Virus diseases of lupins

• I. INTRODUCTION
• II. APHID-TRANSMITTED VIRUSES

• (a) Potyvirus group

• (i) Bean yellow mosaic virus
• (ii) Clover yellow vein virus
• (iii) Bean common mosaic virus
• (iv) Peanut mottle virus
• (v) Bidens mottle virus

• (b) Cucumovirus group

• (i) Cucumber mosaic virus
• (ii) Peanut stunt virus

• (c) Alfalfa mosaic virus
• (d) Fabavirus group: broad bean wilt virus
• (e) Pea enation mosaic virus
• (f) Luteovirus group: soybean dwarf virus
• (g) Rhabdovirus group: lettuce necrotic yellows virus

• III. THRIPS-TRANSMITTED VIRUSES
• Tomato spotted wilt virus

• IV. NEMATODE-TRANSMITTED VIRUSES

• (a) Tobravirus group: pea early browning virus
• (b) Nepovirus group: tomato black ring virus

• V. VIRUS-LIKE DISEASES

• (a) Lupin leaf curl ‘virus’
• (b) ‘Lupin witches’ broom disease

• VI. CONTROL VII. CONCLUSIONS
• VII. CONCLUSIONS

     

Interactions between Apion species (Coleoptera: Curculionidae) and Polygonaceae. I. Apion curtirostre Germ, and Rumex acetosa L.

Abstract.

• 1 Apion curtirostre is the commonest weevil attacking Rumex acetosa in the Lancaster area.
• 2 The ovipositional behaviour, larval development, emergence and hibernation of A. curtirostre are described.
• 3 From dissection of samples of stems of R. acetosa, abundance curves for the stages of A. curtirostre and its chalcid parasitoids were constructed and the between-stage mortalities determined.
• 4 There is an exponential relationship between R. acetosa stem height and number of A. curtirostre eggs laid.
• 5 Male stems of R. acetosa appear earlier and are smaller than female stems. Taller stems, at least in female plants, live longer than shorter ones.
• 6 Apion survival is lower in male than in female stems.
• 7 Stem sex is the primary determinant of opposition choice with stem thickness a secondary determinant.
• 8 A. curtirostre eggs introduced experimentally into stems of four Rumex species survived significiantly better in R. acetosa than in any other species. Survival in R. acetosa female plants was twice that in males.
• 9 Survival of A. curtirostre eggs at densities of 4, 8 and 16 per R. acetosa stem was twice that at densities of 32 and 64 per stem.
• 10 The stem size of female R. acetosa was reduced as the number of attacking weevils increased. There was no significant effect in males. No adverse effect on seed production was detected.
• 11 The nature of the relationship between A. curtirostre and R. acetosa is discussed.

     

Species of the Genus ScrupocellariaVAN BENEDEN (Bryozoa,Anasca) from Indian Waters

Nine species of the genus Scrupocellaria VAN BENEDEN are figured and described in this paper. They are:

• 1 Scrupocellaria maderensis BUSK.
• 2 S. obtecta HASWELL.
• 3 S. mansueta WATERS.
• 4 S diadema BUSK.
• 5 S. scruposa (LINNAEUS).
• 6 S. spatulata (D'ORBIGNY).
• 7 S. delilii (AUDOUIN).
• 8 S. bertholettii (AUDOUIN).
• 9 S. talonis OSBURN.

The specimens were collected from the south west and south east coasts of India. Six species are described for the first time from Indian waters. Variations noticed in the morphology of the above species with those described elsewhere are assessed and discussed. A study of the genus from the available material shows that characters like the number of spines and nature of scuta show considerable intraspecific differences. Variation in spine number is a common occurrence and undue importance to spine number, especially in the case of tropical species, should be given with due caution. The history of S. bertholettii is really confusing especially in view of the creation of the var. tenuirostris. A comparative study of the type specimens would help to clarify the taxonomic ambiguity of this species.     

Seasonal shifts in host usage in Uroleucon gravicorne (Homoptera: Aphididae) and implications for the evolution of host alternation in aphids

ABSTRACT.

• 1 Uroleucon gravicome (Patch) feeds on annual Erigeron species and on perennial Solidago species.
• 2 To test whether Solidago and Erigeron are analogous to winter and summer hosts of typical host-alternating aphids, reproductive performance, host preferences, and host associations were measured for E.strigosus, S.juncea and S.nemoralis during spring, summer and autumn.
• 3 Caged individuals can reproduce on both genera throughout the season, though colonies are rare on Solidago during summer.
• 4 Developmental rate, adult weight, and fecundity decline between May and August on all hosts; however, the drop is least on E.strigosus, intermediate on S.nemoralis, and greatest on S.juncea.
• 5 Throughout the season, reproductive performance is at least as great on Erigeron as on Solidago, the difference being least in spring.
• 6 Soluble nitrogen content shows the same seasonal trends as reproductive performance, declining in all hosts, but declining least in E.strigosus.
• 7 Preference tests and field records show that U.gravicorne moves from Solidago to Erigeron when the first alatae mature in late spring, feeds on Erigeron during the summer, and, in late summer, returns to Solidago where overwintering eggs are laid.
• 8 Solidago is not nutritionally superior during spring or autumn; its use during those seasons may result from the need for good oviposition sites.

     

Study of two forms of the adult Stenocranus minutus

• 1 In studies on Stenocranus minutus, two winged forms of adults have been observed, macropterous and sub-macropterous. Macropterous individuals, with extra-long wings, have not been previously observed or described. Probably only the macropterous form disperses by flight.
• 2 The two forms differ in their wing lengths, intensity and extent of pigmentation.
• 3 The rate of maturation differs in the two forms. In macropters, maturation is delayed; the period of oviposition is shorter and they are less fecund.
• 4 Macropters do not live as long as sub-macropters.
• 5 The macropters weigh less than the sub-macropters.
• 6 Under laboratory conditions, both forms can hop but the macropterous forms fly for a longer time than the sub-macropters.
• 7 At 25°C, more macropterous forms were produced on wilting Dactylis than on green, succulent Dactylis.
• 8 Dispersal of field population was inferred from changes in proportions of the two forms and by simultaneous occurrence of macropters in aerial suction traps.
• 9 The macropterous forms of S.minutus migrate a few weeks after emergence while still immature and migration coincides with drying up of host plant, Dactylis glomerata L.
• 10 Relatively high temperature, low wind speeds and a small number of hours of sunlight seem to favour dispersal by flight in S.minutus.

     

On the neotropical acanthocinini (coleoptera,ceramhycidae, lamiinae) some new genera and generic revisions

In Fortführung seiner Untersuchungen über neotropische Acanthocinini veröffentlicht der Verfasser hiermit Beschreibungen von folgenden neuen Gattungen:

• Nyssodrysilla nov. gen. mit N. irrorata (Melzer) aus Brasilien als Generotype, N. viliata (Melzer), comb, nov., aus Brasilien und N. lineata nov. spec, aus Peru.

• Nyssodrysola nov. gen. mit N. stictica nov. spec. aus Peru als Generotype.

• Sciadosurus nov. gen. mit S. albobrunneus nov. spec. aus Peru als Generotype.

• Acarinozineus nov. gen. mit A. striatus nov. spec. aus Peru als Generotype und A. spinicornis nov. spec, aus Mexiko.

• Alcathousites nov. gen. mit A. chaclacayoi nov. spec. aus Peru als Generotype.

• Xylergatina nov. gen. mit X. pulcher (Lane) aus Peru als Generotype.

• Xylergatoides nov. gen. mit X. asper (Bates) aus Brasilien und Argentinien als Generotype.

Ferner werden revidiert die Gattungen:

• Xylergates Bates, Generotype X. lacteus (Bates), mit Beschreibung der beiden neuen Arten X. elaineae aus Peru und X. dorotheae aus Britisch‐Guayana.

• Chaetanes Bates, Generotype C. setiger (Bates), mit Beschreibung der drei neuen Arten C. costulatus aus Peru, C. nigrobasalis aus Brasilien und C. apicalis aus Französisch‐Guayana.

• Wo es erforderlich ist, sind Bestimmungstabellen gebracht und die Arten abgebildet.

     

Screening known Cerambycidae pheromones for activity with the Peruvian fauna

1. Semiochemicals are powerful tools for the surveillance and suppression of forest insects. Although the literature on the chemical ecology of and use of semiochemicals to manage the Cerambycidae is growing, little is known about the chemical ecology of Cerambycidae fauna in Peru.
2. Trapping studies that screen known attractants in off-shore mitigation programs can provide valuable baseline knowledge to inform management of species introduced outside their native range.
3. Known Cerambycidae pheromones were screened for activity in a year-long field study in Peru to look for activity in the local Cerambycidae fauna.
4. The most frequently captured species were Megacyllene andesiana (Casey), Oreodera bituberculata Bates, Aegomorphus longitarsis (Bates) and Discopus eques Bates.
5. The activity period of A. longitarsis, O. bituberculata and D. eques occurred in mid-September 2020 and for M. andesiana occurred in early October 2020.
6. Responses to anti-2,3-hexanediol, fuscumol and fuscumol acetate by M. andesiana, O. bituberculata and D. eques were observed.
7. We observed antagonism of the responses of M. andesiana, O. bituberculata and D. eques when anti-2,3-hexanediol, fuscumol and fuscumol acetate were tested in blends.

     

Habitat segregation in four species of adult tiger beetles (Coleoptera: Cicindelidae)

ABSTRACT.

• 1 Habitat segregation in four species of tiger beetles, Cicindela cancellata Dejean, C.cardoni Fleutians, C.minuta Olivier and C.sumatrensis Herbst in a river bank ecosystem was studied in dry and wet seasons.
• 2 The four species segregated distinctly along the river beds into separate habitats, with occasional overlapping in both the seasons.
• 3 Among the habitat characteristics considered, vegetation, soil moisture and available prey-size were found to be important in species segregation.
• 4 D ²-analysis showed that the habitat preferences of C.cardoni and C.cancellata were closer to that of C.sumatrensis. The habitat of C.minuta was distinctly separated.
• 5 There was a positive correlation between the mandible length of each tiger beetle species and the length of prey captured.
• 6 Variance in mandible length within species was related to prey-length distribution pattern and to variance in habitats.

     

Attachment may be a basis for specialization in oak aphids

ABSTRACT.

• 1 The potential role of tarsal attachment in host selection was studied in the specialist aphids Tuberculoides annulatus Hartig and Myzocallis schreiberi Hille Ris Lambers and Stroyan.
• 2 M.schreiberi could walk freely on its host, Quercus ilex and on Q.robur, whereas T.annulatus could walk freely on its host, Q.robur but had difficulty on Q. ilex.
• 3 Attachment to the rough-textured leaves of Q.robur was achieved by means of the pretarsal claws, and to the smooth upper surface of individual trichomes on the lower surface of Q.ilex using flexible pretarsal empodia.
• 4 Both behavioural and allometric differences can account for the inability of T.annulatus to grip onto Q.ilex.
• 5 The role of attachment by phytophagous insects in host plant resistance and selection is discussed.

     

Interactions between Apion species (Coleoptera: Curculionidae) and Polygonaceae. II. Apion violaceum Kirby and Rumex obtusifolius L.

Abstract.

• 1 The biology of Apion violaceum is described, particularly with respect to its primary host, Rumex obtusifolius.
• 2 Oviposition in Rumex acetosa is directly into the stem, but in R. obtusifolius it takes place through the sheath enclosing developing flowers, stem leaves and stem.
• 3 Larvae cannot complete development in the leaf petioles and must migrate downwards to the stem or die before pupation.
• 4 Mortality of A. violaceum in the stems was highest in eggs and first instar larvae and in third instar larvae. The latter mortality was caused almost entirely by parasitoids.
• 5 Stems of R. obtusifolius on the study site increased in number up to August and reached the maximum height in late June.
• 6 Over the 4 year study period there was a parallel decline in stem numbers and mean stem height at two of the sites studied. At these sites there was also a decline in A. violaceum numbers and density per stem.
• 7 The quality of sites for A. violaceum, as defined by the product of stem numbers and stem height, showed a significant correlation with A. violaceum numbers.

     

Host plant specificity, oviposition behaviour and egg parasitism in some leafhoppers of the genus Eupteryx (Hemiptera: Cicadellidae)

Abstract.

• 1 Three species of Eupteryx, E.aurata, E.cyclops and E.urticae are regularly found on stinging nettles in South Wales.
• 2 E.aurata host alternates between nettles in spring and autumn, and Heraclewn, Eupatorium and Mentha species in summer. E.cyclops and E.urticae attack only nettles.
• 3 All species are host specific during oviposition and show preferences to lay eggs in discrete plant regions.
• 4 A Mymarid egg parasite of the genus Anagrus was reared more commonly from eggs laid in nettles than from eggs laid in alternative hosts.

     

Studies on the biology and distribution of Leptinus testaceus Müller within a community of mixed small mammal species

• 1 In a mixed small mammal community L.testaceus was found to infest A.sylvaticus more frequently than either C.glareolus or M.agrestis.
• 2 Male and female rodents carried similar numbers of the beetle.
• 3 Peak infestation on A.sylvaticus occurred during spring and summer suggesting a single major emergence period.
• 4 There was good correlation between the beetle index and the numbers of individuals of A.sylvaticus infested; this relationship resembled that found within certain host/ectoparasite relationships.

     

Laboratory study of cannibalism and interspecific predation in ladybirds

Abstract.

• 1 In the absence of aphids, adult females of Adalia bipunctata (L.) showed a greater reluctance to eat eggs than males.
• 2 Eggs and young larvae were more vulnerable to cannibalism than older larvae and starved larvae were more vulnerable than well-fed larvae.
• 3 Both egg and larval cannibalism is inversely related to the abundance of aphids.
• 4 Eggs are a better food, in terms of larval growth and survival, than aphids.
• 5 In the absence of aphids interspecific predation occurred, but not equally, between the coccinellids A.bipunctata, A.decempunctata (L.), Coccinella septempunctata L. and C.undecempunctata L.
• 6 Larvae and adults of A. bipunctata and C.septempunctata were reluctant to eat conspecific eggs painted with a water extract of the other species' eggs and larvae of C. septempunctata were more likely to die after eating a few eggs of A.bipunctata than vice versa.
• 7 These results indicate that cannibalism occurs mainly when aphid prey is scarce and is adaptive in that it improves the chances of survival, and coccinellids, to varying degrees, are defended against interspecific predation.

     

Parasitoid associated with Liriomyza huidobrensis (Diptera: Agromyzidae) outbreaks in tomato fields in Brazil

1. The knowledge of natural factors that affect pest populations is essential in predicting the occurrence of pest outbreaks and in developing integrated pest management programmes. Natural enemies, climatic elements and host plants are among the most important factors affecting pest dynamics.
2. Tomato (Solanum lycopersicum) is the second most consumed vegetable worldwide. The pea leaf miner Liriomyza huidobrensis (Diptera: Agromyzidae) is a major pest to the tomato in Brazil.
3. This study aimed to determine the main natural factors that regulate L. huidobrensis populations in tomato fields in Brazil.
4. Liriomyza huidobrensis densities were evaluated by directly counting the number of active mines on the basal leaf of the middle section of the plant canopy, and predators and parasitoids were assessed using the leaf‐beating‐against‐a‐tray technique. Eight commercial tomato fields were assessed over two years. The phenological growth stages of the tomato plants (vegetative and reproductive) were noted during the assessments.
5. Liriomyza huidobrensis populations peaked between the middle and end of the planting season.
6. Opius sp. (Hymenoptera: Braconidae) was the main natural enemy of L. huidobrensis.
7. Our results suggest that phenological growth stage and Opius sp. are associated with population dynamics of L. huidobrensis in tomato fields.
8. Therefore, integrated pest management programmes should aim to preserve populations of the parasitoid Opius sp.

     

Squash beetle trenching behaviour: avoidance of cucurbitacin induction or mucilaginous plant sap?

Abstract.

• 1 Foraging patterns of the squash beetle, Epilachna borealis Fabricius (Coleoptera: Coccinellidae), in field cages are not consistent with the hypothesis that this beetle avoids leaves in which its feeding damage has caused the induction of cucurbitacins.
• 2 E.borealis feeding does not induce accumulation of cucurbitacins inside or outside of feeding trenches.
• 3 Cucurbitacins do not reduce the survival or growth rate of E. borealis larvae.
• 4 High concentrations of cucurbitacins fail to deter E.borealis feeding; rather, cucurbitacins are feeding stimulants for squash beetles.
• 5 Trenching behaviour in E.borealis is facultative and correlates with leaf turgor and the degree to which sticky phloem sap oozes from damaged leaves.
• 6 Mucilaginous phloem sap in many curcurbit species inhibits feeding by E.borealis when it is applied to beetle mouthparts.

     

Zum Verhalten blinder Fische

• 1 Das Verhalten bei der Nahrungsaufnahme wurde nach Augenexstirpation an Phoxinus phoxinus L., Gasterosteus aculeatus L. und Hemigrammus caudovittatus Ahl beobachtet, sowie zum Vergleich am Höhlenblindfisch Anoptichthys jordani Hubbs und Innes.
• 2 Bei Dressuren auf Saccharose zeigen die genannten Arten unterschiedliches Lernvermögen: Phoxinus benötigt ca. 37, Gasterosteus und Hemigrammus 21 und Anoptichthys lediglich 10 Dressuren (1 Dressur pro Tag), um die Aufgabe zu erlernen.
• 3 Bei Dressuren auf verschiedene Geschmacksstoffe lernt Phoxinus am schnellsten seine Aufgabe bei Saccharose, langsamer bei Essigsäure und Natriumchlorid, am langsamsten bei Chinin-hydrochlorid.
• 4 Ein Einfluß des Wetters auf das Verhalten der Fische während der Dressur konnte nicht festgestellt werden.
• 5 Das Verhalten geblendeter Fische im Schwarm sehender Artgenossen wurde beobachtet.
• 6 Ein geblendeter Hemigrammus kann sich in einem Schwarm des blinden Höhlenfisches Anoptichthys jordani behaupten.
• 7 Von den 3 geblendeten Arten konnte Phoxinus II 3 Jahre und 11 Monate, Hemigrammus XII 2 Jahre und Gasterosteus XVII 4 Monate am Leben erhalten werden.
• 8 Die Beobachtungen werden anhand der Schilderungen anderer Autoren diskutiert, u. a. auch im Hinblick auf die Existenzmöglichkeit geblendeter Fische in natürlichen Gewässern.

     

Seasonal history,plant interactions and egg parasitism of the variegated caper bug Stenozygum coloratum Klug (Heteroptera: Pentatomidae)

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The reproductive biology and diapause of the British fungal-breeding Drosophila

Abstract.

• 1 Seasonal reproductive development was investigated in four obligate fungivorous species, D.phalerata Meigen, D.transversa Fallen, D.cameraria Haliday and D.confusa Staeger.
• 2 Samples of females taken from woodlands over a 2 year period were scored for reproductive status and fat content.
• 3 Populations of D.phalerata and D.cameraria maintained in an outdoor insectary provided information on developmental time and adult mortality throughout the year.
• 4 Experiments in controlled environmental chambers gave percentage diapause curves against day length for all four species.
• 5 In D.phalerata the influence of temperature and fungus upon diapause behaviour was also investigated.
• 6 In D.phalerata the optimal strategy for reproductive development can vary from month to month. Maturation of females may be immediate, dependent upon a fungal cue or completely prevented.

     

Field manipulation of populations of individual staphylinid species in cereals and their impact on aphid populations

Abstract.

• 1 Four species of staphylinids were caged separately on wheat and their effect on the population development of the grain aphid, Sitobion avenae (F.), was investigated over two seasons.
• 2 A novel field cage design was used to exclude all but the staphylinid species under investigation.
• 3 Predator effects were compared with total-exclusion cages in which all predators and parasitoids were kept out.
• 4 During a high-density phase of aphid population development only Philonthus cognutus (Stephens) significantly influenced aphid population numbers.
• 5 At low aphid densities, Tachyporus obtusus (L.), T.chrysomelinus (L.) and P.cognatus reduced aphid population levels.
• 6 The experiments showed that Tachyporus spp. can reduce the numbers of cereal aphids prior to the exponential phase of aphid population increase and that P.cognatus causes some reduction at both the stages of aphid population growth investigated.