African Entomology - Volume 23, Issue 1, 2015
Volumes & issues
Volume 23, Issue 1, 2015
New records of butterflies (Lepidoptera: Papilionoidea) from Bioko, Equatorial Guinea, deposited in the collections of the Museo Nacional de Ciencias Naturales de Madrid, SpainAuthor I. MartinSource: African Entomology 23, pp 187 –195 (2015)More Less
A review of Fernando Poo's Rhopalocera collection in the Museo Nacional de Ciencias Naturales (MNCN) in Madrid led us identify 172 species (14 Papilionidae, 18 Lycaenidae, 29 Pieridae, 94 Nymphalidae, and 17 Hesperiidae), of which 33 are new records for Bioko Island. To identify certain specimens in the genus Graphium, the genitalia of several individuals selected from among specimens captured on different dates and in various locations were examined and all were unequivocally seen to belong to the species Graphium policenes policenes. Therefore, we consider that the distribution of G. biokoense on Bioko Island should be revised.
South African cycads at risk : Aulacaspis yasumatsui (Hemiptera: Coccoidea: Diaspididae) in South AfricaSource: African Entomology 23, pp 196 –206 (2015)More Less
The scale insect Aulacaspis yasumatsui is native to Southeast Asia and a major pest of cycad (Cycadales) plants. Due to an increase in worldwide trading of cycads, A. yasumatsui has spread globally and has become a major threat to many cultivated and native cycads worldwide. In this study we report formally, for the first time, A. yasumatsui infesting cycads in South Africa. This scale insect was observed infesting cycads in three provinces in South Africa, namely, Gauteng, KwaZulu-Natal and Limpopo. Its identification was based on morphology and nucleotide sequences of three gene regions. Although more common and damaging on non-native Cycas species, its presence on some native South African Encephalartos species is of concern and effort should be made to control the spread and impact of this pest in the country.
Evidence that Quadrastichodella nova (Hymenoptera: Eulophidae) is the only gall inducer among four hymenopteran species associated with seed capsules of Eucalyptus camaldulensis (Myrtaceae) in South AfricaSource: African Entomology 23, pp 207 –223 (2015)More Less
Three chalcidoid wasp species, Megastigmus zebrinus Grissell (Torymidae), Quadrastichodella nova Girault (Eulophidae) and Leprosa milga Kim & La Salle (Eulophidae), have each been described independently as gall inducers associated with Eucalyptus species (Myrtaceae). The finding that at times they emerge together from seed capsules of river red gum (Eucalyptus camaldulensis Dehnhardt) collected at the same site in South Africa, cast doubt on the accuracy of these earlier interpretations. The current study examined the gall inducing abilities of each of the three wasp species. During geographical surveys, all three species coexisted in seed capsules at 16 of the 61 sites sampled. A study of the seasonal emergence pattern of the three species, together with a fourth, locally abundant gall associate, Aprostocetus sp., showed that Q. nova and L. milga emerge during early summer, while the remaining two species emerge in smaller numbers throughout the year. Oviposition trials on sleeved branches of E. camaldulensis, from which all insects had previously been excluded, verified that Q. nova had the ability to induce galls, while both M. zebrinus and L. milga failed to do so. Only one type of gall of characteristic structure was encountered, which repudiates the possibility of a second gall inducer, and no indication of inquilinism was found. Megastigmus zebrinus, L. milga and Aprostocetus sp. are thus more likely to be parasitoids. DNA sequences were obtained for the adults of all four these species. By matching the DNA of identified adults with that of juvenile hymenopterans in the galls, it was confirmed that all four hymenopterans species developed within the seed-capsule galls of E. camaldulensis. Regrettably, this technique failed to give a clear indication of the exact host relationships between the various gall inhabitants. By dissecting seed capsules at different stages of gall development, the origin of the gall was proven to be in the placenta of one of the locules of a flower bud, and not in a seed or ovule, as previously reported.
Insecticidal activity of azadirachtin on Drosophila melanogaster and recovery of normal status by exogenous 20-hydroxyecdysoneSource: African Entomology 23, pp 224 –233 (2015)More Less
Azadirachtin, an insect growth disruptor, is known to be an antagonist of the juvenile hormone and 20-hydroxyecdysone (20E). However, its mechanism of action remains to be understood. Furthermore, the effects of the interaction of azadirachtin and 20E have not been investigated. The current study examined the effect of azadirachtin topically applied alone or in combination with 20E on Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae). In initial bioassays, various doses (0.5, 1, 1.5, 2.5 and 4.5 µg) of azadirachtin was tested alone on newly ecdysed pupae and the inhibition doses (ID) of adult emergence determined. In a follow-up experiment, azadirachtin applied alone at its ID25 (0.59 µg) and ID50 (1.10 µg) was evaluated on catalase (CAT) and glutathion S-transferase (GST) activities, and yolk protein content in fat body and ovaries. Results showed that azadirachtin at the two tested doses increased significantly the activity of both GST at 48 and 72 hours, and CAT at 24, 48 and 72 hours following treatment. Moreover, azadirachtin treatment at these doses reduced significantly the yolk protein content in fat body and ovaries as compared to the control series. Finally, the exogenous 20E (0.25 and 0.50 µg), applied 24 or 48 h after azadirachtin treatment, relatively restored the normal values of CAT, GST and yolk protein content in fat body and ovaries. All these results indicate that exogenous 20E can compensate the depressive effects induced by azadirachtin on D. melanogaster.
Phytosanitary host status of apples as a host for false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) : short communicationSource: African Entomology 23, pp 234 –238 (2015)More Less
Recent publications suggest that apples, Malus domestica Borkh., and pears Pyrus communis L., are hosts for false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Timm 2005; Timm et al. 2007; Timm et al. 2010). In these publications Blomefield (1989) and Newton (1998) are cited. However, these last two authors did not actually mention apples or pears as hosts for T. leucotreta. This error has also been alluded to in a recent T. leucotreta pest risk analysis (EPPO 2013). In addition, a personal communication with A.E. Timm(firstname.lastname@example.org) confirmed that she had only caught T. leucotreta in pheromone traps in apple and pear orchards, and had not obtained material directly from infested fruit.
Beauveria and Metarhizium against false codling moth (Lepidoptera: Tortricidae) : a step towards selecting isolates for potential development of a mycoinsecticide : short communicationSource: African Entomology 23, pp 239 –242 (2015)More Less
False codling moth, Thaumatotibia leucotreta Meyrick (1912) (Lepidoptera: Tortricidae), can cause both pre- and post-harvest damage to citrus fruit. Not only can this result in reduced crop yield, but more importantly because of the moth's endemism to sub-Saharan Africa, it is classified as a phytosanitary pest by many export markets. An entire consignment of citrus may be rejected in the presence of a single moth (Moore 2012). Since the bulk of citrus fruit production in South Africa is exported, the control of T. leucotreta is critical (Citrus Growers Association, South Africa 2012). Traditionally, control has been achieved through the use of chemical insecticides; however, residue restrictions, resistance development and concerns about environmental pollution have substantially reduced the dependence on chemical pesticides in citrus. Research on T. leucotreta control has therefore focused on the use of biological organisms (e.g. parasitoids and viruses), which are used as control agents within an integrated pest management (IPM) programme in citrus. These biological control agents, however, only targeted the aboveground life stages of the pest, not the soil-dwelling life stages (late fifth instars, prepupae, pupae), which is the subject of this contribution (Moore 2012).
Laboratory evaluation of temperature effects on the efficacy of Cryptophlebia leucotreta granulovirus (CrleGV-SA) on fourth instar false codling moth larvae : short communicationSource: African Entomology 23, pp 243 –246 (2015)More Less
False codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is an important pest of citrus and subtropical fruit in South Africa, not only because it can cause pre-harvest crop losses, but as it is endemic to sub-Saharan Africa, certain export markets consider it of quarantine importance (Stibick 2008; Timm et al., 2010; EPPO 2013). Consequently, a wide range of measures are employed to control the pest in agricultural systems (Moore & Hattingh 2012). Use of Cryptophlebia leucotreta granulovirus (CrleGV-SA) has been suggested as a suitable biological control method for FCM (Opoku-Debrah 2011). This control agent is a baculovirus that is ingested by larvae and caught in the columnar cells of the midgut (Jehle 2002; Jehle et al. 2003). Since baculoviruses are highly virulent and host specific, they are ideal agents for biological control (Opoku-Debrah 2011). However, like many biological control agents their performance can be erratic, since their interaction with their hosts can be influenced by a number of variables, including temperature (Kirkman 2007).
Sycamore tree lace bug (Corythucha ciliata Say) (Hemiptera: Tingidae) reaches Africa : short communicationSource: African Entomology 23, pp 247 –249 (2015)More Less
In February 2014 colonies of a large and conspicuous lacebug (Fig. 1A) were collected from the undersides of the leaves of London plane trees (Platanus x acerifolia) in the suburb of Newlands, Cape Town, South Africa. Infected leaves could easily be identified by their characteristic bronzed appearance (Fig. 1B). The lace bugs were subsequently identified as Corythucha ciliata (Say) using keys to North American Corythucha species (Mead 1989) and economically important tingids of the world (Stonedahl et al. 1992). Corythucha species have high host-specificity, whilst C. ciliata is the only lace bug known to feed on Platanus species (sycamores) - this association is thus considered to be diagnostic for the species (CABI 2014). C. ciliata has a broad native range across the eastern parts of North America and Canada, where it is largely monophagous on Platanus (sycamore) trees, with P. occidentalis being its main host. However, it also occurs on Platanus hybrids, and in invasive parts of its range feeds on P. orientalis and P. x acerifolia (the hybrid between P. occidentalis and P. orientalis (CABI 1984).
Monitoring the establishment and dispersal of Teretrius nigrescens Lewis (Coleoptera: Histeridae), a predator of Prostephanus truncatus Horn (Coleoptera: Bostrichidae) in Manica Province, Mozambique : short communicationSource: African Entomology 23, pp 250 –254 (2015)More Less
The larger grain borer (LGB), Prostephanus truncatus Horn (Coleoptera: Bostrichidae), was reported in Mozambique for the first time during February 2007, in the Mutarara district, Tete Province. Since then it has spread across all provinces of the country with exception of Nampula. Prostephanus truncatus causes severe damage to maize grain mostly in granaries of smallholder farmers. In Manica, 100% of grain damage and 61.5% grain weight loss have been reported while in Tete 77% grain damage and 50% weight loss were reported (Cugala et al. 2007). These data indicate that Prostephanus truncatus represents a serious risk and threat to maize storage and food security, because it reduces the storage period of maize to less than six months. The availability of maize as food is therefore seriously impacted.
Raunoloma longiceps (Linnavuori, 1977) (Hemiptera: Heteroptera: Cydnidae) : first record from Uganda : short communicationSource: African Entomology 23, pp 255 –256 (2015)More Less
The present note reports the first Ugandan record of Raunoloma longiceps (Linnavuori, 1977), a rarely collected African burrower bug species (Hemiptera: Heteroptera: Cydnidae). This record increases the number of Cydnidae genera reported from Uganda to seven, with a total of 12 species.
Cydnidae belong to the superfamily Pentatomoidea and are known by almost 700 species distributed in all zoogeographical regions of the world (Lis 1996, 1999, 2006; Lis & Lis 2014). Species of the family are well-known by the common name of burrower (or burrowing) bugs, because of their ability to dig into the ground. This behaviour is possible mainly due to their strong and well-developed tibial and coxal combs (Lis & Schaefer 2005; Lis 2010), and the setae on the sides of their heads (Lis & Pluot-Sigwalt 2002).
Pollen Wasps and Flowers in Southern Africa, S.K. Gess & F.W. Gess
Wasps and Bees in Southern Africa, S.K. Gess & F.W. Gess : book reviewAuthor S. Van NoortSource: African Entomology 23 (2015)More Less
A formidable team, Sarah and Fred Gess spent in excess of 40 years patiently observing the lives of wasps and bees on numerous extended field trips, mostly into the more arid western areas of southern Africa. Their passion for insects, combined with careful observation and dedicated documentation of data facilitated the elucidation of the intricate nature of the ecology and behaviour of Africa's wasps and bees. With their complementary expertise and skills, Fred and Sarah compiled a comprehensive knowledge base that will serve the scientific and conservation communities well into the future. The culminated data are now available in two excellent SANBI publications, both richly illustrated with colour photographs and containing a wealth of biological information, providing valuable baseline data for future conservation assessments.