The tortoise beetle Physonota maculiventris (Chrysomelidae: Cassidinae) is suitable for release against the weedy Mexican sunflower Tithonia diversifolia (Asteraceae) in South Africa

The biology and host range of the defoliating beetle Physonota maculiventris Boheman (Chrysomelidae: Cassidinae) were studied in quarantine to determine its suitability for release as a biological control agent against Mexican sunflower, Tithonia diversifolia (Hemsl.) A. Gray (Asteraceae), in South Africa. Females laid 5.25?±?0.25 (mean?±?SE) egg batches during their lifetimes, with each batch consisting of approximately 33 eggs. Larvae were highly gregarious as early instars and both larvae and adults fed voraciously, often defoliating the plants completely. The life cycle of the beetle was completed in 67.5?±?7.5 days under quarantine conditions. Among the 58 test plant species subjected to no-choice tests, P. maculiventris developed successfully on T. diversifolia and some sunflower (Helianthus annuus L.) cultivars. However, only minor damage was recorded on non-target species, notably the exotic weed Xanthium strumarium L. and some H. annuus cultivars. Also, survival to adulthood was considerably lower on sunflower cultivars than on the target weed during these tests. During choice tests, P. maculiventris oviposited and developed successfully on T. diversifolia only, with only minor feeding damage on some H. annuus cultivars, suggesting that the beetle’s field host range will be confined to the target weed. Risk analysis also showed that P. maculiventris presents an extremely low risk to non-target plant species (e.g. within the tribe Heliantheae and other close relatives). The study concluded that P. maculiventris is safe for release in South Africa and an application for its release is being considered by the relevant South African regulatory authorities.     

Host range evaluation of the leaf-feeding beetle,Zygogramma bicolorata and the stem-boring weevil,Listronotus setosipennis demonstrates their suitability for biological control of the invasive weed,Parthenium hysterophorus in Ethiopia

The invasive weed, parthenium (Parthenium hysterophorus L.) (Asteraceae: tribe Heliantheae), damages agriculture, adversely impacts biodiversity and is hazardous to human and animal health in Ethiopia. The host range of two natural enemies, a leaf-feeding beetle, Zygogramma bicolorata (Coleoptera: Chrysomelidae) and a stem-boring weevil, Listronotus setosipennis (Coleoptera: Curculionidae) was evaluated for biological control of the weed in Ethiopia. The specificity of Z. bicolorata and L. setosipennis was assessed against 29 and 31 non-target plant species, respectively. The host range of Z. bicolorata and L. setosipennis was first assessed using no-choice tests to examine their oviposition and feeding response on non-target plants. Although oviposition by Z. bicolorata occurred on six non-target species in four Asteraceae species in no-choice tests, it was significantly lower than on parthenium and no larvae developed. Zygogramma bicolorata nibbled the leaves of one of the five niger seed (Guizotia abyssinica L. – an oil seed crop closely related to parthenium) cultivars tested, but feeding and oviposition were significantly less than on parthenium. Furthermore, choice tests indicated that Z. bicolorata did not oviposit nor feed on G. abyssinica when parthenium was present. In no-choice tests, L. setosipennis did not oviposit on any of the non-target species assessed. Mean oviposition on parthenium was 39.0?±?3.4 eggs per plant whereas no eggs were laid on any of the 31 species tested. Based on these and other host range tests, permission was obtained to field release Z. bicolorata and L. setosipennis in Ethiopia.     

Post introductory risk assessment studies on Zygogramma bicolorata (Coleoptera: Chrysomelidae), a classical biological control agent of Parthenium hysterophorus (Asteraceae) in India

Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), a biological control agent of Parthenium hysterophorus L. (Asteraceae), was feeding on leaves of Helianthus annuus in India, raising concerns of its host range. Based on the age grading technique, it was shown that the majority of Z. bicolorata on sunflower plants at any time were reproductively immature. This establishes that Z. bicolorata does not pose any risk to sunflower in India.     

Host range and risk assessment of Zygogramma bicolorata,a defoliating agent released in South Africa for the biological control of Parthenium hysterophorus

Parthenium hysterophorus (parthenium) is a weed of international importance and is spreading rapidly in sub-Saharan Africa. Consequently, it has been targeted for biocontrol in South Africa since 2003. Based on precedents elsewhere in the world, the defoliating beetle Zygogramma bicolorata was prioritised as a candidate agent. Although no-choice tests, involving some 48 test plant species, indicated a significant preference for parthenium, significantly reduced feeding and oviposition was recorded on some species. Multiple-choice tests resolved many of these non-target results; however, Helianthus annuus (sunflower) was still selected for oviposition and feeding. Of the 12 sunflower cultivars tested, four were selected for oviposition, while two were selected for oviposition and feeding. These six cultivars were then subjected to larval development trials, together with three native and two weed species (in the Asteraceae). These trials showed high levels of complete development on parthenium, significantly reduced development on sunflower cultivars, and partial development on only one of the weed species. Finally, a risk assessment was conducted on the six sunflower cultivars to quantify Z. bicolorata feeding and reproductive performance. Feeding risk calculations revealed these cultivars to have an extremely low risk (<0.2%) of supporting Z. bicolorata feeding and development. Similarly, reproductive risk calculations showed a very low risk (<0.16%) of supporting viable Z. bicolorata populations. These data are supported by findings from both the native (Mexico) and introduced ranges (Australia, India) of Z. bicolorata, where it has never been recorded as a pest of sunflower. These considerations were accepted by the regulatory authorities and in August 2013, Z. bicolorata became the second insect agent to be released in South Africa for the biocontrol of parthenium.     

Interactions of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> Cry1Ac toxin in genetically engineered cotton with predatory heteropterans

A number of cotton varieties have been genetically transformed with genes from Bacillus thuringiensis (Bt) to continuously produce Bt endotoxins, offering whole plant and season-long protection against many lepidopteran larvae. Constant whole-plant toxin expression creates a significant opportunity for non-target herbivores to acquire and bio-accumulate the toxin for higher trophic levels. In the present study we investigated movement of Cry1Ac toxin from the transgenic cotton plant through specific predator-prey pairings, using omnivorous predators with common cotton pests as prey: (1) the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), with the predator Podisus maculiventris (Heteroptera: Pentatomidae); (2) the two-spotted spider mite, Tetranychus urticae (Acarina: Tetranychidae), with the predatory big-eyed bug Geocoris punctipes (Heteroptera: Geocoridae) and (3) with the predatory damsel bug Nabis roseipennis (Heteropera: Nabidae); and (4) the thrips Frankliniella occidentalis (Thysanoptera: Thripidae) with the predatory pirate bug Orius insidiosus (Heteroptera: Anthocoridae). We quantified Cry1Ac toxin in the cotton plants, and in the pests and predators, and the effects of continuous feeding on S. exigua larvae fed either Bt or non-Bt cotton on life history traits of P. maculiventris. All three herbivores were able to convey Cry1Ac toxin to their respective predators. Among the herbivores, T. urticae exhibited 16.8 times more toxin in their bodies than that expressed in Bt-cotton plant, followed by S. exigua (1.05 times), and F. occidentalis immatures and adults (0.63 and 0.73 times, respectively). Of the toxin in the respective herbivorous prey, 4, 40, 17 and 14% of that amount was measured in the predators G. punctipes, P. maculiventris, O. insidiosus, and N. roseipennis, respectively. The predator P. maculiventris exhibited similar life history characteristics (developmental time, survival, longevity, and fecundity) regardless of the prey’s food source. Thus, Cry1Ac toxin is conveyed through non-target herbivores to natural enemies at different levels depending on the herbivore species, but continuous lifetime contact with the toxin by the predator P. maculiventris through its prey had no effect on the predator’s life history. The results found here, supplemented with others already published, suggest that feeding on Cry1Ac contaminated non-target herbivores does not harm predatory heteropterans and, therefore, cultivation of Bt cotton may provide an opportunity for conservation of these predators in cotton ecosystems by reducing insecticide use.     

Achieving improved control of foliar diseases of sesame (Sesamum indicum L.) intercropped with maize (Zea mays L.) through foliar spray of plant extracts

Field trials were conducted to evaluate the effect of foliar spray of aqueous extracts of Tithonia diversifolia or Ocimum gratissimum on Cercospora leaf spot (CLS) and Alternaria leaf blight (ALB) diseases of sesame intercropped with maize. Spraying regime was at 2 weeks interval from 3 weeks after planting (WAP) until 12 WAP. Extracts of T. diversifolia or O. gratissimum reduced the incidence and severity of both diseases. CLS incidence and severity as well as defoliation was significantly (p < 0.05) reduced below what obtained in the unsprayed intercrop. ALB lesion size was significantly (p < 0.05) reduced by T. diversifolia extract at 8.0% (w/v) from 154.7 mm² (sole crop) or 13.4 mm² (unsprayed intercrop) to 4.9 mm² (sprayed intercrop). T. diversifolia extract at 8.0% (w/v) enhanced higher values of grain yield/plant and incidence of normal seeds, and lower incidence of fungal infection of seeds than in the unsprayed intercrop.     

An invasive stink bug as an evolutionary trap for an indigenous egg parasitoid

Invasive alien species can act as ‘evolutionary traps’ for indigenous parasites and predators when the alien species is accepted as prey or a host but is unsuitable for consumption or development. We tested the relationship between acceptance and suitability of eggs of the invasive alien Halyomorpha halys (Hemiptera: Pentatomidae) in North America relative to eggs of the indigenous Podisus maculiventris (Pentatomidae) for the indigenous generalist egg parasitoid Telenomus podisi (Hymenoptera: Scelionidae). T. podisi accepted 0–24 h old H. halys eggs at a rate similar to P. maculiventris eggs (87.5 ± 6.0 and 70.2 ± 9.1 %, respectively). Successful development of T. podisi occurred in 98.3 % of attacked P. maculiventris eggs, but was not observed in H. halys eggs. Oviposition by T. podisi did, however, reduce the developmental success of H. halys embryos relative to unattacked controls by 24.1 % in 0–24 h old eggs and 29.6 % in 24–48 h old eggs. We suggest that as H. halys spreads and increases in abundance in North America, it could operate as an evolutionary trap for indigenous egg parasitoids, thereby indirectly causing an increase in population levels of indigenous pentatomids. This predicted indirect effect would be a result of H. halys eggs acting as an egg sink for T. podisi. We also introduce the concept of a ‘time sink’, which may be particularly relevant for parasitoids such as T. podisi that spend considerable time protecting their reproductive investments.     

Removal of Heavy Metals from Soil Polluted with Effluents from a Paint Industry Using Helianthus annuus L. and Tithonia diversifolia (Hemsl.) as Influenced by Fertilizer Applications

Contamination of soils by effluents from industries is on the increase. There is the possibility of remediating these contaminated soils through the use of certain plants. This work investigated the remediating ability of Helianthus annuus and Tithonia diversifolia on the soil polluted with effluents from a paint industry in Ibadan, Nigeria. The experiment consisted of three treatments (H. annuus, T. diversifolia, and control) each replicated three times in a factorial combination of four different fertility managements, viz mineral fertilizer (MF); Grade A organomineral fertilizer (OMF); control₁, plants without fertilizer application; and control₂, where no fertilizer and no crop was planted using randomized complete block design. A total of 12 plots of 2 × 4 m² each per phytoplant were obtained. Each plot was planted with the viable seeds of the phytoplant at a spacing of 60 × 30 cm² and at the seed rate of four seeds per hole. The seedlings were thinned to two stands per hole 2 weeks after planting (WAP) and also weeded two times (2 and 5 WAP). After in situ second successive cultivation, percentage removal of heavy metals by Helianthus annuus with MF and OMF, respectively, were Cu 32.5 and 41.6; Pb 30.3 and 42.8; and Cd 44.5 and 56.7. Tithonia diversifolia, similarly, removed, respectively, Cu 16.9 and 23.4; Pb 36.9 and 43.7; and Cd 20.1 and 35.1. Lower percentages were removed in the controls where no fertilizer was applied. In the shoot of H. annuus with OMF, significantly (p< .05) higher values of 0.27, 1.72, and 0.11 mg kg^?1 of Cu, Pb, and Cd, respectively, were removed and stored at second cultivation as against 0.21, 3.39 and 0.08 mg kg^?1 in the shoot of T diversifolia. Lower values of Cu, Pb, and Cd were removed with MF, and also at first cultivation with OMF and MF. This study therefore recommends the use of sunflower plants, whether hybrids or wild-types along with the application of OMF for the effective remediation of soils contaminated with heavy metals, particularly in tropical climate.     

Genomic relationships between hexaploid Helianthus resinosus and diploid Helianthus annuus (Asteraceae)

Genus Helianthus comprises diploid and polyploid species. An autoallopolyploid origin has been proposed for hexaploid species but the genomic relationships remain unclear. Mitotic and meiotic studies in annual Helianthus annuus (2n = 2x = 34) and perennial Helianthus resinosus (2n = 6x = 102) as well as the F₁ hybrids between both species were carried out. Chromosome counting confirmed the hybrid origin of the latter plants and their tetraploid condition. Bivalents in hybrids ranged from 12 to 28 ( $ \bar{x} $  = 20.8). Univalents, trivalents and quadrivalents were also observed. Meiotic products comprised dyads, triads and normal tetrads and pollen grains were heterogeneous in size. These observations suggest the occurrence of 2n pollen in addition to the expected n. Genomic in situ hybridization (GISH) of total H. annuus DNA on H. resinosus chromosomes rendered weak but uniform signals; similar hybridization pattern was observed using three other annual species. Hybridization with H. annuus probe performed on root tip cells of F₁ H. annuus × H. resinosus hybrids revealed 17 chromosomes with a strong hybridization signal. GISH in hybrid meiocytes distinguished chromosomes from parental species and revealed autosyndetic pairing of H. resinosus chromosomes, allosyndetic pairing in bivalents, trivalents and quadrivalents, and the presence of univalents derived from parents, H. annuus and H. resinosus. Results obtained from classical and molecular cytogenetics do not support H. annuus as a direct ancestor of H. resinosus. The occurrence of allosyndetic pairing and the relatively high fertility of the F₁ hybrids point to the possibility that useful genes could be transferred from H. resinosus to cultivate sunflower, although the effective rate of recombination has not been evaluated. GISH method proved effective to recognize parental chromosomes in H. annuus × H. resinosus progeny.     

Host range of Secusio extensa (Lepidoptera: Arctiidae), and potential for biological control of Senecio madagascariensis (Asteraceae)

Secusio extensa (Lepidoptera: Arctiidae) was evaluated as a potential biological control agent for Madagascar fireweed, Senecio madagascariensis (Asteraceae), which has invaded over 400 000 acres of rangeland in the Hawaiian Islands and is toxic to cattle and horses. The moth was introduced from southeastern Madagascar into containment facilities in Hawaii, and host specificity tests were conducted on 71 endemic and naturalized species (52 genera) in 12 tribes of Asteraceae and 17 species of non‐Asteraceae including six native shrubs and trees considered key components of Hawaiian ecosystems. No‐choice feeding tests indicated that plant species of the tribe Senecioneae were suitable hosts with first instars completing development to adult stage on S. madagascariensis (78.3%), Delairea odorata (66.1%), Senecio vulgaris (57.1%), Crassocephalum crepidioides (41.2%), and at significantly lower rates on Emilia fosbergii (1.8%) and Erechtites hieracifolia (1.3%). A low rate of complete larval development also was observed on sunflower, Helianthus annuus (11.6%), in the tribe Heliantheae. However, sunflower was rejected as a potential host in larval‐feeding and adult oviposition choice tests involving the primary host S. madagascariensis as control. Although larvae died as first instars on most test species, incomplete development and low levels of feeding were observed on nine species in the tribes Heliantheae, Cardueae and Lactuceae. Larvae did not feed on any non‐Asteraceae tested, including species with similar pyrrolizidene alkaloid chemistry, crops, and six ecologically prominent native species. Because all species of Senecioneae are non‐native and weedy in Hawaii, these results indicate that S. extensa is sufficiently host‐specific for introduction for biological control. High levels of feeding damage observed on potted plants indicate that S. extensa can severely impact the target fireweed as well as D. odorata, a noxious weed in native Hawaiian forests.     

Utilization of the Exotic Weed Pluchea odorata (Asteraceae) and Related Plants by the Introduced Biological Control Agent Acinia picturata (Diptera: Tephritidae) in Hawaii

The flower-head feeding fly Acinia picturata (Diptera: Tephritidae) was deliberately introduced from Mexico into Hawaii in 1959 for biological control of the exotic weed Pluchea odorata (Snow) (Asteraceae). Neither field efficacy nor possible non-target effects of the fly have been evaluated in the 40 years since the introduction. We assessed the impact of the fly on both its target host and on seven non-target plant species. The impact on the target weed was limited, with only 5-13% of the developing seeds in P. odorata flowerheads being destroyed by larval feeding. We did not detect any host range expansion of A. picturata onto flowerheads of two exotic or 5 endemic non-target plant species in the family Asteraceae.     

Interaction between Podisus maculiventris and Harmonia axyridis two predators used in augmentative biological control in greenhouse crops

Intraguild predation (IGP) betweenthe pentatomid Podisus maculiventris(Say) and the coccinellid Harmoniaaxyridis (Pallas) in the absence or presenceof the extraguild prey Spodopteralittoralis (Boisduval) and Myzuspersicae (Sulzer) was studied in thelaboratory. Interactions were asymmetric infavor of the pentatomid. Podisusmaculiventris readily fed upon eggs and larvaeof H. axyridis, but adult beetles wererarely attacked. Success of attacks by P.maculiventris was stage dependent, fourthinstars and adults being more successful inkilling ladybeetle larvae than second instars.Attacks by H. axyridis on the pentatomidwere rare and none of them were successful. Theeffect of introducing extraguild prey on thelevel of IGP was tested both in petri dishesand on caged sweet pepper plants. Whensufficient numbers of S. littoralislarvae were present to satiate the pentatomid,predation on H. axyridis larvae decreasedsignificantly, indicating that the coccinellidis a less preferred or less vulnerable prey.When the aphid M. persicae was presentedas extraguild prey, levels of IGP were notaltered. Nymphs of P. maculiventrissuccessfully completed development whenexclusively fed on larvae of H. axyridis,but developmental time was longer than onlepidopteran prey. No pentatomid nymphs reachedadulthood on aphids alone. IGP by P.maculiventris on H. axyridis may be ofsome importance in greenhouse crops, where bothpredators are being used increasingly inaugmentative biological control programs.Nonetheless, it is expected that in practicelarger larvae and adults of H. axyridiswill escape most attacks by the pentatomid.     

Odor specificity testing in the assessment of efficacy and non-target risk for Trichogramma ostriniae (Hymenoptera: Trichogrammatidae)

Trichogramma ostriniae Pang and Chen (Hymenoptera: Trichogrammatidae) is an indigenous egg parasitoid of Ostrinia furnacalis Guenée (Lepidoptera: Crambidae) in China. We evaluated T. ostriniae's responses in olfactometer and wind tunnel assays to various host and plant odors that are likely to impact the efficacy and non-target risk of utilizing T. ostriniae as an augmentative biocontrol agent against Ostrinia nubilalis Hübner in the USA. In a Y-olfactometer, female T. ostriniae exhibited innate positive responses to the egg mass volatiles, scale volatiles, and synthetic sex pheromones of O. nubilalis. When exposed to O. nubilalis pheromone while walking on a platform in a wind tunnel, the wasps manifested significant changes in patch exploration behavior, including delayed dispersal from the platform and slowed walking. The wasps did not respond innately to the synthetic pheromone of a non-target species, Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae), however. Exposing wasps to S. frugiperda pheromone together with eggs of a factitious rearing host prior to testing also did not alter the wasps’ lack of response to the pheromone, indicating that associative learning of the novel odor did not occur. Lastly, wasps showed no innate responses to leaf volatiles from corn (Zea mays L.) and pepper (Capsicum annuum L.), two crops attacked by O. nubilalis. We conclude that T. ostriniae is likely to be highly efficient at finding O. nubilalis eggs in the field through the exploitation of host chemical cues. Further, T. ostriniae's response to moth pheromone appears to be relatively host-specific, since the wasps responded to the pheromone of a congener to their natural host, but not to the pheromone of a more distantly related non-target species. This type of odor-specificity could be an important mechanism for reducing the risk of T. ostriniae attack on non-target species.     

The dietary relationships of Tribolium castaneum (Herbst) with microfungi

The ecology of Tribolium castaneum (Herbst) outside of grain storage facilities is poorly known. However, high densities of T. castaneum adults are known to infest stored cotton seeds (Gossypium hirsutum (L.)) in Queensland, Australia, despite the absence of stored food products in the immediate vicinity. Previous studies suggest that the beetles are attracted to the fungal colonies growing on the residual fibres that remain on the cotton seeds after ginning, but the specifics of this remain unclear, even as to the species of fungi involved. In the current study, 14 fungal species were isolated from stored cotton seeds collected from four sites in Queensland. The feeding preferences of the adult beetles and the developmental success of the larvae were recorded for each fungal species. Gut analyses of T. castaneum adults, after exposure in no-choice feeding tests, showed that the beetles will feed on any one of the 14 fungal species when exposed (over 14 days) to cotton seeds that had been inoculated with one particular fungal species. The developmental success of the larvae varied depending on the fungal species, with most fungal species supporting only low levels of successful development (<30%). Tests with each fungal species and the volatiles they release revealed that neither adult nor larval survival was significantly affected by the presence of any particular fungal isolate. These results indicate that T. castaneum will feed on a variety of fungal species but that none of the tested fungal species on its own provides a good larval diet for T. castaneum.     

Phythonematoxic properties and nematicidal potential of Tithonia diversifolia extract and residue on Meloidogyne incognita infecting yam (Discoria rotundata)

A laboratory study and a screen house experiment were conducted to determine the phythonematoxic properties and nematicidal potential of extract and residue of Tithonia diversifolia (Hemsl.) A. Gray on Meloidogyne incognita, (Kofoid and White) Chitwood infecting yam. Alkaloids and saponins were found to be present in the constituents of Tithonia ethanol extract. Also, Tithonia water extract significantly (P ≤ 0.05) inhibits M. incognita egg hatch by 98% from 2 days after incubation (DAI) and was more evidenced with 100% inhibition at 9 DAI in the in vitro studies. M. incognita (5000 eggs/plant) reproduction, number of eggs and juveniles and galling were significantly (P ≤ 0.05) suppressed by Tithonia residue treatment at a rate of 30 tons/ha on yam (Discoria rotundata) in the screen house. The extract and residue of T. diversifolia have potential for the control of root-knot nematodes.     

Repellency of Palizin® (Coconut Soap) with three laboratory techniques against five stored-product insect pests

The heavy economic damages are the major concern in storage that was caused by coleopteran pests. The conventional control that is accomplished by synthetic pesticides created toxicity to non-target organisms, development of resistance and residue’s problems. Nowadays, with changes in legislation and consumer demand, alternatives to synthetic pesticide to manage the store product pest are increasingly needed. The repellent compounds could be considered as one of the mentioned methods in storage. In this study, five widespread species of stored product pest including Sitophilus oryzae Linnaeus, Tribolium castaneum Herbst, Rhizopertha dominica Fabricius, Oryzaephilus surinamensis Linnaeus and Lasioderma serricorne Fabricius were conducted to assay the percentage repellency (PR) of Palizin^® (Coconut Soap 65%). Percentage repellency was achieved with beetles which were exposed to 0, 0.5, 1, 5 and 10% concentration using three techniques: filter papers, Y-shape tube and cup bioassays. In each of these methods, the means of PR reacted to increasing concentration except T. castaneum and O. surinamensis after 72 and 48 h. The maximum PR of Palizin^® belonged to a concentration of 10% (except R. dominica at 5% and 48 h). Among the methods, except filter paper, degradation process resulted to a decreasing trend of PR. In the present experiment, Palizin^® can be recommended as a limiting factor of all beetles and the data which were exported by Cub bioassay were closely adapted to reality condition of storage.     

Development of nuclear microsatellite markers for the Japanese conifers Tsuga diversifolia and T. sieboldii (Pinaceae)

Nuclear microsatellite markers were developed for the two Tsuga species native to the Japanese Archipelago, Tsuga diversifolia and T. sieboldii, and a population with genetic affinities to T. diversifolia on Ulleung Island, Korea. Tsuga diversifolia and T. sieboldii are widespread dominant trees of temperate and subalpine forests in Japan but to date no genetic markers have been developed for these species. Fifteen polymorphic loci were developed and characterized, of which 14 are reliably amplified in each taxon. Across both species and the Ulleung Island population, the number of alleles per locus ranged from 3 to 26 (average = 13.93) and observed heterozygosity ranged from 0.005 to 0.935 (average = 0.535). In addition, all 15 loci were successfully amplified in a single accession of the Chinese species, T. chinensis. These markers will be useful for investigating the species’ biogeography, range‐wide genetic diversity, conservation genetic issues and potential for hybridisation.     

Impact of the shoot-boring moth Dichrorampha odorata (Lepidoptera: Tortricidae) on growth and reproductive potential of Chromolaena odorata (Asteraceae) in the laboratory

A 9-month laboratory study was carried out to determine the impact of herbivory by a moth with shoot-boring larvae, Dichrorampha odorata Brown and Zachariades (Lepidoptera: Tortricidae) on growth and reproductive ability of its host plant, Chromolaena odorata (L.) King and Robinson (Asteraceae), a major invasive alien plant species in southern Africa. Newly hatched D. odorata larvae were inoculated onto 0 (control), 50 and 100% of the shoot tips of C. odorata in the laboratory. At all treatment levels, the basal stem diameter of C. odorata was not affected by D. odorata larval feeding. Larval feeding by D. odorata significantly reduced the height of the main shoot and flower production in C. odorata relative to the control treatment but promoted branching by increasing the number of shoot tips. However, the differences in plant height and number of flowers between the 50 and 100% inoculation levels were not statistically significant. Dichrorampha odorata is the first shoot-tip attacking agent that is being released as a biological control agent against C. odorata in South Africa. In general, the impacts of D. odorata on the weed were relatively small even though statistically significant. The findings of this study suggest that high levels of damage by the moth will modestly reduce the height, flower production, and the competitiveness of C. odorata, thereby contributing to the biological control of the weed in South Africa.     

White grubs,Holotrichia rustica and Holotrichia mucida (Coleoptera: Scarabaeidae) as pests of teak (Tectona grandis L. f.) seedlings

Abstract Field observations were carried out between 2002 and 2005 on bio‐ecology of white grubs infesting teak (Tectona grandis Linn. f.) seedlings at Ramdongari Forest Nursery, Forest Development Corporation of Maharashtra, Nagpur in central India. The study collected the data required for an integrated pest management strategy against the white grubs. The species damaging teak seedlings were Holotrichia rustica (Burmeister) and H. mucida Gyllenhal. The beetles (adults) of both these species began to emerge just after the pre‐monsoon showers and when the relative humidity had risen rapidly over several days, but before the first monsoon rains. While the adults fed and mated on naturally growing bushes of Ziziphus jujuba, Z. mauritiana, Z. xylopyra, Acacia leucophloea and A. catechu immediately after the emergence from the teak beds in the nursery, the immature stages (grubs) of both species fed on roots of the teak seedling, leading to plant death. This is the first report of (i) damage caused to teak seedlings by grubs of H. rustica and H. mucida, and (ii) of Z. jujuba and Z. mauritiana being hosts for the beetles of H. mucida and H. rustica. It is also the first detailed report on the field bio‐ecology of the H. rustica and H. mucida as major pests of teak. White grubs are among the toughest‐to‐manage pests of economic importance and information presented here on the pest incidence and damage of H. rustica and H. mucida is important to researchers and nursery field managers for the management of these pests on teak.     

中国橐吾属(菊科-千里光族)的分类学研究(五):君范橐吾、长毛槖吾和南川橐吾原白中一些排印错误的改正

对我国菊科橐吾属(Ligularia Cass.) 3种植物原白中模式标本引证的排印错误进行了改正。君范橐吾(L. lingiana S.W. Liu)原白中错误地将主模式标本引证为赵清盛82946,实际应为赵清盛、牟克平和杨亚斌8294。长毛槖吾(L. changiana S.W. Liu ex Y. L. Chen & Z. Yu Li)(=L. heterophylla C. C. Chang,为L. heterophylla Rupr.的晚出同名)主模式为蔡希陶59771,但L. heterophylla C. C. Chang 的原白中错误地将主模式标本引证为蔡希陶59711;该号标本属于唇形科的灯笼草[Clinopodium polycephalum (Vaniot) C. Y. Wu & Hsuan]。南川橐吾(L. nanchuanica S. W. Liu)原白中引证的副模式标本熊济华和周子林93871实际应为李国凤63871,前者属于桤叶树科的城口桤叶树(Clethra fargesii Franch.)。