African Entomology - Volume 6, Issue 2, 1998
Volumes & issues
Volume 6, Issue 2, 1998
Katacamilla Papp, 1978, a genus of Camillidae (Diptera: Schizophora) associated with the dung of bats, birds and hyraxes in Africa and the Arabian PeninsulaAuthor D.A. BarracloughSource: African Entomology 6, pp 159 –176 (1998)More Less
Katacamilla Papp, 1978, hitherto a monotypic genus of Camillidae known only from Namibia, is revised to include five species from Africa and the southern part of the Arabian Peninsula. The revision is based on more than 400 specimens. The placement of Katacamilla in the Camillidae is confirmed. A revised diagnosis of the genus is given. Katacamilla is distinguished from all other camillid genera by at least 10 character states, six of which are autapomorphies. A key to the species is presented. illustrations of head profiles, male forefemur and terminalia are provided for all species. Katacamilla cavernicola Papp is redescriptionbed from three Namibian localities. Four new species are descriptionbed: K. braacki from northeastern South Africa, K. ctenidia from northern Nigeria, K. gallagheri from eastern Oman and K. procavia from central Namibia. Katacamilla cavernicola is known only from caves, where it exhibits both parietal and troglophilic habitat preferences; it has been reared from dung of the rock pigeon, Columba guinea Linnaeus (parietal), and of the common slit-faced bat, Nycteris thebaica Geoffroy (troglophilic). Katacamilla braacki has been collected in close association with dung of the Egyptian fruit bat, Rousettus aegyptiacus (Geoffroy), in a troglophilic habitat. Katacamilla procavia has been reared from the dung of the rock hyrax, Procavia capensis (Pallas), taken from the shelter of a rocky overhang. Katacamilla ctenidia and K. gallagheri are probably associated with the dung of birds and/or small mammals in relatively exposed habitats. A preliminary cladistic analysis suggests that the clade comprising the bat-associated (cavernicolous) sister species, K. cavernicola and K. braacki, is the most highly derived in the genus and, consequently, that association with bats is a recent specialization.
Oviposition site preferences of potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), a pest on tobacco, Nicotiana tabacum L. (Solanaceae)Source: African Entomology 6, pp 177 –183 (1998)More Less
The most frequent oviposition site of potato tuber moth, Phthorimaea aperculella (Zeller), the primary pest on tobacco in South Africa, is in the soil under the plant, irrespective of growth stage. The oviposition site should be taken into consideration in a chemical control programme. High trichome densities in the upper two thirds of the tobacco plant deters the moth from ovipositing in this region. Of the few eggs laid on leaves, most were on leaves on the bottom third of the plant where trichomes were less dense. Potato tuber moth prefers dry soil for oviposition, indicating that microclimate should be considered in an Integrated Pest Management System.?
Feeding behaviour of Cicadulina storeyi China (Homoptera: Cicadellidae) on maize varieties susceptible or resistant to maize streak virusSource: African Entomology 6, pp 185 –191 (1998)More Less
The feeding behaviour of Cicadulina storeyi China on healthy and virus-infected plants of maize varieties with different levels of resistance to maize streak geminivirus (MSV) was studied using an alternating current (AC) electronic monitor. Three maize varieties were tested: 8321-21 (fully resistant), 8329-15 (moderately resistant) and FR114 x FR303 (susceptible). Typical waveforms that have previously been associated with salivation, ingestion and non-probing activities were recorded. Variety and disease status influenced feeding behaviour. Leafhoppers probed more frequently, had a higher number of non-probing activities such as walking or resting, and a significantly shorter duration of phloem feeding on healthy plants of 8321-21 compared to those of other varieties. These results suggest that 8321-21 manifests antixenosis-type resistance to C. storeyi. The percentage of time spent on patterns associated with phloem ingestion was significantly greater on healthy plants of all varieties than on virus-infected ones. The Significance of Cicadulina feeding behaviour in relation to transmission of MSV is discussed.
Revision and cladistic analysis of the Afrotropical genus Areotilla Bischoff (Hymenoptera: Mutillidae: Ticoplinae)Author D.J. Mitchell, A. & BrothersSource: African Entomology 6, pp 193 –214 (1998)More Less
The genus Areotilla Bischoff, 1920, is revised and females are descriptionbed for the first time. Males are known for eight species: A. areolata Bischoff, A. marshalli (Andre), A. aurea sp. n., A. bilobata sp. n., A. michaeli sp. n., A. trifaseiata sp. n.,A. vulgaris sp. n. and A. montana sp. n. Two are known only from females: A. ferruginea sp. n. and A. perplexa sp. n. Direct association of males and females was not possible. The genus is distributed from Malawi to the Western Cape Province of South Africa, generally in forest or dense bushveld with moderate to high rainfall. The cladistically basal species tend to be more northern in distribution and the more apical ones occur further south.
Hot-water treatment for the control of the banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae), in UgandaSource: African Entomology 6, pp 215 –221 (1998)More Less
Paring and hot-water treatment of banana suckers have been recommended to prevent the spread of banana weevil, Cosmopolites sordidus Germar, into new banana plantations. Mortality of banana weevil eggs and larvae were recorded after immersion of infested banana suckers in four hot-water regimes: 43C for 2 hours, 43 C for 3 hours, 54 C for 20 minutes and 60 C for 15 minutes. Paring removed 90 % of banana weevil eggs, while all hot-water treatments resulted in 100 % mortality of eggs. However, only hot-water baths of 43C for 3 h resulted in high mortality (94 %) of weevil larvae. Larval mortality in other treatments ranged from 26-32 %. It is unlikely that Ugandan farmers will implement three-hour hot-water baths for banana weevil control. Also, the hot-water treatment that is most effective for nematode control (54 C for 20 min) provided limited control of banana weevil The data suggest that paring alone may be the most appropriate measure for resource-poor farmers to eliminate banana weevil from planting material.
Source: African Entomology 6, pp 223 –251 (1998)More Less
Regional and catchment distributions of blackflies (Diptera: Simuliidae) in southern Africa are presented and discussed relative to the biology and environmental preferences of the aquatic stages. Distribution data are based on all known records, both published and unpublished. Thirty nine blackfly species are recorded: 13 are widespread with no particular geographical affinities, 18 are restricted in distribution and eight are rare. Distributions are closely related to downstream changes in rivers, although eight species are endemic to parts of the southern and southwestern Cape, while eight are absent from the southern and southwestern Cape. The most common and widespread species are Simulium nigritarse s.l. Coquillett, S. medusaeforme Pomeroy, S. damnosum s.l, Theobald and S, adersi Pomeroy, all of which are associated with medium-sized rivers, and all of which are likely to be species complexes. Seven specles occur in large rivers, three of which are restricted to large rivers, A further six species were recorded in temporary streams, Some species, such as S, medusae forme, inhabit a wide range of water-quality conditions, but at least five species are restricted to excellent-quality water, and three species were typically found in polluted water: Temporal changes in blackfly distribution and abundance are related to long term drought/flood cycles, as well as increased river regulation and catchment development. The mammalophillc S, damnosum s.l. is recorded for the first time from the southwestern Cape, and S, lumbwanum de Meillon, a specles whose larvae and pupae are phoretic on certain mayfly nymphs, is recorded for the first time from South Africa and Swaziland,
Infestation levels 0f banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae), in banana plants established from treated propagules in UgandaSource: African Entomology 6, pp 253 –263 (1998)More Less
Spread of banana weevil, Cosmopolites sordidus Germar, occurs primarily through infested suckers used for propagation. The use of clean planting material, from which weevils have been removed by paring and/or hot-water treatment, has been recommended as a culturalcontrol strategy. In this study, two trials were undertaken to quantify the effects of cleaned planting material on the level of weevil and nematode infestation and on plant growth and yield. Treatments included: (1) untreated suckers (controls), (2) pared corms and (3) pared and hot-water-treated corms. Initial weevil populations were lower in plots established with cleaned planting material than in controls. In Trial 1, weevil numbers in pared and pared/hot-water-treated material were lower than in control plots for up to 11 months, whilein Trial 2, plots established from pared and pared/hot-water-treated planting material had lower numbers of the pest for 27 months and 20 months, respectively. Weevil damage levels in controls were 70-200 % higher than in plots cultivated from treated planting material for the entire crop cycle. All treatments had similar levels of weevil damage in the first ratoon. Hot-water treatment afforded excellent nematode control for the duration of both trials. In both trials, treated plants had faster plant maturation rates and lower levels of plant loss due to pests. In Trial 1, 21 % of plants in the control crop were lost to weevils and nematodes compared to 2 % in treated plots. In Trial 2, plant loss to weevil and nematodes was 34 % in controls, 6 % in pared and 2 % in hot-water treatments. Eventual bunch size was similaramong treatments in both trials. However, plots with treated plants provided higher yields as a greater number of bunches was harvested during the course of the study.
Identification and evaluation of priority conservation areas for Buprestidae (Coleoptera) in South Africa, Lesotho, Swaziland and NamibiaSource: African Entomology 6, pp 265 –274 (1998)More Less
Representative priority conservation areas of quarter-degree grid size (approximately 25 x 25 km) were identified using an iterative rarity-based algorithm for the beetle family Buprestidae (Coleoptera) in South Africa, Lesotho, Swaziland and Namibia. This algorithm provided similar results (number of grids chosen, grid identity and efficiency) to an algorithm that based selection of areas on the taxonomic distinctiveness of each species. The algorithms were also run after pre-selecting grids containing buprestid records and at least 25, 50, 75 and 100 % protection in the form of established reserves, and the number of additional grids required to adequately represent all species was determined. The existing reserve network was found to be inefficient for the conservation of Buprestidae, although many records fall into grids within or containing protected areas. The Nama Karoo, Northern Cape savanna, and grassland are evident as areas of least known richness owing to undersampling. When the algorithms were run for the entire study area, considerably fewer grids, as well as a different spatial arrangement of grids, was selected within Namibia, but not within the combined regions of South Africa, Lesotho and Swaziland. This illustrates possible asymmetry when sharing conservation responsibilities between nations.
Herbivorous insect fauna associated with Azolla species (Pteridophyta: Azollaceae) in southern Africa : short communicationAuthor M.P. HillSource: African Entomology 6, pp 270 –272 (1998)More Less
The genus Eupodes Koch (Acari: Prostigmata: Eupodidae) from southern Africa with a redescription of E. parafusifer Meyer & Ryke and descriptions of two new speciesSource: African Entomology 6, pp 275 –288 (1998)More Less
Two new species, Eupodes minipilus and E. acanthus, are descriptionbed and illustrated, and E. parajusifer Meyer & Ryke is redescriptionbed. An identification key to the southern African species of the genus Eupodes is provided. Special emphasis is placed on the shape and position of dorsal idiosomal setae, chaetotaxy of the palp, leg chaetotaxy and solenidiotaxy. Eupodes fusiferellus Meyer & Ryke, E. variegatus Koch and E. longipilus Thor, previously reported from South Africa, are discussed.
Infestation patterns and parasitism of the maize stalk borer, Busseala fusea (Fuller) (Lepidoptera: Noctuidae), in the Ivory CoastAuthor P. MoyalSource: African Entomology 6, pp 289 –296 (1998)More Less
The abundance and parasitism rates of preimaginal instars of the maize stalk borel; Busseola fusca (Fuller), were studied for the first time in the Ivory Coast. Maize crops were sampled in different ecological regions over a seven-year period. High population levels were only observed in the Mesophil sector of the Guinean ecological zone, where densities varied from 2-5 borers per stem in June plantings. Fluctuations in population density were attributed to three major factors: (1) timing of infestations, that appeared to be dependent on diapauses termination, which was influenced by rainfall at the end of March and during April; (2) numbers of larvae surviving diapause, that was dependent on severity of the dry season, on the occurrence of bush fires and on egg parasitism; (3) maize planting dates, which resulted in a coincidence between the plant growth stage favourable to the pest and the oviposition periods. Two egg parasitoids, Telenomus busseolae Gahan and T. isis Polaszek (Hymenoptera: Scelionidae) were collected. The first species was predominant (72 % of parasitized eggs). Five parasitoids were reared from larvae and pupae. Of these, Tetrastichus atriclavus Waterston (Hymenoptera: Eulophidae) was dominant (91 % of parasitized insects). The percentage parasitism of larvae and pupae was less than 10 % and appeared to have little influence on the population dynamics of B. fusca in the Ivory Coast.
Source: African Entomology 6, pp 297 –301 (1998)More Less
Glossidion gen. n. is descriptionbed from larvae from Uganda. The genus is distinguished by cleft mandibular incisors, short glossae and subrectanguIar paraglossae, and smooth posterior margin of the terga. Glossidion belongs to the Baetis complex of genera and is hypothesized to be closely related to Labiobaetis Novikova & Kluge. Two species, G. demoulini sp. n. and G. mysticum sp. n., are descriptionbed, and their diagnoses are discussed.
Description of the stages of the white wax-scale, Ceroplastes destructor Newstead (Homoptera: Coccidae)Source: African Entomology 6, pp 303 –316 (1998)More Less
The white wax-scale, Ceroplastes destructor Newstead, has recently increased in numbers and distribution in some Easy-peel (Citrus reticulata (Blanco)) orchards in the Western Cape Province of South Africa. A study was conducted to investigate its morphology and biology. Characteristics of the immature and adult females are descriptionbed and illustrated from field-collected and slide-mounted specimens. A key to the different stages is provided. The biology of C. destructor is briefly descriptionbed. Morphometric characteristics useful for separating the stages are discussed.
Xylose as a nectar sugar: the response of Cape honeybees, Apis mellifera capensis Eschscholtz (Hymenoptera: Apidae)Source: African Entomology 6, pp 317 –323 (1998)More Less
The pentose sugar xylose has recently been reported as a major sugar in the nectar of Protea and Faurea (Proteaceae). Because honeybees are potentially important pollinators of both Protea and Faurea, we investigated the responses of Cape honeybees to xylose solutions. Preference tests were conducted outdoors using a single colony of bees trained to visit feeding dishes. Sugar solutions (20 or 40 ml, usually 30 % w/w) were set out at 13:00, and the number of bees on each dish was recorded at IS-min intervals. The tests showed: (1) that pure xylose is unattractive compared to the common nectar sugars; (2) that bees presented with a range of glucose/xylose mixtures prefer those with the smallest proportion of xylose; (3) that xylose has a repellent effect, the bees preferring, for example, 9 % glucose to 9 %glucose + 21 % xylose. During survival tests, 50 or 100 newly-emerged bees were placed in Liebeveld cages, each with a wax comb and two gravity feeders. Cages were kept at 30 C, and dead bees were removed and counted daily. When bees were fed sucrose, glucose, fructose and xylose (all 30 % w/w) and water only, survival on xylose was as poor as on water. With different glucose/xylose mixtures, survival time was inversely related to the proportion of xylose in the diet, each 5 % increment in xylose causing an additional increase in mortality. We conclude that the xylose in Protea and Faurea nectar is not there for the benefit of honeybees.