Enhancing biological control of basal stem rot disease (<Emphasis Type="Italic">Ganoderma boninense</Emphasis>) in oil palm plantations

Basal Stem Rot (BSR) disease caused by Ganoderma boninense is the most destructive disease in oil palm, especially in Indonesia and Malaysia. The available control measures for BSR disease such as cultural practices and mechanical and chemical treatment have not proved satisfactory due to the fact that Ganoderma has various resting stages such as melanised mycelium, basidiospores and pseudosclerotia. Alternative control measures to overcome the Ganoderma problem are focused on the use of biological control agents and planting resistant material. Present studies conducted at Indonesian Oil Palm Research Institute (IOPRI) are focused on enhancing the use of biological control agents for Ganoderma. These activities include screening biological agents from the oil palm rhizosphere in order to evaluate their effectiveness as biological agents in glasshouse and field trials, testing their antagonistic activities in large scale experiments and eradicating potential disease inoculum with biological agents. Several promising biological agents have been isolated, mainly Trichoderma harzianum, T. viride, Gliocladium viride, Pseudomonas fluorescens, and Bacillus sp. A glasshouse and field trial for Ganoderma control indicated that treatment with T. harzianum and G. viride was superior to Bacillus sp. A large scale trial showed that the disease incidence was lower in a field treated with biological agents than in untreated fields. In a short term programme, research activities at IOPRI are currently focusing on selecting fungi that can completely degrade plant material in order to eradicate inoculum. Digging holes around the palm bole and adding empty fruit bunches have been investigated as ways to stimulate biological agents.     

Artificial plasmid engineered to simulate multiple biological threat agents

The objective of this study was to develop a non-virulent simulant to replace several virulent organisms during the development of detection and identification methods for biological threat agents. We identified and selected specific genes to detect Yersinia pestis, Francisella tularensis, Burkholderia mallei, Burkholderia pseudomallei, Rickettsia sp., Coxiella burnetii, Brucella sp., enterohemorrhagic Escherichia coli O157:H7, Bacillus anthracis, and variola (smallpox) virus. We then designed and engineered a non-infectious simulant that included the nucleic-acid signature of each microorganism in a single chimerical molecule. Here, we reported an approach that by direct (de novo) chemical synthesis permitted the production of a single chimerical construct 2,040bp long that included the nucleic-acid signature of the bacterial and viral biological threat agents listed above without requiring access to these agents. Sequences corresponding to each one of the biological agents in the synthetic simulant were amplified by PCR, resulting in amplicons of the expected length, of similar intensity, and without any detectable unspecific products. The novel simulant described here could reduce the need for infectious agents in the development of detection and diagnostic methods and should also be useful as a non-virulent positive control in nucleic-acid-based tests against biological threat agents.     

Intraguild Predation and Feeding Preferences in Three Species of Phytoseiid Mite Used for Biological Control

The ecological impact of introduced biological control agents on native species of arthropods is a matter of considerable debate. This study investigated the ability of the non-native predatory mite Neoseiulus californicus to feed on the native Typhlodromus pyri and vice versa, as both species now co-occur in UK orchards. Typhlodromips montdorensis is a candidate for introduction into the UK as a glasshouse biological control agent. The ability of T. montdorensis to feed on the widely used N. californicus was investigated to identify possible intraguild predation, which might influence the effectiveness of either or both species as predators of Tetranychus urticae. Both N. californicus and T. pyri consumed larval stages of each other, but in choice experiments both showed a preference for T. urticae. Both N. californicus and T. montdorensis also fed on each other, but whereas N. californicus again showed a preference for T. urticae, T. montdorensis fed equally on T. urticae and N. californicus. Interactions between N. californicus and T. pyri and N. californicus and T. montdorensis are discussed in relation to their effectiveness as biological control agents in the glasshouse and the natural control of spider mite in the field.     

Integrated biological control of bacterial speck and spot of tomato under field conditions using foliar biological control agents and plant growth-promoting rhizobacteria

Integration of foliar bacterial biological control agents and plant growth promoting rhizobacteria (PGPR) was investigated to determine whether biological control of bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, and bacterial spot of tomato, caused by Xanthomonas campestris pv. vesicatoria and Xanthomonas vesicatoria, could be improved. Three foliar biological control agents and two selected PGPR strains were employed in pairwise combinations. The foliar biological control agents had previously demonstrated moderate control of bacterial speck or bacterial spot when applied as foliar sprays. The PGPR strains were selected in this study based on their capacity to induce resistance against bacterial speck when applied as seed and soil treatments in the greenhouse. Field trials were conducted in Alabama, Florida, and California for evaluation of the efficacy in control of bacterial speck and in Alabama and Florida for control of bacterial spot. The foliar biological control agent P. syringae strain Cit7 was the most effective of the three foliar biological control agents, providing significant suppression of bacterial speck in all field trials and bacterial spot in two out of three field trials. When applied as a seed treatment and soil drench, PGPR strain Pseudomonas fluorescens 89B-61 significantly reduced foliar severity of bacterial speck in the field trial in California and in three of six disease ratings in the field trials in Alabama. PGPR strains 89B-61 and Bacillus pumilus SE34 both provided significant suppression of bacterial spot in the two field trials conducted in Alabama. Combined use of foliar biological control agent Cit7 and PGPR strain 89B-61 provided significant control of bacterial speck and spot of tomato in each trial. In one field trial, control was enhanced significantly with combined biological control agents compared to single agent inoculations. These results suggest that some PGPR strains may induce plant resistance under field conditions, providing effective suppression of bacterial speck and spot of tomato, and that there may be some benefit to the integration of rhizosphere-applied PGPR and foliar-applied biological control agents.     

Insect natural enemies of coffee green scales [Hemiptera: Coccidae] in Kenya and their potential for biological control ofCoccus celatus andC. viridis in Papua New Guinea

Coffee green scales,Coccus celatus De Lotto andC. viridis (Green), are major pests of coffee in Papua New Guinea (PNG). Surveys for insect natural enemies of coffee green scales were conducted in Kenya to find species suitable for introduction to PNG. Natural enemy communities in Kenya were found to be diverse, particularly those located in the central highlands where 3 primary parasitoids,Metaphycus stanleyi Compere,M. baruensis Noyes andDiversinervus stramineus Compere (Encyrtidae), were dominant onC. celatus andC. alpinus De Lotto. It is suggested that these 3 parasitoids may be potential biological control agents forC. celatus. Several insect predators were found associated withC. celatus in the central highlands but most were only common in ant-free scale populations. An aphelinid primary parasitoid,Coccophagus rusti Compere, was the only natural enemy ofC. viridis located. This species, however, could be of potential as a biological control agent, especially in view of its previous use in biological control against soft scales.      

Bone morphogenetic protein (BMP)1-3 enhances bone repair

Small molecules that exhibit biological activity have contributed to the understanding of the molecular mechanisms of various biological phenomena. 5-Bromodeoxyuridine (BrdU) is a thymidine analogue that modulates various biological phenomena such as cellular differentiation and cellular senescence in cultured mammalian cells. Although BrdU is thought to function through changing chromatin structure and gene expression, its precise molecular mechanisms are not understood. To study the molecular mechanism for the action of BrdU, we have employed the yeast Saccharomycescerevisiae as a model system, and screened multi-copy suppressor genes that confer resistance to BrdU. Our genetic screen has revealed that expression of the N-terminal short fragment of TUP1, and also disruption of HDA1 or HOS1, histone deacetylases that interact with TUP1, conferred resistance to BrdU. These results suggest the implication of the chromatin proteins in the function of BrdU, and would provide novel clues to answer the old question of how BrdU modulates various biological phenomena.     

信号分子AI-2合成关键基因luxS对副溶血性弧菌生物学特性的影响

[背景]副溶血性弧菌是全球范围重要的食源性病原菌,能引起急性肠胃炎。群体感应系统LuxS/AI-2影响细菌的生物学特性,为研究副溶血性弧菌的传播机制和控制技术提供了新的途径。[目的]探讨群体感应信号分子AI-2合成关键基因luxS对海产品中分离的副溶血性弧菌Vp2009027生物学特性的影响。[方法]利用自杀质粒同源重组技术敲除信号分子AI-2合成关键基因luxS,构建副溶血性弧菌Vp2009027的luxS基因缺失株,通过比较野生株与luxS基因缺失株的生长曲线、AI-2活性、运动能力、生物膜形成能力和耐药性,分析LuxS/AI-2系统对副溶血性弧菌生物学特性的影响。[结果]构建了副溶血性弧菌Vp2009027的luxS基因缺失株,野生株和luxS基因缺失株的生长无明显差异,luxS基因的缺失导致AI-2合成受阻、运动能力和生物膜形成能力增强、四环素耐药性降低。[结论]luxS基因对副溶血性弧菌的生物学特性具有重要的调控作用,为进一步研究副溶血性弧菌的传播机制和研发控制技术提供基础。     

Natural establishment of a parasitoid complex on Bactrocera latifrons (Diptera: Tephritidae) in Hawaii

Bactrocera latifrons (Hendel) (Diptera: Tephritidae) is the most recent of four tephritid fruit fly species accidentally introduced into Hawaii. Although parasitoids have been released against other tephritid fruit fly species and have shown partial success in Hawaii, no parasitoids were released until 2004 to suppress populations of B. latifrons. The present study was conducted to document the parasitoid complex that has naturally established against B. latifrons in Hawaii and to assess whether there is a need for improving the biological control of this species. Based on ripe turkeyberry (Solanum torvum Sw) fruit collections over three consecutive years B. latifrons was the dominant tephritid fruit fly infestating turkeyberry at all four sites surveyed, across three major islands in Hawaii. The overall percentage parasitism of B. latifrons ranged from a low of 0.8% (Hana, Maui) to a high of 8.8% (Kahaluu, Oahu). Five primary parasitoid species were recovered from individually held B. latifrons puparia: Fopius arisanus (Sonan), Psyttalia incisi (Silvestri), Diachasmimorpha longicaudata (Ashmead), D. tryoni (Cameron), and Tetrastichus giffardianus Silvestri. F. arisanus was the predominant parasitoid at three of the four sites. Low levels of parasitism suggest that there is a need to improve biological control of B. latifrons, to minimize chances of this species causing economic impacts on crop production in Hawaii. We discuss the possibility of improving biological control of B. latifrons through augmentative releases of F. arisanus or introduction and release of specific and efficient new parasitoid species.     

Integration of biological control agents with other weed management technologies: Successes from the leafy spurge (Euphorbia esula) IPM program

An invasive weed can occupy a variety of environments and ecological niches and generally no single control method can be used across all areas the weed is found. Biological control agents integrated with other methods can increase and/or improve site-specific weed control, but such combinatorial approaches have not been widely utilized. The successful leafy spurge (Euphorbia esula L.) control program provides examples for future integrated weed programs that utilize biological control agents with traditional methods. Weed control methods can be used separately, such as when the leafy spurge gall midge (Spurgia esulae Gagné) reduced seed production in wooded areas while herbicides prevented further spread outside the tree line. Traditional methods also can be used directly with biological control agents. Incorporation of Aphthona spp. with herbicides has resulted in more rapid and complete leafy spurge control than either method used alone. Also, the insect population often increased rapidly following herbicide treatment, especially in areas where Aphthona spp. were established for several years but had been ineffective. Incorporation of Aphthona spp. with sheep or goat grazing has resulted in a larger decline in leafy spurge production than insects alone and in weed density than grazing alone. Controlled burns can aid establishment of biological control agents in marginally suitable environments, but timing of the fire must be coordinated to the insect’s life-cycle to ensure survival. Integration of biological control agents with revegetation programs required the agent to be the last method introduced because the cultivation and herbicide treatments necessary to establish desirable grasses and forbs were destructive to the insect. In a practical application, herbicides were combined with Aphthona spp. to help the insect establish and control leafy spurge in the habitat of the western prairie fringed orchid (Platanthera praeclara Sheviak and Bowles), an endangered species. Several experimental designs can be used to evaluate biological control agents with cultural, mechanical, and chemical control methods or with additional biological agents.     

Life history comparison between two competitive Aleochara species in the cabbage root fly, Delia radicum: implications for their use in biological control

This study evaluates the efficacy of Aleochara bilineata Gyll and Aleochara bipustulata L. (Coleoptera: Staphylinidae) as biological control agents against the cabbage root fly, Delia radicum L. (Diptera: Anthomyiidae). Biological and demographic characters are documented and comparisons made between the two species. The following results were obtained:(1) The reproductive potential and longevity of A. bipustulata females are significantly higher than those of A. bilineata. These differences are correlated with the biology and ecology of the hosts of both species.(2) Under laboratory conditions the rate of increase (r_m) of both staphylinids species is significantly higher than that of the pest and their major competitor Trybliographa rapae West. (Hymenoptera:Figitidae). This may indicate that A. bilineata and A. bipustulata can be effective biological control agents.(3) Aleochara bilineata appears to be the most interesting biological control agent against D. radicum, because of its higher rate of increase, higher host specificity and host acceptance, and a development time which is well synchronised with that of its host. With its higher competitive ability, a population of A. bilineata may increase even if competition occurs. However, A. bipustulata presents interesting biocontrol characteristics, but the best strategy may be only to use the potential of its natural populations.     

Lutte biologique contre les mollusques vecteurs de Bilharziose. Action predatrice de Tilapia rendalli,Boulenger et de Sarotherodon mossambica,Peters a l'égard de Biomphalaria glabrata,Say

Laboratory experiments indicate that the Cichlidae Sarotherodon mossambica and, mainly, Tilapia rendalli may be promising biological control agents of Schistosomiasis by acting as predators of eggs and young Biomphalaria glabrata less than 10 mm diameter.

     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Tomato-aphid-hoverfly: a tritrophic interaction incompatible for pest management

Trichome-based tomato resistance offers the potential to reduce pesticide use, but its compatibility with biological control remains poorly understood. We evaluated Episyrphus balteatus De Geer (Diptera, Syrphidae), an efficient aphidophagous predator, as a potential biological control agent of Myzus persicae Sulzer (Hemiptera, Aphididae) on trichome-bearing tomato cultivars. Episyrphus balteatus’ foraging and oviposition behavior, as well as larval mobility and aphid accessibility, were compared between two tomato cultivars (Lycopersicon esculentum Mill. ‘Moneymaker’ and ‘Roma’) and two other crop plants; broad bean (Vicia faba L.) and potato (Solanum tuberosum L.). Hoverfly adults landed and laid more eggs on broad beans than on three species of Solanaceae. Hoverfly larval movement was drastically reduced on tomato, and a high proportion of hoverfly larvae fell from the plant before reaching aphid prey. After quantifying trichome abundance on each of these four plants, we suggest that proprieties of the plant surface, specifically trichomes, are a key factor contributing to reduced efficacy of E. balteatus as a biological agent for aphid control on tomatoes. Handling editor: Stanislaw Gorb     

马齿苋内生菌橘青霉和波兰青霉中抗青枯菌的活性物质

为了挖掘农作物病害生物防治新资源,以药用植物马齿苋(Portulaca oleracea)为材料,通过培养基种植法分离和纯化其根、茎、叶中的内生菌,以青枯菌(Ralstonia solanacearum)的抑菌试验评价其活性,采用菌落形态观察和ITS序列分析鉴定菌种。结果表明,从马齿苋筛选出2种具有抑制青枯菌的内生菌橘青霉(Penicillium citrinum)和波兰青霉(P. polonicum),采用液相与四极杆飞行时间串联质谱(UPLC-QTOF-MS)鉴定2种内生菌的主要活性物质为橘霉素,其对青枯菌的抑制效果比链霉素更好。因此,这为植物青枯病的生物防治提供科学依据。     

Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado

Abundances and interactions among biological control insects and their effects on target invasive plants were monitored within the flower heads and roots of diffuse knapweed, Centaurea diffusa, and in spotted knapweed, Centaurea stoebe, along the Colorado Front Range. Flower weevils, (Larinus species) and root-feeders (Cyphocleonus achates and Sphenoptera jugoslavica) were released on knapweed that already supported biological control gall flies (Urophora species). At a single monitoring site, seed production by C. diffusa declined from 4400 seeds m⁻² in 1997 to zero seeds m⁻² on the monitoring sites in 2006, while the flowering stem density of C. diffusa declined from a peak of almost 30 stems m⁻² in 2000 to zero stems m⁻² in 2006. The average abundance of Urophora and Larinus in flower heads fluctuated independently during the 2001–2006 interval, while the relative abundance of C. achates and S. jugoslavica in roots exhibited a weak inverse relationship that appeared driven by climate effects. The relative abundance of insects on a population of C. stoebe was monitored for five years as Larinus species and C. achates became established on spotted knapweed that already supported Urophora species. Spotted knapweed seed production on our monitoring site declined from 4600 seeds m⁻² in 2003 to zero seeds m⁻² in 2006. Unlike C. diffusa, substantial numbers of rosettes of C. stoebe remained present. Larinus consumed almost all Urophora encountered in C. diffusa, and consumed about 40% of the Urophora in co-infested flower heads of C. stoebe (ca. 10–15% of the total Urophora population). No negative correlations between the relative densities of flower head and root-feeding insects were observed. The effects of these insects on target plants have produced results consistent with the ‘cumulative stress hypothesis’ for biological control of Centaurea species.     

Biological control of thrips [Thysanoptera: Thripidae] on greenhouse cucumber byAmblyseius cucumeris

The predatory miteAmblyseius cucumeris (Oudemans) [Acarina: Phytoseiidae] was evaluated as a biological control forThrips tabaci Lindeman andFrankliniella occidentalis (Pergande) [Thysanoptera: Thripidae] on greenhouse grown seedless cucumber.A. cucumeris spread throughout the greenhouses and provided control of both species of thrips.A. cucumeris adults persisted on plants for 7 weeks in the virtual absence of prey, and increased numerically in response to increases in prey population. On the basis of these resultsA. cucumeris is recommended as a useful biological control forT. tabaci andF. occidentalis on greenhouse cucumber. Publication No. 361, Agassiz Research Station, Agriculture Canada, Agassiz, B.C. Canada VOM 1AO.     

Insecticidal effects of some biological agents on Agelastica alni (Coleoptera: Chrysomelidae)

The alder leaf beetle (Agelastica alni L., Coleoptera: Chrysomelidae) causes approximately 10% of total economic damage to hazelnut product per year in Turkey. A. alni larvae are susceptible to several pathogens indigenous to the area in which these insects occur in Turkey. In the present study, in order to find a more effective and safer biological control agent against this common pest, we evaluated the various biological agents’ insecticidal activity during the four hazelnut seasons from 2002 to 2005 on the larvae of the alder leaf beetle collected from the vicinity of Trabzon, Turkey. The tested agents are 25 insect-originating bacteria, 2 bacterial toxins and 1 viral preparation. The results showed that the highest insecticidal activity was obtained by bacterial isolates at 1.8 × 10⁹ bacteria/mL dose, within ten days on the larvae of A. alni. These are 90% for Bacillus thuringiensis biovar tenebrionis (4AA1), Bacillus sphaericus (Ar4, isolated from Anoplus roboris L., Col.: Curculionidae), and Bacillus thuringiensis (Mm2, isolated from Melolontha melolontha L., Col.: Scarabaeidae). Our results indicate that these isolates may be valuable as biological control agent.     

Changes in secondary metabolism during stromatal ontogeny of Hypoxylon fragiforme

Stromata of Hypoxylon fragiforme were studied during the vegetation period by hplc profiling, revealing changes in the composition during stromatal development. Cytochalasin H and two new cytochalasins named fragiformins A–B were identified as major constituents of the young, maturing stromata, whereas mature, ascogenous material yielded large amounts of mitorubrin-type azaphilones. The above compounds, further cytochalasins from Xylariaceae and other fungi, and additional azaphilones of the mitorubrin type were assayed for their nematicidal effects against Caenorhabditis elegans and their antimicrobial activities against Bacillus subtilis, Yarrowia lipolytica, and various filamentous fungi. The results confirmed data in the literature on broad-spectrum non-selective activities of azaphilones and cytochalasins in biological systems. Most interestingly, laboratory cultures of the above Hypoxylon spp. mainly produced dihydroisocoumarin derivatives and were found devoid of mitorubrins and cytochalasins. These rather drastic changes in the secondary metabolism of H. fragiforme and the above biological activities are discussed in relation to the possible biological functions of secondary metabolites (extrolites) in the Hypoxyloideae.     

Some effects of pre-release host-plant on the biological control of Panonychus ulmi by the predatory mite Amblyseius fallacis

Amblyseius fallacis Garman has been selected for pyrethroid resistance and mass reared for experimental release as a biological control agent for tetranychid mites on a number of crops in Canada. Several releases of this predator onto apple and peach trees have failed to result in the establishment of A. fallacis, or in the biological control of Panonychus ulmi Koch. Here, we test the hypothesis that the change of host-plant at the time of release is a critical factor in the establishment of A. fallacis for biological control of P. ulmi. Functional and numerical response studies were undertaken on two populations of A. fallacis: a wild strain collected from the canopy foliage of an apple orchard near Vineland, Ontario; and a second strain reared on bean plants in a commercial insectary with Tetranychus urticae as prey. Each population consumed significantly more P. ulmi and produced significantly more eggs when on leaf disks from the plant species they were reared on, than on leaf disks from the novel host plant. A further experiment was conducted to determine if establishment and biological control of mass-reared A. fallacis could be affected by rearing a population for a short term on apple leaves prior to release on apple trees. Three release treatments were made into potted apple trees in a glasshouse, using predators commercially mass-reared on bean and T. urticae: A. fallacis released directly; A. fallacis reared in the laboratory for four weeks on bean and T. urticae; A. fallacis reared on apple leaves and T. urticae for four weeks. They were compared with a control treatment lacking predator release. Contrary to results of the functional and numerical response studies, no difference was observed between release treatments. All release treatments adding A. fallacis resulted in a similar, if limited, degree of biological control of P. ulmi. These results indicated that there may be short-term effects of host plant on the establishment of A. fallacis and biological control of P. ulmi, which in our study were observed as an initial reduction of the predatory response. However, in a test, the predators appeared to overcome these short-term effects and successfully established on the new host-plant to control P. ulmi.     

Ecology and impact of Allorhogas sp. (Hymenoptera: Braconidae) and Apion sp. (Coleoptera: Curculionoidea) on fruits of Miconia calvescens DC (Melastomataceae) in Brazil

Two fruit-feeding insects, a gall wasp, Allorhogas sp. (Hymenoptera: Braconidae), and a beetle, Apion sp. (Coleoptera: Curculionoidea), were evaluated in their native habitat in Brazil as potential biological control agents of Miconia calvescens DC (Melastomataceae). Allorhogas sp. occurred at two out of three field sites with native populations of M. calvescens, and Apion sp. occurred at all three sites. Both species exhibited aggregated distributions among M. calvescens trees sampled at each site. Allorhogas sp. infested 9.0% and 3.8% of fruits at each of two sites. The number of larvae and pupae of Allorhogas sp. and/or an unidentified parasitoid (Hymenopetera: Eulophidae: Tetrastichinae) ranged from one to five per infested fruit. Fruits infested with Allorhogas sp. were 20% larger and had 79% fewer seeds than healthy fruits. Although adults of Apion sp. were found on leaves and inflorescences of M. calvescens at all three sites, larvae and pupae were found in fruits at only one site, where a maximum of 1.4% of fruits were infested. Fruits infested by Apion sp. contained only one larva or pupa, and were 15% smaller and had 62% fewer seeds than healthy fruits. While a variety of apionids have been used for biological control in the past, this is the first time a braconid wasp has been considered for biological control of a weed.