African Entomology - Volume 9, Issue 1, 2001
Volumes & issues
Volume 9, Issue 1, 2001
A non-paraphyletic classification of the Afrotropical genus Acanthiops Waltz & McCafferty (Ephemeroptera : Baetidae)Source: African Entomology 9, pp 1 –15 (2001)More Less
Acanthiops Waltz & McCafferty (Ephemeroptera : Baetidae) is shown to be a monophyletic grouping defined by an anteromedially emarginate and laterally expanded and flattened pronotum in the larva. Attempts to restrict the concept of Acanthiops to Ac. marlieri (Demoulin) and re-erect Afroptiloides Gillies, syn. n., for Ac. elgonensis Lugo-Ortiz & McCafferty, Ac. griffithsi Lugo-Ortiz & McCafferty, Ac. tsitsa Barber-James & McCafferty, Ac. variegatus (Gillies), Ac. varius (Crass) and Ac. zomba Lugo-Ortiz & McCafferty, are shown to be based on inconsistent and inadequate morphological features that result in a paraphyletic taxonomy. The unofficial separate treatment of Ac. cooperi (Gillies & Wuillot) and Ac. erepens (Gillies) under Platycloeon Gillies & Wuillot is also shown to be paraphyletic. Acanthiops faro Barber-James & McCafferty, sp. n., is described from larvae from Guinea, and is distinguished by the combination of a papillate projection on labial palp segment 2, small tubercles on terga 1?8 and abdominal colour pattern. Acanthiops io Lugo-Ortiz & McCafferty, sp. n., is described from larvae from the Democratic Republic of Congo, and is distinguished by the combination of a papillate projection on palp segment 2, elongate tubercles on terga 1?9 and abdominal colour pattern. The larva of Ac. erepens (Gillies) is redescribed to incorporate morphological features and variability previously not accounted for, and larvae originally assigned to Baetis cataractae Crass are shown to be equivalent to Ac. erepens. New locality data or emendations on locality data are provided for Ac. griffithsi, Ac. tsitsa Barber-James & McCafferty and Ac. varius (Crass).
A review of synonyms and subspecies in the genus Opistophthalmus C.L. Koch (Scorpiones : Scorpionidae)Author L. PrendiniSource: African Entomology 9, pp 17 –48 (2001)More Less
The synonyms and subspecies attributed to species of Opistophthalmus C.L. Koch, 1837 (Scorpiones : Scorpionidae) are reviewed, based mostly upon examination of type material. Four species and seven subspecies are synonymized, five species are reinstated, and six subspecies (three of which were originally described as species) are elevated to the rank of species, bringing the total number of species recognized in the genus to 59. A list of the 34 synonyms accepted for the species of Opistophthalmus is appended. New synonyms : O. austerus monticola Hewitt, 1927 = O. austerus Karsch, 1879; O. ecristatus Pocock, 1899 = O. boehmi (Kraepelin, 1896); O. karrooensis rugosus Lawrence, 1946 = O. karrooensis Purcell, 1898; O. laticauda crinita Lawrence, 1955 = O. pallipes C.L. Koch, 1842; O. latimanus austeroides Hewitt, 1914 = O. latimanus C.L. Koch, 1841; O. latimanus kalaharicus Hewitt, 1935 = O. pugnax Thorell, 1876; O. lundensis Monard, 1937 = O. wahlbergii (Thorell, 1876); O. pilosus Werner, 1936 = O. flavescens Purcell, 1898; O. pugnax natalensis Hewitt, 1915 = O. praedo Thorell, 1876; O. wahlbergi robustus Newlands, 1969 = O. wahlbergii (Thorell, 1876); O. werneri Lamoral & Reynders, 1975 = O. flavescens Purcell, 1898. Removed from synonymy : O. chaperi Simon, 1880; O. latro Thorell, 1876; O. luciranus Lawrence, 1959; O. praedo Thorell, 1876; O. scabrifrons Hewitt, 1918. Subspecies elevated to species : O. fuscipes Purcell, 1898; O. keilandsi Hewitt, 1914; O. lawrencei Newlands, 1969; O. leipoldti Purcell, 1898; O. pluridens Hewitt, 1918; O. pugnax Thorell, 1876.
Temperature effects on development and survival of the sweetpotato weevil, Cylas puncticollis Boheman (Coleoptera : Apionidae)Source: African Entomology 9, pp 49 –57 (2001)More Less
The effects of temperature on the development and survival of the sweetpotato weevil, Cylas puncticollis were studied in the laboratory at six constant temperatures (16.03, 18.60, 24.11, 26.38, 31.23 and 35.82 °C). The photoperiod was maintained at 12L : 12D for all temperatures, but RH was not controlled. Thermal requirements (r and k) of this pest species were estimated for all the immature stages and for the total life-cycle. Duration of development from hatching to pupation was observed for individuals disturbed at regular intervals to determine instar-specific development rate. This was compared with total development duration for sets of individuals not disturbed in this way. As expected, development rate was slower at lower temperatures. At 16.03 °C there was no development beyond the first larval instar. The larval period was longer than other stages at all temperatures. A significant difference in total development rate of adults was observed between the two treatments (disturbed and undisturbed), except at 18.60 °C. Mortalities were highest at 16.03, 18.60 and 35.82 °C. Temperature had no effect on the sex ratio of C. puncticollis.
Source: African Entomology 9, pp 59 –65 (2001)More Less
A two-year longitudinal malaria vector study was carried out in two communities, Dodowa and Prampram, located in the coastal forest and coastal savannah zones, respectively, of the Dangme West district of Ghana. Anopheles gambiae s.l. Giles was most prevalent in both study areas, followed by An. funestus Giles in Dodowa and An. pharoensis Theobald in Prampram. Anopheles gambiae s.s. occurred in sympatry with An. melas Theobald in Prampram. Small numbers of An. nili Theobald, An. hancocki Edwards, An. coustani Laveran, An. moucheti Evans and An. hargreavesi Evans were collected in Dodowa and their role in transmission was negligible. Anopheles gambiae s.l. and An. funestus were found to be the major human-biting species in Dodowa, while An. gambiae s.l. and An. pharoensis were the most common biting mosquitoes in Prampram. The overall biting rate of the anophelines at Dodowa was twice that at Prampram. Anopheles gambiae s.l. and An. funestus were identified as the main vectors of malaria by salivary gland dissections. Overall mean infectivity rate of both species was approximately 2.5 times higher at Dodowa than at Prampram. Anopheles pharoensis was not found to be infected with Plasmodium parasites. The intensity of malaria transmission at Dodowa, the coastal forest area, was about six times higher than Prampram, the coastal savanna area. Some aspects of control strategies are discussed.
Source: African Entomology 9, pp 67 –75 (2001)More Less
The species composition of maize stemborers and prevalence of their natural enemies at five highveld (> 1200 m) sites were studied by random sampling of borer life stages in maize fields. Busseola fusca Fuller (Lepidoptera : Noctuidae) was the dominant species and constituted 99 % of all larvae and pupae sampled during the study. Cotesia sesamiae Cameron (Hymenoptera : Braconidae) was the most abundant and widely distributed parasitoid reared from B. fusca larvae, followed by Sturmiopsis parasitica (Curran) (Diptera : Tachinidae). Two hyperparasitoids, Aphanogmus fijiensis (Ferrière) (Hymenoptera : Ceraphronidae) (from C. sesamiae cocoons) and Dendrocerus rodhaini (Bequaert) (Hymenoptera : Megaspilidae) (from S. parasitica puparia) were recorded. Preliminary data on the occurrence of C. sesamiae and S. parasitica suggested that these two parasitoids complement each other by partially partitioning their niche and thus minimizing competition. However, firm conclusions concerning the host range and ecological adaptations of the two parasitoids cannot be drawn until detailed studies have been conducted countrywide, especially at lower altitudes (< 900 m a.s.l.) where Chilo partellus (Swinhoe) (Lepidoptera : Pyralidae) and Sesamia calamistis Hampson (Lepidoptera : Noctuidae) predominate.
The incidence of Dorylus helvolus (Linnaeus) (Hymenoptera : Formicidae) and parasitoids (Hymenoptera : Braconidae) as mortality factors of Busseola fusca Fuller (Lepidoptera : Noctuidae) and Chilo partellus (Swinhoe) (Lepidoptera : Crambidae) in LesothoSource: African Entomology 9, pp 77 –84 (2001)More Less
Predatory ants and parasitoids of the stemborers Busseola fusca Fuller (Lepidoptera : Noctuidae) and Chilo partellus (Swinhoe) (Lepidoptera : Crambidae) were collected during field surveys conducted in the 1995 / 96 and 1996 / 97 seasons in Lesotho. Parasitoids (Hymenoptera : Braconidae) and Dorylus helvolus (Linnaeus) (Hymenoptera : Formicidae) were sampled at regular intervals in field trials. Two braconid species, Bracon sesamiae Cameron and Cotesia sesamiae (Cameron), were found to parasitize both B. fusca and C. partellus larvae in maize and sorghum. Two other species, Euvipio sp. and Bracon (Habrobracon) brevicornis (Wesmael), were reared from B. fusca larvae. Bracon sesamiae was the most abundant and widespread of the four larval parasitoids. Pupal parasitism was rare. Egg parasitism was not observed. Dorylus helvolus was found to be an important and widely distributed predator of both B. fusca and C. partellus larvae. Parasitism of B. fusca by B. sesamiae was higher in sorghum than in maize. Parasitism levels were generally low during the season except during April and May, when 21 % and 31 % parasitism was recorded on sorghum in the 1995 / 96 and 1996 / 97 seasons, respectively. Because the activities of natural enemies increased only towards the end of the growing season, they are unlikely to exert a pronounced effect on stemborer populations during the growing season. They may, however, play an important role in reducing the size of overwintering populations.
Source: African Entomology 9, pp 85 –94 (2001)More Less
Natural habitat is under increasing pressure from urbanization. Urban and suburban areas are therefore growing in significance as elements of the matrix within which conservation must be undertaken. The ability of such areas to maintain biodiversity may be assessed using biological indicators. However, the robustness of such bioindicators must be established by independent tests of initially identified patterns and relationships, i.e. by repeating studies at different times and localities. Here, the utility of a Lepidoptera assemblage inhabiting fungus-induced galls, as a bioindicator of habitat quality in urban areas, is reassessed. Marked differences were found in gall resources, as well as Lepidoptera larval abundances and species rank abundances between studies. These were attributed to weather and phenological differences between years. Although assemblage structure and species composition is highly dependent on gall resource quality and quantity and the latter differed significantly between studies, habitat-associated differences in the lepidopteran assemblage were consistent between studies. Species richness, larval density and larval abundance were generally lower at sites closest to the city centre than at those further away. Larval abundance and density was significantly lower at roadside sites than at rural and suburban garden sites. This study has thus shown that this lepidopteran assemblage is a robust bioindicator, and also re-emphasized the importance of green areas for conserving diversity in cities and urban environments.
Author M. CoetzeeSource: African Entomology 9, pp 95 –96 (2001)More Less
Botha de Meillon was a founding member of the Entomological Society of Southern Africa and was awarded life membership in 1986. Born Schalk Jacobus Botha de Meillon on 15 October 1902 in Prieska, northern Cape Province, this pioneering South African scientist passed away peacefully in the U.S.A. on 6 December 2000 at age 98.