雌花期榕小蜂进入榕果的行为及其活动时间

在西双版纳,钝叶榕传粉榕小蜂Eupristina sp.和杨氏榕树金小蜂Diaziella yangi均在雌花期进入钝叶榕果内繁殖和传粉,比较研究它们进入榕果的行为和活动时间。结果显示:在搜寻苞片处进蜂口时,2种榕小蜂的种内均出现打斗行为,并且杨氏榕树金小蜂的打斗更为激烈,但种间没有打斗行为发生,杨氏榕树金小蜂总是等待钝叶榕传粉榕小蜂先期进入榕果,然后才跟随着进入。在搜寻和进入苞片口通道阶段,钝叶榕传粉榕小蜂均比杨氏榕树金小蜂花费较长时间;而在果腔内产卵、传粉的时间,2种榕小蜂均最多不超过3d。相似的进蜂过程和活动时间,可能是2种榕小蜂与寄主榕树长期协同进化的结果。     

The potential of South African indigenous plants for the international cut flower trade

A broad review is presented of recent developments in the commercialization of southern Africa indigenous flora for the cut flower trade, including potted flowers and foliages (“greens”). The botany, horticultural traits and potential for commercialization of several indigenous plants have been reported in several publications. The contribution of species indigenous and/or endemic to southern Africa in the development of cut flower crop plants is widely acknowledged. These include what is known in the trade as gladiolus, freesia, gerbera, ornithogalum, clivia, agapanthus, strelitzia, plumbago and protea. Despite the wealth of South African flower bulb species, relatively few have become commercially important in the international bulb industry. Trade figures on the international markets also reflect the importance of a few species of southern African origin. The development of new research tools are contributing to the commercialization of South African plants, although propagation, cultivation and post-harvest handling need to be improved. A list of commercially relevant southern African cut flowers (including those used for fresh flowers, dried flowers, foliage and potted flowers) is presented, together with a subjective evaluation of several genera and species with perceived potential for the development of new crops for the florist trade. It is concluded that research should be focused on potential markets rather than on preconceived product concepts. A special national effort is required to maximize the opportunities presented by the rich diversity of the flora and to develop an internationally competitive cut flower industry.     

Dactylopius opuntiae,a new prickly pear cactus pest in the Mediterranean: an overview

The Opuntia cochineal scale or false carmine cochineal scale, Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), is spreading rapidly in many countries, especially in the Mediterranean basin, where it has become a serious pest of prickly pear crops, Opuntia ficus‐indica (L.) Miller (Cactaceae). This crop is an important food resource both for humans and livestock. The cochineal was originally used as a biological agent to control cactaceous weeds in many countries where Opuntiaceae had been introduced. Currently, in some countries where the prickly pear is no longer considered a weed but a productive crop, as in the Mediterranean area, D. opuntiae has changed its role from a highly prized biological control agent to the status of serious pest. This paper provides an overview of the current knowledge on D. opuntiae for farmers and stakeholders in order to indicate the most appropriate way to limit or counteract the spread of this pest especially in new cultivated areas.     

Benzyladenine Promotes Flowering in <Emphasis Type="Italic">Doritaenopsis</Emphasis> and <Emphasis Type="Italic">Phalaenopsis</Emphasis> Orchids

Two experiments were performed to determine how application of the cytokinin benzyladenine (BA) influenced flowering in Doritaenopsis and Phalaenopsis orchid clones. In the first experiment, two vegetative orchid clones growing in 15-cm pots were transferred from a 28°C greenhouse that inhibited flowering to a 23°C greenhouse for flower induction (day 0). A foliar spray (0.2 L m⁻²) containing BA at 100, 200, or 400 mg L⁻¹ or 25, 50, or 100 mg L⁻¹ each of BA and gibberellins A₄ + A₇ (BA+GA) was applied on days 0, 7, and 14. Plants treated with BA alone at 200 or 400 mg L⁻¹ had a visible inflorescence 3–9 days earlier and had a mean of 0.7–3.5 more inflorescences and 3–8 more flowers per plant than nontreated plants. The application of BA+GA had no effect on inflorescence number and total flower number at the rates tested. In the second experiment, three orchid clones received a single foliar spray of BA at 200 mg L⁻¹ at six time points relative to time of transfer from 29°C to 23°C (−1, 0, +1, +2, +4, or +6 weeks). A separate group of plants received a BA application at week 0 but was maintained at 29°C. Inflorescence number was greatest in all three orchid clones when plants were treated with BA 1 week after the temperature transfer. Plants that were sprayed with BA and maintained at 29°C did not initiate inflorescences. The promotion of flowering by the application of BA suggests that cytokinins at least partially regulate inflorescence initiation of Doritaenopsis and Phalaenopsis, but its promotion is conditional and BA application cannot completely substitute for an inductive low temperature.     

Effect of lectins from Opuntia ficus indica cladodes and Moringa oleifera seeds on survival of Nasutitermes corniger

Biodegradation by termites is a serious problem for wood and crop industries worldwide, and new environmentally friendly alternatives for termite control have been developed. This work investigated the effects of crude and purified preparations containing lectins from Opuntia ficus indica cladodes (OfiL) and Moringa oleifera seeds (WSMoL and cMoL) on Nasutitermes corniger workers and soldiers. Purified OfiL was more active than cladode extracts, showing a stronger termiticidal activity against workers (LC₅₀ of 0.116 mg ml⁻¹) than against soldiers. OfiL was active against soldiers only at 1.5 mg ml⁻¹. All preparations containing WSMoL and cMoL were active only at concentrations of 1.0 and 1.5 mg ml⁻¹. The tested preparations did not exert repellent activity against N. corniger. OfiL was able to kill workers and therefore is potentially a new tool for N. corniger control; as a consequence, this lectin could disturb organization, structure, and maintenance of termite colonies.     

Spatial distribution of ants (Hymenoptera: Formicidae), vine mealybugs and mealybug parasitoids in vineyards

The mutualistic association between some ant species and honeydew‐producing Hemiptera has been shown to influence the distribution patterns and abundance of these hemipterans and their natural enemies. We studied the spatial distribution patterns of three ant species, mealybugs and mealybug parasitoids for two consecutive growing seasons on three wine grape farms in the Western Cape, South Africa. During the study period, no ant or mealybug controls were applied. Ant and mealybug monitoring was conducted on a total of 21 ha using a presence/absence sampling system, while parasitoids were collected from infested mealybug females. Spatial analysis by distance indices was used to analyse spatial distribution of insects and ArcView? was used to map the gap, patch and local association indices where significant association and disassociation occurred. Significant associations were found between some ants and parasitoids, while significant disassociations between the ants Crematogaster peringueyi and Linepithema humile; and also between Crematogaster peringueyi and Anoplolepis steingroeveri were found. Interspecific competition between ant species could play a role in the distribution of parasitoids and mealybugs. Our results stress the importance of monitoring for ants and mealybugs and further highlight the importance of restricted chemical applications against ants during the growing season.     

Aquaculture of sponges on scallops for natural products research and antifouling

Suspended culture of scallops (Pectinidae: Bivalvia) is plagued by invertebrate fouling. Scallops covered in an orange sponge (Suberites ficus ssp. rubrus), however, do not have any other invertebrates fouling their shells and the sponge is easily removed. Sponges may also be valuable sources of bioactive compounds. Seven species of sponge were found to be associated with Chlamys opercularis but none were found associated with Pecten maximus. Standing crop of sponge on the scallop farm was just over one tonne. If all the scallops were covered by sponge this would rise to approximately 4.5 tonnes (from three million scallops). Primary cell cultures of (S.f. rubrus) were successfully established but no cell lines were achieved. A number of techniques were tried for establishing cells and pieces of sponge tissue onto scallop shells but none gave satisfactory results. Likewise mechanical methods for sticking small pieces of sponge to scallop shells were deemed impractical even where they resulted in subsequent sponge growth. Improving natural settlement of sponges onto the scallops was the only economically practical method for increasing sponge yield for C. opercularis, though other methods would need to be devised for P. maximus.     

盆栽榕树蓟马种类及优势种榕管蓟马对寄主植物的致害性

为明确盆栽榕树蓟马的种类, 了解蓟马优势种对在同一温室内混合种植的榕属及非榕属盆栽植物的致害性差异, 以福建漳州、 福州和泉州等地的盆栽榕树种植基地为观测点, 采集榕树叶片, 调查蓟马种类, 确定优势种蓟马; 以天南星科喜林芋属、 紫葳科菜豆树属、 木棉科瓜栗属和桑科榕属等不同科属盆栽植物为试验材料, 测试榕管蓟马Gynaikothrips uzeli Zimmerman对寄主植物的致害性。结果表明： 盆栽榕树蓟马种类有2亚目, 2科, 8属, 9种, 优势种为榕管蓟马, 常见种为棘腿管蓟马Androthrips ramachandrai Karny和榕腿管蓟马Mesothrips jordani Zimmermann, 其他6种蓟马均为偶见种。榕管蓟马对不同寄主植物的致害性差异显著, 以对桑科榕属植物致害性为最强, 而对天南星科喜林芋属、 紫葳科菜豆树属和木棉科瓜栗属等其他植物的致害性较弱。在6种榕属植物中, 榕管蓟马对垂叶榕Ficus benjamina Linn.、 榕树F. microcarpa Linn. f.、 花叶垂叶榕F. benjamina cv. Golden Princess等3种榕属植物的为害等级均达3级以上, 以垂叶榕最重, 榕树次之, 花叶垂叶榕略轻; 对金叶榕F. microcarpa cv. Golden Leaves、 黑叶橡胶榕F. elastica cv. Deocora Burgundy、 斑叶橡胶榕F. elastica var. variegata等3种榕属植物的为害很轻, 为害等级均仅为1级; 同时, 榕管蓟马在金叶榕、 黑叶橡胶榕和斑叶橡胶榕上繁殖力弱、 无法完成世代, 而在榕树、 垂叶榕和花叶垂叶榕上繁殖力强、 能完成世代, 但以在垂叶榕上的发育情况最好。研究可为选择利用寄主植物抗虫性来有效防控盆栽榕树蓟马提供技术支撑。     

Keratinophilic fungi in soil of potted plants of indoor environments in Kanpur,India, and their proteolytic ability

One hundred nine isolates of 10 genera representing 20 species of keratinophilic fungi were isolated from soil of planted earthen pots in indoor environments of 15 localities of Kanpur, India, by the hair baiting technique. Microsporum gypseum, Trichophyton vanbreuseghemii, and Botryotrichum piluliferum were found to release 698.66, 512.99, and 519.99 μg/ml net protein, respectively, whereas Arthroderma cuniculi released the minimum, 107.99 μg/ml. All other isolates were keratinolytically active.