition and the occurrence frequency of dust mites collected from three rural houses of different development stages, as well as to determine the toxicity limits of different concentrations of three essential plant oils against two species of the family Pyroglyphidae, the main cause of allergies to humans. The results revealed 11 mite species belonging to five families (Pyroglyphidae, Chortoglyphidae, Glycyphagidae, Acaridae, and Cheyletidae). Of the total collected number of mites (5276) the most dominant species were the dust mites Dermatophagoides farinae (66.1 %), followed by D. pteronyssinus (23.3 %), while the rest of the species, Chortoglyphus arcuatus, Lepidoglyphus destructor, Glycyphagus domesticus, Gohieria fusca, Tyrophagus putrescentiae, Caloglyphus sp, Cheyletus malaccensis, Blomia sp. and Acarus siro ranged between 0.16 and 2.0%. Regarding the effect of temperature on mite populations, temperature more than 25 °C in summer decreased the numbers of D. farinae and D. pteronyssinus. Toxicological tests of three essential plant oils against adult stages of D. farinae and D. pteronyssinus showed that lemon grass oil was more effective than geranium and thyme oils, with a mortality of approximately 100% at 800 ppm concentration for both species. The LC50 of lemon grass was 228.992 ppm and 293.615 ppm against the two species, respectively. From these results it is recommended that application of control measures during summer when the mite population density is at its lowest and to use botanical oil extracts which can be effectively implemented in integrated pest management programmes.
Effect of Syzygium aromaticum cloves on larvae of the rhinoceros beetle,Oryctes agamemnon (Coleoptera: Scarabaeidae)Source: African Entomology 23, pp 458 –466 (2015)More Less
The susceptibility of rhinoceros beetle larvae, Oryctes agamemnon, to different concentrations of Syzygium aromaticum cloves was studied under laboratory conditions. Two forms of cloves were applied, first as finely powdered flower buds and later as an essential oil. The clovepowder concentrations used against the larvae were 1, 3, 5, 7 and 9%, and the clove essential oil (CEO) was used at concentrations of 1, 2, 3, 4 and 5 %. The highest (68.5%) and lowest (2%) larval mortality were caused by 9% and 1% clove flower bud powder (CFBP), respectively. However, the CEO was more effective against the larvae of O. agamemnon than the powder. Mortalities ranged from 12.5 to 87.9 % at oil concentrations of 1 and 5%, respectively. The results also showed that the two forms of cloves persist in the treated soil for 7 to 8 days. Additionally, the clove oil and powder have a residual effect in treated soil that provides sustainable protection for date palms against root borers. Accordingly, it was concluded that cloves in either powder or essential oil form are very promising for controlling Oryctes larvae. These results indicate that clove flower buds and essential oils are desirable tools for crop protection in the future, promoting environmentally friendly pest control strategies.
Tiger beetles (Coleoptera : Carabidae : Cicindelinae) of Tunisia : distribution, phenology, taxa list and new recordsSource: African Entomology 23, pp 467 –485 (2015)More Less
Based on the literature and new faunistic records, the diversity and distribution of the tiger beetles in Tunisia are summarized and discussed. In total, 15 species (one with two subspecies) are reported from the country. However, the occurrence of Cicindela maroccana maroccana is questionable, and should be confirmed by newer data. Checklists of tiger beetles are also provided for each Tunisian governorate. The highest diversity was recorded in the region adjacent to the Mediterranean Sea coastline. The area is mainly up to 100ma.s.l. with salt marshes, strands of sandy sea beaches and river banks as main types of habitats occupied by Cicindelinae (14 species or 94% of tiger beetle fauna). Mountainous and desert regions are characterized by much lower diversity (six species or 38% of fauna and two species or 13% of fauna, respectively). Cicindelinae occurring in these areas inhabit predominantly river banks and oases. In chorotype classification, Tunisian tiger beetles fall into six different groups including West Mediterranean species (50% of fauna), Maghreb endemics (19%), Mediterranean, North-African, Mediterranean-Westturanian and Afrotropico-Indo-Mediterranean species (each of them 6% of fauna). According to their phenology, the Tunisian tiger beetles may be divided into three main groups : 1) spring-active species (Cicindela campestris atlantis and all Neolaphyra taxa), 2) spring-summer-active species (Calomera littoralis littoralis, C. lunulata lunulata, Cassolaia maura cupreothoracica, Lophyra flexuosa flexuosa, Myriochila melancholica melancholica, Grammognatha euphratica euphratica), and 3) summer-active species (Calomera aulica aulica, Cylindera trisignata sciliensis and Cephalota spp.).
Author R.A. IbrahimSource: African Entomology 23, pp 486 –493 (2015)More Less
For two successive years, a survey was conducted of entomopathogenic fungi associated with two naturally infected predatory insect species on different plantations of the Nile Delta in northern Egypt. Adults of the eleven-spotted ladybird beetle, Coccinella undecimpunctata L. (Coleoptera : Coccinellidae), are frequently observed with infections of the entomopathogenic fungus Beauveria bassiana, which caused mortality of 4.1% and 5.4% in the adult ladybird beetle population sampled in July 2006 and 2007, respectively. However, mycosed individuals of the seven-spotted ladybird, Coccinella septempunctata, were rarely encountered. Adults of the syrphid fly Syrphus corollae (Diptera: Syrphidae) are also subject to infection with the entomopathogenic fungus Entomophthora syrphi. Data showed that E. syrphi caused mortality in syrphid fly adults at rates of 4.6% in April to 0.2% in June 2006, whereas mortality rates ranged from 6.1% in April to 0.9% in June 2007. Mycosed syrphid adults were always found in an elevated position (frequently near the tips of artichoke leaves). Two years of field monitoring revealed that both entomopathogenic fungi, B. bassiana and E. syrphi, fail to distinguish between their original hosts and the predatory insects that coexist in the same ecosystem.
Surveying Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiideae), in North Tunisia reveals changes in insect virulence and cultivar responsesSource: African Entomology 23, pp 494 –501 (2015)More Less
Hessian fly, Mayetiola destructor (Say), is an endemic pest in Tunisia and is among the most destructive biotic stresses of commercial cereals. Genes in wheat that confer resistance to this insect provide the most efficient and economical means of crop protection. Yet, attempts to breed for resistant cereal genotypes are hampered by the periodic emergence of virulent pest biotypes that are unaffected by the plant's resistance factors in use. Therefore, it is crucial to undertake permanent surveys in order to establish baseline information on the status of germplasm resources. A survey of infestation was conducted during the growing season 2011/2012, over the four most important cereal-growing provinces of Tunisia (Béja, Jendouba, Kef and Siliana), which highlighted variation in the incidence and severity of attacks between regions and periods of the year. We recorded two intense outbreaks occurring in early March and late April, suggesting that eradication should be applied in the month of February to hinder the development of subsequent generations. Unlike this constancy in the insect biological rhythm, the genetics of its physiological interaction with the cereal host seems to be altered by mutations leading to the development of new virulent strains. When testing 25 cereal genotypes to infestation by Hessian fly in Béja, Jendouba and Kef, we found that the bread wheat cultivar 'Salambo 80' was susceptible. This genotype was resistant to Hessian fly in North Tunisia ten years before. In contrast to 'Salambo 80', bread wheat 'Mahon 73' was characterized by stable resistance across different infestation circumstances, indicating that it would provide a solution for breeding against the Hessian fly races currently prevailing in North Tunisia. The herein reported results represent an additional step of a long-term effort that should be maintained and updated to keep up with the co-evolutionary dynamics associating cereals to their feeding fly, and stay continuously alerted of biotype development.
Tracking microRNAs with a potential for virulence regulation in the pea aphid, Acyrthosiphon pisum Harris (Hemiptera : Aphidae), and the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae)Source: African Entomology 23, pp 502 –509 (2015)More Less
The pea aphid, Acyrthosiphon pisum (Hemiptera : Aphidae), and the Asian citrus psyllid, Diaphorina citri (Hemiptera : Psyllidae), are two major pests that conjunct in their virulence pathways against hosts by settling a gene-for-gene interaction model. The most effective controlling method of these pests is the deployment of host resistance (R) genes, which strongly depends on both host and insect genotypes. MicroRNAs (miRs) are noncoding RNAs of ~22 nucleotides inducing sequence-specific post-transcriptional gene silencing. The identification and analysis of miRs is nowadays a useful reverse genetics tool for studying insect virulence and host resistance pathways. in the present study, we utilized 15 virulence-regulatory miRs of the Hessian fly, Mayetiola destructor (Diptera: Cecidomyiidae), to search for homologies across 103 A. pisum mature miRs and 86 D. citri miR-like expressed sequence tags (ESTs), mined from several databases. Our results showed that reference miRs from M. destructor could be grouped with their most similar microRNA counterparts from A. pisum and D. citri within eight phylogenetic clades, and that seven of A. pisum miRs clustered with M. destructor ones at a similarity threshold of 90%. Such structural similarities strongly suggest that different avirulence (Avr) genes from M. destructor, A. pisum and D. citri would be tightly regulated by a regulatory network including similar miRs. Our study offers a promising way to further explore the structural similarity between miRs toward their potential use in Integrated Pest Management (IPM).
Infestation of two tephritid fruit flies, Bactrocera dorsalis (syn. B. invadens) and Ceratitis capitata, in guava fruits from selected regions of Eritrea : short communicationSource: African Entomology 23, pp 510 –513 (2015)More Less
In Eritrea, guava (Psidium guajava L.) is the third most important fruit in terms of total area of cultivation (269 ha) and fruit production (3550 t) (MOA 2011a); first two being banana and orange. It is mainly grown in Anseba (area of cultivation 140 ha; fruit production 2100 t), Gashbarka (38 ha and 470 t), Maekel (40 ha and 480 t) and Debub (45 ha and 381 t), respectively (MOA 2011b). Generally, fruit crops such as guava, orange and mango are produced in small-scale traditional orchards except banana, which is produced in a range of small- to large-scale farms. The fruit is also cultivated in home gardens and orchards together with vegetables for consumption and supply to local markets mostly in Elabered, Ghinde, Hamelmalo, Durfo, Akordat, Barentu, Filfil and Mai-aini.
First record of Pachycrepoideus vindemmiae (Rondani) (Hymenoptera: Pteromalidae) parasitizing pupae of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in Tunisia : short communicationSource: African Entomology 23, pp 514 –518 (2015)More Less
The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann) (Diptera : Tephritidae), isone of the most devastating pests of fruits and vegetables worldwide (Liquido et al. 1991; Chueca et al. 2007). It is the most invasive species of all members of the Tephritidae (Zucchi 2001) and a key pest of citrus and other fruits in the Mediterranean countries, including Tunisia (Enkerlin & Mumford 1997; Jerraya 2003). Serious economic damage is caused by this insect in Tunisia; in mixed fruit cultivation crop losses can be from 80 to 100% (Jerraya 2003). Citrus is the most affected host crop, with direct annual losses attributed to C. capitata of up to 38% of annual income from Tunisian citrus production (Driouchi 1990; Lebdi Grissa 2010).
The host status of lemons for the false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera : Tortricidae) with particular reference to export protocolsSource: African Entomology 23, pp 519 –525 (2015)More Less
The South African citrus industry is dependent on export of fresh fruit to many markets around the world, with approximately 70% of South Africa's citrus crop being exported (CGA 2013). The false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera : Tortricidae), is recorded as a pest of citrus fruit in southern Africa (Newton 1998; Grout & Moore 2015). As a result of its endemism to sub-Saharan Africa (Moore 2002), certain export markets of importance for the South African citrus industry, such as Peoples Republic of China, U.S.A. and South Korea, regulate it as a quarantine pest.Control of the pest in the field can be highly effective, using a suite of integrated control options, applied with diligent management (Moore & Hattingh 2012). These can succeed in reducing T. leucotreta infestation by 97% or more (Moore et al. 2015). Such an integrated system, using the sterile insect technique as the mainstay of the programme, has succeeded in reducing moth catches by 99%, fruit infestation by 96% and export rejections by 89% in the Western Cape Province of South Africa, since the inception of the programme in 2007 (Barnes et al. 2015).