Twenty‐five years after: post‐introduction association of Mecinus janthinus s.l. with invasive host toadflaxes Linaria vulgaris and Linaria dalmatica in North America

Linaria vulgaris, common or yellow toadflax, and Linaria dalmatica, Dalmatian toadflax (Plantaginaceae), are Eurasian perennial forbs invasive throughout temperate North America. These Linaria species have been the targets of classical biological control programmes in Canada and the USA since the 1960s. The first effective toadflax biological control agent, the stem‐mining weevil Mecinus janthinus (Coleoptera: Curculionidae) was introduced from Europe in the 1990s. This weevil has become established on L. dalmatica and L. vulgaris in both countries, although it has shown greater success in controlling the former toadflax species. Genetic and ecological studies of native range M. janthinus populations revealed that weevils previously identified as a single species in fact include two cryptic species, now recognised as M. janthinus, associated with yellow toadflax, and the recently confirmed species Mecinus janthiniformis, associated with Dalmatian toadflax. The results of a comprehensive study characterising haplotype identities, distributions and frequencies within M. janthinus s.l. native range source populations were compared to those populations currently established in the USA and Canada. The presence of both Mecinus species in North America was confirmed, and revealed with a few exceptions a high and consistent level of host fidelity throughout the adopted and native ranges. Genetic analysis based on mitochondrial cytochrome oxidase subunit II gene (mtCOII) defined the origin and records the subsequent North American establishment, by haplotype, of the European founder populations of M. janthinus (northern Switzerland and southern Germany) and M. janthiniformis (southern Macedonia), and provided population genetic indices for the studied populations. This analysis together with existing North American shipment receipt, release and rearing records elucidates probable redistribution routes and sources of both weevil species from initially released and established adopted range populations.     

Regional-scale impact of the weed biocontrol agent Mecinus janthinus on Dalmatian toadflax (Linaria dalmatica)

Dalmatian toadflax (Linaria dalmatica (L.) Mill.) is an important invasive plant on rangelands throughout western North America. In 1991, the stem-mining weevil, Mecinus janthinus Germar, was introduced into Canada from Europe as a classical biological control agent to reduce toadflax densities and improve rangelands, particularly in British Columbia. To determine if the program was a success at a regional level, this paper answers three key questions: (1) has M. janthinus spread throughout the study area, (2) is M. janthinus causing a decline in toadflax plant size or density at the regional scale, and (3) has the distribution of toadflax plants changed following M. janthinus introduction? These questions are answered by combining historical survey data and mensurative experimental data on plant and weevil densities across a 40,000 km² area in southern British Columbia. The results show that through a combination of intentional redistribution and natural dispersal weevils have spread throughout the study area. Stem densities at naturally colonized sites and historical release sites were equally low. Across weevil populations between 3 and 10 years old, weevil densities peaked in the eighth year, and there was a negative relationship between weevil density and stem length. Between 2000 and 2007, toadflax patches were found to both decrease in density and become more fragmented over time, with 15% of patches disappearing completely. These findings show that M. janthinus has had a significant negative impact on both the density and distribution of Dalmatian toadflax throughout a large part of its range in British Columbia.     

Top-down and bottom-up controls on Dalmatian toadflax (<Emphasis Type="Italic">Linaria dalmatica</Emphasis>) performance along the Colorado Front Range,USA

Plant performance is influenced by both top-down (e.g., herbivores) and bottom-up (e.g., soil nutrients) controls. Research investigating the collective effects of such factors may provide important insight into the success and management of invasive plants. Through a combination of observational and experimental field studies, we examined top-down and bottom-up effects on the growth and reproduction of an invasive plant, Linaria dalmatica. First, we assessed attack levels and impacts of an introduced biocontrol agent, the stem-mining weevil Mecinus janthinus, on L. dalmatica plants across multiple years and sites. Then, we conducted a manipulative experiment to examine the effects of weevil attack, soil nitrogen availability, and interspecific competition on L. dalmatica. We found substantial variations in weevil attack within populations as well as across sites and years. Observational and experimental data showed that increased weevil attack was associated with a reduction in plant biomass and seed production, but only at the highest levels of attack. Nitrogen addition had a strong positive effect on plant performance, with a two-fold increase in biomass and seed production. Clipping neighboring vegetation resulted in no significant effects on L. dalmatica performance, suggesting that plants remained resource limited or continued to experienced belowground competitive effects. Overall, our research indicates that M. janthinus can exert top-down effects on L. dalmatica; however, weevil densities and attack rates observed in this study have not reached sufficient levels to yield effective control. Moreover, bottom-up controls, in particular, soil nitrogen availability, may have a large influence on the success and spread of this invasive plant.     

Morphological,molecular and biological evidence reveal two cryptic species in Mecinus janthinus Germar (Coleoptera,Curculionidae), a successful biological control agent of Dalmatian toadflax,Linaria dalmatica (Lamiales,Plantaginaceae)

A combined morphological, molecular and biological study shows that the weevil species presently named Mecinus janthinus is actually composed of two different cryptic species: M. janthinus Germar, 1821 and M. janthiniformis To?evski & Caldara sp.n. These species are morphologically distinguishable from each other by a few very subtle morphological characters. On the contrary, they are more readily distinguishable by both molecular and biological characters. A molecular assessment based on the mitochondrial DNA cytochrome oxidase subunit II gene revealed fixed differences between the two species with p‐distances between samples of both species ranging from 1.3 to 2.4%. In addition to this, the larvae of the two species are found to develop on different species within the genus Linaria (Plantaginaceae): M. janthinus is associated with yellow toadflax (L. vulgaris) and M. janthiniformis with broomleaf toadflax (L. genistifolia) and Dalmatian toadflax (L. dalmatica). Molecular and host use records further suggest the occurrence of a third species associated with L. vulgaris within M. janthinus, sampled from north Switzerland, central Hungary and east Serbia. The significance of these new findings is of particular importance because species of the M. janthinus group are used, or are potential candidates, for the biological control of invasive toadflaxes in North America.     

Host-plant preference of Brachypterolus pulicarius, an inadvertently introduced biological control insect of toadflaxes

Brachypterolus pulicarius (L.) (Coleoptera: Kateridae) is an inadvertently introduced biological control agent that can reduce seed set in two North American invasive species, yellow (Linaria vulgaris P. Mill.) (Scrophulariaceae) and Dalmatian toadflax (Linaria genistifolia (L.) P. Mill. ssp. dalmatica). The beetles are more common on yellow toadflax than on Dalmatian toadflax. To understand their distribution on the two host plants, we investigated whether they prefer one host to the other and whether individuals aggregate toward conspecifics. In field and laboratory experiments where beetles were presented with a choice of both toadflax species, B. pulicarius sampled from both host plants preferred yellow toadflax. However, in the laboratory experiment, beetles collected from Dalmatian toadflax showed a weaker preference for yellow toadflax than beetles collected from yellow toadflax. In the field experiment, all beetle populations sampled showed similar preferences. When given a choice between yellow toadflax plants with and without trapped adult B. pulicarius, beetles preferred plants with conspecifics, suggesting aggregation toward beetle pheromones or host‐plant volatiles induced by beetle activity. These results do not support the current practice of redistributing North American B. pulicarius onto Dalmatian toadflax because of their preference for yellow toadflax.     

Establishment and dispersal of the biological control weevil Rhinoncomimus latipes on mile-a-minute weed, Persicaria perfoliata

Mile-a-minute weed, Persicaria perfoliata (L.) H. Gross (Polygonaceae), is an annual vine from Asia that has invaded the eastern US where it can form dense monocultures and outcompete other vegetation in a variety of habitats. The host-specific Asian weevil Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) was first released in the US in 2004 as part of a classical biological control program. The weevil was intensively monitored in three release arrays over 4 years, and field cages at each site were used to determine the number of generations produced. The weevil established at all three sites and produced three to four generations before entering a reproductive diapause in late summer. Weevils dispersed at an average rate of 1.5–2.9 m wk⁻¹ through the 50 m diameter arrays, which had fairly contiguous mile-a-minute cover. Weevils dispersing in the broader, more variable landscape located both large monocultures and small isolated patches of mile-a-minute 600–760 m from the release within 14 months. Weevil density ranged from fewer than 10 to nearly 200 weevils m⁻² mile-a-minute weed. Mile-a-minute cover decreased at the site with the highest weevil density. The production of P. perfoliata seed clusters decreased with increasing weevil populations at two sites, and seedling production declined over time at two sites by 75% and 87%. The ability of the weevil to establish, produce multiple generations per season, disperse to new patches, and likelihood of having an impact on plants in the field suggests that R. latipes has the potential to be a successful biological control agent.     

Costs of mass-producing the root weevil, Mogulones cruciger, a biological control agent for houndstongue (Cynoglossum officinale L.)

The cost of rearing the root-feeding weevil, Mogulones cruciger Herbst, to control the invasive weed houndstongue (Cynoglossum officinale L.) was determined for two managed production methods. Production in an insectary setting provides control over rearing and all adult weevils that emerge can be collected, but required facility investment and high labor input. Mass-rearing in a managed ‘field crop’ setting required less facilities and labor while the insects were multiplying, but capture of the emerged adults was challenging and labor intensive. Estimated per adult weevil production costs were $CDN 2.65 for the insectary approach, and from $CDN 0.10 to $CDN 0.14 for mass-rearing in the managed field crop setting. Even though collection of adult weevils in the field crop production system was challenging, commercial production of M. cruciger should consider use of this mass-rearing method because of its lower cost.     

Biology and host specificity of Mecinus Janthinus Germar (col.: Curculionidae), a candidate for the biological control of yellow and dalmatian toadflax,Linaria Vulgaris (l.) mill,and Linaria Dalmatica (l.) mill. (scrophulariaceae) in North America

The biology and host specificity of Mecinus janthinus Germar, an oligophagous, univoltine stem‐borer of Linaria spp. are discussed. The results of feeding and oviposition tests with 38 species in 13 families and of larval transfer tests with four plant species are presented. They show that M. janthinus is restricted to the genus Linaria and does not develop on snapdragon Antirrhinum majus, an important ornamental in North America. The weevil is widely distributed in Europe. It accepts and develops normally on plants from the target North American toadflax populations. Therefore, it should be relatively easy to establish M. janthinus where the control of L. dalmatica and L. vulgaris is required. The release of M. janthinus in Canada and the USA is recommended.     

Biology of Lilioceris spp. (Coleoptera: Chrysomelidae) and their parasitoids in Europe

The biology and parasitoid complex of the lily leaf beetle (LLB), Lilioceris lilii Scopoli, and two congeneric species were investigated in Europe, as part of a biological control program against the LLB in North America. Eggs, larvae, and adults of L. lilii were collected in several countries in Europe, on both cultivated and wild Lilium spp., and reared in the laboratory and under natural conditions. Parasitoids were obtained and their biologies were studied. Similar investigations were made in Switzerland on two closely related species Lilioceris tibialis (Villa) found on wild Lilium spp., and Lilioceris merdigera (L.) on several other Liliaceae. The three species are strictly univoltine. Adults overwinter and lay eggs on leaves in early spring. The three beetle species have four instars, which were characterized by their head capsule width. Pupation occurs in a cocoon in the soil. Adults emerge in late summer and start feeding before reaching overwintering sites. Egg and larval parasitoids were obtained. Eggs of L. lilii and L. merdigera were parasitized by the mymarid Anaphes sp., a multivoltine species that needs alternate hosts for overwintering. Larvae were heavily attacked by several parasitoids, among which the most abundant were three ichneumonids, Lemophagus pulcher (Szepligeti), L. errabundus (Gravenhorst), and Diaparsis jucunda (Holmgren), and the eulophid Tetrastichus setifer Thomson. All four parasitoid species were found in the three beetles and in most European regions, but strong variations were observed in their relative abundance among hosts and geographic regions. Three of the four main larval parasitoids are strictly univoltine, whereas L. pulcher has a partial second generation. Lemophagus spp. are frequently parasitized by the ichneumonid hyperparasitoid Mesochorus lilioceriphilus Schwenke. Further details of the biology of the parasitoids are described, and their potential as biological control agents is discussed.     

大型海藻龙须菜抽提液对褶皱臂尾轮虫生命表参数的影响

大型海藻富含多种活性物质,具有抗衰老等生物活性;轮虫是良好的潜在抗衰老研究模式生物。本研究以褶皱臂尾轮虫(Brachionus plicatilis)作为实验对象,研究了不同浓度的大型海藻龙须菜抽提液(0,250,500,750,1000 mg/L)和不同浓度的食物(蛋白核小球藻和普通小球藻)对褶皱臂尾轮虫生命表参数的影响。结果表明:与对照组相比,食物浓度为1.0×10~6个/mL蛋白核小球藻时,不同浓度龙须菜抽提液对轮虫产卵数、平均寿命、净生长率以及世代时间有显著促进效应(P0.05);轮虫平均产卵数及寿命在龙须菜抽提液浓度750 mg/L处达到最高,分别为16只和13.9d(P0.05)。食物浓度为2.0×10~6个/mL普通小球藻时,轮虫平均产卵数和寿命在抽提液浓度为500 mg/L处达到最高,分别为16只和13.6d(P0.05),轮虫平均寿命和净生长率均有显著提高(P0.05)。相同龙须菜抽提液浓度下,食物浓度为1.0×10~6个/mL蛋白核小球藻下轮虫的净生长率、世代时间均显著高于食物浓度为2.0×10~6个/mL蛋白核小球藻培养的轮虫(P0.05);食物浓度为2.0×10~6个/mL时,普通小球藻培养轮虫的净生长率和世代时间均显著高于蛋白核小球藻实验组(P0.05)。交互作用分析显示,龙须菜抽提液与小球藻的交互作用对褶皱臂尾轮虫的内禀增长率有显著影响(P0.05)。研究结果表明,大型海藻龙须菜抽提液对褶皱臂尾轮虫的生长与生殖有促进作用,延长轮虫寿命。     

Suppression of Boll Weevil Infestations (Coleoptera: Curculionidae) Occurring on Fallow-Season Cotton in Southern Texas by Augmentative Releases ofCatolaccus grandis(Hymenoptera: Pteromalidae)

Augmentative releases ofCatolaccus grandis(Burks) were conducted in the Lower Rio Grande Valley of Texas in an attempt to suppress infestations of boll weevil,Anthonomus grandisBoheman, occurring in stands of “fallow-season” cotton (i.e., fields in violation of the 1 September stalk destruction deadline mandated by Texas law). In each of five release sites monitored during the study period (October, 1994–March 1995), augmentative releases ofC. grandiswere accompanied by an appreciable increase in the incidence of parasitized boll weevils (primarily third-stage larvae and pupae infesting abcised cotton squares) within a relatively brief time period. The relatively high incidence of host mortality caused byC. grandisin each release site was largely indispensible (i.e., would not have occurred in the absence of the parasite) and served to destroy significant numbers of immature boll weevils that appear to have been predisposed to successfully overwinter. The potential role of parasite augmentation in the management of the overwintering boll weevil population in southern Texas is discussed.     

The demography of native and non-native plant species in mountain systems: examples in the Greater Yellowstone Ecosystem

In mountainous areas, native and non-native plants will be exposed to climate change and increased disturbance in the future. Non-native plants may be more successful than natives in disturbed areas and thus be able to respond quicker to shifting climatic zones. In 2009, monitoring plots were established for populations of a non-native species (Linaria dalmatica) and a closely related native species (Castilleja miniata) on an elevation gradient in the Greater Yellowstone Ecosystem, USA. Population data were collected twice during the growing season for 3 years and used to calculate population vital rates for both species, and to construct population dynamics models for L. dalmatica. Linaria dalmatica vital rates were more associated with climatic/environmental factors than those of C. miniata. Population dynamics models for L. dalmatica showed no trend in population growth rate (λ) vs. elevation. The highest λ corresponded with the lowest vegetation and litter cover, and the highest bare ground cover. All populations with λ < 1 corresponded with the lowest measured winter minimum temperature. There was a negative association between λ and number of weeks of adequate soil moisture, and a weak positive association between λ and mean winter minimum temperature. Variance in vital rates and λ of L. dalmatica suggest broad adaptation within its current range, with the potential to spread further with or without future changes in climate. There is evidence that λ is negatively affected by persistent soil moisture which promotes the growth of other plant species, suggesting that it might expand further if other species were removed by disturbance.     

Two new species of Linaria section Linaria (Scrophulariaceae‐Antirrhineae) from Iran

Linaria azerbaijanensis and Linaria shahroudensis are described as new species from the Azerbaijan and Semnan provinces of Iran, respectively, belong to section Linaria.The new species are compared to their closest relative Linaria lineolata. Linaria azerbaijanensis differs from L. lineolata in having shorter bracts, a shorter corolla, shorter spur and smaller capsules and a different microsculpturing pattern of the testa cells. Linaria shahroudensis differs from L. lineolata in having shorter stems, shorter calyx‐lobes, a longer spur, a smaller capsule and a different microsculpturing pattern of the testa cells. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 734–742.     

Evaluation of the field impact of an adventitious herbivore on an invasive plant,yellow toadflax,in Colorado,USA

Although some introduced plants arrive into their new range without their generalist and specialist herbivores, for others, their herbivores arrive prior to, with, or after the introduction of the plant, reestablishing the link between natural enemies and invaders in the introduced range. Research documenting the effects of adventitiously introduced herbivores on their target plants in the introduced range, and the mechanisms by which those effects occur, can provide insight into potential biological weed control. We studied the effects of an accidentally introduced beetle Brachypterolus pulicarius on the growth and reproduction of its host, the invasive plant Linaria vulgaris (yellow toadflax), growing under field conditions across multiple years and sites in western Colorado, USA. We found that feeding by B. pulicarius on L. vulgaris was variable among 3 years (2002–2004) and across eight local sites. Part of the variation in damage was explained by ramet density; sites with greater ramet density experienced a higher proportion of damage. In an observational study across 2 years, damage was positively correlated with estimates of sexual reproduction, ramet growth, and clonal shoot production. However, opposite trends were observed in an experiment; damage by B. pulicarius decreased estimates of sexual reproduction. Differences between the results of the observational and experimental studies were likely driven by selective feeding by B. pulicarius on larger ramets. Nonetheless, the ability of B. pulicarius to control established L. vulgaris population growth remains uncertain under the environmental conditions we studied. In both the observational and experimental study, B. pulicarius did not affect L. vulgaris survival, and we found no evidence that established L. vulgaris populations were seed limited, suggesting that reductions in seeds may not translate into demographic changes in heavily infested populations. Interactions among insect foraging behavior, individual plant responses to damage, and the demographic consequences of seed input may help to explain the varying degrees to which herbivores affect plants and populations in this and other systems.     

Insecticidal action of Bauhinia monandra leaf lectin (BmoLL) against Anagasta kuehniella (Lepidoptera: Pyralidae), Zabrotes subfasciatus and Callosobruchus maculatus (Coleoptera: Bruchidae)

Bruchid beetle larvae cause major losses in grain legume crops throughout the world. Some bruchid species, such as the cowpea weevil (Callosobruchus maculatus) and the Mexican bean weevil (Zabrotes subfasciatus), are pests that damage stored seeds. The Mediterranean flour moth (Anagasta kuehniella) is of major economic importance as a flour and grain feeder; it is often a severe pest in flour mills. Plant lectins have been implicated as antibiosis factors against insects. Bauhinia monandra leaf lectin (BmoLL) was tested for anti-insect activity against C. maculatus, Z. subfasciatus and A. kuehniella larvae. BmoLL produced ca. 50% mortality to Z. subfaciatus and C. maculatus when incorporated into an artificial diet at a level of 0.5% and 0.3% (w/w), respectively. BmooLL up to 1% did not significantly decrease the survival of A. kuehniella larvae, but produced a decrease of 40% in weight. Affinity chromatography showed that BmoLL bound to midgut proteins of the insect C. maculatus. 33 kDa subunit BmoLL was not digested by midgut preparations of these bruchids. BmoLL-fed C. maculatus larvae increased the digestion of potato starch by 25% compared with the control. The transformation of the genes coding for this lectin could be useful in the development of insect resistance in important agricultural crops.     

Monitored releases of Rhinoncomimus latipes (Coleoptera: Curculionidae), a biological control agent of mile-a-minute weed (Persicaria perfoliata), 2004–2008

Mile-a-minute weed, Persicaria perfoliata (L.) H. Gross, is an invasive annual vine of Asian origin that has developed extensive monocultures, especially in disturbed open areas in the Mid-Atlantic region of the United States. A host-specific Asian weevil, Rhinoncomimus latipes Korotyaev, was approved for release in North America in 2004, and weevils have been reared at the New Jersey Department of Agriculture Beneficial Insect Laboratory since then. By the end of 2007 more than 53,000 weevils had been reared and released, mostly in New Jersey, but also in Delaware, Maryland, Pennsylvania, and West Virginia. The beetles established at 63 out of 65 sites (96.9%) where they were released between 2004 and 2007, with successful releases consisting of as few as 200 weevils. Weevils were recorded at 30 additional non-release sites in New Jersey, where they had dispersed at an average rate of 4.3 km/year. Standardized monitoring of fixed quadrats was conducted in paired release and control sites at eight locations. Significant differences in mile-a-minute weed populations in the presence and absence of weevils were found at three locations, with reduction in spring densities to 25% or less of what they had been at the start within 2–3 years at release sites, while weed densities at control sites were largely unchanged. Mile-a-minute weed populations at a fourth site were similarly reduced at the release site, but without control data for comparison due to rapid colonization of the paired control site. At the other four locations, all on islands, mile-a-minute weed populations were reduced at both release and control sites without large weevil populations developing, apparently due to environmental conditions such as late frost and extreme drought.     

The phylogenetic placement of the Leucogastrales, including Mycolevis siccigleba (Cribbeaceae), in the Albatrellaceae using morphological and molecular data

The morphology of many hypogeous fungi converges on a homogeneous reduced form, suggesting that disparate lineages are subject to a uniform selection pressure. The primary goal of this study was to evaluate the morphology and infer the phylogeny of the Leucogastrales with Mycolevis siccigleba using a Bayesian methodology. A comprehensive morphological assessment was used for an a priori phylogenetic inference to guide the sequencing effort. All structures except spore ornamentation pointed to the Albatrellaceae as the most likely sister taxon. Polyporoletus sublividus, a close relative of Albatrellus, produces ornamented basidiospores with a similar structure to M. siccigleba basidiospores. The ITS from 30 taxa was used for the molecular phylogenetic analysis. P. sublividus was found sister to Mycolevis. Leucophleps spinispora and L. magnata formed a group sister to the Polyporoletus/Mycolevis group, whereas Leucogaster was polyphyletic with respect to the core of the Leucogastrales and sister to A. caeruleoporus. This relationship was expected as previously undescribed chlamydospores produced by members of Albatrellus had a similar morphology to the basidiospores of L. rubescens.     

Life history of the Onopordum capitulum weevil Larinus latus (Coleoptera: Curculionidae)

The population structure and stage-specific survival of the capitulum weevil, Larinus latus, a potential control agent for weedy Onopordum thistles in Australia, was studied in its native range in Greece. Although fecundity of this univoltine insect was low (35.4 eggs/female), survival was relatively high, with 45% of eggs reaching adulthood when protected from predators and parasitoids, and 23% surviving when exposed to these natural enemies. Other mortality factors of importance for immature stages were a failure to establish, due largely to oviposition by females on inappropriate sites on the thistle capitula, and inter- and intraspecific competition for larval resources. Once emerged, adult losses due to overwintering mortality and net migration were estimated at a further 48%. Despite these losses there was a net doubling of the population at the study site between Onopordum flowering seasons. The data suggest that movement of adults occurs both within and between patches and that variability in population size relative to the resource base is low. Overall, L. latus may be considered a K-strategist which forms relatively stable populations over a fragmented habitat and which maintains its population integrity through a certain degree of annual redistribution. The implications of these data for the potential effectiveness of L. latus as a biological control agent of weedy Onopordum spp. are discussed.     

镇江香醋核心酿造微生物醋酸杆菌和乳酸杆菌共培养对生长代谢的影响

[目的]研究镇江香醋酿造过程核心功能微生物醋酸杆菌属与乳酸杆菌属菌株之间的相互作用关系.[方法]本文以分离到的镇江香醋酿造中的核心微生物2株醋酸杆菌和8株孔酸杆菌为研究对象,构建醋酸杆菌和乳酸杆菌共培养发酵体系,比较异位与原位条件下,纯培养及共培养中菌株的生长和代谢(包括还原糖、乙醇和总酸等含量)差异;采用GC-MS检...     

Dissemination of entomopathogenic fungi using Busseola fusca male as vector

The stem borer, Busseola fusca (Fuller), is an important pest of maize Zea mays L. and sorghum Sorghum bicolor (L.) in eastern and southern Africa. To control this pest, biological control methods including the use of entomopathogenic fungi are being considered. The pathogenicity of one isolate of Metarhizium anisopliae (Metsch.) Sorok. and one isolate of Beauveria bassiana Bals. (Vuill.) were first tested on different developmental stages of B. fusca including eggs, neonate, 2nd and 3rd-instar larvae. Both fungal isolates were pathogenic to all the stages tested. However, differences in mortality were observed among larvae that hatched from treated egg masses. Experiments were conducted thereafter to test whether B. fusca males could serve as a vector for fungal conidia to contaminate B. fusca females and subsequently eggs and larvae. Results demonstrated that B. fusca males successfully transferred inoculum to females during copulation, which in turn transmitted it to the eggs they laid on maize plants, resulting in the decrease of leaf damages.