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Entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis and their associated symbiotic bacteria of the genera Xenorhabdus and Photorhabdus, are efficient biological control agents, due to their ease of culture, their high fatality against key insect pests and their safety in use. However, their commercial utilisation is limited by their finite shelf life, both in storage and in formulations. Thus, efficient storage in the formulation of EPNs is essential so as to attain success in integrated insect pest management strategies. This paper reviews the latest information that is available on EPN storage, formulation, quality and application methods, coupled with improvement strategies for the effective control of insects. Nematode survival mechanisms investigated were heat and cold tolerance, desiccation, osmotic stress, hypoxia and energy reserves, among others, in storage, field or formulations. Their influence on the formulation of EPNs is also discussed.
The Afrotropical Stichopogoninae is discussed. Nanoculcita kenya gen. et sp. n. is described from 10 localities in Kenya. A key for the identification of Afrotropical stichopogonine genera is provided. The distribution of Clinopogon nicobarensis (Schiner, 1868) is reviewed, showing its wide distribution on beaches throughout the region.
As parasitoid development is dependent on resources provided by a single host, the quality and quantity of resources its herbivore host obtains from different host plants can influence parasitoid fitness. Laboratory studies were conducted on several fitness parameters (developmental time, pupal weights, longevity, fecundity and sex ratio of progeny) of a larval parasitoid Cotesia vestalis (Haliday) (Hymenoptera: Braconidae) when its host Plutella xylostella (L.) (Lepidoptera: Plutellidae) developed on seven cabbage cultivars. In addition, population increase parameters of the parasitoid were compared on the various cultivars. The generation time of the parasitoid was shortest on Karabo (10.10 days) and Leano (10.38 days), and longest on Megaton (12.57 days) and Empowa (12.80 days). The heaviest C. vestalis pupae were recorded from Menzania (5.4 mg), Megaton (5.25 mg) and Beverly Hills (4.85 mg) and the lightest on Karabo (3.8 mg). Parasitoids reared on larvae that fed on Hollywood F1 lived the longest (2.28 days) followed by Menzania (1.94 days) and Beverly Hills (1.8 days), whereas those whose hosts fed on Leano lived the shortest period (0.83 days). Despite the parasitoids from Megaton hosts being bigger, their fecundity and number of female progeny per female (16.87 and 3.60, respectively) were lowest. Cotesia vestalis fecundity and daughters produced per female were highest on hosts fed on Menzania (38.00 and 9.13, respectively) and Beverly Hills (32.87 and 9.07, respectively). As a consequence, the net reproductive rate (R0) and intrinsic rate of increase (r) were higher on Menzania (7.87 and 0.58, respectively) and Beverly Hills (8.29 and 0.62, respectively). Not only do these results suggest that the overall fitness of C. vestalis is higher on hosts developing on Menzania and Beverly Hills, the critical density of the parasitoid required to suppress the host population at a lower average density will be reached quicker on these two cultivars than on others.
Robusta coffee (Coffea canephora) is of great economic importance to Uganda. However, its production is recently impeded by the ambrosia twig borer Xylosandrus compactus. A survey was conducted in 10 randomly selected districts in the main Robusta coffee-growing regions of mid-eastern, central and mid-western Uganda to determine (1) diversity, incidence and abundance of twig borers attacking C. canephora in Uganda and (2) ambrosia fungi associated with these twig borers. In each district, 10 randomly selected farms were inspected for twig borer species attacks. Up to 20 twigs infested by twig borers per farm were sampled and dissected to morphologically identify borer species inside the twigs and enumerate different stages of the borers per twig. Ambrosia fungi from galleries of each distinct twig borer were isolated and identified using molecular techniques. Five twig borer species, X. compactus, Xylosandrus sp., Hypothenemus sp. and two unidentified twig borers (K1 and K2), were found attacking C. canephora. Whereas the rest of these species were detected in only single coffee twigs from single farms, X. compactus occurred in nine of the 10 study districts. The proportion of X. compactus-infested farmsin each of these districts ranged from 0.1 to 1 and the number of X. compactus individuals per twig per district ranged from 2.5 ± 1.9 to 29 ± 28.1. Fusarium solani was isolated from galleries of both X. compactus and K1, whereas Glomerella cingulata was isolated from a gallery of K2.
Many animals engage in contests with conspecifics for access to resources. Understanding which resources individuals are contesting for, and what influences the outcome is central to our understanding of contest behaviour. We initially observed female bees of the genus Tetralonia (sp. n.) aggressively competing for access to burrows in the ground, without any clear indication of exactly which resources were being contested, or what factors might predict the outcome.We then individually marked bees and assigned ownership of burrows to individuals, before observing over 100 aggressive interactions. After excavating burrows cast with molten wax, we concluded that burrows were nests for provisioning larvae. We found that ownership (as putatively designated by us) had no influence on contest outcome, but rather that the position of the bees in the burrow was decisive; whichever bee was already in the burrowwhenthe contest beganwonthe vast majority of interactions. Furthermore, bees that were designated ownership of a burrow did not engage in longer fights for possession of that specific burrow, indicating either that they were not committing any kind of ‘Concorde fallacy’ by basing decisions on past investment, or that the assignment of ownership was incorrect. Instead, fights were longer later in the day, presumably as the value of the burrow as a refuge from the cold and/or predation increased as night approached. Nest parasitism does not seem to be a common strategy in this species, as owners were not more likely to attempt ejecting an intruder than vice versa. This indicates that contest settlement may not always follow theoretical predictions, but rather that insights and inferences into a species' ecology can be made from observations of dyadic contests.
Effects of transgenic Bacillus thuringiensis (Bt) riceandnon-Bt riceonthe arthropodcommunity structure during storage were studied. Dried and cleaned grains (200 kg of F1 hybrid transgenic rice) from each rice variety were stored at unlidded ceramic pots (100 cm high, 80 cm diameter), and then stored in a 10-year-old barn. To investigate the species and number of arthropods using a needle-point sampler, each pot had 1 kg of grain sampled from both the upper layer (0–35 cm) and the lower layer (35–70 cm) every 15 days. The results showed 12 species of arthropods including Corrodentia, Acarina, Chelonethida, Lepidoptera, Coleoptera and Hymenoptera were found. No significant differences were observed in the community structure parameters of the arthropods between transgenic Bt rice and non-Bt rice. In both rice varieties, Liposcelis bostrychophilus exhibited the highest level of abundance of community structure, followed by Rhizopertha dominica and Tyrophagus putrescentiae. Overall, there was no significant difference in the temporal dominance curve profiles of the three dominant arthropods between Bt and non-Bt rice. Our results indicated that transgenic Bt rice generally exerts no remarkable negative effects on the arthropod community during storage.
Earias biplaga (Walker) (Lepidoptera: Noctuidae) forms part of the bollworm pest complex of cotton in South Africa. Genetically modified Bt cotton that expresses Cry insecticidal proteins successfully controls the bollworm complex in South Africa. Although many insecticides are registered for use against Lepidoptera on this crop, Bt sprays are not registered for control of E. biplaga. The aim of this study was to determine the efficacy of Bacillus thuringiensis spray applications for the control of E. biplaga on non-Bt cotton and to compare the efficacy of sprays to that provided by Bt cotton. Bioassays were conducted in which cotton bolls of a non-Bt cotton cultivar (Delta Opal) were sprayed with different dosage rates of Dipel DF®, which contains the following insecticidal proteins: Cry1Aa, Cry1Ab, Cry1Ac, Cry2Aa and Cry2Ab. Bollgard® and Bollgard II® cotton which expresses Cry1Ac and both Cry 1Ac and Cry2Ab were used in the study. Neonate larvae were inoculated onto cotton bolls and survival observed 4, 7 and 10 days later. The Bt spray dosage rate recommended for control of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on groundnut and sunflower in South Africa was used in this study and provided between 77 and 88%control of E. biplaga after 10 days. Bt cotton provided 100%control after 10 days. This study provides baseline data on the susceptibility of E. biplaga against Bt cotton which can also be used for future monitoring of resistance evolution.
The nucleotide and amino acid sequence of the ecdysteroid UDP-glucosyltransferase (egt), polyhedrin (pol), inhibitor of apoptosis (iap2 and iap3), late expression factor (lef) 9 and vp1054 genes of a South African isolate of Trichoplusia ni single nucleopolyhedrovirus (TnSNPV) was compared to a Canadian isolate of TnSNPV. Nucleotide and amino acid sequence identity for the compared genes ranged from 89%to 98%and 95%to 99%, respectively. The deduced amino acid sequences of the TnSNPV egt, pol, iap3, lef-9 and vp1054 genes were used to infer phylogenetic trees and these were compared to the tree inferred from combined data sets consisting of the amino acid sequences of polyhedrin/granulin, lef-8 and lef-9 genes of 48 completely sequenced baculoviruses. The topologies of trees for the baculovirus core genes pol, lef-9 and vp1054 were better resolved than that of the auxiliary genes iap2, iap3 and egt when compared to the tree inferred from complete genome sequences. Sequence and phylogenetic analysis confirms that the two geographically disparate isolates are closely related. The tree inferred from the combined data set represents a quick and reliable method of identification particularly, when whole genome data are not available.
The susceptibility of the American cockroach, Periplaneta americana L. (Blattodea: Blattidae), against malathion was tested in the laboratory. The levels of insecticide detoxifying enzymes among different populations of P. americana were also compared. Standard methods were used for the estimation of non-specific esterases, glutathione S-transferases (GSTs) and monooxygenases. All populations showed resistance against malathion and significantly higher activities of insecticide detoxifying enzymes were recorded as compared to the susceptible population (control). This higher enzymatic activity and elevated levels of GSTs and monooxygenases is the possible reason for malathion resistance in P. americana. However, non-specific esterases and monooxygenases might be involved in the development of resistance in other populations at the same localities. The development of the resistance mechanism was noticed in all tested populations of P. americana and it is an indication to replace malathion insecticides against American cockroaches in the investigated regions especially, and also a warning for other regions in the world.
Laboratory tests using the dry film method were conducted to assess the toxicity of different commonly used insecticides and insect growth regulators to Bracon brevicornis. The carbamate insecticide, carbosulfan, was highly toxic to B. brevicornis with a LC50 value of 0.0001 mg a.i./l, whereas pymetrozine and buprofezin had LC50 values of 0.1056 and 0.0374 mg a.i./l, respectively. Among the three neonicotinoids, acetamiprid showed the highest toxicity to B. brevicornis with a LC50 of 0.0041mga.i./l followed by thiamethoxam and imidacloprid. The order of toxicity based on the LC50 values was: carbosulfan > lambdacyhalothrin > bifenthrin > indoxacarb > acetamiprid > thiamethoxam > imidacloprid > buprofezin>pymetrozine. Pymetrozine showed slight to moderate toxicity to B. brevicornis, with a risk quotient (RQ) of 1420, while the RQ value for all other insecticides were dangerously toxic to B. brevicornis. The mean activity of cytochrome P450 in B. brevicornis was 4.2817 nM/mg protein with a frequency distribution ranged from 3.001 to 5.446 nM/mg protein. The mean activity of acetyl choline esterase in B. brevicornis was 1.7056 nM/Min with a frequency destitution ranged from 0.7572 to 3.1951 nM/Min. The mean activity of carboxylesterase was 37.5 mOD/Bracon/min with a frequency destitution ranged from 27.8 to 47.1 mOD/Bracon/min. Use of selective insecticides to conserve B. brevicornis may improve the compatibility of biological control with the IPM programme.
The role of Culex pipiens larval ingestion rate in the effectiveness of three Bacillus sphaericus strains, namely 2362, B1-634BNI and 6491 was assessed. Two concentrations, namely LC50 and LC80, were tested. Studied parameters included bacterial exposure time and mosquito larval density. Exposure time periods were 0.5, 1, 2, 4, and 24 h. Larval density varied by exposing different numbers of larvae yielding larval density of 0.1, 0.2, 0.4, 0.8 and 1.6 larva/ml. Larval density also varied by exposing 20 larvae in different water volumes yielding larval density of 0.8, 0.4, 0.2 and 0.1 larva/ml. Strain B1-634BNI was the most active (LC50 = 0.02 ppm) among the tested strains. Mortality rates of larvae varied at different exposure periods and with the different larval densities. Mortality rates of Cx. pipiens larvae increased with the increase of the exposure period of the larvae to the bacterial suspension of strain B1-634BNI either at its LC50 or LC80. As larval density increased, mortality rates of larvae decreased when treated with each of the three tested bacterial strains whether at its LC50 or LC80. Adjusting bacterial application in control programmes according to those elements is thus indispensable to ensure a satisfactory result.
The current study was undertaken in order to determine the chemical composition of the leaf essential oils of Lavandula dentata L. (Lamiaceae) cultivated in Tebessa (Algeria) and to evaluate its potential larvicidal activity against fourth instar larvae of Culiseta longiareolata Macquart and Culex pipiens L. (Diptera: Culicidae). The essential oil content of L. dentata leaves obtained by hydrodistillation was 1.18%dry weight. The chemical analysis performed by gas chromatography-mass spectrometry showed that this essential oil contained eight compounds. The major chemical constituents identified were a-terpinolene (51.13 %) and camphor (13.43 %). Bioassay test done following the World Health Organization standard protocol revealed that this essential oil exhibited larvicidal activity. The LC50 and LC90 values against fourth instar larvae were 77.09 and 104.45 ppm for Cs. longiareolata and 113.38 and 150.38 ppm for Cx. pipiens, respectively. The results proved the potential use of this natural product as an alternative to synthetic insecticides for controlling mosquitoes.
The legume pod borer, Maruca vitrata (Geyer) (Lepidoptera: Crambidae), is an important pest of pulses globally. The laboratory study investigated its development, survivorship and food intake on different pulses, namely pigeon pea (CO RG 6), black gram (CO BG 6), green gram (CO GG 7), cowpea (CO 7) and lablab (Rohini) in an environment of 27.9±2.2 °C and 76.6 ± 9.1%RH. The highest food consumption was recorded in lablab flowers (433.02 mg) while the maximum larval weight gain was in pigeon pea flowers (71.85 mg). The maximum assimilation rate (375.33 mg) was in flowers of lablab. The relative growth rate was maximum in flowers of black gram (2.27) and whereas efficiency of conversion of digested food was 36.60 % and efficiency of conversion of ingested food was highest on green gram flowers (72.96 %). An attempt on mass-culturing was made on its natural hosts and as per the studies, the culture could be maintained only up to first generation on all hosts except lablab. The results of the first-generation study revealed that, in lablab, the maximum number of Maruca larvae (38.2) successfully completed with the maximum pupation rate (71.1 %) and adult emergence (81.5 %). It was found that lablab was able to support four to six generations under laboratory conditions and the sex ratio (male:female) of 1:2 had the maximum number of eggs laid (86) on lablab. The results of significant differences among the hosts indicated that lablab was highly suitable host for rearing of M. vitrata.
A new species, Attagenus (s. str.) pseudocinereus collected in South Africa near the border with Namibia, is described, illustrated and compared with the similar looking species Attagenus cinereus (Thunberg, 1815) occurring in the same country. Furthermore, a list of all species belonging to this genus so far recorded from South Africa is provided.
The savannah honeybee, Apis mellifera scutellata Lepeletier (Hymenoptera: Apidae), is a eusocial insect that forages for nectar and pollen on a variety of flowering plants. However, it is selective of plants from which it forages. The preferred species are called bee-plants. The concept of bee-plants recognises that flowers do not have the same pollen and nectar value to honeybees. Thus, the strength of honeybee colonies is dependent on the presence of bee-plants throughout the year at any given locality. A study was conducted during March 2013–February 2015 to establish the presence of bee-plants and their phenology within 2 km radius of the apiary at ARC-Plant Protection Research Institute's farm in Rietondale, a suburb of Pretoria. A total of 247 flowering plant species from 70 families, comprising indigenous and exotic trees, shrubs and grasses, was recorded during March 2013–February 2014. Most plant species flowered during April, a smaller proportion during February and October, and only a few during June. Flowers of each plant species were sampled in order to make reference pollen grain slides. To determine bee-plants, a pollen trap was fitted to the entrance of one of five Langstroth hives on a fortnightly rotation during March 2014–February 2015 in order to intercept pollen pellets from the hind legs of returning foragers. A total of 2403 pollen pellets were recovered, most of which (1263) were collected during April and none during October. At the laboratory, about a quarter of each pellet was dissolved in distilled water and pollen grain slides were prepared. These slides were matched against reference pollen grain slides using a compound microscope. It was established that honeybees foraged from only 30 plant species. During summer (December–February), pollen was collected mostly from Persicaria capitata (Polygonaceae), Tithonia rotundifolia (Asteraceae) during autumn (March-May), Acacia galpinnii (Fabaceae) during winter (June–August), and Ageratum conyzoides (Asteraceae) during spring (September–November). These results show that honeybees had access to pollen sources that were sufficient to sustain their colonies throughout the year. As bee-plants were continuously available in the vicinity of the Rietondale farm, this site could be ideal for urban beekeeping.
Myrmecological investigations were conducted in an olive grove agro-ecosystem. Among the taxa we report the presence of the cryptic ant species Lioponera longitarsus, subfamily Dorylinae, for the first time in Algeria. Standard morphological measurements are presented for worker and queen. The discovery of this genus for the fourth time in North Africa in different habitats within a semi-arid climate suggests that the populations of Lioponera may be native but it is not possible to exclude them having been transported by humans.
An inventory of insects visiting Lavandula officinalis flowers was established during three years (2009, 2010 and 2013) in a plot in the Constantine region (northeast Algeria). Three orders of insects were recorded on the flowers: Hymenoptera, Lepidoptera and Diptera. The majority (81 %) of taxa identified on the plant showed very low average abundances (≤1 individual/day) and 73 % of these taxa were bees and included the honeybee, Apis mellifera, the bumblebee, Bombus terrestris, Ceratina cucurbitina and two Megachilidae, Anthidium florentinum and A. manicatum. The bees had higher visitation rates than Lepidopterans (Iphiclides podalirius, Pieris rapae and Polyommatus dorylas). The ‘quantitative’ interaction of the plant with its main visitors, determined by the abundance and the visitation rate, showed that B. terrestris and A. mellifera are the most dominant pollinators of the plant. Analysis of the ‘qualitative’ component of the interaction of L. officinalis with the five major bees by counting pollen grains transported on their bodies revealed that B. terrestris, in addition to its dominance, was also the most efficient pollinator of the plant.
The Steelpoort River is affected by a wide range of pollutants resulting from mining, industrial and agricultural activities and domestic sewage. Benthic macroinvertebrates are often used to assess water quality as they respond to changes in the aquatic environment. The study was to assess the benthic macroinvertebrate communities in the Steelpoort River along a pollution gradient, from less polluted upstream to highly polluted downstream. The impacted downstream sites generally had the highest turbidity, total dissolved solids (TDS) and conductivity values but lowest dissolved oxygen. While the upstream sites generally exhibited low turbidity, TDS and conductivity values but high dissolved oxygen. The physical and chemical changes between sites were accompanied by shifts in macroinvertebrate community composition. The sensitive macroinvertebrate families such as Baetidae, Leptophlebiidae and Perlidae dominated the upstream sites with low water turbidity, low conductivity, low TDS, and high dissolved oxygen while the tolerant families such as Chironomidae, were abundant in highly impacted downstream sites with high water turbidity, high conductivity, high TDS, and low dissolved oxygen. The study revealed differences in physico-chemical parameters, and in the composition of the macroinvertebrate community. Hence, changes in the abundance and diversity of macroinvertebrates reflected the longitudinal pollution gradient in the river.
Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), larvae wriggle violently backwards when disturbed. As they vary greatly in size from 1.3mm in length of L1 instar to 12 mm of fully grown L4 instar, the 2.1 mm long female Cotesia vestalis (Haliday) (Hymenoptera: Braconidae) has to gain control of each host to insert ovipositor and lay an egg. This study tested the hypotheses that parasitism rates of L2 to L4 instars correspond with 1) ability of female wasps to subdue them, and 2) their suitability for parasitism. In a choice test involving direct observations, C. vestalis gained control of L2 and L3 instars until ovipositor removal, but it was unable to subdue L4 instar, which limited ovipositor insertions. As parasitoids increasingly avoided wrestling L4 instar in subsequent encounters, it was worth investigating if limited capability to subdue these hosts deprives C. vestalis access to a high quality resource. In both choice and no-choice tests, parasitism rates of L2 and L3 instars were similar, and they were significantly higher than of L4 instar. Although parasitoid developmental time was shorter on L4 than on both L2 and L3 instars, a significantly higher proportion of parasitoids and daughters emerged from L2 and L3 instars than those parasitised at L4 instar in both choice and no-choice tests. These results imply that L4 instar is a lower quality resource for intrinsic rate of increase of C. vestalis, and its limited capability to subdue this instar leads to higher parasitism of themoresuitable L2 and L3 instars.
Lantana camara L. (Verbenaceae) is one of the most problematic plant invaders in South Africa and has been targeted for biological control for over 50 years. Essential oil constituents which often change in response to insect herbivory are reported to play a crucial role in plant—insect interactions. However, nothing is known about the chemical profiles of essential oils of L. camara varieties in South Africa and how this changes under herbivory. Therefore, essential oils were collected using hydrodistillation from undamaged and insect-damaged leaves of four L. camara varieties and analysed using gas chromatography-mass spectrometry to elucidate their chemical profiles. A total of 163 compounds were identified from the undamaged leaves of the various L. camara varieties. Feeding by the biocontrol agent Falconia intermedia Distant (Hemiptera: Miridae) resulted in changes in the quality and quantity of chemical constituents of the essential oils. Only 75 compounds were identified from the insect-damaged leaves of L. camara varieties.Terpenes were the major components across the varieties, while caryophyllene, hexane, naphthalene, copaene and α-caryophyllene were commonin all the varieties tested from both undamaged and insect-damaged leaves. Results from this study indicated the chemical distinctiveness of the Whitney Farm variety from other varieties. The changes in chemical concentrations indicated that feeding by the mirid on L. camara varieties causes an induction by either reducing or increasing the chemical concentrations. These inductions following the feeding by F. intermedia could be having a negative impact on the success of biological control against L. camara varieties. However, the focus of this paper is to report on the chemical baseline of L. camara varieties. Hence, comparisons of chemical compound concentrations of L. camara essential oils tested and the feeding-induced changes with respect to their quality and quantity are discussed.
Ectomyeolis ceratoniae Zeller (Lepidoptera: Pyralidae), carob moth, is a pest of several crops in South Africa. A laboratory culture was established from field-collected larvae infesting mummified pecan nuts. Biological parameters of larvae reared on an artificial diet were measured. The insect goes through five larval instars, and the head capsule sizes of the five instars were determined to be ≤0.34 mm, 0.35–0.64 mm, 0.65–0.94 mm, 0.95–1.14 mm and ≥0.15 mm for the five instars, respectively. The insect was reared individually and communally in glass vials, the latter to develop a mass-rearing technique. Developmental time from neonate to pupa was significantly slower when larvae were individually reared (38.18 ± 1.2 days) compared to when they were communally reared (24.6 ± 0.65 days).Amicrosporidian infection (Nosema sp.) was recorded in the culture, causing significantly (F1,6 = 14.99, P = 0.0082) higher mortality of communally reared larvae (76.25 % ± 11.87) than individually reared larvae (24.9 % ± 9.6).
Five species of AphaniosomaBecker, 1903 are recorded for the first time from Algeria: Aphaniosoma annulatumLyneborg, 1973, A. approximatumBecker, 1903, A. fissumCollin, 1949, A. nigricaudaEbejer, 1998 and Aphaniosoma sp. All were collected in the northern Sahara of Algeria in the oases of Oued M'Zab and in the region of Ghardaïa. The limited information on distribution, biology and ecology of each species is presented and discussed.
The exotic Bactrocera dorsalis and the native Ceratitis anonae infest citrus and constitute a threat to citrus production in Nigeria. The immature stages of the two species are difficult to differentiate morphologically and share the same fruit in the study area. A 658 bp portion of the COI gene was amplified and sequenced in 88 life stages of the species using LCO1490/HCO2198 primers. The enzymes RsaI, Sau3AI and Hsp92II were used to construct banding patterns distinguishing life stages of B. dorsalis from C. anonae. DNA barcoding confirmed the species to be B. invadens syn. n. B. dorsalis and C. anonae. Rsa I produced bands of 322 and 336 bp in B. dorsalis and 201 and 457 bp in C. anonae. Sau3AI produced bands of 103, 144 and 364 bp in B. dorsalis and 164 and 471 bp in C. anonae. Hsp92II produced fragment lengths of 137 and 521 bp in B. dorsalis and 110, 231 and 290 bp in C. anonae. The identification method was confirmed by DNA barcoding and molecular phylogenetic analysis. All the life stages within a species produced the same banding patterns with the enzymes. This molecular method will be applied at quarantine checkpoints for interception of the invasive B. dorsalis. It will also be crucial for early detection of infestation and in creating and maintaining fruit fly exclusion zones by implementation of appropriate management programmes for B. dorsalis and C. anonae infesting citrus in Nigeria.
Recent studies have demonstrated that geographically isolated populations of Thaumatotibia leucotreta (Meyrick), an important pest of some crops in southern Africa, show minor genetic divergence. Because sexual selection can cause rapid evolution of male genitalia in insects, particularly in widespread, polyphagous species, differences in the morphology of these structures among different populations may be evidence of divergence. Hence, variation in the shape of the valva in the male genitalia within and among three different populations of T. leucotreta was analysed using geometric morphometrics. Although some variation was detected among mean population values for certain traits, there was no overall pattern. Principal component analysis showed no distinct clustering of valval shape among populations, providing no evidence for divergence in genitalic structures, at least in the shape of the valva.
The queen caste of the Arabian species Meranoplus pulcherSharaf, 2014 is described and illustrated for the first time. The queen caste of the species is apparently rare with only a single specimen collected over a two-year period of intensive field work in southwestern Asir Mountains of Saudi Arabia. A distribution map of the species is presented.
This study aimed to characterise mosquito species distribution based on the nature and type of breeding habitats and the influence of the vegetation that occupies these sites. Knowledge of variation in breeding site types can help in the design of optimal vector control strategies. In different areas of Biskra (southeast Algeria), mosquito immature stages were collected using standard dippers. Twenty-four breeding sites were found in four areas of Biskra (Chetma, Bbordj Ben Azouz, Sidi Okba and Biskra). With a total of 44 677 individuals, the inventory of Culicidae revealed 22 species distributed through six genera from 2009 to 2013. Three species — Aedes caspius, Culex pipiens and Culiseta longiareolata — were the most predominant, occupying several different types of permanent and temporary breeding sites. In addition, analysis of the distribution of species based on the flora occupying these sites revealed that Culex laticinctus, Aedes annulipes, Anopheles sergentii, Culiseta longiareolata, Culex pipiens and Aedes caspius were species that had a strong ability to cohabit.
The morphology and histology of the female reproductive system of Spilostethus pandurus (Hemiptera: Lygaeidae) were examined by light and scanning electron microscopy. The female has a pair of ovaries, each with seven meroistic telotrophic ovarioles, a pair of lateral oviducts, acommonoviduct, a spermatheca, and a genital chamber.Accessory gland was not visible. Each ovariole is composed of four main regions: 1) the thread-like terminal filament, 2) the germarium, a chamber housing anteriorly the nurse cells and posteriorly the young oocytes, 3) a long vitellarium composed of a series of oocytes, which become progressively large toward the posterior end, and 4) the pedicel (ovariolar stalk) in which the mature eggs are lodged before passing into the lateral oviduct. Morphological changes of the ovary were examined by light microscopy.
The presence of Brevipalpus lewisi (Trombidiformes: Tenuipalpidae) is reported from South Africa for the first time. Previously this mite was a listed phytosanitary pest to South Africa, and entry of infested goods was prohibited. During a country-wide survey, B. lewisi was found on grapevine in the Western Cape and Northern Cape provinces. It has not been found in other provinces or on other crops, most notably on citrus, on which it is considered a pest in other countries. Brevipalpus lewisi was regularly collected together with several other mite species, including predatory species. Other Brevipalpus species collected were B. californicus and B. obovatus on grapevine and citrus and B. yothersi on grapevine.
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