Terebrospira chattoni sp. n., a Parasite of the Endocuticle of the Shrimp Palaemonetes pugio Holthuis*

SYNOPSIS. Terebrospira chattoni sp. n. may be a species in transition between ectosymbiosis and endosymbiosis. It penetrates the epicuticle of Palaemonetes pugio and feeds on the endocuticle by dissolving galleries through it and absorbing the products of dissolution. Although similar in some respects to species of the endosymbiotic apostome genus Synophrya, T. chattoni is clearly related to ectosymbiotic apostomes that feed on exuvial fluid. However, instead of stimulating the metamorphosis of a phoront to a trophont, the host's ecdysis stimulates T. chattoni to metamorphose from a dedifferentiated trophont with 13 meridional kineties to a protomont, a predivision stage with 10 spiralled kineties. The protomont encysts and dedifferentiates to the division stage, an orthotomont with 13 kineties, either on the new exoskeleton before ecdysis, within a chamber in the endocuticle of the old exoskeleton, or on a substrate away from the host and the molt. The site of division determines the product of the division. On the new exoskeleton, the tomites in the reproductive cyst secrete walls around themselves thereby forming the lenticular, compartmented cysts characteristic of Terebrospira. Each daughter tunnels out of its compartment into the endocuticle. Although its infraciliature remains undifferentiated like that of the orthotomont, the ciliate in the gallery is the trophont, the only feeding stage in the life cycle. Daughters originating from the division of the orthotomont in a chamber in the endocuticle swim out of the exoskeleton at ecdysis. encyst on the substrate, and presumably form tomites. When the protomont itself leaves the molt, it encysts on the substrate and divides to form daughter cells with a rosette and the pattern of ciliature of the conventional tomite of other apostome genera. Tomites carry the infection to new hosts while compartmented cysts insure that the original host retains the infection. Terebrospira chattoni is always astomatous, although a dedifferentiated oral ciliature appears in the orthotomont and persists in the trophont. Terebrospira chattoni sp. n. is separated from T. lenticularis Debaisieux the other species in the genus because the latter species may divide outside a cyst and because T. chattoni has an extra reproductive stage in its life cycle.     

Host plant acceptance by the phytophagous mite Tetranychus kanzawai Kishida is affected by the availability of a refuge on the leaf surface

We used 11 wild plants to experimentally test the effects of leaf trichomes and leaf quality on host plant acceptance by a phytophagous spider mite, Tetranychus kanzawai, in the absence of predators. There was a positive correlation between leaf hair traits (height/density) and host plant acceptance. We used two model plants (Phaseolus vulgaris and Phaseolus lunatus; the former had higher and denser leaf hairs than the latter) to examine the effects of leaf hairs on the dispersal and fecundity of T. kanzawai in the presence of a predatory mite, Neoseiulus womersleyi. In the presence of N. womersleyi, significantly fewer T. kanzawai females dispersed from a P. vulgaris leaf than from a P. lunatus leaf. Moreover, in the presence of the predator the fecundity of T. kanzawai females on P. lunatus was significantly lower than on P. vulgaris, although in terms of host quality the two plants were equivalent. In the presence of N. womersleyi, T. kanzawai females on P. vulgaris spent more time on webs than those on P. lunatus. Moreover, webs seemed to be less accessible than leaf surfaces to the predator. These results suggest that leaf hairs provide a refuge for T. kanzawai adult females.     

Attachment of bean rust cell wall material to host and non-host plant tissue

A preparation of bean rust (Uromyces phaseoli) germ tube walls, consisting of short, filamentous particles, was labeled with fluorescein iso-thiocyanate. Freeze sections of host and non-host tissue were incubated in the labeled preparation. Maximum staining was observed in host plant tissue (Phaseolus vulgaris), in which bean rust regularly forms haustoria. In tissue of the non-host plantsVigna sinensis andPhaseolus lunatus, where fewer haustoria were formed, staining was only weak. However, no staining was observed in the non-host tissue ofPhaseolus aureus, Helianthus annuus, Brassica oleracea andHordeum vulgare in which the infection hypha did not form haustoria. This would appear to indicate that formation of haustoria is induced by a specific attachment of the hyphal wall to the host wall. The possibility that elicitors attach in a similar way, is discussed.Abbreviations FITC Fluorescein iso-thiocyanate - cv cultivar     

The role of the antennae and maxillary palps in mediating food preference by larvae of the tobacco hornworm, Manduca sexta

The role of antennae and maxillary palps in mediating food preferences by Manduca sexta (Johan.) (Lepidoptera: Sphingidae) was examined. Fifth‐instar larvae, having different chemosensory organs remaining after microsurgery, were tested in two‐choice feeding assays using three solanaceous host species Lycopersicon esculentum (Mill.), Datura innoxia (Mill.), and Solanum pseudocapsicum (L.), an acceptable non‐host Raphanus sativus (L.) (Cruciferae), and an unacceptable non‐host Pelargonium hortorum (L.H. Bailey) (Geraniaceae). Larvae had a choice between leaf discs of two plant species or between one species and moist filter paper discs (water). The antennae are fully competent in mediating normal (unimpaired) food preferences for S. pseudocapsicum vs. water and P. hortorum vs. water. Thus, the antennae alone can mediate both acceptance and rejection behaviour. The latter is the first report of such a function in M. sexta. The antennae are partly competent (reduced preference) for S. pseudocapsicum vs. P. hortorum. No antennal competence could be demonstrated using the other plant species tested. The antennae alone are either partly needed (R. sativus vs. water) or not necessary to elicit normal food preferences for the plant species tested. The maxillary palps are fully competent in mediating normal food preference for S. pseudocapsicum vs. water, and D. innoxia vs. water. The palps are partly competent for S. pseudocapsicum vs. P. hortorum and incompetent for the other plant species tested. Thus, the maxillary palps alone could only mediate acceptance behaviour in this study. The need of the maxillary palps in normal food preferences could not be demonstrated. Interestingly, the maxillary palps alone can mediate food preferences for two normally rejected plants, R. sativus and P. hortorum. Similar results are reported for two other non‐host plant species, Vigna unguiculata (Walp.) (Leguminosae) and Vinca rosea (L.) (Apocynaceae). Perhaps, the maxillary palps inform M. sexta mostly about feeding stimulatory chemicals common to most plant species.     

Variation in pathogenicity among isolates of Elsinoe phaseoli from Phaseolus species

Expanding primary leaves of 11 cultivars of Phaseolus vulgaris, and one each of Phaseolus coccineus, Phaseolus lunatus and Vigna unguiculata were inoculated with 23 isolates of Elsinoe phaseoli from Phaseolus spp. and one from Vigna unguiculata. On the basis of the macroscopic and microscopic appearance of the lesions, symptoms were placed into five classes. Spore yields from the lesions in each class were used to classify the types of lesions as representing resistance or susceptibility to each isolate. There was a differential response of cultivars to isolates. According to the reaction of five cultivars of P. vulgaris to infection, isolates were placed in four pathogenicity groups. In addition to the differential reaction of cultivars, there was some evidence of host specificity among the isolates. Thus, P. lunatus was susceptible to most of the P. vulgaris isolates but resistant to the ones from P. coccineus. Vigna unguiculata was susceptible only to the V. unguiculata isolate and was resistant to all the isolates from Phaseolus spp. The isolate from V. unguiculata failed to infect any of the bean cultivars or the other Phaseolus spp. The need to select suitable isolates for challenging cultivars in a breeding programme is stressed.     

Laboratory study of the grass shrimp feeding preferences

Grass shrimps are very common in various aquatic habitats, and are generally considered omnivorous. But, despite the numerous studies on interspecific trophic interactions, few studies have evaluated their feeding strategy, especially by experimental approaches.In this study, we determined, in the absence of both intra and interspecific competitive interactions, the feeding preferences of the freshwater grass shrimp Palaemonetes antennarius for the most common potential resources in its habitat. Plant and animal items were offered as food to each adult shrimp in multiple-choice laboratory experiments. Resource selection was determined under conditions of low and high food availability and related to the shrimp body size. The role of microbial colonisation in favouring detritivory was also investigated.Results of these experiments showed that P. antennarius consumed only animal items, mostly preferring the isopod Proasellus coxalis. In addition, palatability of the unselected plant remains and non-living prey was not improved by the microbial enrichment. Shrimps also resorted to cannibalism at low ration. By contrast, at high ration they specialised on a narrower range of resources, directing more their feeding efforts towards isopods. The preference ranking of the selected food types was inversely related to the average mass of the prey and varied with the shrimp body size. In particular, the number of live isopods in the diet increased exponentially with the shrimp mass at food high ration, which resulted not to be limiting. In conclusion, food availability influences the food niche of P. antennarius whose feeding strategy in the laboratory is facultative specialisation on dead and live animals rather than omnivory. Ease of handling and/or capture seems to play a role in the food preference ranking.     

Characterization of the exoskeleton of the Antarctic king crab Paralomis birsteini

Ocean acidification is projected to inhibit the biogenic production of calcium carbonate skeletons in marine organisms. Antarctic waters represent a natural environment in which to examine the long‐term effects of carbonate undersaturation on calcification in marine predators. King crabs (Decapoda: Anomura: Lithodidae), which currently inhabit the undersaturated environment of the continental slope off Antarctica, are potential invasives on the Antarctic shelf as oceanic temperatures rise. Here, we describe the chemical, physical, and mechanical properties of the exoskeleton of the deep‐water Antarctic lithodid Paralomis birsteini and compare our measurements with two decapod species from shallow water at lower latitudes, Callinectes sapidus (Brachyura: Portunidae) and Cancer borealis (Brachyura: Cancridae). In Paralomis birsteini, crabs deposit proportionally more calcium carbonate in their predatory chelae than their protective carapaces, compared with the other two crab species. When exoskeleton thickness and microhardness were compared between the chelae and carapace, the magnitude of the difference between these body regions was significantly greater in P. birsteini than in the other species tested. Hence, there appeared to be a greater disparity in P. birsteini in overall investment in calcium carbonate structures among regions of the exoskeleton. The imperatives of prey consumption and predator avoidance may be influencing the deposition of calcium to different parts of the exoskeleton in lithodids living in an environment undersaturated with respect to calcium carbonate.     

Interspecific hybridization of phaseolus vulgaris with P. lunatus and P. acutifolius

Summary The influence of genotypic combinations on the growth of hybrid embryos between Phaseolus vulgaris and P. lunatus, and between P. vulgaris and P. acutifolius was examined. All embryos obtained from P. vulgaris × P. lunatus crosses developed only to a stage which appears to be comparable to the pre-heart-shape stage of selfed embryos. Reciprocal crosses were attempted, but pods abscised at a very early stage. Embryos derived from P. vulgaris × P. acutifolius and reciprocal crosses attained the cotyledon stage although no mature seeds were formed. A distinct characteristic of these embryos was the uneven development of the two cotyledons. The rate of growth and final size of these hybrid embryos seemed to be influenced by the genotypes of both parents.Immature embryos were cultured on defined medium and the effects of glutamine and gibberellin (GA₃) were examined. Glutamine was effective in increasing the survival rate; gibberellin had no apparent effect. Plants derived from cultured embryos of P. vulgaris × P. lunatus, P. vulgaris × P. acutifolius and P. acutifolius × P. vulgaris were obtained.Technical paper No. 00 of the Oregon Agricultural Experiment Station. Research was supported by the Oregon Agricultural Experiment Station, the Research Council of Oregon State University (National Institute of Health Biomedical Research Support Grant RR07079) and the Processor Research Council of Oregon. A.R. is supported by an African Graduate Fellowship from the African-American Institute     

Reproduction and oviposition preferences of Zabrotes subfasciatus stocks reared from two host plant species

The reproductive activity of a specialist bruchid (Zabrotes subfasciatus Boh., Coleoptera) was studied in two beetle stocks obtained from the same area. The first was harvested on the insect's wild host plant, Phaseolus lunatus L. The second was collected on a cultivated host plant, P. vulgaris L.Within each of the two insect stocks, fecundities and ovarian productions were similar whether females were offered seeds of the host plant on which they completed their larval development or an alternative host. When given the choice of host plants, females of both stock oviposited preferentially on P. vulgaris. The substrate used for larval development did not influence the choice of subsequent oviposition sites.There appears to be no behavioural or physiological barriers preventing a single population of Z. subfasciatus from reproducing on both wild and cultivated host plants where they grow together.

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Reproduction et choix du lieu de ponte de Zabrotes subfasciatus en présence de plantes hôtes sauvages et cultivées

Résumé L'activité reproductrice d'un insecte spécialiste (Zabrotes subfasciatus) est étudiée sur deux lots d'individus provenant de la même zone. Le premier a été récolté sur une plante hôte sauvage de l'insecte, Phaseolus lunatus L., et le deuxième sur une plante hôte cultivée, P. vulgaris L.La fécondité, la production ovarienne et les préférences d'oviposition des femelles en présence de graines de P. lunatus ou de P. vulgaris ou en présence de graines des deux plantes hôtes sont analysées séparément pour chaque lot.En présence de graines de l'une ou de l'autre plante hôte (absence de choix du lieu de ponte) les fécondités et productions ovariennes des femelles de chacun des lots sont comparables. Par contre, lorsqu'on leur donne le choix de pondre sur les deux plantes hôtes, les femelles pondent préférentiellement sur P. vulgaris. Le substrat utilisé pour le développement larvaire n'influence pas le choix du lieu de ponte.Il n'y a donc pas d'obstacle physiologique ou comportemental empêchant Z. subfasciatus de se reproduire sur ces deux plantes hôtes, dans le contexte écologique d'où proviennent les insectes étudiés ici.

     

Species relationships inPhaseolus: Electrophoretic analysis of seed storage proteins

Relationships among storage proteins in seeds from cultivars and primitive accessions of the four economically most important species ofPhaseolus — P. vulgaris, P. coccineus, P. acutifolius andP. lunatus — were studied. Analysis of SDS-polyacrylamide gel electrophoretic patterns of storage seed proteins revealed common characteristics in the major groups of polypeptides forP. vulgaris, P. coccineus andP. acutifolius, while clear differences existed between thesePhaseolus species and P.lunatus.     

Phylogenetic study on wild allies of Lima bean,Phaseolus lunatus (Fabaceae), and implications on its origin

An investigation was made of the phylogenetic relationships among wild accessions of Lima bean (Phaseolus lunatus) and wild allies of Mesoamerican and Andean origins, using electrophoresis of seed storage proteins and isozymes. Mesoamerican wild species are phylogenetically more distant fromP. lunatus than Andean species, and apparently belong to the tertiary gene pool of Lima bean. The Andean wild species, which are investigated for the first time, reveal a high similarity to the Lima bean, and particularly with its Mesoamerican gene pool. These Andean species probably constitute a secondary gene pool of Lima bean, and are thus of considerable interest in the context of genetic improvement of the crop. Based on these observations, an Andean origin is suggested for the Andean wild species and forP. lunatus. These results point out the importance of collecting and conserving AndeanPhaseolus germplasm.     

Food and water resources used by the Madagascan hissing-cockroach mite,Gromphadorholaelaps schaeferi

We determined the food source and water balance properties of the hissing-cockroach mite, Gromphadorholaelaps schaeferi. The food source for mites was identified using Evans blue dye by direct injection into a fasting host cockroach, Gromphadorhina portentosa, or by incorporation into cockroach food. No coloration was observed in mites on dye-injected cockroaches, but coloration was present in mites when only the food for the cockroaches had been stained. Thus, the mites are scavengers of cockroach food, and are not parasitic as previously thought. Our results demonstrate that the mites can absorb water from the air anywhere between 0.84 and 0.93 a _v (%RH/100), and wax-block experiments revealed that the mouth is the site of uptake. The mites are normally clumped together on the host, typically in between the cockroach's legs and around the spiracles. Water loss rates for mites in groups (0.16% h^-1) were far lower than for isolated mites (0.30% h^-1), suggesting a group effect with regard to water balance. Above the transition temperature of 30°C rate of water loss was rapid. The sites occupied by mites on the cockroach's body seem to be highly specific for feeding and absorption of water vapour.     

The interaction between host and host plant influences the oviposition and performance of a generalist ectoparasitoid

The successful development of parasitoids of herbivores depends on the quality of their host, which is often affected by the host plant. Therefore, a parasitoid’s oviposition decisions will directly depend on the host, but also on plant quality. Here, we investigated the direct effects of host species and the indirect effects of the host’s food plant on the oviposition decisions and performance of the gregarious ectoparasitoid Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae). With a series of no‐choice experiments, we determined the oviposition and performance of the parasitoid on: (1) two caterpillar species, fall armyworm, Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae), and velvet armyworm, Spodoptera latifascia Walker, reared on maize (Zea mays L., Poaceae), (2) the same caterpillars reared on maize, bean (Phaseolus vulgaris L., Fabaceae), or squash (Cucurbita pepo L., Cucurbitaceae) leaves, and (3) S. latifascia caterpillars reared on leaves of wild and cultivated lima bean, Phaseolus lunatus L. All these insects and plants originate from Mesoamerica where they have coexisted for thousands of years in the traditional agricultural system known as Milpa in which maize, beans, and squash are planted together. We found that the preferred and best combination of host and host plant for parasitoid performance was S. frugiperda on maize. Parasitoids laid larger clutches, had higher survival, and more females and larger adults emerged from S. frugiperda reared on maize. However, when both caterpillar species were reared on squash, S. latifascia was the better host. Contrary to the literature, S. frugiperda was not able to develop on bean plants. Results from the lima bean experiment showed that parasitoid performance was best when S. latifascia was reared on leaves of cultivated compared to wild lima bean. These findings are discussed in the context of mixed cropping in which the ability of generalist parasitoids to switch among hosts and host plant species could be advantageous for pest management.     

Larval settlement of the nemertean egg predator Carcinonemertes errans on the Dungeness crab,Metacarcinus magister

Due to their habitat specificity, marine parasites present excellent systems for studying the processes and patterns of larval settlement. Settlement of Carcinonermertes errans, an egg predator of the Dungeness crab, is described here for the first time. Upon contact with a host individual, competent larvae of C. errans settled on the crab's exoskeleton and migrated under the abdominal flap within 24 h. When removed from the host, recently settled worms retained their larval characteristics. After 48 h on the host, however, metamorphosis proceeded and larvae became juvenile worms. Additional field studies showed that competent larvae were present in the waters of the Coos Bay Estuary during the months of August through early November, could infect crab hosts directly from the water column, and exhibited density‐dependent gregarious settlement.     

Intraspecific variation in bionomic characters of the Mexican bean weevil, Zabrotes subfasciatus

Zabrotes subfasciatus (Boheman) (Coleoptera:Bruchidae) is native to parts of Central and South America but has now been spread to many others areas. It commonly infests the seeds of both Lima beans, Phaseolus lunatus, and common beans, Phaseolus vulgaris. Five geographic populations were found to differ in fecundity, patterns of egg distribution, times of development and adult sizes when they were kept under the same conditions. Each population also differed unpredictably from the others in its response to different cultivars of host seed. These differences have been shown to be of considerable importance in determining the potential pest status of the populations and should also promote caution in making predictions about the responses of different populations to new cultivars of bean for agricultural use.     

Phaseolus lunatus,a New Host of Xanthomonas axonopodis pv. phaseoli in Iran

Common bacterial blight caused by Xanthomonas axonopodis pv. phaseoli (Xap) is one of the most destructive diseases limiting the production of common bean (Phaseolus vulgaris) in Iran. The disease has previously been described on common bean and mung bean from several regions of Iran, including the central plain and south‐western provinces. In this study, lima bean (Phaseolus lunatus cv. Christmas) plants are being reported as a new natural host of Xap in East Azerbaijan and West Azerbaijan Provinces, northwestern Iran. Disease symptoms consisted initially of water‐soaked spots that progressed to irregular necrotic lesions with chlorotic margins. Infection was observed to affect up to 40% of plants in the field. Identification of the pathogen was based on the biochemical and molecular characteristics, as well as the pathogenicity tests. To our knowledge, this is the first report of X. axonopodis pv. phaseoli causing common bacterial blight on lima bean plants in Iran.     

Attachment sites of the tick Amblyomma marmoreum on its tortoise host,Geochelone pardalis

Leopard tortoises (n=162) were collected over a period of 19 months at the National Zoological gardens, Pretoria, South Africa and the attachment sites of larvae, nymphs and adults of A. marmoreum monitored. Most of the larvae (80%) and nymphs (87%) were found on the anterior parts of the tortoise while adults (90%) were found mainly on the posterior regions of the host body. The immature stages were predominant in soft skinned areas protected by the carapace especially the neck and upper leg areas. Male and female ticks were most commonly found on the posterior armpit. posterior legs and the areas surrounding the base of the tail. Interstadial competition as a major factor influencing attachment site segregation is doubtful. Anterior attachment site selection of the immature stages is believed to result largely from ticks lying passively in wait and then climbing onto the host as it moves through the vegetation and the requirement for soft skinned and protected areas to allow for blood feeding. Adult females usually attach posteriorly in areas that allow them to fully engorge without being dislodged by mechanical disturbance, while males prefer to attach at sites where they are protected but still remain in close proximity to female pheromone signals.     

The bioenergetic fuel for non-feeding larval development in an endemic palaemonid shrimp from the Iberian Peninsula,Palaemonetes zariquieyi

Palaemonetes zariquieyi, an endemic palaemonid species of shrimp that lives in freshwater and brackish coastal habitats in eastern Spain, shows an abbreviated, non-feeding larval development comprising only three zoeal stages. To identify the endogenous bioenergetic fuel that allows for food-independent development from hatching to metamorphosis, larvae were reared under controlled laboratory conditions, and ontogenetic changes in dry weight (W), elemental (CHN), and lipid composition (total lipids, principal lipid classes, and fatty acids [FA]) were quantified at the onset of each zoeal stage and in the first juvenile. Values of W, C, and H per larva and per mass unit of W decreased throughout the time of larval development, while the N content showed only a weak decline (suggesting strong lipid but only little protein degradation). Correspondingly, directly measured values of total lipids (both in μg/larva and in % of W) decreased gradually, with neutral lipids (NL) consistently remaining the predominant and most strongly used fraction; sterol esters and waxes were not detected. In contrast to the NL, the fraction of polar lipids (PL) per larva remained stable and, as a consequence, tended to increase as a percentage of total lipids. Likewise, other important lipid fractions such as free FA and cholesterol remained stable throughout the time of larval development. Among the FA, palmitic (16:0), oleic (18:1n–9), linoleic (18:2n–6), and eicosapentaenoic (20:5n–3) acid were predominant, showing a significant decrease during larval development; stearic (18:0), vaccenic (18:1n–7), and arachidonic acid (20:4n–6) were found only in small amounts. Our results indicate that the lecithotrophic development of P. zariquieyi is primarily fuelled by the utilization of lipids (especially triacylglycerides and other NL), which is reflected by a decreasing carbon content. Proteins and PL, by contrast, are preserved as structurally indispensable components (nerve and muscle tissues, cell membranes). The abbreviated and non-feeding mode of larval development of P. zariquieyi may have an adaptive value in land-locked freshwater habitats, where planktonic food limitation is likely to occur. The patterns of reserve utilization are similar to those previously observed in other palaemonid shrimps and various other groups of decapod crustaceans with lecithotrophic larvae. This suggests a multiple convergent evolution of bioenergetic traits allowing for reproduction in food-limited aquatic environments.     

Food Preference and Reproductive Plasticity in an Invasive Freshwater Snail

The freshwater apple snail Pomacea canaliculata has become a major crop pest in southeast Asia and Hawai'i and threatens natural wetland habitats in these regions and elsewhere. Deliberately introduced as a potential human food resource, it has also been proposed as a possible biocontrol agent against aquatic weeds. Various factors may facilitate its rapid invasion of new areas; we focus on two: growth rate and food preference. Our field observations and laboratory experiments suggest that in Hawai'i P. canaliculata reaches reproductive maturity in 10 months or more, less time than in its native temperate and seasonal Argentina, where it takes 2 years, but longer than in parts of southeast Asia, where it may take as little as 2 months. This increased growth rate, and thence reproductive rate, probably facilitate rapid population growth. Although P. canaliculata is usually considered an indiscriminate generalist macrophytophagous feeder, laboratory experiments indicated preferences among the dominant plants at our field site and growth rate differences when constrained to feed only on one of these plants. Water hyacinth (Eichhornia crassipes), a major invasive weed, was not preferred in food choice experiments, and snails offered only water hyacinth on which to feed did not differ in growth rate from unfed snails. Another important invasive weed, water lettuce (Pistia stratiotes), was also not preferred, but snails fed on it did grow, though not as quickly as those fed on green-leaf lettuce. Among the food plants offered in the experiments the native Vigna marina was the most preferred. Therefore, although a generalist, P. canaliculata exhibits some discrimination among food plants. We recommend that it not be introduced for use as a biological control agent for aquatic weeds.