Farmers’ perception of termites in agriculture production and their indigenous utilization in Northwest Benin

Background

Although termites are considered as agricultural pests, they play an important role in maintaining the ecosystem. Therefore, it matters to investigate the farmers’ perception of the impacts of the termites on the agriculture and their indigenous utilization.

Methods

A semi-structured questionnaire was used to interview 94 farmers through 10 villages of Atacora department, in the northwestern region of Benin, to obtain information for the development of successful strategies of termite management and conservation. Their perceptions on the importance and management of termites along with the indigenous nomenclature and utilization of termite mounds were assessed. Termite species identified by farmers were collected and preserved in 80% alcohol for identification.

Results

Eight crops were identified by farmers as susceptible to termites with maize, sorghum, and yam as being the most susceptible. According to farmers, the susceptibility to termites of these crops is due to their high-water content and sweet taste. A total of 27 vernacular names of termites were recorded corresponding to 10 species, Amitermes evuncifer, Macrotermes subhyalinus, and Trinervitermes oeconomus being the most damaging termite species. All the names given to termite species had a meaning. The drought was identified by farmers as the main factor favouring termite attacks. Demolition of termite mounds in the fields was the most commonly reported control method. Salt and other pesticides were commonly used by farmers to protect stored farm products. The lack of effective control methods is the main constraint for termite management. In northwestern Benin, farmers reported different purpose utilizations of termite mounds and termites.

Conclusions

The study has shown that farmers perceived termites as pests of several agricultural crops and apply various indigenous control practices whose efficiency need to be verified. Utilization of termites and termite mound soil as food and medicinal resources underlines the need for a more focused approach to termite control for the conservation of non-pest termite species. The sensitization of farmers on the importance of termites as well as the development of an integrated control method to combat termite pests proved necessary.

     

The Trojan horse approach for managing invasive ants: a study with Asian needle ants, <Emphasis Type="Italic">Pachycondyla chinensis</Emphasis>

Ants are among the most ecologically and economically significant biological invaders and are notoriously difficult to eradicate once established. Invasive ants are typically managed with toxic baits which are often unattractive to the target species, toxic to non-targets, and environmentally persistent. The current study evaluated a novel Trojan horse approach for managing invasive ants in natural habitats based on the use of poisoned prey. Eastern subterranean termites (Reticulitermes flavipes) were topically exposed to fipronil and presented to Asian needle ants (Pachycondyla chinensis) which are a significant invader in natural and disturbed habitats in the eastern United States. In laboratory assays, P. chinensis colonies were offered fipronil-treated termites within experimental arenas. The termites were readily attacked and consumed and results demonstrate that a single termite exposed to 25 ppm fipronil for 1 h is capable of killing 100 P. chinensis workers in 9 h. To evaluate population effects, field studies were conducted in forested areas invaded by P. chinensis. Fipronil-treated termites scattered on the forest floor provided rapid control of P. chinensis and ant densities throughout the treated plots declined by 98 ± 5 % within 28 days. I demonstrate that the poison baiting approach based on fipronil-treated termite prey is highly effective against P. chinensis and may offer an effective alternative to traditional bait treatments against other invasive ants, especially those with predatory and generalist feeding habits. Furthermore, I demonstrate that the poison baiting approach offers environmental benefits by delivering substantially less toxicant to the environment relative to current control methods which rely on commercial bait formulations. In summary, the poison baiting approach evaluated in this study appears highly suitable for controlling invasive ants and should be further tested against other invasive ants.     

Environmental and biological determinants of <Emphasis Type="Italic">Termitomyces</Emphasis> species seasonal fructification in central and southern Côte d’Ivoire

The Macrotermitinae subfamily is characterized by its symbiosis with fungi of the genus Termitomyces. The most common and presumably primitive mode of reproduction for these fungi is to produce basidiocarps on the mounds of the host termite colony. The seasonal fructification pattern of the fungi seems to depend on the habitat type and termite ecology. We examined Termitomyces diversity and distribution in two phytogeographic zones in central and southern Côte d’Ivoire. Data were collected in different habitats in exhaustive searches with standardized methods for termites and basidiocarps as well. The respective findings were complemented with behavioral and life cycle data of the associated termite species. Basidiocarps occur species-specifically either during the long or the short rainy season in wooded habitats. The diversity and abundance of termites and their associated basidiocarps were significantly correlated only with woody plant species richness. Nuptial flight of termites, comb biomass and Termitomyces fructification periods were correlated. Termitomyces appear to fructify during (1) the period of strong precipitation, (2) in habitats with appropriate microclimatic characteristics.     

Interspecific Agonistic Behavior of <Emphasis Type="Italic">Macrotermes gilvus</Emphasis> (Isoptera: Termitidae): Implication on Termite Baiting in the Philippines

The study investigated interspecific agonistic behavior of Macrotermes gilvus Hagen (Isoptera: Termitidae: Macrotermitinae) against three economically important subterranean termites in the Philippines, viz., Coptotermes gestroi Wasmann, Nasutitermes luzonicus Oshima and Microcerotermes losbanosensis Oshima. Termite-termite interactions after a 1:1 pairing experiment showed that M. gilvus workers and soldiers were highly aggressive against C. gestroi, N. luzonicus and M. losbanosensis leading to severe injury or death of the opponent termite species in a short period of time. The levels of agonism were caste and species specific. Worker termites of M. gilvus showed an equally aggressive behavior as soldiers contributing to the high mortality of opponent species used in this study. It is likely that the highly aggressive behavior of M. gilvus limits foraging activity of C. gestroi, N. luzonicus and M. losbanosensis around in-ground bait stations contributing to the low success of termite baits containing chitin synthesis inhibitors in the Philippines.     

Exploring virulence of new and less studied species of <Emphasis Type="Italic">Metarhizium</Emphasis> spp. from Brazil for two-spotted spider mite control

The two-spotted spider mite Tetranychus urticae is an important pest of strawberry crops in Brazil and many other countries. Focus for biocontrol studies involving entomopathogenic fungi has been on three species from the genus Metarhizium: M. anisopliae sensu stricto (s.s.), M. brunneum and M. robertsii. Also, the species Beauveria bassiana has been studied for spider mite control and one isolate (ESALQPL63) is commercially available in Brazil. New and undescribed Metarhizium species have been found recently in Brazil and provide a pool of isolates with potential for biocontrol in Brazil and probably also elsewhere. The mortality of adult females of T. urticae when exposed to four new Brazilian species of Metarhizium was compared to the mortality when exposed to M. anisopliae s.s., M. brunneum, M. pingshaense, M. robertsii and Beauveria bassiana ESALQPL63. Fungal suspensions were sprayed onto mites at 10⁷ conidia/mL with 0.05% Tween 80 in laboratory bio-assays. We measured total mortality and percentage sporulating cadavers 10 days after exposure and calculated median lethal time (LT₅₀). The lowest LT₅₀ (4.0 ± 0.17) was observed for mites treated with Metarhizium sp. Indet. 1 (ESALQ1638), which also performed well with respect to mortality after 10 days and capacity to sporulate from cadavers. Among the other little studied species tested, M. pingshaense (ESALQ3069 and ESALQ3222) and Metarhizium Indet. 2 (ESALQ1476) performed well and were comparable to B. bassiana (ESALQPL63). The new Metarhizium isolates and species thus showed potential for biological control.     

Termite diversity along a land use intensification gradient in a semi-arid savanna

Disturbance, particularly agricultural expansion is one of the major threats to the biodiversity and ecological functions of tropical and sub-tropical ecosystems. In this regard, we examined changes in the species richness, abundance, and diversity of termites across different disturbance treatments in a sub-tropical semi-arid savanna in south eastern Zimbabwe. Nine transects (100?×?2 m) representing three habitat disturbance treatments (primary woodland; grazing area; agricultural field) were sampled for termites using a rapid biodiversity assessment protocol. Termites were more abundant and species-rich in primary woodland and grazing area than in the agricultural field. Twelve termite species from three sub-families were present, with Microtermes sp. constituting 35% of the identified termite species. Termite feeding group structure differed significantly among land-use types, and of all termites present, wood-feeding termites were the most abundant while soil-feeders were rare in the agricultural field. In conclusion the observed pattern in termite species richness and relative abundance indicates that termites are very resilient to natural disturbance and might actually benefit from some natural disturbances like they did in the grazing area of this study, but they are not resilient to extreme anthropogenic disturbance. Although there was no notable difference in termite species richness and relative abundance between agricultural field and primary woodland, the pattern observed across the three sites may be potential support for the IDH suggesting that intermediate levels of physical disturbance intensity influence the structure and functioning of termite assemblages in semi-arid savanna.     

Hand Preference for a Novel Bimanual Coordinated Task During Termite Feeding in Wild Western Gorillas (<Emphasis Type="Italic">Gorilla gorilla gorilla</Emphasis>)

Although the level of handedness in humans varies cross-culturally, humans are generally described as right-handed, which has been considered a uniquely human trait. Recently, captive chimpanzees (Pan troglodytes) have been shown to exhibit right-hand preference when performing bimanual but not unimanual tasks. Less clear is whether this pattern also occurs in wild chimpanzees and other African apes. Using videos (N = 49) of six wild western gorillas (Gorilla gorilla gorilla) feeding on termites at the Mondika Research Center (Republic of Congo), we tested whether they exhibit hand preference when performing unimanual, i.e., reaching for termite mound pieces; bimanual, i.e., “termite tapping”: rhythmically shaking a piece of termite mound with the dominant hand and collecting the termites in the other hand tasks; or hand transfer prior to bimanual tasks, i.e., transferring a piece of termite mound from one hand to the other. All individuals exhibited exclusive hand preference when performing the bimanual tasks, with five of six gorillas preferring the right hand. Conversely, most individuals did not show any manual preference during the unimanual task. In addition, hand preference during hand transfer revealed clear hand dominance of similar strength and direction of those shown for the bimanual task, suggesting that this measure is as sensitive as the bimanual task itself. Thus, we propose “termite feeding” as a novel task to be considered in future hand-preference studies in wild western gorillas. Our results are in concordance with those for chimpanzees and captive gorillas showing hemispheric specialization for bimanual actions in apes.     

Review of bees as guests in termite nests,with a new record of the communal bee, <Emphasis Type="Italic">Gaesochira obscura</Emphasis> (Smith, 1879) (Hymenoptera,Apidae), in nests of <Emphasis Type="Italic">Anoplotermes banksi</Emphasis> Emerson, 1925 (Isoptera,Termitidae, Apicotermitinae)

Associations between bees and termites are documented infrequently, but records are available for bee species ranging in behavior from solitary to highly eusocial. The subtribe Meliponina (stingless bees) is the most common bee group reported in termite nests, and, for some species, the occupancy of termite nests may be obligatory. The records of solitary bees nesting within termite nests include species of the tribes Emphorini, Centridini, Megachilini, and Paracolletini. Most of these bees can probably nest in other substrates, and their relationships with termite nests are presumably opportunistic. This study provides a review of published records of bees as guests in termite nests, and also describes the aggregation of nests of Gaesochira obscura within one nest of Anoplotermes banksi in Brazilian Amazonia. One termite nest contained at least ten nest entrances of G. obscura, with burrows 4–6 mm in diameter and about 10 cm long. Each burrow ended in brood cells in different stages of food provisioning and larval development. As commonly reported for other associations of this nature, there was no connection between the tunnels of bees and those of termites. This record adds important data on the biology of A. banksi. Because this is a single record, it is impossible to classify G. obscura either as a termitophile or termitariophile; this species may be opportunistic in relation to nesting substrate.     

Clavicipitaceous entomopathogens: new species in <Emphasis Type="Italic">Metarhizium</Emphasis> and a new genus <Emphasis Type="Italic">Nigelia</Emphasis>

In several surveys in the tropical forests in Thailand, specimens that looked morphologically similar to Metarhizium martiale and Cordyceps variegata, as well as other Metarhizium species were collected and cultured in vitro. A combined phylogeny of several genes including the small (18S) and large (28S) subunits of the ribosomal DNA, elongation factor 1-α (TEF), RNA polymerase II subunits 1 and 2 (RPB1, RPB2) genes has shown these to be new taxa in the Clavicipitaceae. Nigelia is described as a new genus closely related to Metarhizium, to the scale insect pathogens Aschersonia (Hypocrella), Samuelsia and Moelleriella, and to plant pathogens in Claviceps and Balansia, and other relatives. Nigelia comprises M. martiale and a new species Nigelia aurantiaca, which has been found infecting lepidopteran larvae and which produces pseudoimmersed, obliquely arranged, obpyriform perithecia with curved or bent ostioles and with whole (non-separating) cylindric ascospores. Metarhizium chaiyaphumense, M. kalasinense, M. prachinense, M. samlanense, and M. takense are described as new species of Metarhizium. Metarhizium martiale is transferred to Nigelia, and Paecilomyces reniformis is transferred to Metarhizium.     

Potential spread of the invasive North American termite, <Emphasis Type="Italic">Reticulitermes flavipes</Emphasis>, and the impact of climate warming

Reticulitermes flavipes is an invasive termite from North America that is found in several European countries, including France from north to south. It feeds on several timber species and can cause major damage when it infests lumber. Termites are urban pests: they are often found in and around towns and their expansion is closely linked to human activity. Although, by law, termite infestations must be reported and treated, R. flavipes continues to spread. To better identify areas that may soon be colonized, it is crucial to understand the mechanisms underlying the termite’s spread at a fine spatial scale. However, the complexity of the species’ dispersal dynamics (i.e., via swarming, budding, or human-mediated transport of infested material) and social organization render this process difficult. The goal of our study was to determine R. flavipes’ potential to expand its current range within a region of France: Centre-Val de Loire. We focused on one administrative department within the region—Indre and Loire—where infestations are common and data on termite presence date back to the 1980s. We developed a spatiotemporal model to study the growth and dispersal of termite colonies within favorable habitat. Habitat favorability was defined based on the density of urbanization and annual mean minimum temperature. First, we modeled temporal population dynamics, using biological parameters describing the transitions between life stages/castes within colonies; we could thus estimate alates production. Then, using this information, we modeled termite dispersal within favorable habitat, and determined the termite’s potential spread. We validated the results by comparing the model’s output with actual data on the termite’s range expansion between 1985 (when the termite was first observed in the region) and 2013. Finally, the model was used to predict the termite’s future spread given climate warming for the period from 2013 to 2030. The results show that an increase in temperature should increase the amount of favorable habitat and, as a consequence, termites could continue to spread within this region. In addition to continuing current control efforts, it will be necessary to enact preventative strategies in newly favorable habitat. In these areas, monitoring efforts should therefore be intensified, as they might be able to slow down the termite’s spread and limit its impact.     

Genotoxic effects of pesticide fipronil in somatic and generative cells of mice

The pronounced genotoxic effect of fipronil in all used doses (4.75, 9.50, 19.00, and 31.70 mg/kg) at a single exposure in the liver, lungs and spleen was ascertained by the Comet assay. Organ specificity of genotoxic effects of the pesticide was revealed. The liver was the most sensitive to fipronil. Fipronil at a dose of 9.50 mg/kg in a single and repeated exposure (within 10 days) induced aberrations in mouse bone marrow cells with the frequency exceeding the spontaneous mutation rate (p < 0.01 and p < 0.001, respectively). Fipronil also showed genotoxic activity in the germ cells of the experimental animals, causing abnormalities of the structure of synaptonemal complexes in the spermatocytes.     

Physiological and phylogenetic variability of Mexican <Emphasis Type="Italic">Metarhizium</Emphasis> strains

Metarhizium Sorokin is a wide spread entomopathogenic fungal genus that is also a root symbiont and some isolates may be potentially useful in agriculture applications. Physiological variations applicable in biological control have not been fully evaluated in Mexican strains. This study identified 30 strains from different insect hosts and states of Mexico selected because they represent the main sugar cane and corn plantations of the country. Their thermotolerance profiles (8, 15, 28 and 35 °C), insect virulence (LT50 in Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae) larvae), possible association with plant roots, and phylogenetic placement (using 5′TEF, IGS sequence information, and RFLP analysis) were assessed. Results showed no cold-active strains and most showed restricted growth at 35 °C. Insect virulence bioassays against G. mellonella showed highly virulent strains. Most of the strains showed an ability to associate with roots of Phaseolus vulgaris (Burkart) (Fabales: Fabaceae). RFLP analysis with 5′TEF and Pr1 revealed three distinct genetic groups. Phylogenetic analysis identified the 30 strains as Metarhizium anisopliae. (Metchnikoff) Sorokin, M. robertsii (J.F. Bisch., Rehner & Humber), M. guizhouense (Q. T. Chen & H. L. Guo), or M. pinghaense (Q.T. Chen & H.L. Guo), as well as two strains that belong to a new clade (Metarhizium sp. indet. 1). These data demonstrate the complexity of Metarhizium species and the need to study their physiological and phylogenetic aspects for a more adequate assessment of their potential use in agricultural systems.     

Photochemical studies on the binding of an organic fluoride to bovine serum albumin

The interaction of fipronil (FPN), a pesticide containing fluorine, to bovine serum albumin (BSA) was studied by spectroscopy including fluorescence spectra, UV–Visible absorption, scattering spectra, circular dichroism (CD) spectra, synchronous and three-dimensional fluorescence spectra. The number of binding sites n and observed binding constant Kb was measured by fluorescence quenching method. The thermodynamic parameters ΔH, ΔG, ΔS at different temperatures were calculated and the results indicate that hydrophobic forces played major role in the reaction. The distance r between donor (BSA) and acceptor (FPN) was obtained according to the Förster theory of non-radiation energy transfer. The structural change of BSA molecules with addition of FPN was analyzed and the results may be helpful to biologists, chemists and therapeutists.     

Toxicity, uptake, and transfer efficiency of fipronil in western subterranean termite (Isoptera: Rhinotermitidae)

The potential horizontal transfer ofnonrepellent termiticides has become an important paradigm to control termites in recent years. In this study, 14C-radiolabeled fipronil was used in a series of laboratory experiments to demonstrate the extent and ability of termites to transfer lethal amounts of fipronil to unexposed nestmates. Fipronil is an active and nonrepellent termiticide against western subterranean termites, Reticulitermes hesperus Banks, on sand at relevant doses. It exhibited delayed toxicity with the lowest LD50 approximately 0.2 ng/termite expressed between day 4 and 7. Both continuous and brief exposures to fipronil-treated sand seriously impaired the termite's ability to move and respond to a dodecatrienol trail, limiting potential horizontal transfer. In tunneling studies, fipronil prevented termite tunneling at concentrations as low as 0.5 ppm and was nonrepellent even at 500 ppm. Greater than 90% mortality was recorded by day 7 with concentrations ranging from 0.5 to 500 ppm. There was a linear relationship between the time of exposure and uptake of [14C]fipronil when termites were continuously exposed to 0.5, 1.0, and 5.0 ppm for 24 h. However, uptake discontinued when the termites were immobilized. Maximum transfer of fipronil from donors to recipients occurred within the first 24 h. Fipronil was transferred by body contact and trophallaxis did not play a major role in horizontal transfer. In successive transfer studies, there was not enough fipronil on recipients for them to serve as secondary donors and kill other termites. In a linear arena study, there was an inverse relationship between the amount offipronil on dead termites and their distance from the treated zone. Maximum mortality was observed within 1.5 m from the treated zone. Results in our laboratory studies suggest that horizontal transfer was not a major factor contributing to the efficacy of fipronil in the field.     

The Predation Strategy of the Recluse Spider <Emphasis Type="Italic">Loxosceles rufipes</Emphasis> (Lucas, 1834) against four Prey Species

Generalist predators have to deal with prey with sometimes very different morphologies and defensive behaviors. Therefore, such predators are expected to express plasticity in their predation strategy. Here we investigated the predatory behavior of the recluse spider Loxosceles rufipes (Araneae, Sicariidae) when attacking prey with different morphologies and defensive mechanisms. We expected L. rufipes to show different prey capture strategies and variable acceptance towards each prey type. Potential prey species were collected directly from the web or in the surroundings of the web-building site of L. rufipes. We collected and used the following in our experiments: termite workers (Nasutitermes sp.), lepidopteran larvae (Eurema salome), ants (Camponotus sp.) and isopods (Tylidae). We paired these prey with L. rufipes and recorded their behavior in captivity, quantifying acceptance rate, immobilization time and the sequence of behaviors by the predator. The acceptance rate was lower for isopods but not different among other prey. The immobilization time was higher for isopods than for termites and similar for the other pairwise comparisons. The behavioral sequence was similar for all prey except for isopods, which were also bit more often. Our combined results show plasticity in the behavior of L. rufipes and also show it subdues a potentially dangerous prey (ant) and an armored prey (isopod).     

Preventive application of an entomopathogenic fungus in cover crops for wireworm control

Efficacy of the Metarhizium brunneum Petch (Hypocreales: Clavicipitaceae) strain ART2825 for control of wireworms (Agriotes obscurus (L.), Coleoptera: Elateridae) was examined in a semi-field pot experiment. Pots were treated in late summer during sowing of spring oat as a cover crop. Survival of wireworms was assessed four weeks after their release in October 2013, and 30 weeks after release in April 2014. Viability and persistence of the fungus was determined by counting colony forming units from substrate samples and microsatellite analyses of recovered Metarhizium isolates. The number of colonies detected in the substrate in October 2013 increased with increasing concentrations of applied conidia, and no significant reduction was observed at the second evaluation date in April 2014. Increasing conidia application rates significantly increased mycosis and reduced wireworm survival, to a level comparable to that of treatment using insecticide-coated oat seeds. The preventive application of M. brunneum conidia to reduce wireworm populations in cover crops, preceding a damage-sensitive crop like potatoes, may be a promising biocontrol strategy.     

Laboratory bioassays and field-cage trials of <Emphasis Type="Italic">Metarhizium</Emphasis> spp. isolates with field-collected Mormon crickets (<Emphasis Type="Italic">Anabrus simplex</Emphasis>)

The Mormon cricket (MC) is an important pest in the western United States. This study evaluated the virulence in the laboratory of 32 isolates of Metarhizium spp. towards field-collected MCs. Additionally, four isolates were tested in outdoor field-cage studies. All 32 Metarhizium isolates were pathogenic towards the MC (could induce some mortality in the laboratory), including four isolates of the grasshopper-specialist species M. acridum. Virulence varied considerably among the isolates. Field studies, conducted in 2008–2009, showed a statistically significant effect of fungal treatments in both years. Pairwise comparison of the survival curves, however, revealed that, in 2008, three of the isolates did not differ statistically from the non-fungus control treatment. In 2009, all three of the isolates tested had significantly lower survival rates than the control treatment: MCs exposed to M. robertsii isolate DWR 346 had the lowest survival with a LT₅₀ of 16 days. We hypothesize that the poor field performance resulted from a combination of negative environmental effects and isolate selection, and propose that further field studies with additional isolates are needed to identify an efficacious fungal agent for MC biocontrol.     

The influence of climate on patterns of termite eating in Australian mammals and lizards

Abstract The present paper examines patterns of termite eating in Australian mammals and lizards (total numbers of species, volume percentage of diet) relative to climate (arid, semi-arid, temperate-mesic). Most termite eaters in arid and semi-arid Australia are lizards. Termite consumptio as a proportion of total lizard diet decreases from arid to mesic climates. More mammal species are relatively termite specialized (>50%) in arid than in semi-arid and mesic regions. Termite consumption in echidnas resembles that of the lizards: relatively high in the arid and relatively low in the mesic zone. For the Dasyuridae, termites comprise only a minor fraction (< 10%) in their diet, irrespective of climate. It is argued that the climatic peculiarities of inland Australia (scant and variable rainfall) cause marked seasonality in termite availability, supporting specialized termite eaters in only the most energy-frugal forms (lizards, echidnas). Areas of future research are identified.     

Effect of entomopathogenic fungus <Emphasis Type="Italic">Metarhizium robertsii</Emphasis> on non-target organisms,water bugs (Heteroptera: Corixidae,Naucoridae, Notonectidae)

The influence of the fungus Metarhizium robertsii Bischoff, Rehner and Humber on the mortality of four water bug species, Cymatia coleoptrata (Fabricius), Sigara assimilis (Fieber), Ilyocoris cimicoides cimicoides (Linnaeus), and Notonecta reuteri Hungerford, and bloodsucking mosquito Anopheles messeae Falleroni, was investigated under various concentrations of conidia and different treatment types. We found that the mortality of adults of the water bug species was similar or higher than that of A. messeae, with C. coleoptrata and S. assimilis being more susceptible to M. robertsii than N. reuteri, I. c. cimicoides, and the mosquito A. messeae. Treatment with dry conidia at concentrations of 5 × 10⁴ and 5 × 10⁵ conidia/ml caused higher mortality of the water bug species than did treatment at the same concentrations with conidia in an aqueous suspension. In contrast, higher concentrations (5 × 10⁶ conidia/ml) led to higher mortality after treatment with the aqueous suspension, relative to treatment with dry conidia. Our studies showed that water bugs exhibited the classical development of a mycosis with hemocoel colonization, mummification, and conidia formation on cadavers directly on the surface of the water. Possible changes in invertebrate communities in aquatic ecosystems after treatment with Metarhizium are discussed.     

<Emphasis Type="Italic">Metarhizium bibionidarum</Emphasis> and <Emphasis Type="Italic">M. purpureogenum</Emphasis>: new species from Japan

Two new species of Metarhizium, M. bibionidarum and M. purpureogenum are described from Japan. Metarhizium bibionidarum is the phylogenetic sister species of M. pemphigi and a member of the M. flavoviride species complex. It is distinguished morphologically from M. pemphigi by its larger conidia. The species is based on a collection of an infected March fly larva (Diptera: Bibionidae) but is also known to occur on fruit beetle (Coleoptera: Scarabaeidae) encountered in France. Metarhizium purpureogenum was isolated from soil by plating and insect baiting methods and represents a unique phylogenetic lineage placed outside the M. anisopliae and M. flavoviride species complexes. Three isolates of M. purpureogenum excreted a distinctive red-purple pigment into agar medium when co-cultured with M. robertsii or Aspergillus oryzae.