African Entomology (29/03/2013)

Grapevine leafroll-associated virus 3 (GLRaV-3) transmission by three soft scale insect species (Hemiptera: Coccidae) with notes on their biology

2013-03-28T06:53:18Z

Author: Kruger, K. Douglas-Smit, N.
Vol 21 Issue 1
Publication: 2013
Page: 1-8
Abstract: Several mealybug and two soft scale species have been identified as vectors of Grapevine leafroll-associated virus 3 (GLRaV-3), the most abundant of the Closteroviridae associated with grapevine leafroll disease. To identify further soft scale vectors of GLRaV-3, the ability of three species, Coccus longulus, Parasaissetia nigra and a Saissetia sp., to transmit the virus to grapevine was determined under laboratory conditions. Using cultured soft scales, first-instar nymphs of C. longulus and P. nigra were given acquisition access to GLRaV-3-infected rootstock hybrid LN33. Saissetia sp. was reared on LN33 infected with GLRaV-3 and Grapevine virus A (GVA). Nymphs were transferred from virus source to virus-free grapevine plants (cv. Cabernet franc). Recipient plants were tested for GLRaV-3 and GVA with nested reverse transcription polymerase chain reaction (nested RT-PCR) and RT-PCR, respectively. The study shows for the first time that C. longulus, P. nigra and a Saissetia sp. are vectors of GLRaV-3. Saissetia sp. did not transmit GVA. The biology of C. longulus and P. nigra on grapevine was examined at different constant temperatures ranging between 18 and 35 °C, and at 25 and 30 °C, respectively. None of the nymphs survived past the second-instar stage except for one C. longulus female at 30 °C, which produced 117 offspring. The low survival rate could explain the low abundance and patchy distribution of soft scales in South African vineyards. However, outbreaks of soft scales in European vineyards have been reported and this study shows that more soft scale insect species than hitherto thought are able to transmit the virus.

Large colonies and striking sexual investment in the African stink ant, Paltothyreus tarsatus (subfamily Ponerinae)

2013-03-28T06:53:18Z

Author: Peeters, C. Braun, U. Holldobler, B.
Vol 21 Issue 1
Publication: 2013
Page: 9-14
Abstract: Most ponerine ants have colonies with up to a few hundreds of workers, but there has been sporadic evolution of species with more populous colonies. Forty two nests of Paltothyreus tarsatus were excavated from three distinct habitats in the Ivory Coast. Colonies were monogynous in Comoé (forest and savanna), but polygynous in Taï (rainforest). Mean colony size was 1576 ± 1543 workers, with the biggest colonies (exceeding 5000 adults) restricted to forest. Hundreds of sexuals occurred in many nests. Unlike males, young queens stay in the nests at least six months before the mating flight, presumably to accumulate fat reserves. This together with high absolute numbers of gynes and their large size relative to workers, amounts to a striking reproductive investment. We discuss this investment in the context of non-claustral independent colony foundation. Mating was observed in large male aggregations, unlike in South Africa where queens mate near the natal nests.

A study on the dynamics of Aedes caspius larval uptake and release of novel haematoporphyrin

2013-03-28T06:53:18Z

Author: El-Tayeb, T.A. Abd El-Aziz, N.M. Awad, H.H.
Vol 21 Issue 1
Publication: 2013
Page: 15-23
Abstract: Haematoporphyrin efficiency on Aedes caspius increased the larval mortality with the increase of haematoporphyrin formulation (HPF) concentration (1 x 10³ M/l). Larval mortality increased with increase the solar simulator light irradiances (350-650 W/m²) and exposure times (45 min). Dynamics of HPF accumulation and release as a function of time feeding and consumption was investigated using confocal laser scanning microscopy (CLSM). HPF accumulation in the larval body reached its maximum level after incubation for 12 h. Remaining HPF concentration decreased as the time elapsed reaching its minimal level after 15 h of HPF removal from the treatment medium.

A revision of Bana Londt, 1992 with the description of Bana madiba sp. n. from South Africa (Diptera: Asilidae: Stenopogoninae)

2013-03-28T06:53:18Z

Author: Londt, J.G.H.
Vol 21 Issue 1
Publication: 2013
Page: 24-28
Abstract: The genus Bana Londt, 1992 is revised. This Afrotropical genus, endemic to southern Africa, has been monotypic until now, the only known species being B. apicida Londt, 1992 from Namibia. A second species, B. madiba sp. n., is here described from South Africa thus significantly extending the known generic distribution. A key for the separation of the species is provided while the taxonomy, distribution and biology for the group is discussed.

A new Afromochtherus Lehr, 1996 from Madagascar (Diptera: Asilidae: Asilinae)

2013-03-28T06:53:18Z

Author: Londt, J.G.H. Vieira, R.
Vol 21 Issue 1
Publication: 2013
Page: 29-35
Abstract: Afromochtherus nesomyia sp. n. is described from Madagascar (Beza Mahafaly Special Reserve, Toliara Province) and notes are provided relating to A. annulata (Martin, 1964), the only other species of Afromochtherus Lehr, 1996 known from the island. A key for the separation of these two species is provided.

Respiration of Opistophthalmus pugnax (Thorell) (Scorpionidae) after treadmill exercise and book lung occlusion

2013-03-28T06:53:18Z

Author: Van Aardt, W.J.
Vol 21 Issue 1
Publication: 2013
Page: 36-40
Abstract: After the four spiracle pairs of Opistophthalmus pugnax were stepwise occluded, the oxygen consumption rate (MO₂) and the accumulation of d-lactate in the haemolymph were measured. D-lactate and MO₂ was also measured during a 15-minute treadmill exercise at a run speed of 0.025 m/sec. The highest d-lactate concentration of 15 mmol/l was obtained after a 15-minute exercise followed by 11 mmol/l d-lactate when all eight spiracles were closed off for one hour. The MO₂ value of 1.93 mmol/l obtained from four closed spiracles does not differ significantly (P<0.05, t-test) compared with the MO₂ value of eight open spiracles. Possible mechanisms of metabolic rate depression and metabolic down-regulation are discussed. Low haemolymphpH (7.38±0.08) in O. latimanus and other scorpions compared with other terrestrial arthropods are a hallmark inherent to scorpions living in dry xeric conditions.

The roles of food plants on the dispersion activities of the variegated grasshopper, Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae)

2013-03-28T06:53:18Z

Author: Ademolu, K.O. Idowu, A.B. Onabiyi, O. Oke, O.A.
Vol 21 Issue 1
Publication: 2013
Page: 41-44
Abstract: Dispersion activities in insects depend on many factors, including diet. The variegated grasshopper, Zonocerus variegatus moves from one place to another in the field when disturbed and in search food and mates. The effect of diets on the tissues (femoral and thoracic muscles) responsible for dispersion in Z. variegatus was investigated in this study. Acalypha wilkesiana, Chromolaena odorata, Carica papaya, Manihot esculenta and a mixture of the four plants were fed to newly emerged adult males (two days after emergence) for eight weeks. After feeding, insect tissues were assayed and activities of five enzymes namely: α-glucosidase, amylase, cellulase, lipase and proteinase were investigated. All the enzymes were detected in the muscles of Z. variegatus. The food plants significantly affected the enzyme activities in these tissues. Z. variegatus fed A. wilkesiana had significantly higher enzyme activities than those insects fed other plants (31.6, 16.2, 5.0, 5.8 absorbance/minute for proteinase, lipase, cellulase and α-glucosidase, respectively, in the femoral muscles). Proteinase and lipase had higher activities than the carbohydrases.

Does thermoregulation occur in the mounds of the harvester termite, Trinervitermes trinervoides (Sjöstedt) (Isoptera: Termitidae)?

2013-03-28T06:53:18Z

Author: Field, M.A. Duncan, F.D.
Vol 21 Issue 1
Publication: 2013
Page: 45-57
Abstract: The aim of this study was to obtain a seasonal profile of the mound temperatures of a harvester termite, Trinervitermes trinervoides (Sjöstedt), to ascertain whether the temperatures in different regions of the mound were constant across seasonal temperature fluctuations. Temperatures were measured in six mounds in the Melville Koppies Nature Reserve (Johannesburg, South Africa). Unlike most epigeous mound-building termites, their mounds were wholly restricted to the surface with no subterranean component. Brood and queen were found at the core of the mound at the soil interface. Core temperatures were constant on a monthly basis but fluctuated seasonally. They were kept within narrow limits of 20 °C in May (winter air temperatures of 16.80 ± 3.82 °C) and at 30 °C in October (summer air temperatures of 21.4 ± 5.61 °C). Mound architecture was found to be an important influence on core temperatures as the core temperatures in the uninhabited mounds were also kept relatively constant. Large mounds had higher core temperatures than medium mounds during every month except May, but the same pattern of a lowered core temperature during the winter months was also observed. The daily core temperature variation during each month was also less in the larger mounds. The mound structure achieved the equivalent buffering of air temperature as would have possibly occurred if the nest was 20 mm below the surface. The increase in core temperature from August throughout the summer months was attributed to the presence of alate larval instars within the nest. These T. trinervoides colonies were unable to build subterranean nests due to the bedrock layer occurring close to the soil surface, but achieved constant core temperatures through the insulating properties of the mound.

Distribution and diversity of epigaeic invertebrate assemblages in Silaka Nature Reserve, Eastern Cape, South Africa

2013-03-28T06:53:18Z

Author: Forbanka, D.N. Niba, A.S.
Vol 21 Issue 1
Publication: 2013
Page: 58-69
Abstract: Disturbance in habitat complexity and niche availability affect competitive interactions between faunal species which may result in their extinction. This study was conducted to assess the conservation value of four a priori selected sites, A: 'minimally disturbed natural forest patch', B: 'herbaceous grassland patch', C: 'road verge patch' and D: 'highly disturbed natural forest patch' using epigaeic invertebrate assemblages in Silaka Nature Reserve. A total of 2415 specimens belonging to three phyla (Arthropoda, Mollusca and Annelida) were caught from all sites using pitfall traps, and these were sorted into 14 orders, 15 families, 21 species and 17 morphospecies. Multivariate approaches using canonical correspondence analysis (CCA) showed that some measured site variables, e.g. litter depth, grazing intensity, soil pH, soil phosphorus content and texture (percentage clay and silt) accounted for species distribution trends across sites. Site A had both common/widespread and rare/typical invertebrate taxa, and therefore was of high value for conserving invertebrate biotic communities within the reserve. The other three sites also offered optimal and unique habitat requirements for protecting and preserving species such as Ancylotrypha zuluensis, Lycosidae sp. 2, and the Opiliones. Biotope management in the reserve should therefore aim at preserving a variety of habitat patches that differ in structural and compositional vegetation. Furthermore, anthropogenic pressures resulting from frequent clearing should be regulated especially during the summer to cater for various developmental (including immature) stages of the invertebrate assemblage of the reserve.

Evaluation of 15 varieties of okra (Abelmoschus esculentus (L.) Moench to field infestation by flea beetles (Podagrica spp.)

2013-03-28T06:53:18Z

Author: Mohammed, I.G. Osipitan, A.A. Pitan, O.R. Atayese, M.
Vol 21 Issue 1
Publication: 2013
Page: 70-78
Abstract: The study evaluated 15 okra varieties to field infestation by flea beetles, Podagrica spp., in the early and late planting seasons of 2009, at the Teaching and Research Farm, Federal University of Agriculture, Abeokuta, Nigeria (7°15'N 3°25'E), located in a sub-humid zone. The experiment was arranged in a split plot design, with three replicates. The main plot consisted of spraying regime (sprayed and unsprayed) while the sub-plot consisted of 15 okra varieties: V-35, V2-Oyo, V45-2, NH99/28, NH99/DA NH88/1-8-16-2, Enugu1, Osadep:purple Tall, LD88/1-8-5-2, LD88/1-8-16-2, Ola99/13, Ola3 Local, Olak2005, Short Mouth and Dajofolowo1. Lambda-cyhalothrin was sprayed to the appropriate plots weekly. The results showed that in both early and late seasons, sprayed okra had significantly (P<0.05) lower number of flea beetles, lower leaf damage per plant, lower number of holes per leaf, wider stem girth, higher total plant dry biomass, higher number of pods compared with unsprayed okra. The sprayed okra had significantly (P < 0.05) higher shoot dry biomass, higher root dry weight, higher total plant dry biomass, wider pods and higher pod weight in the early planting season compared with the late season. Varieties with leaf pubescence, namely NH99/DA, V-35 and Dajofolowo1, had the lowest flea beetle population, leaf damage per plant and number of holes per leaf compared to glaborous varieties. Likewise, the okra varieties NH99/28, V-35 and Dajofolowo1 which have thorny pods had no pod damage at all in both early and late planting seasons. LD88/1-8-5-2 had the highest number of pods per plant, whereas okra variety Ola99/13 had significantly (P < 0.05) higher pod weight during early planting. There was no significant difference in okra pods weight in all varieties evaluated in the late planting season.

Infestation of Mangifera indica by the mango gall fly, Procontarinia matteiana, (Kieffer & Cecconi) (Diptera: Cecidomyiidae)

2013-03-28T06:53:19Z

Author: Augustyn, W.A. Du Plooy, W. Botha, B.M. Van Wilpe, E.
Vol 21 Issue 1
Publication: 2013
Page: 79-88
Abstract: Mango gall fly (Procontarinia matteiana Kieffer & Cecconi, 1906) is an orchard pest that infests flush leaves of mango, forming wart-like structures on the leaves. Serious outbreaks may result in reduced fruit yield. A natural parasite (Chrysonotomyia pulcherimma Kerrich, 1970) of the gall fly lays its eggs inside the gall and the larvae feed on the gall fly. Mango cultivars present varying susceptibilities to gall fly infestation, with cultivars ranging from completely resistant, highly susceptible to intermediate stages where pseudo-galls are formed. The latter cultivars are ovipositioned by the gall fly, but secondary metabolites within the leaves possibly halt the development, thereby preventing the development of true galls. Microscopy was used to identify characteristic features of the gall fly and its parasite inside the gall, to study the development of the insects and to distinguish them. Evidence was obtained that the use of insecticides curbs the development of the larvae. Tissue development within true and pseudo-galls was studied to provide insights into the role of secondary plant metabolites in arresting true gall formation. This study will contribute to a more holistic approach to pest management of mango.

Insecticide resistance in Anopheles arabiensis from Ethiopia

2013-03-28T06:53:19Z

Author: Fettene, M. Olana, D. Christian, R.N. Koekemoer, L.L. Coetzee, M.
Vol 21 Issue 1
Publication: 2013
Page: 89-94
Abstract: The status of insecticide susceptibility of Anopheles arabiensis populations was monitored in northern and southern Ethiopia using one- to three-day-old mosquitoes reared from larval collections. Anopheles gambiae complex mosquitoes, identified by PCR as An. arabiensis, were exposed to diagnostic concentrations of DDT, malathion, fenitrothion, bendiocarb, propoxur and deltamethrin according to the standard WHO procedure. A heterogeneous and focal distribution of resistance phenotypes was observed in surveyed districts of the country. In Tach Armacho in northern Ethiopia, only resistance to DDT was detected. In the other two northern sites, An. arabiensis populations were susceptible to fenitrothion, resistant to malathion, propoxur and DDT and showed low levels of survival when exposed to bendiocarb requiring further investigations. In three areas of southern Ethiopia, An. arabiensis was susceptible to bendiocarb, propoxur and malathion, with low levels of survival on fenitrothion needing further confirmation. These samples were resistant to DDT and deltamethrin. Analyses for the knockdown resistant (kdr) mutations showed only the L1014F mutation was present with frequencies ranging from 68 to 100 %. The need for routine monitoring and surveillance as part of an insecticide resistance management programme is highlighted.

Patterns of lacewing (Neuroptera: Chrysopidae) flight activity, flight height and spatial distribution of eggs on maize plants

2013-03-28T06:53:19Z

Author: Keulder, R. Van den Berg, J.
Vol 21 Issue 1
Publication: 2013
Page: 95-102
Abstract: Lacewings (Chrysopidae) are important beneficial insects in nearly all cropping systems. However, monitoring of lacewing numbers is difficult due to the nocturnal behaviour of adults and the difficulty of finding eggs and larvae on plants. Techniques facilitating easy finding of eggs and adults will result in improved pest management decisions and monitoring of these beneficial organisms. This study was conducted to determine flight activity patterns as well as preferred oviposition sites of lacewings on maize plants to facilitate time-effective searching for eggs. The daily flight activity pattern and flight height of lacewings were recorded and sweep-net samples were taken to determine lacewing numbers in different adjacent vegetation types (maize, lucerne, natural veld). The preferred area of oviposition was determined by inspecting maize plants for lacewing eggs and recording the distribution of eggs on leaves. Chrysoperla pudica (Navás) was the predominant species in maize. Lacewings were most active between 16:00 and 22:00 and flew largely between 0.5 and 2.5 m above ground level. Oviposition occurred predominantly on leaves near maize ears. Data on spatial distribution of eggs facilitate monitoring of eggs numbers in maize cropping systems and is also of use in general pest management.

Diel patterns of mating, oviposition and feeding in the coconut bug, Pseudotheraptus wayi Brown (Heteroptera: Coreidae)

2013-03-28T06:53:19Z

Author: Egonyu, J.P.
Vol 21 Issue 1
Publication: 2013
Page: 103-107
Abstract: The coconut bug, Pseudotheraptus wayi Brown (Heteroptera: Coreidae), is a polyphagous pest of economically important crops as well as wild plants in eastern and southern Africa. This study was undertaken to determine peak mating, oviposition and feeding times of this pest and compare incidences of these activities between photophase and scotophase with a view to providing a basis for further studies on this pest as well as proper timing of control interventions against it in the field. The study was laboratory based and the insects were observed in cages containing French bean pods as their food. Data show that mating incidences were approximately four times more prevalent during scotophase than photophase with a peak at mid scotophase. Diel oviposition curve had a major peak at late photophase and a minor one at late scotophase; and approximately twice more eggs were laid during photophase than scotophase. Nymphal feeding patterns had extended peaks between 18:00 and 0:00, with approximately twice as many nymphs feeding during scotophase than during photophase. Adult feeding pattern was different from that of nymphs, i.e. it was unaffected by time of day or light and darkness, probably because the adults had to balance feeding with mating and oviposition.

Comparing abundance of predacious and phytophagous mites (Acarina) in conjunction with resistance identification between Bt and non-Bt cotton cultivars

2013-03-28T06:53:19Z

Author: Sarwar, M.
Vol 21 Issue 1
Publication: 2013
Page: 108-118
Abstract: Knowledge of the arthropod complex associated with any crop is essential for developing pest control strategies. Bt (GK-12, Lu-23 and SGK-321) and non-Bt (Zhong-12, Shiyuan-321 and Simian-3) cotton varieties were used for assessing differences in harbouring populations of the carmine spider mite Tetranychus cinnabarinus (Boisduval) and predatory mite Neoseiulus cucumeris (Oudemans). Two Bt cotton varieties GK-12 and Lu-23, and two non-Bt varieties Zhong-12 and Simian-3 appeared more supportive for maintaining T. cinnabarinus, whereas, SGK-321 (Bt) and Shiyuan-321 (non-Bt) clearly showed reduced pest susceptibility, but efficient in maintaining N. cucumeris population. Throughout the study period, the densities of T. cinnabarinus remained higher (1.77 and 1.40 per leaf) in Bt than non-Bt varieties following insecticides application against the cotton pest complex. The beneficial mite N. cucumeris remained active in both Bt and non-Bt varieties, but Bt cotton had slightly higher numbers of the predator (0.58 per leaf) than non-Bt cotton (0.40 per leaf). Consequently, there were no great impacts on the predatory natural enemy associated with Bt cotton and the predator population in Bt fields was not negatively affected in comparison with conventional cotton. All tested varieties of cotton significantly differed in relation to their morphological characteristics. Of the different factors found to affect the populations of predacious and phytophagous mites, in general, the trichome density on the lower surface of the leaf, leaf thickness and plant height had positive relations with arthropod abundance. Our results showed that SGK-321 (Bt) and Shiyuan-321 (non-Bt) could be recommended for use in creating new resistant cotton varieties as a component of an integrated pest management strategy. Hence, the differences in the response of pest and predator to host plant and leaf architectures should be considered to enhance their roles in biological control strategy.

Fluctuation of fertility with number in a real insect population and a virtual population

2013-03-28T06:53:19Z

Author: Herbert, M.L. Lewis, M.G.
Vol 21 Issue 1
Publication: 2013
Page: 119-125
Abstract: Real fruit fly fertility increases with average consanguinity thus decreasing with population size in a pattern that is modelled successfully with a virtual population. This invites the deliberate manipulation of wild insect populations for the control of vectors of human disease.

Impact of farnesol on the food consumption and utilization, digestive enzymes and fat body proteins of the desert locust Schistocerca gregaria Forskål (Orthoptera: Acrididae)

2013-03-28T06:53:19Z

Author: Awad, H.H. Ghazawy, N.A. Abdel Rahman, K.M.
Vol 21 Issue 1
Publication: 2013
Page: 126-131
Abstract: The food consumption, nutritional indices and the digestive enzymes (protease, invertase, amylase, trehalase and chitinase) of Schistocerca gregaria were affected by treatment with farnesol. Treated insects oviposited fewer eggs. The total haemolymph and midgut protein significantly increased in farnesol-treated insects as compared with the control. Protein profiles in the fat body of treated females showed a significant (P < 0.05) change compared with the control females. This change in the intensity might reflect the decline in the synthesis or the increase in the utilization of this protein.

An effective method for maintaining the African termite-raiding ant Pachycondyla analis in the laboratory

2013-03-28T06:53:19Z

Author: Yusuf, A.A. Crewe, R.M. Pirk, C.W.W.
Vol 21 Issue 1
Publication: 2013
Page: 132-136
Abstract: Pachycondyla analis Latreille (Hymenoptera: Formicidae) is a common African Ponerine ant that organizes group raids on termites considered a huge burden to agriculture. This ant has been the subject of various entomological and natural history studies aimed at understanding their group raiding behaviour and impact on the ecosystem as well as the roles they play in regulating field termite populations. However, colony maintenance under laboratory conditions for long-term research purposes has largely been unsuccessful. Herein, we report an effective method for maintaining P. analis in the laboratory for long-term studies that may include behavioural, life history and chemical ecology. Using a simple set-up made up of a Perspex foraging arena and an aluminum nest box in the laboratory, queen right colonies were successfully maintained for an average of 27.0±6.0 weeks and a maximum of 34 weeks before declining. High ant mortality (6-48 %) was observed in the first week of captivity in the laboratory. This declined to a weekly mortality of 4.0 ± 3.6% (24 ± 22.5 ants per colony) after the ants had settled in their new laboratory nest. Therefore, using our laboratory rearing set-up, and keeping laboratory conditions similar to those in the field, as well as feeding P. analis on its usual diet of termites, could increase colony survival time up to 4.5 times longer than previously reported rearing protocols.

Silkworm moths inventory in their natural tapia forest habitat (Madagascar) : diversity, population dynamics and host plants

2013-03-28T06:53:19Z

Author: Razafimanantsoa, T.M. Raminosoa, N. Rakotondrasoa, O.L. Rajoelison, G.L. Bogaert, J. Rabearisoa, M.R. Ramamonjisoa, B.S. Poncelet, M. Haubruge, E. Verheggen, F.J.
Vol 21 Issue 1
Publication: 2013
Page: 137-150
Abstract: Endemic silk moths (Lepidoptera: Lasiocampidae) in Madagascar have been collected and exploited for centuries by local populations either for food or as a source of silk cocoons from which textiles are made. Moth natural forest habitat has also been degraded, leading to a drastic decrease in silk moth populations. However, very few scientific reports highlighted these observations well known by the local people. We have inventoried silk moths species in tapia (Uapaca bojeri Baill.) forests located in the central highlands of Madagascar. Inventories have been conducted during one year from August 2009 to July 2010 by sampling transects in Imamo forests. Three species of Lasiocampidae belonging to two genera were found: Borocera cajani Vinson, Borocera marginepunctata Guérin-Méneville and Europtera punctillata Guenée. These three silk moth species are endemic to Madagascar but only one (B. cajani) is commercially exploited in the silk industry. The habitat, host plants, abundance, life cycle and feeding behaviour of these species in their natural habitat are described.

Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), a potential biological control agent for the submerged aquatic weed, Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae)

2013-03-28T06:53:19Z

Author: Martin, G.D. Coetzee, J.A. Baars, J-R.
Vol 21 Issue 1
Publication: 2013
Page: 151-160
Abstract: The leaf-mining fly, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), was investigated in its native range in South Africa, to determine its potential as a biological control agent for Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae), an invasive submerged macrophyte that is weedy in many parts of the world. The fly was found throughout the indigenous range of the plant in South Africa. High larval abundance was recorded at field sites with nearly all L. major shoots sampled containing larvae, with densities of up to 10 larvae per shoot. Adults laid batches of up to 15 eggs, usually on the abaxial sides of L. major leaves. The larvae mined internally, leaving the epidermal tissues of the upper and lower leaves intact. The larvae underwent three instars which took an average of 24 days and pupated within the leaf tissue, from which the adults emerged. Impact studies in the laboratory showed that H. lagarosiphon larval feeding significantly restricted the formation of L. major side branches. Based on its biology and damage caused to the plant, Hydrellia lagarosiphon could be considered as a useful biological control candidate for L. major in countries where the plant is invasive.

Acanthaegilopsis malagasy gen. n. and sp. n. of Anacharitinae (Hymenoptera: Cynipoidea: Figitidae) from Madagascar and the Comoros

2013-03-28T06:53:19Z

Author: Mata-Casanova, N. Pujade-Villar, J.
Vol 21 Issue 1
Publication: 2013
Page: 161-164
Abstract: A new genus of the subfamily Anacharitinae (Hymenoptera: Figitidae), Acanthaegilopsis gen. n., from Comoros and Madagascar is described. Diagnostic characters of the new genus are illustrated and discussed.

Detection of Leptoglossus occidentalis Heidemann, 1910 (Heteroptera: Coreidae) in Tunisia : short communication

2013-03-28T06:53:19Z

Author: Ben Jamaa, M.L. Mejri, M. Naves, P. Sousa, E.
Vol 21 Issue 1
Publication: 2013
Page: 165-167
Abstract: In this paper we report the collection of L. occidentalis from a new location in a pine forest in northern Tunisia, this being the first record for the country and the entire African continent.

Morphological and genetic characterization of a South African Plutella xylostella granulovirus (PlxyGV) isolate : short communication

2013-03-28T06:53:19Z

Author: Abdulkadir, F. Marsberg, T. Knox, C.M. Hill, M.P. Moore, S.D.
Vol 21 Issue 1
Publication: 2013
Page: 168-171
Abstract: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar & Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.

Spread and impacts of the Agapanthus borer (Neuranethes spodopterodes (Hampson, 1908), comb. nov.), a translocated native moth species (Lepidoptera: Noctuidae) : short communication

2013-03-28T06:53:19Z

Author: Picker, M.D. Kruger, M.
Vol 21 Issue 1
Publication: 2013
Page: 172-176
Abstract: Alien species are known to impact biodiversity and ecosystem function in their introduced range, and may be the major threat to endangered species through competitive or predatory interactions. In agroecosystems the economic costs of such impacts are considerable (Pimental et al. 2005), and are typically associated with phytophagous crop pests. While the impacts of translocated native species may also be significant, attention has generally been focused on translocations of vertebrates, where these anthropogenically-facilitated movements are more readily detected and documented (Van Rensburg et al. 2011).

A new species of the rare African wool-carder bee genus Anthidioma (Hymenoptera: Megachilidae) from Namibia : short communication

2013-03-28T06:53:19Z

Author: Griswold, T.L. Gonzalez, V.H.
Vol 21 Issue 1
Publication: 2013
Page: 177-180
Abstract: The African bee genus Anthidioma Pasteels is a rare representative of the megachilid tribe Anthidiini that occurs in Namibia and the Western Cape Province, South Africa (Michener 2007). The genus was proposed by Pasteels (1984) based upon a female with long, abundant hairs and without the common yellow maculations found on the body of most anthidiine bees (i.e. Anthidioma chalicodomoides Pasteels; Figs 1-4).

Insect Outbreaks Revisited, P. Barbosa, D.K. Letourneau & A.A. Agrawal (Eds.) : book review

2013-03-28T06:53:19Z

Author: Hanrahan, S.A.
Vol 21 Issue 1
Publication: 2013
Page: 181-182
Abstract: This revised version of the classical textbook, Insect Outbreaks (Barbosa & Schultz 1987), is an absolute must for those interested in applied entomology, either as a book to own or to recommend for the library. The very broad approach to the topic makes the book useful for both the novice wishing to obtain a general background as well as for the specialist, expert in a specific field but needing to catch up on contemporary ideas in the broader topic. The text is well written, easy to read and presented in an interesting and accessible way.