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Tortrimosaica polypodivora Brown & Baixeras, new genus and new species, is described and illustrated from São Paulo, Brazil. We also describe and illustrate the last instar and pupa and provide notes on the life history. Larvae of the new species are gall inducers on the stems of Microgramma squamulosa (Kauf.) Sota (Polypodiaceae), an unusual behavior and host for a tortricid. Although placed provisionally in Hilarographini, tribal and subfamilial assignment of the new genus is extremely problematic owing to a mosaic of morphological characters, suggesting placement in a variety of different higher taxa. The larvae have a bisetose L-group on the prothorax, and the pupa has multiple rows of spines near the anterior edge of the dorsum of abdominal segments 3–8; both of these characters previously have been reported in the Tortricidae only in Thaumatographa (Hilarographini). Although the gall-inducing habit of the new species is not unique within Tortricidae, it is highly unusual within nonolethreutine lineages.
Based on morphological and genetic comparisons, an established population of the African termite, Coptotermes sjostedti Holmgren, was identified on the island of Guadeloupe. This is the sixth recorded species of an endemic Old World termite becoming established in the New World. We hypothesize that this species arrived from tropical West Africa by maritime transport.
Two new species of mites in the family Eriophyidae, Calepitrimerus crataegi sp. nov. collected from Crataegus spp. and Platyphytoptus juniperi sp. nov. collected from Juniperus oxycedrus L. and Juniperus communis L., are described and illustrated.
Burmaculex antiquus new genus, new species, is described from a single partially preserved adult female in Burmese amber. The fossil has several plesiomorphic features, indicating that it is the sister group of all other fossil and extant Culicidae: a relatively short proboscis, the palpi extending beyond the apex of the proboscis, a clypeus with several setae, and the palpus without scales. Antennal and mouthpart structure suggest the female of this fossil species was a vertebrate blood feeder. The age of Burmese amber has been estimated as between Upper Albian to Turonian, 100–90 million years ago but the origins of the Culicidae are likely significantly older. The sister group of the Culicidae are the Chaoboridae, known as Jurassic fossils, and the Culicidae therefore must be equally as old. Although fossil adults of the two families may not be distinct at this early stage of evolution, the immatures would likely provide distinguishing features.
The new species Diabrotica calchaqui Cabrera & Cabrera Walsh is described and illustrated based on specimens collected from Cachi, Salta Province, Argentina. This new species is assigned to the Diabrotica virgifera group, subtribe Diabroticina, tribe Luperini. D. calchaqui is recognized by the combined characters of elytra green with yellow vittae in some specimens reduced to two or three spots, humeral plicae subparallel, elytral sulcus sometimes obsolete, and internal sac of median lobe with five sclerites. Differences between D. calchaqui with Diabrotica porracea Harold, Diabrotica tumidicornis Erichson, Diabrotica mapiriensis Krysan & Smith, and Diabrotica fulvofasciata Jacoby, of similar morphology, also are discussed. Adults have been found associated with cultivated Cucurbitaceae and wild Asteraceae flowers.
Imagos of Rhithrogena (Tumungula) unica subgen. n., sp. n. from Yunnan and Guizhou provinces, China, have a series of unique characteristics. Male imagos have a hypertrophied foreclaw and a first tarsal segment ≈1.5 times the length of the second. The male styliger plate has two sharp projections, and the penis lobes are divergent without titillators but with spiny median lobes. Nymphal characters are those of the genus as presently defined: three caudal filaments and gills modified to form an adhesive disc.
Forficulina, the largest suborder of Dermaptera (earwigs), has eight families. In five families (Pygidicranidae, Diplatyidae, Anisolabididae, Apachyidae, and Labiduridae), the males have two penises, whereas the males of the other three families (Spongiphoridae, Chelisochidae, and Forficulidae) have a single penis. Several cladograms have been proposed for Forficulina. However, those systems are constructed mainly from observations of male genital morphology and outstandingly inconsistent. This study reconstructed an earwig phylogeny with representatives of seven families (excluding Apachyidae) by using partial sequences of the mitochondrial 16S and nuclear 28S rRNA genes, sequences that are independent of genital evolution. To avoid difficulties caused by outgroup-rooting for a deep phylogeny, ingroup relationships were first established as unrooted trees based on the 16S, 28S, and combined data sets. The resulting affinities of the earwig families supported several superfamilies, such as Forficuloidea (single-penis families) and Pygidicranoidea (Pygidicranidae Diplatyidae). Inclusion of the outgroup (Glylloblattodea and Blattodea) did not distort the established ingroup relationships. However, the root position varied according to the genes and outgroup taxa used. Kishino–Hasegawa tests based on the maximum likelihood criterion suggested that the common ancestor of contemporary Forficulina had twin penises, each with one gonopore.
Antlion larvae that construct conical pits to capture prey may strongly affect foraging of ants and other arthropods, yet are usually abundant only in sheltered microhabitats. Larval antlion (Myrmeleon crudelis Walker) densities increased in exposed areas in central Texas in late summer and early autumn of 1998, presumably because of extended dry conditions. I conducted a study to quantify larval antlion pit densities in sheltered and exposed areas over time, and to examine the effect of variation in pit density on the foraging activity of ants and other arthropods. Isolated rainfall events decreased pit densities in exposed areas, sometimes to zero, but pit densities returned to high levels as the soil dried out. Pitfall traps at sheltered sites caught significantly fewer ants and other arthropods inside antlion zones (i.e., areas of high antlion density) than in adjacent areas without antlions. At exposed sites, pitfall traps caught significantly fewer ants in antlion zones when pits were present (dry conditions) than when they were absent (wet conditions); there was no significant difference in foraging outside the antlion zones in wet compared with dry conditions. Significantly fewer ants were caught inside antlion zones at sheltered sites (that were permanent) compared with exposed sites (that were transient), although pit densities were similar at both types of sites. Attraction of ants to baits revealed similar patterns. Spatiotemporal variation in antlion pit densities and the associated predation risk to ants and other arthropods may result in behavioral modifications of foraging patterns, higher mortality rates, or both.
We have documented the secondary use of vacant leaf mines of a lepidopteran leaf miner, Phyllonorycter pastorella (Zellar), by other arthropods. At least six species were identified as secondary users of the vacant mines. Among secondary users, aphids and springtails were most abundant. Distribution patterns of these two insects showed that aphids used vacant mines by chance and that springtails used them selectively as feeding and reproductive sites. Hole diameter of mines did not affect the use of vacant leaf mines by aphids and springtails. We believe this is the first report on leaf miners as physical ecosystem engineers that provide modified habitats to other organisms.
The geographic distribution of three braconid parasitoids of the Caribbean fruit fly, Anastrepha suspensa (Loew), was determined by collecting host fruit throughout central and southern Florida. Diachasmimorpha longicaudata (Ashmead) was most abundant in southern Florida, occurring at higher latitudes along the Atlantic and Gulf coasts. Distribution of this species was negatively related to variance of monthly temperatures. This suggests that D. longicaudata may be dependent on a relatively constant supply of hosts. Doryctobracon areolatus (Szepligeti) was the dominant species at the majority of interior locations, but it was uncommon or absent along both coasts. Utetes anastrephae (Viereck) was widespread but usually less common than the other species. Parasitism levels of both D. areolatus and D. longicaudata were positively related to density of common guava, Psidium guajava L., trees. Parasitism levels of both D. longicaudata and U. anastrephae were positively related to numbers of A. suspensa captured in McPhail traps. Abundance of D. areolatus was inversely related to that of both D. longicaudata and U. anastrephae. The absence of D. areolatus in southeastern Florida, where it was originally established, suggests that a process of competitive displacement may have occurred. Parasitoid distribution is consistent with the hypothesis that D. areolatus is a superior searcher and D. longicaudata is a superior intrinsic competitor.
Domain III of the mitochondrial 12S rRNA gene from Hessian fly, Mayetiola destructor (Say), was sequenced in 21 populations from the United States, two populations from Canada, five populations from the Mediterranean basin, one population from Southwest Asia, and one population from New Zealand. From the total alignment, seven unique mitochondrial DNA (mtDNA) sequences (haplotypes) were identified. Of the seven 12S haplotypes only three (haplotypes 1, 2, and 3) occurred in populations from North America, indicating these were most likely the introduced haplotypes. Haplotypes were not restricted to any given biotype of M. destructor as defined by virulence to resistance genes in wheat. Thus, neutral markers did not show structure based on biotype. Populations of M. destructor showed a predominance of one haplotype over the others in specific geographic regions. However, Wolbachia DNA was not detected in any population, indicating that inheritance patterns of mtDNA in M. destructor were most likely due to repeated bottlenecks leading to the expansion of one lineage over another. The complete complement of 12S sequences in the M. destructor populations was subjected to a phylogenetic reconstruction by using haplotypes 1 and 3 of the gall midge Orseolia oryzae (Wood-Mason), as outgroups. Results from this initial study indicate a more robust phylogenetic reconstruction and analysis of population history will test the hypothesis of a single introduction of M. destructor into North America.
The white pine weevil, Pissodes strobi (Peck), is a major source of damage to young spruce and pine trees across North America. The species contains a substantial amount of genetic, morphological, and behavioral variation, and identification of patterns of genetic variation on a broad geographic scale may contribute toward more effective pest management strategies. To estimate maternal gene flow and examine the genetic structure of P. strobi we sequenced an 826-bp fragment of the mitochondrial DNA (mtDNA) COI gene in 130 individuals from 11 locations across Canada. Nested clade analysis of 36 haplotypes yielded three patterns of genetic structuring that are inferred as due primarily to restricted gene flow and contiguous range expansion, with one case of long-distance colonization. Analysis of molecular variance analysis also showed significant genetic structuring and restricted gene flow among regional populations. Eastern and western populations were divergent, as were the four populations surveyed in British Columbia. Findings were comparable with those of previous studies based on allozyme or randomly amplified polymorphic DNA data, although population differentiation was greater in mtDNA. Detection of such genetic structure may be important for control programs, because other studies have shown that the conifer hosts of P. strobi provide geographically structured variation in resistance to damage.
Inter- and intraspecific differences between Asteralobia gall midges (Diptera: Cecidomyiidae) that induce axillary bud galls on several Ilex species were studied from morphological, molecular, and ecological points of view. Asteralobia sasakii (Monzen) and Asteralobia soyogo (Kikuti) were clearly distinguished from one another by thoracic setal and scale counts and by sequences of partial mitochondrial DNA cytochrome oxidase subunit I region. Because adults of A. sasakii emerged within a shorter period of time and later in the season than those of A. soyogo, they were considered to be temporally isolated. The host ranges of A. sasakii and A. soyogo did not overlap. A. sasakii was confirmed to use Ilex crenata Thunberg, Ilex crenata var. paludosa (Nakai) Hara, and Ilex maximowicziana Loesener for galling, and A. soyogo included galls on Ilex chinensis Sims, Ilex integra Thunberg, Ilex leucoclada (Maximowicz) Makino, and Ilex pedunculosa Miquel. Molecular phylogenetic analysis revealed that host races were not formed either in A. sasakii or in A. soyogo populations, whereas geographical variations were detected for both species at the DNA level. The haplotype diversity was significantly higher in A. soyogo than in A. sasakii. The DNA analysis suggested that A. sasakii and A. soyogo had speciated allopatrically. On the basis of the current study, we concluded that A. soyogo had been already established in Honshu, Shikoku, and Kyushu, Japan, when A. sasakii arrived in these areas from the southwest islands more recently.
The Argentine ant, Linepithema humile (Mayr), is a significant pest species, having become established on almost every continent, particularly in areas with a Mediterranean climate. In its introduced range, the Argentine ant has been associated with reductions in the abundance and diversity of native ant and nonant invertebrate fauna, as well as the interruption of ant–plant mutualisms. The distribution of Argentine ants has been correlated with particular abiotic factors, including soil moisture, relative humidity, disturbance, and particular soil and vegetation types. This study assessed the importance of temperature on the survival of Argentine ants and two native ant species (Iridomyrmex “rufoniger” and Rhytidoponera “convexa”) in the laboratory. Workers were placed in incubators of varying temperatures (25, 32, 40, 45, 47, and 50°C), and counts of the numbers dead and alive were recorded after 1, 2, and 3 h. The results showed that all species displayed almost 100% survival at 25, 32, 40, and 45°C, but at 47°C the mortality rate of all species increased, with Argentine ants experiencing 100% mortality after 3 h. At 50°C, Argentine ants displayed no survival at 1 h, whereas the Iridomyrmex exhibited ≈50% survival after 3 h. These results may have significant implications in Australia, where the ground surface temperatures may become very high during the summer, potentially limiting the spread of Argentine ants.
Lepidopteran larvae can exclude some organelles that have invaded the hemocoel by defense systems such as phagocytosis, encapsulation, and nodule formation. However, Plusiinae loopers have another system that can exclude organelles such as endoparasitoids by forming a cyst on the penultimate segment, i.e., cuticular encystment. In this study, we examined whether cuticular encystment is common in six species of Plusiinae loopers [Autographa nigrisigna Walker, Anadevidia peponis F., Trichoplusia ni (Hübner), Acanthoplusia agnata Staudinger, Erythroplusia rutilifrons Walker, and Trichoplusia intermixta Warren) from the first to the fourth stadia. Loopers were parasitized artificially by the gregarious endoparasitoid Cotesia glomerata L. Different rates of cuticular cyst formation were shown among species. More than one-half of the loopers formed a cuticular cyst in all species except T. intermixta. A. nigrisigna and A. peponis, in particular, formed >80% cysts in the first to third instars. However, almost all parasitized host larvae died before the larval emergence of the parasitoid in spite of the high proportion of cyst formation. Death of the parasitized host larvae seemed to be caused by an overload in the number of eggs laid. We also examined, in A. nigrisigna, the number of parasitoid larvae that this looper can exclude by cuticular encystment. The number of eggs laid in the gregarious endoparasitoid can be regulated artificially. A sudden disturbance of the oviposition sequence by removing the female C. glomerata with a brush caused various numbers of eggs to be laid in the host. When the oviposition time was restricted to 0.4–4.0 s (i.e., the number of eggs laid was <5), survival rate of the loopers clearly increased. We conclude that parasitoid larvae can be expelled by cuticular encystment only if a few eggs are laid in Plusiinae loopers.
The developmental biology of citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae), was studied at constant and varying temperatures on roses, Rosa hybrida L. Mealybug populations were sampled daily to determine thermal constants and day-degrees (DD) at 18.3°C, 26.6 d/15.5°C night and a fluctuating temperature averaging 20.3°C. The thermal constant at 18.3°C was 289 DD for females and 346 DD for males; the median number of days from egg to adult was 39 for females and 47 (±1 SEM) mean days for males. At fluctuating temperatures averaging 20.3°C, the thermal constant for females was 365 DD and 421 DD for males; the median number of days from egg to adult for females was 39, and 45 (±2.0 SEM) mean days for males. For females reared at 26.6°C during the day and 15.5°C during the night, the thermal constant was 326 DD, and the median days to egg hatch, second instar, third instar, and adulthood were 6, 17, 26, and 32, respectively. The lower developmental threshold was determined to be 10.9°C for the egg stage. Information about development of the citrus mealybug on roses is discussed in terms of effective pest management.
External and internal mycoflora of the cave cricket Hadenoecus cumberlandicus Hubbell were examined and consisted of eight deuteromycetes (Aspergillus niger, Beauveria sp., Colletotrichum acutatum, Geotrichum candidum, Penicillium sp., Pestalotia sp., Trichoderma sp., and Mycelia sterilia), five zygomycetes (Absidia corymbifera, Cunninghamella sp., Mucor racemosus, Phycomyces sp., and Rhizopus sp.), and one ascomycete (Thielavia terrestris). Most are soil saprophytes and typical in a cave setting. Internal isolates included Colletotrichum acutatum and Pestalotia sp., plant pathogens that were probably acquired during foraging. Noteworthy among external fungi was Beauveria sp., a genus of entomopathogens, revealing that fungi may have the potential to impact the cave ecosystem by reducing cave cricket populations.
The hyperparasitoid Trichomalopsis apanteloctena (Crawford) is an idiobiont ectoparasitoid that uses the prepupa or pupa of the primary parasitoid Cotesia kariyai (Watanabe), which is paralyzed by venom at parasitization. Changes in nutrient quality of the primary parasitoid were evaluated during its development. The primary parasitoid C. kariyai was available as a host for 5 d, because C. kariyai eclosed at 5 d after emergence. The lipid contents of the primary parasitoid decreased during these 5 d. The size of individual T. apanteloctena progeny paralleled the available nutritional resources of these primary parasitoids. A decrease in body mass, that is, the change in the quality of the fat body in the primary parasitoid development affected the adult size and sex ratio of the hyperparasitoid. The hyperparasitoid had no preference of developmental stage of the primary parasitoid. However, adult sizes of the individual progeny that parasitized at 4 d after pupation were smaller and the sex ratio was male biased.
We examined the stage and sex-related changes in total lipid, total fatty acids, and fatty acid composition of Apanteles galleriae Wilkinson (Hymenoptera: Braconidae) reared on Achoria grisella Fabr. (Lepidoptera: Pyralidae). The effect of parasitism on the total lipid and fatty acids of host larvae was also investigated and compared with the fatty acid composition of parasitoids. The changes in fatty acid composition of host larvae after parasitization were investigated and the degree of similarity between the fatty acid composition of parasitoid and host larvae was determined. Total lipid of A. galleriae considerably increased in adults compared with immature stages. There was a significant increase in fatty acid levels between the larval and pupal stages. Fatty acids continued to accumulate in adult males, but declined in females. Total fatty acids of parasitoid larvae were significantly higher than that of parasitized or nonparasitized host larvae. All stages of A. galleriae contained the 10–24 carbon fatty acids. Oleic acid was the most abundant fatty acid in all stages. A large proportion of the fatty acid composition at each developmental stage of the wasp analyzed comprised palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic acids. The fatty acid composition of the parasitoid larvae was qualitatively similar to that of the host larvae. Parasitism did not affect the total lipid and fatty acid levels of host larvae.
Several hypotheses attempt to explain why male genitalia typically diverge rapidly over evolutionary time. Predictions of the lock and key and the sexually antagonistic coevolution hypotheses were tested by studying the functional morphology of several male genitalic traits by freezing copulating pairs of four species of Drosophila: saltans, willistoni, melanogaster, and malerkotliana. Contrary to the predictions of the hypotheses, there were no species-specific differences in female morphology that corresponded to interspecific differences in the morphology of the male surstylus (which pressed and perhaps spread the distal tip of the oviscape), the epandrium (which grasped the external surface of the extended oviscape), and the aedeagus and paraphyses (which, in willistoni, clamped the oviscape). Antagonistic coevolution could possibly explain the diverse male genitalic morphology if female resistance behavior rather than morphology has coevolved with male morphology, but there are reasons doubt this explanation.
The DNA sequence of the coding region of the wild-type and mutant alleles of the white eye gene from the melon fly, Bactrocera cucurbitae Coquillett, was obtained. The mutant white eye allele had a single base pair mutation at the 5′ end of intron 4b in the RNA splice recognition site. Due to the disrupted splice recognition site, intron 4b was not removed from the mutant RNA transcript. The resulting mRNA transcript was 68 bp longer than that of the wild type, containing a frameshift and premature stop codon. Transport of pigment precursors would be blocked, resulting in a lack of pigmentation deposition consistent with the known mutant phenotype.
The first genetic sexing system for the melon fly, Bactrocera cucurbitae (Coquillett), based on pupal color was developed. The recessive white pupae mutant, wh, was used in a putative chromosome translocation linking the wildtype allele to the male sex. This system permits the separation of males (wildtype brown pupae) from females (mutant white pupae). Results from laboratory studies indicated that egg hatch averaged 42% for flies 2–5 wk old, with higher rates (≈50%) for younger flies in this age range. Male larvae left the diet to pupate earlier than females, averaging >60% of the pupae in the first day of collection, whereas only ≈40% on the fourth day of collection. Adult emergence rate was normal, averaging ≈92%. Adult egg fecundity and fertility (both sexes) were very low (<1% of normal) after irradiation at 100 Gy at 1, 2, or 3 d before emergence. Adult flight ability from standard 20-cm tubes averaged ≈65%. Irradiated females landed on, and oviposited into, zucchini fruit significantly fewer times than nonirradiated females. Field cage survival tests indicated that the new strain survived as well (>80%) as wild males over a 7-d period when provided with food and water. Mating tests indicated that male-only sterile flies mated significantly more (about double) with wild females than sterile males from bisexual (male and female) sterile populations competing with wild males. Males fed only sugar until tested in the cages failed to mate with wild females, whereas males fed a low protein diet (6:1 sugar:protein) or the standard 3:1 diet mated as well as wild males for wild females. Finally, males exposed to the attractant, cuelure, failed to improve their mating performance compared with control, unexposed males. The results are discussed in the context of the potential for using the new strain in current or future melon fly sterile insect technique programs in Hawaii and elsewhere.
Two genetically differentiated forms of fall armyworm, Spodoptera frugiperda (J. E. Smith), use different graminaceous host plants, coexist sympatrically throughout their ranges, yet seem to hybridize. To address the taxonomic status of the two forms, determine extent and directionality of hybridization, and examine host specificity, we compiled multilocus genotypes consisting of mitochondrial DNA (mtDNA) haplotypes, an esterase locus, and eight amplified fragment-length polymorphism (AFLP) loci in moths collected across a broad geographic range. Multilocus analyses indicated 16% of individuals sampled were potentially hybrids with a minority being F1 in origin. Analysis of host use indicated asymmetries in host specificity with one strain specific to corn, Zea mays L., and the other strain predominating on pasture grasses and rice, but occasionally using corn. Location of hybrids in nature was biased toward cornfields, the habitat used by both strains. To assess genetic divergence of each gene, we calculated their relative strain discriminating ability. Eight AFLP loci collectively had the greatest discriminating power (98%), followed by a single AFLP locus (93%) and mtDNA (91%). Esterase exhibited 89% discrimination. Esterase is X-linked along with an assortative mating trait, suggesting esterase differentiation may be maintained by association with strain-specific fitness genes. Despite strong discrimination of these genes, most of the genome surveyed was not distinct. Cytonuclear comparisons provided evidence for unidirectional matings consistent with mate preference studies. Collectively, these data support introgressive hybridization between recently evolved species that are not completely reproductively isolated. Genetic divergence in the presence of gene flow may be a common phase in the speciation process, especially in taxa whose ranges have been altered dramatically by humans.
Two new body color mutations are described in both a wild-type, usually green (GG), and a red strain (gg) of Canthon cyanellus cyanellus LeConte, a scarab from the tropical forest in Los Tuxtlas, Veracruz, Mexico. One mutation changed the testaceous (TT) color of mouthparts, antennae, palpi, and tarsi in the red and wild-type strains to a piceous (tt) color, retaining the red and green body color, respectively. Specimens with this mutation were reared in laboratory to determine whether the genetic behavior of the character was controlled by a single autosomal recessive allele. Specimens of the new strain, recessive homozygous (gg/tt), were crossed with wild-type beetles. The phenotype of F2 offspring from these crosses segregated in a ratio of 9:3:3:1 according to a dihybrid cross. Specimens of the GG/TT genotype were intercrossed, and in F1 a second mutation changed the brown (BB) eye color to nonmelanin (bb), retaining the green body color. Crosses were made between beetles with this character (GG/bb) and the wild-type (GG/BB). The nonmelanin eye mutation also was controlled by a single autosomal recessive allele. The new mutations tt and bb showed uniform expression in both sexes. The red beetles with the piceous character were not as reproductively successful as wild-type beetles, whereas the other strains showed reproductive success similar to that of the wild type.
Mallophora ruficauda Wiedemann (Diptera: Asilidae) is a pestiferous robber fly affecting beekeeping in the South American open grasslands. This insect preys upon other insects during its adult stage and parasitizes scarab beetle larva in the soil as larvae. As a first step toward population management, we studied basic reproductive behavioral traits. We investigated the size and fertility of egg clusters and whether females exhibit preferences for oviposition sites. We collected egg clusters close to bee farms in the Argentine grasslands and estimated egg eclosion rates and aggregation. We also measured the height at which clusters were found on both natural vegetation and artificial wire supports. We determined the number of eggs per egg cluster, eclosion rates, and egg developmental time. Egg clusters were usually highly aggregated in the field and were found on elevated places, including the tallest plant species. We discuss height selectivity in robber flies in relation to host availability and robber fly fecundity, as a means of increasing larval dispersal and hence encountering success with larval hosts.
The glassy-winged sharpshooter, Homalodisca coagulata (Say), is an important agricultural pest because it is an effective vector of Xylella fastidiosa, the pathogen that causes Pierce’s disease in grapevines. Knowledge of the feeding behavior of H. coagulata is important in understanding pathogen transmission, and this knowledge is important in developing innovative pathogen control strategies. Ingestion of fluid by sharpshooters was monitored as movement of fluid from reservoirs connected to short stems of plant tissue. We quantified the amount of fluid processed while the insects were freely moving on the plants stems offered for feeding. Females fed longer than males, and both ingested large amounts of plant fluid and both excreted large amounts of fluid. Excreta droplets were often actively flung from the body by flicking the abdomen. While actively ingesting, the abdomen made exaggerated movements that stopped during excretion. These movements only appeared after mouthparts penetrated the plant tissues. The abdominal movements were correlated with ingestion of plant fluids as monitored by fluid uptake from the reservoir.
We evaluated responses of protein-deprived and protein-fed mature (26–30-d-old) female melon flies, Bactrocera cucurbitae (Coquillett), to odor of host fruit and of proteinaceous baits by using 1 by 1 by 1-m cages containing nonhost plants. Protein-deprived and protein-fed females were attracted equally to odor of host fruit. For both types of females, odor of cucumber, Cucumis sativis L., and cantaloupe, Cucumis melo L., was more attractive than odor of tomato, Lycopersicon esculentum L. Odor of kabocha, Cucurbita maxima Duchesne, was more attractive than the odor of bittermelon, Momordica charantia L., but not more attractive than zucchini squash, Cucurbita pepo L. In choice tests, protein-fed females preferred cucumber odor over protein odor, whereas protein-deprived flies showed an almost identical response to the two odors. Our findings suggest that some feral host-seeking B. cucurbitae females that have fed recently on natural sources of protein and carry mature eggs might bypass proteinaceous baits, reducing the effectiveness of current approaches to melon fly management.
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