Resistance of temperate Chinese elms (Ulmus spp.) to feeding by the adult elm leaf beetle (Coleoptera: Chrysomelidae)

Newly acquired Ulmus species from the temperate regions of China growing at The Morton Arboretum, Lisle, IL, were evaluated in laboratory bioassays for feeding preference and suitability for larvae and adults of the elm leaf beetle, Pyrrhalta luteola (Müller). Larval and adult no-choice and adult multiple-choice feeding studies revealed that U changii, U. lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis were the least suitable for feeding and reproduction by the elm leaf beetle. Ulmus wallichiana and the highly preferred U pumila were more suitable for feeding and reproduction. Suitability had no significant effect on male and female longevity. The least suitable species of U. changii, U. lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis show promise for future elm breeding programs.     

啃食性端足类强壮藻钩虾对筼筜湖三种大型海藻的摄食选择性

为了评估啃食性端足类强壮藻钩虾Ampithoe valida对筼筜湖大型海藻群落的影响,作者在实验室内开展了强壮藻钩虾对筼筜湖三种大型海藻(绿藻石莼Ulva lactuca和根枝藻Rhizoclonium sp.、红藻细基江蓠繁枝变种Gracilaria tenuistipitata var. liui)的摄食实验,并分析了大型海藻的营养价值是否对强壮藻钩虾的摄食选择产生影响。结果显示,在无选择性摄食实验中,强壮藻钩虾的摄食率与海藻的干湿比和鲜藻总有机碳含量有着明显的负相关关系,这表明强壮藻钩虾有明显的补偿摄食行为,能通过增加低营养价值藻类的摄食量来满足自身代谢的需求。强壮藻钩虾对绿藻石莼和根枝藻有明显的摄食偏好,对它们的摄食率分别占总摄食率的40.6%和57.1%,而红藻细基江蓠繁枝变种则属于偶然性摄食的种类,海藻的营养价值并没有对强壮藻钩虾的摄食选择产生影响。不过,强壮藻钩虾对绿藻的摄食偏好并没有在筼筜湖形成一个以红藻占主导的大型海藻群落,这可能是由于筼筜湖超富营养化的水体使得来自强壮藻钩虾的下行控制已经无法抑制来自超富营养化的水体通过上行控制对绿藻生长的促进作用。     

Feeding and attraction of Agelastica coerulea (Coleoptera: Chrysomelidae) to Betulaceae plants

The feeding and attraction of Agelastica coerulea (Baly) to nine species of Betulaceae in four genera (Alnus, Betula, Carpinus, and Corylus) were examined in the laboratory by using choice and no-choice as well as olfactometer bioassays. In no-choice feeding bioassays with A. coerulea larvae, Alnus hirsuta (Spach) Ruprecht, Alnus japonica Steudel, Corylus sieboldiana variety mandshurica (Max.) c. k. Schneider, and Corylus heterophylla variety thunbergii Blume were the most preferred, whereas Betula davurica Pallas, Betula schmidtii Regel, and Carpinus cordata Blume were the least preferred. The larvae showed moderate preference for Alnus maximowiczii Callier and Carpinus tschonoskii variety brevicalycina Nakai. In choice feeding bioassays, no differences in preference between A. hirsuta and A. japonica were observed. However, there were significant differences in preference between A. hirsuta and each of the other seven plant species. In olfactometer bioassays with adult female A. coerulea, fresh leaf odor from A. hirsuta attracted significantly more adults than that from A. japonica and C. sieboldiana variety mandshurica. These results indicate that A. coerulea differed in its ability to discriminate among the Betulaceae plants at the feeding preference and attraction of host selection.     

Preference-performance linkage of the xylem feeding leafhopper, Homalodisca vitripennis (Hemiptera Cicadellidae)

Insect species exhibiting a weak linkage between adult preference and immature performance have frequently been shown to be prone to outbreaks. We used choice and no-choice tests to examine the preference-performance linkage of the xylem fluid-feeding leafhopper, Homalodisca vitripennis Germar. Leafhoppers were offered a choice of hosts common to their native range and also a choice from hosts where they have been recently introduced. Behavior (residence preference, oviposition preference, and consumption rates) was quantified in choice tests. Performance (development of immature leafhoppers, fecundity, body weights, and survivorship) was quantified in no-choice tests. Virtually all aspects of leafhopper behavior and performance varied with host species, yet there were no linkages between adult preference and immature performance. Lagerstroemia indica and Citrus sinensis were the preferred hosts, but both species supported <30% of neonate development until the second stadia. Glycine max was the superior developmental host with development to the adult stage exceeding 40%, but this host was seldom used by adult leafhoppers. Adult preference reflected aspects of adult performance including increases in fecundity, body weights, and survivorship. These preference-performance linkages were impacted by environmental context, insect reproductive status, and insect feeding history. Essential amino acids were consistently correlated with performance of both adult and developing insects; relationships between nutrients and preference were less consistent. The weak linkage of adult preference and immature leafhopper performance are discussed in terms of outbreaks of H. vitripennis.     

A comparison of methodologies for the assessment of host preference of the gregarious egg parasitoid Trichogramma platneri

The innate preference of Trichogramma platneri for the eggs of six host species (Chrysoperla carnea (Stephens), Cydia pomonella (L.), Ephestia kuehniella (Zeller), Helicoverpa zea (Boddie), Manduca sexta (L.), and Sitotroga cerealella (Olivier)) was evaluated as the first host accepted by an individual female parasitoid when eggs were presented simultaneously. Selective exploitation of the same hosts by T. platneri was evaluated in no-choice, paired-choice, and multiple-choice tests, using number of parasitoids emerged, proportion of female offspring, and proportion of time spent on host eggs as different measures of preference. T. platneri showed a strong innate preference for C. pomonella and M. sexta. H. zea and M. sexta were the most preferred hosts and S. cerealella the least preferred, in the no-choice and choice tests. The number of progeny emerged and proportion of female offspring were equally suitable measures of host preference for T. platneri. Although no-choice and choice tests provided very similar preference ranking for T. platneri, a polyphagous species, the no-choice tests appeared poorer at separating hosts that were close in rank and multiple-choice tests were considered likely to be more realistic for more specialized control agents.     

Nutritional ecology of the formosan subterranean termite (Isoptera: Rhinotermitidae): feeding response to commercial wood species

The feeding preferences of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were tested in three separate experiments on 28 different wood species. Experiment 1 was a multiple-choice test designed to test relative preferences among 24 wood species commercially available in New Orleans, LA. Experiment 2 was a similar study designed to test relative preferences among 21 wood species shown or reported to be unpalatable to the Formosan subterranean termite. Experiment 3 was a no-choice test to examine the feeding deterrence of the 10 least preferred wood species. Preference was determined by consumption rates. Birch (Betula alleghaniensis Britton), red gum (Liquidambar styraciflua L.), Parana pine [Araucaria angustifolia (Bert.) 1, sugar maple (Acer saccharum Marsh.), pecan (Carya illinoensis Wangenh.), and northern red oak (Quercus rubra L.) were the most preferred species by C. formosanus in order of consumption rate. All of these species were significantly more preferred than southern yellow pine (Pinus taeda L.), widely used for monitoring. Sinker cypress [ = old growth bald cypress, Taxodium distichum (L.)], western red cedar (Thuja plicata Donn), Alaskan yellow cedar (Chamaecyparis nootkatensis D. Don), eastern red cedar (Juniperus virginiana L.), sassafras [Sassafras albidum (Nutt.)], Spanish cedar (Cedrella odorata L.), Honduras mahogany (Swietenia macrophyla King), Indian rosewood (Dalbergia latifolia Roxb.), Honduras rosewood (D. stevensonii Standl.), and morado (Machaerium sp.) induced significant feeding deterrence and mortality to C. formosanus. The last eight species produced 100% mortality after 3 mo.     

Conserved oviposition preferences in alpine leaf beetle populations despite host shifts and isolation

Abstract.  1. Choosing the plant on which to lay their eggs is the last act of care that most female herbivorous insects bestow upon their offspring. These decisions play a pivotal role in insect–plant interactions, placing host preference under strong selection and contributing to the diversity of phytophagous insects as one of the first traits to adapt to new hosts.
2. This study presents a test of whether extreme isolation and exposure to different host plants can produce intra-specific divergence in oviposition preference in alpine insects. Geographic variation should impose selection to fine-tune host plant ranking and specificity to the plants normally encountered, to avoid wasting time during the very limited reproductive season experienced at high altitudes.
3. Beetles from five populations of Oreina elongata differing in host availability were offered three natural hosts: Cirsium spinosissimum , Adenostyles alliariae , and Adenostyles glabra . A novel application of a continuation ratio model (logistic regression) was made to sequential no-choice experiments, combined with quasi-likelihood analysis of multiple-choice experiments.
4. The results show little geographic variation in host plant choice: all populations strongly preferred Cirsium in multiple-choice trials, and in no-choice experiments laid around 47% of their remaining eggs during each stage, almost regardless of the host present.
5. Enemy-free space seems to explain the preference for Cirsium , but isolation and exposure to different plants has clearly not caused local adaptation in host plant ranking or specificity. Reasons for this conservatism despite divergence in other characteristics are discussed.     

Life history and host range of Sauris nr. purpurotincta,an unsuitable biological control agent for Chinese tallowtree

Foreign surveys in China discovered a defoliating insect species feeding on the leaves of Chinese tallowtree (Triadica sebifera), an invasive weed of the southeastern U.S.A. The life history of this species, Sauris nr. purpurotincta (Lepidoptera: Geometridae), was examined and larval no-choice and adult multiple-choice host range tests were conducted in quarantine to evaluate their suitability for biological control of Chinese tallowtree. The results indicated that the larvae have five instars and require approximately 22 days to complete development to the adult stage. Host range tests indicated that the larvae could not feed and complete development on most species tested. However, 40% of the larvae survived when fed leaves of Hippomane mancinella, a state-listed endangered species in Florida, and all larvae survived when fed Morella cerifera, a common native species of the southeastern U.S.A. Multiple-choice oviposition tests indicated eggs were laid on leaves of both a south Florida native plant Gymnanthes lucida and Chinese tallowtree. Considering this broad host range, this species will not be considered further for biological control of Chinese tallowtree in the U.S.A.     

Choosing between good and better: optimal oviposition drives host plant selection when parents and offspring agree on best resources

Insect preferences for particular plant species might be subjected to trade-offs among several selective forces. Here, we evaluated, through laboratory and field experiments, the feeding and ovipositing preferences of the polyphagous leafminer Liriomyza?huidobrensis (Diptera: Agromyzidae) in relation to adult and offspring performance and enemy-free space. Female leafminers preferred laying their eggs on Vicia?faba (Fabaceae) over Beta?vulgaris var. cicla (Chenopodiaceae), in both laboratory and field choice experiments, although no oviposition preference was observed in no-choice tests. Females fed more often on B.?v.?var.?cicla (no-choice test) or showed no feeding preference (choice test), even when their realized fecundity was remarkably higher on V.?faba. Offspring developed faster, tended to survive better, and attained bigger adult size on the preferred host plant. Also, a field experiment showed higher overall parasitism rates for leafminers developing on B.?v.?var.?cicla, with a nonsignificant similar tendency in field surveys. According to these results, host plant selection by L.?huidobrensis appears to be driven mainly by variation in host quality. Moreover, the consistent oviposition choices for the best host and the labile feeding preferences observed here, suggest that host plant selection might be driven by maximization of offspring fitness even without a conflict of interest between parents and offspring. Overall, these results highlight the complexity of decisions performed by phytophagous insects regarding their host plants, and the importance of simultaneous evaluation of the various driving forces involved, in order to unravel the adaptive significance of female choices.     

Host range of the emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) in North America: results of multiple-choice field experiments

Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae), an invasive phloem-feeding pest, was identified as the cause of widespread ash (Fraxinus) mortality in southeast Michigan and Windsor, Ontario, Canada, in 2002. A. planipennis reportedly colonizes other genera in its native range in Asia, including Ulmus L., Juglans L., and Pterocarya Kunth. Attacks on nonash species have not been observed in North America to date, but there is concern that other genera could be colonized. From 2003 to 2005, we assessed adult A. planipennis landing rates, oviposition, and larval development on North American ash species and congeners of its reported hosts in Asia in multiple-choice field studies conducted at several southeast Michigan sites. Nonash species evaluated included American elm (U. americana L.), hackberry (Celtis occidentalis L.), black walnut (J. nigra L.), shagbark hickory [Carya ovata (Mill.) K.Koch], and Japanese tree lilac (Syringa reticulata Bl.). In studies with freshly cut logs, adult beetles occasionally landed on nonash logs but generally laid fewer eggs than on ash logs. Larvae fed and developed normally on ash logs, which were often heavily infested. No larvae were able to survive, grow, or develop on any nonash logs, although failed first-instar galleries occurred on some walnut logs. High densities of larvae developed on live green ash and white ash nursery trees, but there was no evidence of larval survival or development on Japanese tree lilac and black walnut trees in the same plantation. We felled, debarked, and intensively examined >28 m2 of phloem area on nine American elm trees growing in contact with or adjacent to heavily infested ash trees. We found no sign of A. planipennis feeding on any elm.     

Feeding and oviposition preference of Phyllophaga cuyabana (Moser) (Coleoptera: Melolonthidae) on several crops

Laboratory and greenhouse experiments were carried out to study food and oviposition preference by Phyllophaga cuyabana (Moser) on different plant species as Cajanus cajan L. (pigeon pea), Crotalaria juncea L. (sun hemp), Crotalaria spectabilis Roth (showy crotalaria), Crotalaria ochroleuca G. Don (slenderleaf rattlebox), Glycine max [L.] Merrill (soybean), Gossypium hirsutum L. (cotton), Helianthus annuus L. (sunflower), Stizolobium aterrimum [Mucuna aterrima] Piper Tracey (velvetbean) and Zea mays L. (mayze). In no-choice experiments, the number of eggs layed in sunflower, C. juncea and soybean was larger compared to cotton. Despite the fact that the adults did not discriminate among plants, in dual-choice test, the proportion of eggs layed and leaf consumption by P. cuyabana adults in soybean were significantly higher than in C. spectabilis. The larval distribution in the soil was at random in multiple-choice, without any trend of preference, but in dual-choice, when soybean was the control, larvae always preferred to feed on its roots. P. cuyabana adults had preference for more suitable hosts and that could stand their offspring survival. This behaviour can be usefully exploited in an integrated management program for this pest.     

Feeding preference of Coptotermes formosanus (Isoptera: Rhinotermitidae) for gamma-irradiated wood impregnated with benzoylphenylurea compounds under laboratory conditions

The feeding preference of Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) for 200-kGy gamma-irradiated Cryptomeria japonica D. Don (Japanese cedar) sapwood impregnated with benzoylphenylurea compounds such as hexaflumuron and noviflumuron was examined by three laboratory tests. Although termites were not deterred from feeding on gamma-irradiated wood samples that had been impregnated with hexaflumuron or noviflumuron, termite mortality was significantly higher compared with solvent controls in the no-choice test. All live termites were transferred to paper disks immediately after the no-choice test to investigate changes in mortality with time, and this test also confirmed the effects of hexaflumuron and noviflumuron on worker termites, which showed a significant feeding preference for gamma-irradiated wood. Only the 1480 ppm noviflumuron-impregnated gamma-irradiated wood specimens showed significant differences in mortality in the two-choice test. These results suggest that gamma-irradiated C. japonica wood, which is locally abundant in Japan, may have potential as a bait substrate for benzoylphenylurea compounds.     

Asymmetry of larval diet breadth and oviposition preference in Leptinotarsa undecimlineata

The relationship between preference and performance was studied under laboratory conditions for larvae and adult females of Leptinotarsa undecimlineata (Stål) (Coleoptera: Chrysomelidae). Leptinotarsa undecimlineata feeds exclusively on Solanum lanceolatum L. (Solanaceae) in the centre of Veracruz, Mexico. A common sympatric species, Solanum myriacanthum Dunal, is not used as host. We conducted a series of laboratory experiments to detect reasons for the exclusive use of one host plant. Leptinotarsa undecimlineata larvae were reared under laboratory conditions on both plant species, Solanum lanceolatum and S. myriacanthum . Length of larval stages, pupal weight, and percent adult eclosion were compared, and larval preference for both Solanum species was tested. Upon eclosion, adult females were exposed to each of the plants, and the effect of larval diet on adult preference was determined. Oviposition on both Solanum species was observed in no-choice tests. Larvae showed no significant preferences for either plant species. Pupal weight, however, was significantly higher on S. lanceolatum . Female beetles significantly preferred S. lanceolatum leaves, and no effect of preimaginal conditioning was found. Females reproduced in lower numbers after feeding on S. myriacanthum , oviposition initiated later, and females laid fewer eggs than females fed with S. lanceolatum . No female accepted S. myriacanthum for oviposition. Results obtained suggest that the potential host breadth of L. undecimlineata is broader in larvae than in female beetles.     

The leaf-tying moth Hypocosmia pyrochroma (Lep., Pyralidae), a host-specific biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia

Abstract:  Cat's claw creeper, Macfadyena unguis-cati , a major environmental weed in coastal and sub-coastal areas of Queensland and New South Wales, Australia is a target for classical biological control. Host specificity of Hypocosmia pyrochroma Jones (Lep., Pyralidae), as a potential biological control agent was evaluated on the basis of no-choice and choice larval feeding and survival, and adult oviposition preference tests, involving 38 plant species in 10 families. In no-choice tests, larval feeding and development occurred only on cat's claw creeper. In choice tests, oviposition and larval development was evident only on cat's claw creeper. The results support the host-specificity tests conducted in South Africa, and suggest that H. pyrochroma is a highly specific biological control agent that does not pose any risk to non-target plants tested in Australia. This agent has been approved for field release by relevant regulatory authorities in Australia.     

河南榆科植物二新异名

将太行榆 Ulmus taihangshaneasis S．Y．Wang并入脱皮榆U．lamellosa Wang ex S．L．Chang ex L．K． Fu作为新异名;将毛叶朴Celtis pubescens S．Y. Wang et C．L. Chang并入朴树C．sinensis Pers．作为新异名。     

Host Specificity of Altica carduorum Guer. Chrysomelidae: Coleoptera , a Defoliator of Cirsium arvense L. Scop. Asteraceae from North-western China

Traditionally, insects are not approved for release in North America as agents for the biological control of weeds if the larvae complete development on desirable plants in no-choice tests. This criterion excludes the use of the leaf-feeding beetle Altica carduroum Guer. since it can complete development on all Cirsium spp., including rare North American species, although in nature it is only known from the target weed Cirsium arvense. Host suitability is the result of a sequence of selection factors, and this study shows that most discrimination between thistle species is the result of host finding and egg production, and not larval developmental ability. In no-choice tests, the larvae completed development on 18 Cirsium species in five sections of the genus that were tested and on Silybum marianum, but not on other genera in the tribe Cardueae or more distantly related Asteraceae. The adult food consumption on C. arvense was two to eight times greater than on other Cirsium species, many of which, such as C. pitcheri and C. drummondii, received no feeding by over 50 of the beetles in the first 24 h. The best North American thistle for egg production was C. scariosum, but this was only 28 of that on C. arvense. The preference for C. arvense in multiple-choice tests increased with the size 2 of the arena. In the largest, an area of 6 m , 80 of the beetles and eggs were found on C. arvense and none were found on plants outside the subtribe Carduineae. Thus, as theory predicts, host discrimination between thistle species takes place at earlier stages than suitability for larval development, and this should be considered when determining the safety of candidate agents.     

Two new synonyms of Ulmaceae in Henan,China

Ulmus taihangshanensis S. Y. Wang is reduced as a synonym of U. lamellosa Wang et S. L. Chang ex L. K. Fu, and Celtis pubescens S. Y. Wang et C. L. Chang as a synonym of C.sinensis Pers. respectively.     

Feeding and oviposition preferences of Drosophila buzzatii for microbial species isolated from its natural environment

Mature, mated female Drosophila buzzatii were given a choice of nine microbial communities actively growing on cactus homogenate in laboratory population cages. All communities contained identical naturally occurring bacteria, and comprised bacteria only and bacteria plus one of eight yeast species. Relative frequency of each yeast species ingested and number of eggs laid on each community were measured daily for three successive days. Flies generally preferred to feed and oviposit on those yeast species which are most abundant in rots of Opuntia cactus, and Pichia caclophila was the most preferred yeast. Light intensity, position of the yeast in the cage, and probably aggregation behaviour affected preference. Direct observation of adults was found to be inadequate for determining feeding preference. The ability of the flies to discriminate between yeasts developed with time. By day three, there was a significant correlation ( r = 0.96) between the yeasts preferred for feeding and those preferred for oviposition. Feeding preference may be determined in part by oviposition preference; and the latter appears to be the most fruitful avenue for future research into habitat selection by D. buzzatii-     

Effect of larval density and host species on preimaginal development of Bactrocera tau (Diptera: Tephritidae)

The fruit fly, Bactrocera tau (Walker) (Diptera: Tephritidae), is an important pest of fruit and vegetable crops. In this study, host preference of B. tau females and the effects of host species and larval density on larval survival, pupal weight, adult emergence, and developmental duration were investigated on cucumber (Cucumis sativus L.), sponge gourd (Luffa cylindrical L. (Roem)), bitter gourd [Momordica charantia (Cucurbitaceae) L.], guava [Psidium guajava (Myrtaceae) L.], and tangerine [Citrus reticulata (Rutaceae) (Blanco)]. The results showed that females preferred to cucumber over other host species. Larval feeding experience affected subsequent host oviposition preference of adult females. Host species and initial larval density affected certain aspects of the biology of B. tau. Larval density negatively affected insect performance. Survival rates at low densities were significantly higher than that at high densities. Total developmental duration reduced at high larval densities. Cucumber was more suitable to larval growth. Larvae on cucumber grew faster and the puparia were heavier than that on other host species. Larval survival, pupation rate and adult emergence were higher on cucumber compared with those in other host species. Oviposition preference of adult females was correlated with performance of their offspring.     

Nymphal and adult performance of Apolygus lucorum (Hemiptera: Miridae) on a preferred host plant, mungbean Vigna radiata

Mungbean, Vigna radiata (L.) Wilczek, a preferred host plant of Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae), is used in China as a trap crop for this pest in cotton fields. Little is known, though, about the relationship between adult oviposition preference and offspring performance of A. lucorum on mungbean. In this study, we compared the oviposition preference of A. lucorum on mungbean versus cotton plants in both open-field plots and field cages. Field-plot experiments demonstrated that the population density of first instar nymphs of A. lucorum and the ratio of first instar nymphs to adults were significantly higher on mungbean than on cotton. Choice and no-choice cage experiments revealed that the number of eggs laid on mungbean was significantly higher than on cotton. We also compared adult longevity and fecundity, as well as offspring survival and development on these two host plants. We found that A. lucorum adult females survived longer and laid more eggs on mungbean than on cotton (P?<?0.05). Mungbean also promoted higher rates of development than did cotton (P?<?0.05), but did not affect nymphal survival (P?>?0.05). In summary, the preference of A. lucorum adults for mungbean is consistent with both adult and nymphal performance. This study furthers the understanding of the relationship between the polyphagous species A. lucorum and its host plants, which will help improve trap-cropping strategies for the control of A. lucorum that are based on the use of mungbean.