bluuebunny/crossref_metadata_2025 huggingface dataset:
Platynota flavedana Clem. (Lepidoptera, Tortricidae) on Citrus in Jamaica
Authors: Strangways-Dixon J.
Published: July 2009

Platynota flavedana Clem. (Lepidoptera, Torticidae), the ‘fruit-dropping caterpillar’ or ‘citrus tortrix’, is an important but sporadic pest of Citrus in Jamaica.

Damage is confined to part of the period between April and June, and in a heavy attack large numbers of young Citrus fruits, each bearing a scar or hole in the area shielded by the sepals, are found beneath the trees. At other times of the year the insect is present in the orchards in small numbers only.

In the field, the eggs, which are laid in clusters, were found on the leaves of Citrus, the larvae in webbing tunnels, usually beneath the sepals of young fruits but also between leaves drawn together with silk, and the pupae within the webbing. Fertilished females isolated in 3 × l-in. glass subes oviposited readily and continued to do so for rather less than a week. The incubation period of the eggs was 6.5 days. Preliminary experments showed that the young larvae require either new, rapidly growing leaves or young fruits of diameter less than ½ in., and a technique for rearing individual larvae in described. The durations of the larvae and pupal phases were 17–35 and 5–10 days, respectively.

In the past, chemical control measures had been attempted when large numbers of small fruits had already fallen. It is suggested that such measures cannot be effective because the hardness of texture, that makes them unsuitable for the development of young larvae. Some evidence is provided of effective control by natural factors, throught to be of a pathogenic nature, and it is recommended that the possibility of biological control should be investigated. The difficulties of fitting biological control into the pattern of routine fungicidal spray-applications is mentioned.

It is concluded that a comprehensive investigation of both chemical and biological control is necessary, and it is suggested that in areas where outbreaks of the pest occur at all regulary it would be wise, meanwhile, to apply an insecticide, preferably when the new leaves and flower buds are developing and at latest before completioon of petal-fall.
A theoretical evaluation of population growth after removing individuals from some age groups
Authors: Lefkovitch L. P.
Published: July 2009

A mathematical treatment is proposed, utilising the methods and notation of matrix algebra, for evaluating the theroetical effects on the growth and structure of a population of the removal of individuals in particular age groups or stages in the life history. Formulae are derived to establish what proportions of given age groups or stages, individually or in combination, can be withdraw from the population whilst permitting its maintenance at a constant level. It is pointed out that these methods, appropriate to the situtation in which the population is exploited by a cropping procedure, can be extened to the special case of population control, in which it is desired to minimise or eliminate the population. The methods are illustated by numerical examples based on census observations on a growing population ofLasioderma serricorne(F.).
Digestion in the tsetse fly Glossina morsitans Westw.: the effect of feeding field-caught flies on guineapigs in the laboratory
Authors: Langley P. A.
Published: July 2009

It has been shown that adults of Glossina morsitans Westw. that have fed from a bait ox in their natural environment digest their blood meals more rapidly than others that have emerged and been fed in the laboratory, even when both are maintained under identical environmental conditions after feeding.

In further experiments with G. morsitans in Rhodesia, flies caught in the field and fed in the laboratory were found to lose their ability to digest their meals rapidly. Measurements, made throughout three hunger cycles, of the rate of digestion, as reflected in the rate of excretion, of blood meals by field-caught flies fed on guineapigs in the laboratory showed that this was not significantly different from that of the normal, flied-fed flies during the first two hunger cycles but that during the third it fell to a level comparable to that of flise that emerged and were fed in the laboratory.

It is concluded that whatever may be the events that condition the field flies to digest their meals rapidly in the natural environment, these are repeated with the ingestion of each meal, and that laboratory conditions cause a rapid loss of this greater digestive capability.
The humidity responses ofTrogoderma granariumEverts (Col., Dermestidae)
Authors: Yinon U. , Shulov A.
Published: July 2009

The humidity responses ofTrogoderma granariumEvents were tested in humidity gradients set up in choice-chambers, each comprising a petri-dish with the lower half divided diametrically into two compartments containing sulphuric-acid soluctions affording different relative humidities and surmounted by a copper-gauze platform on which the insects, released centrally, could move about. Counts of the numbers in either half of the arena were made at 15–minute intervals over two hours.

In a gradient of 20–80 per cent. relative humidity, at 20°C., the average count was significantly greater on the drier side than on the moister one for larvae and adults tested in groups and for larvae and adult males, but not females, tested singly; the response was greater when the insects were tested in groups. Antennectomised adults, tested at 25°C. in a gradient of 20–100 per cent. relative humidity, showed no response, although intact control beetles showed a significant perference for the drier side. When adults were tested in groups at 25°C. in a range of gradients, from 20–10 to 20–100 per cent, a preference for the drier side was invariably shown, the response tending to be greater and to occur more rapidly in larvae than in adults, and as the humidity gradient steepened.
Further studies on age and trypanosome infection rates in Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. in Uganda
Authors: Harley J. M. B.
Published: July 2009

Between June 1964 and May 1965, samples of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. were caught in an area on the north-eastern shore of Lake Victoria in Uganda. Both males and females were classified into age-categories according to the degree of wear of the wings. Females were also classified into ovarian age-categories according to the exact or approximate number of ovulations that had taken place. All were examined for presence of infections with Trypanosoma, which were classified as vivax-type, congolense-type or brucei-type according to their location in the flies.

The percentage compositions of the samples by wing-fray category are compared. The mean wing-fray category of females of G. palpalis fuscipes and G. brevipalpis was somewhat lower, and that of females of G. pallidipes somewhat higher, than that of the corresponding males. However, the figures for infection rate in females of all three species were higher than in the corresponding males, significantly so in G. pallidipes and G. palpalis fuscipes, and it seems probable that the mean age of females, at least of the two latter species, was greater than that of males. Among females, the range of calendar ages of flies in the various fray categories was wide.

The physiological age-determination method, in which females older than about 42 days are classified iDto four age-categories, does not extend sufficiently far to give a reasonable pattern for the age-composition of any of the species at Lugala, and many of the individuals caught must have been more than about 80 days old.

Seasonal fluctuations in mean wing-fray and in the proportion of old flies in the population were correlated with changes in infection rate of females of G. palpalis fuscipes but not of females of G. pallidipes. Among males of neither species were seasonal fluctuations in mean fray correlated with changes in infection rate, though among those of G. palpalis fuscipes the two varied similarly between June and February.

Females of G. pallidipes and G. palpalis fuscipes about 31–42 days old had significantly fewer brucei-type infections than those over 42 days old, and either the developmental cycle in the field must normally be longer than that recorded in laboratory investigations or many of the flies must become infected when more than just a few days old.
The tethered flight performance of a laboratory population of Triatoma infestans (Klug) (Hemiptera: Reduviidae)
Authors: Ward J. P. , Baker P. S.
Published: July 2009

The flight performance of a laboratory population of Triatoma infestans (Klug) was tested on a flight balance. Bugs adopted a typical flight posture which is described. They were capable of steady flight and produced reasonable amounts of lift. Flight durations were generally short, but capacity for flight rose to a peak in the third week after adult eclosion with the longest recorded flight being one of 2 h 40 min by a male. Sexual differences were slight; males had a slightly higher mean wing-beat frequency (57·8 Hz against 55·6 Hz), and a few more females than males made longer flights. Differences were noted between short and long fliers; the latter producing significantly more lift and showing signs of a flight pattern divisible into rising, steady and falling phases. The short fliers showed only rising and falling phases. Lift and wing-beat frequency were correlated, but it is evident that lift also depends on other variables such as stroke-plane angle, body angle and wing-beat amplitude, which are discussed.
Pulvinaria iceryi (Signoret) (Hemiptera: Coccidae) and its allies on sugar-cane and other grasses
Authors: Williams D. J.
Published: July 2009

The recent attack by Pulvinaria iceryi (Sign.) on sugar-cane in Mauritius is discussed in the context of other attacks by sap-sucking Hemiptera in the Mascarenes. P. iceryi is compared with its allies P. elongata Newst., P. saccharia DeLotto, P. sorghicola De Lotto and P. tenuivalvata (Newst.). The name of P. longisqua De Lotto is sunk as a synonym of P. elongata and a key is presented for the five related species.
The influence of salinity on larval development and population dynamics of Anopheles merus Dönitz (Diptera: Culicidae)
Authors: Mosha F. W. , Mutero C. M.
Published: July 2009

Variations in density of adults of Anopheles merus Dön. in Jimbo Village on the Kenya Coast were found to be correlated both with rainfall and with salinity at their breeding sites. Densities started to increase at the beginning of the rains when several breeding sites were formed. This was followed by a decline in numbers resulting mainly from the decrease in salinity in the semi-permanent breeding sites. A second rise occurred after the end of the rains, corresponding with an increase in salinity in the semi-permanent breeding sites due to evaporation. Peak density coincided with salinities of 30–50% sea water in the breeding sites. Laboratory breeding experiments showed that the larvae were usually capable of completing development in 0–100% sea water, with optimum development at 0, 40 and 60% sea water. Failure to complete development in 100% sea water at certain periods of the year indicated that there could be some seasonal variation in salt tolerance. The larvae were also found to complete development in alkaline saline water collected from an inland location around Lake Jipe in Kenya. The LC50s of sea water for first and fourth-instar larvae after exposure for 2 h were 135·0 and 930·0%, respectively. First-instar larvae were less to lerant of sodium chloride than of sea water of equivalent strength. The LC50 of sodium chloride for first-instar larvae was only 102·5%, sea water equivalent. In tests against first-instar larvae of other soluble chemical salts normally present in sea water, the highest LC50 (122·0g/litre) was of sodium sulphate and the lowest (10·5g/litre) of potassium carbonate.
A field screening technique for resistance of cowpea (Vigna unguiculata) to the pod-borer Maruca testulalis (Geyer) (Lepidoptera: Pyralidae)
Authors: Jackai Louis E. N.
Published: July 2009

A method for screening resistance of cowpea (Vigna unguiculata) to the legume pod-borer Maruca testulalis (Geyer) was developed. Several damage parameters were measured, including damage to stem, flowers, pods and seeds. Some of these parameters were assessed in more than one way. A decision was made at the end of the study as to which parameters were most appropriate for a field screening methodology. A plant resistance index, Ipr, was generated to aid in this decision. Based on this, it was concluded that flower, pod, and seed damage measurements provided the most important assessment of resistance to the borer. The larval population in the flowers showed marked differences in infestation levels between cultivars and is suggested as a means of comparing results in the future. Based on the methodology described, TVu 946 was the most resistant cowpea cultivar in every category of assessment. Five other cultivars were also selected for further evaluation as probable resistance donors: Kamboinse Local, TVu 1, VITA-5, TVx 3890–010F and VICAM-1/SP. The rationale behind the development of a field-screening methodology and some of its shortfalls are discussed.
The mechanisms of organophosphate and carbamate resistance in Culex quinquefasciatus (Diptera: Culicidae) from Cuba
Authors: Bisset J.A. , Rodriguez M.M. , Diaz C. , Ortiz E. , Marquetti M.C. , Hemingway J.
Published: July 2009

Two field-collected strains of Culex quinquefasciatus Say, collected 50 km apart in Havana City, Cuba, were both resistant to malathion and propoxur, while one population also showed low level resistance to temephos. Laboratory selection of the latter population with malathion for 22 generations increased the malathion resistance 1050-fold, temephos resistance 24-fold and propoxur resistance 453-fold compared to the standard laboratory susceptible strain. Synergist studies and biochemical tests indicated that two mechanisms, an elevated esterase and an insensitive acetylcholinesterase, were operative in these strains. The esterase mechanism conferred resistance to malathion, but not to temephos or propoxur. The acetylcholinesterase mechanism increased the level of malathion resistance and extended the cross-resistance spectrum to temephos and propoxur.
Survival of unfedRhipicephalus appendiculatus(Acarina: Ixodidae) in relation to host resistance and environmental factors in Kenya
Authors: Chiera J.W. , Punyua D.K.
Published: July 2009

Mean survival times for unfed ticks,Rhipicephalus appendiculatusNeumann exposed initially during the hot dry season (January) in Kenya were significantly higher than those of ticks exposed during the wet season (May). This was partly due to the timing of the next hot dry season which triggered the beginning of decline in survival, and partly due to the overall severity of the weather. The implication is that the time when the ticks feed affects the survival of the subsequent instar. The mean survival times for nymphs exposed initially during the wet and the hot dry seasons were 30 weeks and 44 weeks, respectively. Those for adult ticks ranged between 59–75 weeks and 62–79 weeks, respectively. Maximum survival times were, however, similar for adults but not for nymphs. Adult ticks had an initial period of 32–48 weeks of excellent survival, apparently independent of weather factors. Thereafter, mortality rates and adverse environmental factors were correlated. The survival of ticks fed on hosts of differing resistance status was also different. The most resistant host produced the smallest adult ticks and these gave the lowest survival, and vice versa. Male and female ticks from highly resistant hosts had similar survival, but the females from a moderately resistant host survived significantly better than the males. These results indicate the importance of weather and host resistance inR. appendiculatussurvival.
Control of tsetse fly (Diptera: Glossinidae) populations using traps at Nguruman, south-west Kenya
Authors: Dransfield R.D. , Brightwell R. , Kyorku C. , Williams B.
Published: July 2009

A field trial was carried out in a Maasai group ranch to assess the use of odour-baited traps for suppression of a population of the tsetse fly Glossina pallidipes Austen. In January, 1987, local people made 100 NG2B traps in their homesteads. These were then deployed within the suppression zone of about 100 km2, primarily in the areas of woodland where flies aggregate in the dry season. Traps were baited with acetone (ca. 150 mg/h) and cow urine (ca. 1000 mg/h) and checked at monthly intervals in order to replenish odours and repair damage. A further 90 traps were added between October and December to enlarge the suppression area slightly and to strengthen the trap barriers. The population was monitored using biconical and NG2B traps as well as by mark-release-recapture estimates of population size. By October the number of G. pallidipes in the suppression zone was reduced by 98–99% relative to the number 3 km outside the suppression zone. Some reinvasion, mainly of parous females, occurred in November during the short rains but these flies were rapidly trapped out again. Average mortality rates due to trapping were estimated at 4–5% per day, which, combined with the natural mortality, reduced the adult population at a rate of about 2.6% per day during the dry season. The traps had less effect on the smaller population of G. longipennis Corti but still gave a reduction of up to 90% in the dry season. The use of this low technology approach offers good prospects for future community-based tsetse control operations.
Estimating levels of gene flow between natural populations of cereal aphids (Homoptera: Aphididae)
Authors: Loxdale Hugh D.
Published: July 2009

Gene flow between field populations of the cereal aphidsSitobion avenae(Fabricius),Sitobion fragariae(Walker) andRhopalosiphum padi(Linnaeus) is examined using statistical analyses of allozyme frequency data (both Slatkin's andFstatistics). Analysis using Slatkin's method confirms the conclusions previously drawn from earlier analyses. Thus there is found to be high gene flow between subpopulations ofS. avenaeandR. padi, and a more restricted level between localS. fragariaesubpopulations, especially when infesting the secondary host (cocksfoot grass,Dactylis glomerata). The value ofNm(number of immigrants per generation) calculated forS. avenaewas approximately 2 and is indicative of high gene flow i.e.Nm>1.0. Also, as previously found by x2genetic contingency testing, theFstatistical analysis confirms thatS. fragariaesubpopulations infestingD. glomerataare genetically more heterogeneous than those infesting the primary host, blackberry,Rubus fruticosusagg. Hence, there may be less gene flow between populations on the secondary host compared with that on the primary. The results obtained are compared with the flight behaviour of these particular aphid species and to their respective host plant abundances. The advantages and disadvantages of both Slatkin's method andFstatistics for analysing insect population genetic structure are noted.
Honeydew sugars in wild-caught Italian phlebotomine sandflies (Diptera: Psychodidae) as detected by high performance liquid chromatography
Authors: MacVicker Jane A.K. , Moore J.S. , Molyneux D.H. , Maroli M.
Published: July 2009

Phlebotomus perfiliewi perfiliewiParrott andPhlebotomus perniciosusNewstead (Diptera: Psychodidae,) known vectors ofLeishmania infantumwere caught in light traps in five different sites in Italy. Sandflies were cryopreserved and transported to the laboratory where they were thawed and aqueous extracts of the crushed flies were analysed for their carbohydrate content using high performance liquid chromatography. Several sugars were detected, including significant amounts of the trisaccharide melezitose, known to be available as a natural source from aphid or coccid honeydew. There was no difference between the analyses of sugar meals ofP. p. perfiliewifrom different sites within its range, or betweenP. p. perfiliewiandP. perniciosus.The results indicate that both males and females ofP. p. perfiliewiandP. perniciosusfeed on honeydew.
The evaluation of antibiosis of selected lines for resistance of melon to the carmine spider mite Tetranychus cinnabarinus (Acari: Tetranychidae)
Authors: Mansour Fadel , Karchi Zvi
Published: July 2009

Antibiosis of resistant melon lines to the carmine spider mite, Tetranychus cinnabarinus (Boisduval), was evaluated in the laboratory. Significant differences among lines were observed seven days after the inoculation of detached leaf disks. The most resistant lines, namely CHI-8, BUS-7 and BUS-3, reduced the average mite daily fecundity by 49%, 40% and 33%, respectively, as compared to the susceptible NY line. Resistance did not appear to be related to the growth habit. Selfing resistant melon parents resulted in a significant increase in the number of plants on which female mites produced less than one egg per day.
Distribution and species composition of lepidopterous maize borers in southern Nigeria
Authors: Bosque-Pérez N.A. , Mareck J.H.
Published: July 2009

The distribution and species composition of lepidopterous maize borers was studied in six locations in southern Nigeria during the second planting season (August-November) of 1985 and 1986. Sesamia calamistis Hampson (Noctuidae) and Eldana saccharina Walker (Pyralidae) were the stem borers most abundantly found in the locations sampled. S. calamistis was the dominant species up to eight weeks after planting in all locations. E. saccharina was the most abundant species from nine weeks after planting onwards, except at Umuahia where S. calamistis always comprised over 50% of the borer population. Mussidia nigrivenella Ragonot (Pyralidae) was found attacking maize ears in all locations, while Busseola fusca Fuller (Noctuidae) was found only at Idah and Alabata, and even there constituted only a small proportion of the population. Other borer species found were Coniesta (= Acigona) ignefusalis (Hampson) (Pyralidae) and Cryptophlebia species (Olethreutidae).
The impact ofAphidius rhopalosiphi(Hymenoptera: Aphidiidae) on populations of the rose grain aphid (Metopolophium dirhodum) (Hemiptera: Aphididae) on cereals in Canterbury, New Zealand
Authors: Farrell J.A. , Stufkens M.W.
Published: July 2009

The parasitoidAphidius rhopalosiphiDe Stefani-Perez was imported into New Zealand as a biological control agent against the rose-grain aphid (Metopolophium dirhodum(Walker)) in 1985. In 1988–89, the rate of parasitism byA. rhopalosiphiwas studied by rearing fourth instarM. dirhodumcollected from barley at Lincoln and other sites in Canterbury. The rate of parasitism at the time of peak aphid numbers at Lincoln was approximately 50% in winter barley and 100% in spring barley. In spring barley, peak numbers did not exceed five aphids per tiller, and regulation of aphid population density below this level was attributed to parasitism following a large immigration of adultA. rhopalosiphi.Suction trap catches ofA. rhopalosiphiincreased between 1984, prior to release, and 1989, while catches ofM. dirhodumshowed a corresponding decline.
Impact of fauna on mortality and size of Haematobia spp. (Diptera: Muscidae) in natural dung pads in Australia and South Africa
Authors: Fay H.A.C. , Macqueen A. , Doube B.M. , Kerr J.D.
Published: July 2009

Two field experiments examined the effect of dung fauna on the breeding success of Haematobia irritans exigua DeMeijere at Rockhampton, Australia, and Haematobia thirouxi potans (Bezzi) at Hluhluwe Game Reserve, Republic of South Africa. Dung pads naturally infested with Haematobia eggs were produced by cattle at Rockhampton and by Cape buffalo at Hluhluwe. Pads were either exposed to, or protected from, all dung fauna for various periods up to four days. The effect of dung fauna on the immature stages of Haematobia spp. was estimated from differences in the numbers and size of flies that emerged from treated and control pads. In the first experiment, pads produced during the morning and afternoon were exposed for one, two or four days on seven different occasions. At Rockhampton, fauna-induced mortality was substantial but did not increase significantly after the pads had been exposed for one day. At Hluhluwe, in pads produced during the morning, fauna-induced mortality rose substantially with duration of exposure; in afternoon pads the increase was not statistically significant. Fly size, indicated by the mean headcapsule width of surviving females, decreased as exposure of pads to dung fauna increased from zero to four days, except in the afternoon pads at Rockhampton. In the second experiment, pads produced in the afternoon were exposed in the field for four days on 16 occasions at Rockhampton, and on 17 at Hluhluwe. Fauna-induced mortality averaged 79% and 84%, respectively. The activities of the dung fauna reduced the headcapsule widths of surviving flies by an average 2% at Rockhampton and by 7% at Hluhluwe, despite similar levels of dung dispersal. The dung fauna associated with the highest mortality of H. irriatans exigua at Rockhampton were Scarabaeinae and Macrocheles spp., while there were no significant associations between fly mortality and particular fauna in the Hluhluwe data.
Polyandry in nulliparous Anopheles gambiae mosquitoes (Diptera: Culicidae)
Authors: Gomulski Ludvik
Published: July 2009

A wild-type black-eyed strain (PALA DR) and a mutant white-eyed strain (S104) of Anopheles gambiae Giles were used to determine whether nulliparous mosquitoes of this species are polyandrous. White-eyed females were given the opportunity to mate with black-eyed and white-eyed males. As the white-eye gene is recessive and is located on the X chromosome the presence of both white- and black-eyed females in a female's egg batch denotes that she mated with males of both types. Three out of 52 egg batches gave rise to both white-and black-eyed females. Only a proportion of multiple matings can be detected in this way; those involving males of only one type go undetected. It is estimated that, under the conditions prevailing during the experiment, 12% of nulliparous A. gambiae are polyandrous.
Tribolium aggregation pheromone: monitoring, range of attraction and orientation behaviour of T. castaneum (Coleoptera: Tenebrionidae)
Authors: Obeng-Ofori D. , Coaker T.H.
Published: July 2009

Adult male Tribolium castaneum (Herbst) secrete an aggregation pheromone that is attractive to both sexes. The responses of T. castaneum to different pheromone concentrations (0.5, 1.0, 2.0, 4.0 and 8.0 mg/septa) were tested in the laboratory. In general, pheromone-baited pitfall and probe traps were over 50% more effective than unbaited traps. A curvilinear relationship between numbers trapped and pheromone concentration indicated that 2.0 mg of pheromone per trap elicited an optimum response. The proportion of marked beetles released in 2.5 m × 0.3 m × 0.4 m trough, filled with wheat and caught by unbaited probe traps, declined with distance from release point, whereas pheromone traps captured a similar proportion up to 2.0 m from the traps. Tracks of T. castaneum responding to different pheromone concentrations in still and moving air in a 2.5 m × 0.4 m olfactometer indicated that the aggregation pheromone stimulated the beetles to walk faster at higher concentrations, to increase the frequency and magnitude of turning and to decrease track reversal distances and distances between turns. The behavioural responses of the beetles to the pheromone in still and moving air were similar, indicating chemotaxis as the major orientation mechanism used by T. castaneum to locate an odour source. The beetles showed greater orientation efficiency within a discrete pheromone plume than a diffuse plume.
Mechanisms of insecticide resistance in a temephos selected Culex quinquefasciatus (Diptera: Culicidae) strain from Sri Lanka
Authors: Peiris H.T.R. , Hemingway J.
Published: July 2009

Culex quinquefasciatus Say from Peliyagoda, Sri Lanka, has larval resistance to temephos, malathion, fenitrothion and chlorpyrifos. Biochemical assays on individual resistant and susceptible mosquitoes of this strain showed that there was a good correlation between this resistance and increased esterase activity with both 1-and 2-naphthyl acetate, which appears to be the major resistance mechanism in this multiple organophosphate resistant strain. There was no significant difference in malaoxon, bendiocarb or propoxur sensitivity of the acetylcholinesterase from the resistant and susceptible strains, indicating that the sensitivity of the target site has not been altered. Biochemical assays on mass homogenates of the resistant and susceptible strains showed no correlation between resistance and the level of glutathione s-transferase activity, or the amount of cytochrome P450 present.
The Anopheles maculipennis complex (Diptera: Culicidae): comparison of the cuticular hydrocarbon profiles determined in adults of five Palaearctic species
Authors: Phillips A. , Sabatini A. , Milligan P.J.M. , Boccolini D. , Broomfield G. , Molyneux D.H.
Published: July 2009

A comparison was made between the cuticular hydrocarbons of five Palaearctic species of the Anopheles maculipennis Meigen complex; A. maculipennis sensu stricto, A. melanoon Hackett, A. messeae Falleroni, A. labranchiae Falleroni and A. atroparvus Van Thiel. Females of these species had their cuticular lipid removed and the hydrocarbons separated and quantified by gas chromatography. Discriminant analysis determined the degree of difference between the species. Wild caught adults of the complex had an average correct classification rate of 77.9%. A. atroparvus and A. labranchiae are homosequential and have no uniquely diagnostic isoenzymes, but expressed distinct hydrocarbon profiles enabling them to be separated in more than 86% of cases. Similarly, A. maculipennis sensu stricto and A. melanoon differ only by minor karyotype alterations, yet their hydrocarbon profiles could be separated with 83% correct classification. A dendrogram was drawn up, based on the hydrocarbons, using the Mahalanobis distances between species. A. maculipennis sensu stricto and A. melanoon were the two closest groups; A. messeae was next to join the cluster, followed by A. labranchiae and then A. atroparvus. These last two species were also very close to each other, but quite distant from A. maculipennis sensu stricto and A. melanoon. The species' relationships based on hydrocarbons thus reflect the tentative chromosomal phylogeny of the complex. In nature, hydrocarbon differences between species may be a device enabling the recognition of suitable mates. Studies showing that hydrocarbon dissimilarity is elevated between sympatric populations are also discussed in support of this theory.
Stages of bush fly, Musca vetustissima (Diptera: Muscidae), killed by scarabaeine dung beetles (Coleoptera: Scarabaeidae) in unfavourable cattle dung
Authors: Ridsdill-Smith T.J. , Hayles L.
Published: July 2009

The stages of bush fly Musca vetustissima Walker, killed by the dung beetles, Onthophagus binodis Thunberg and Onitis alexis Klug, at low and high densities were measured in cattle dung of low nutritive value. A high level of M. vetustissima mortality occurred in the presence of Onitis alexis and Onthophagus binodis in experiments both in the laboratory at a constant 25°C, and exposed to summer fluctuating temperatures outside. The K values for total eggpuparia mortality increased curvilinearly with increasing log10 beetle numbers. The mortality of older larvae, k3, was most closely correlated with total mortality, K, where b = 0.720 and r2 = 0.931, while a lesser but significant correlation was obtained with mortality of young larvae, k2, where b = 0.291 and r2 = 0.645, but no correlation was obtained with egg mortality, k1, where b = −0.010 and r2 = 0.058. It is predicted that in unfavourable dung which occurs during summer, mortality of older bush fly larvae will be the key mortality caused by scarabaeine dung beetles.
Side effects of solvents, especially acetone, used for the application of juvenile hormone mimics and chemosterilants
Authors: Critchley B. R. , Almeida A. A.
Published: July 2009

Acetone at a dose of 1 μl was one of the least toxic of 11 solvents applied topically to fifth-instar nymphs of Dysdercus fasciatus Sign., while ctronellal, n-dodecane and n-tridecane at a dose of 0.5 μl were the most toxic. Acetone applied at 0.3 μl to third- and fourth-instar numphs caused negligible mortalities but about 60% of the treated nymphs gave rise to abnormal adults which, although capable of mating, laid eggs which were significantly less fertile than those from treated individuals which emerged as normal adults. These abnormalities could be attributed to a hormonal imbalance. Apparently normal adults arising from nymphs treated at the third instar with 0.6 μl acetone had 35% fertile matings (controls 70%) due to interference in the production and transference of motile sperm. The effects of acetone as a solvent in laboratory experiments could therefore be confounded with those attributed to juvenile hormones.
Preliminary studies on the taxonomy and distribution of the melon weevil,Acythopeus Curvirostris(Boheman) (includingBaris granulipennis(Tournier)) (Coleoptera, Curculionidae)
Authors: Thompson R. T.
Published: July 2009

The melon weevil,Acythopeus curvirostris(Boheman), is a speciescomplex comprising at least four allopatric forms, here regarded as subspecies. Of the seven available species-group names, three are retained for subspecies and four placed in synonymy; an eighth name is proposed for the fourth subspecies. The generic and subgeneric placements of the melon weevil and its relatives are discussed. The following check-list of the species ofAcythopeus (Carpobaris)summarizes the present position (synonyms all new):A. (C.) curvirostris(Boheman) (=traegardhi(Aurivillius)),A. (C.) c. granulipennis(Tournier) (=colocynthaeVoss,globulicollisVoss,cucumidisVoss),A. (C.) c. persicussubsp. n.,A. (C.) c. citrulliMarshall,A. (C.) alcyoneus(Erichson) (=atrocoeruleus(Boheman)),A. (C.) cucurbitae(Marshall),A. (C.) speciosus(Gerstaecker),A. (C.) coelestis(Pascoe). (Acythopeus franciscinom.n. =A curvirostrisPascoe, 1874, nee Boheman, 1844.) Simple biometric procedures indicate differences between the subspecies ofA. curvirostris; some characters show clinal variation. The melon weevil occurs across the Sudan Belt, in the Middle East, Iran and South India. It is generally a minor and transient pest of cucurbit fruits. One parasite and one predator are known.
Evaluation of biological control of the oak leaf-miner Phyllonorycter messaniella (Zell.) (Lep., Gracillariidae) in New Zealand
Authors: Swan D. I.
Published: July 2009

To evaluate the effectiveness of the introduced Hymenopterous parasites Apanteles circumscriptus (Nees) and Enaysma splendens Delucchi in the control of Phyllonorycter messaniella (Zell.) samples of leaves were taken from infested oaks during 1969–70. In Christchurch there were three generations of P. messaniella per year with spring, summer, and autumn emergence periods. Infestation on deciduous oaks was negligible in some areas but was 6.3 mines/leaf in the lower crown of oaks close to evergreen oaks on which P. messaniella overwinters. On deciduous oaks total parasitism ranged from 30% to 80%. Apanteles was the most abundant parasite but Enaysma assumed almost equal importance on oaks with low infestations. Pnigalio pectinicornis (L.), a self-introduced parasite, has been almost completely displaced by the other two parasites since their introduction in 1957. The infestation intensity recorded in Nelson (2.3 mines/leaf) was much lower than the level reported before the release of the parasites (40+ mines/leaf), but still much higher than levels in Europe.
A net and a catch-segregating apparatus mounted in a motor vehicle for field studies on flight activity of simuliidae and other insects
Authors: Davies L. , Roberts D. M.
Published: July 2009

A method for collecting flying insects is described, developed for studies on the dispersal of Simuliidae. The apparatus consists of a net mounted on the roof of a motor vehicle, leading to a catch-segregating apparatus within it, such that the catches over any desired distance at speeds up to 48 km/h can be segregated without stopping until 50 catches have been obtained. The volume of air filtered is measured with a counter anemometer mounted in the net mouth. Specimen results for one day are given as an illustration of the efficiency of the method.
The influence of moonlight on catches of insects in light-traps in Africa. Part I. The moon and moonlight
Authors: Bowden John
Published: July 2009

An account is presented of the distribution and amounts of moonlight in latitudes near the equator. This includes a Table on the amount of moonlight for each hour of the night throughout a standard lunar cycle, applicable to any locality between 10°N and 10°S, and a Table of standard groups of moon phase which can be used at any locality irrespective of latitude. The construction of these Tables is described in detail and their use briefly discussed. A method is described which enables light-trap catch records to be arranged for analysis directly against moon phase.
African gall bugs of the genusPhytolyma(Hemiptera, Psylloidea)
Authors: Hollis David
Published: July 2009

The genusPhytolymais defined and a key is given to its four species. Two of the species,P. minutaandP. tuberculata, are described as new, another (P. fusca Alibert) is elevated from varietal status and the fourth (P. lata(Walker)) is redescribed. The host-plants are African forest trees,Chlorophoraspp. andMorussp. (Moraceae).
The developmental periods of the Ixodid tick Rhipicephalus appendiculatus Neum. under laboratory conditions
Authors: Branagan Denis
Published: July 2009

A study, begun in 1966 at Edinburgh University, and completed during the ensuing 30 months at Muguga, Kenya, of the developmental periods of Rhipicephalus appendiculatus Neum. under controlled temperature and humidity was carried out to provide basic background information for an intensified FAO/EAVRO programme of East Coast fever research. Quantitative data are given on the preoviposition, pre-eclosion and, for larvae and nymphs, premoulting periods at three constant temperatures, 25, 21 and 18°C. The rate of development at all stages was accelerated by raising the temperature and retarded by lowering it. A “pre-immobilization period” which precedes the entry of engorged larvae and nymphs to the true moulting process also appeared to be temperature dependent. Development became very prolonged as temperatures fell below 18°C, being negligible at 15°C and having apparently ceased altogether at 9°C. Continuous exposure for more than two or three days to temperatures of 4°C and below were lethal to all engorged instars. Humidity (controlled at levels between 18 and 87% r.h.) had no influence on the rate of development. It is concluded that within limits of tolerable aridity, developmental periods would be completed within the times dictated by temperature regardless of the level of humidity or changes in the level of humidity. No suggestion of any diapause mechanism was discerned.
Differences in susceptibility to a granulosis virus between field populations of the potato moth, Phthorimaea Operculella (Zeller) (Lepidoptera: Gelechiidae)
Authors: Briese D. T. , Mende H. A.
Published: July 2009

A laboratory bioassay technique was used to compare the susceptibility to a granulosis virus of 16 field populations of Phthorimaea operculella (Zell.) in Australia. A difference of 11·6× was found between the most and least susceptible population, while a laboratory strain was over 30 × as resistant as some field populations. It is suggested that this variability might reflect the past history of exposure of different populations to the virus, which appears to be endemic. The implications for the use of this virus as a microbial control agent are discussed.
Rhyzobius ventralis (Erichson) and R. forestieri (Mulsant) (Coleoptera: Coccinellidae), their biology and value for scale insect control
Authors: Richards Aola M.
Published: July 2009

Life-cycles and voltinism are described for Rhyzobius ventralis (Erichs.) and R. forestieri (Muls.) living in the region of Sydney, Australia, and also the role each plays in its particular biocoenosis. Colour variation and wax production are described for the larvae, prepupae, pupae and adults of both species, also the defensive and feeding behaviour. New and known host records are listed for both species. Reasons are suggested for the success, partial failure or failure of the species as biological control agents in various parts of the world.
Field experiments with a wind tunnel on the flight speed of some west African mosquitoes (Diptera: Culicidae)
Authors: Gillies M. T. , Wilkes T. J.
Published: July 2009

An open wind tunnel, down which air was blown from over a bait animal, was used in the field in the Gambia to measure the flight speed of host-seeking mosquitoes. Insects were trapped on an electrocuting grid fitted halfway up the tunnel. As the speed of air movement through the electrocuting grid was increased from 0·5 m/s, catches of Mansonia spp. fell off steeply, reaching negligible levels above 1·4 m/s. At air speeds lower than 0·5 m/s, catches at the grid were greatly reduced. Similar results were obtained for Anopheles ziemanni Griinb. and other species of Anopheles. It is concluded that the maximum flight speed of hostseeking females of all these species was in the range 1·4–1·8 m/s.
Studies on the biology ofCuliseta longiareolata(Macquart) (Diptera: Culicidae)
Authors: Pletzen R. Van , Van Der Linde T. C. De K.
Published: July 2009

The dark-scaled form ofCuliseta longiareolata(Macq.) was found near Bloemfontein in South Africa. Breeding took place in various kinds of flooded pools, small containers and drinking troughs. It was multivoltine and overwintered as hibernating second-, third- and fourthinstar larvae and adult females. Laboratory colonisation was easily accomplished. Adults were maintained alive at 23°C and 70% relative humidity, and survival rates were high for 40–50 days. Starved females fed readily on blood from pigeons at night or on a 3:1 mixture of human blood and 10% sucrose solution from cotton-wool pads. Mating swarms were not observed in the field, but swarming activity occurred in laboratory populations provided with simulated dawn and dusk conditions. The fact that mating activity could be readily induced at any time was taken to show that it is not governed by a rigid endogenous rhythm. Egg-rafts varied in shape from round to oblong. Oviposition was invariably nocturnal. Some substance, probably emitted by bacteria, served as an oviposition attractant. The anterior pole of each egg lacks an exochorion and is hydrophilic. The posterior pole bears a lipid droplet. The exochorion is sculptured, the sculpturing consisting of bosses connected to one another by bridges constituting the outlines of a series of pores. The exochorial pattern varies in different regions of the egg. Pupation and emergence occurred mainly at night, and there was an approximately normal sex ratio.
Observations on the insect fauna of shaded and unshaded Amelonado cocoa
Authors: Bigger M.
Published: July 2009

The insect fauna of a block of Amelonado cocoa trees at Tafo, Ghana, partly shaded by Gliricidia sepium and partly unshaded was sampled. Crematogaster clariventris (Mayr) and Oecopyhlla longinoda (Latr.) were the most numerous species of ants, the former occurring on 84% of the trees and the latter on 17%. There was a considerable overlap in the distribution of the two species. Thirty-two other species of ant were collected by pyrethrum knockdown sprays from the cocoa canopy, and 47 species were collected from leaf litter beneath the trees. More species of ant were recovered from litter on shaded plots than on unshaded ones. There was some avoidance of trees occupied by O. longinoda by certain canopy .ants. A greater number of Lepidoptera larvae, Orthoptera and the mirid Sahlbergella singularis Hagl were collected by pyrethrum knockdown sprays from unshaded plots than from shaded ones, whereas Diptera and Hymenoptera other than ants were more numerous on shaded plots. The most abundant coccid was Stictococcus sjostedti Ckll., a species tended for its honeydew by both dominant ants; it was more common on shaded plots. Mealybug species, of which Planococcoides njalensis (Laing) was the most common, were more abundant on unshaded plots.
A new species of Tachinidae (Diptera) parasitic on the sugarcane borer Eldana saccharina (Lepidoptera: Pyralidae), in Natal, South Africa
Authors: Barraclough D.A.
Published: July 2009

Schembria eldana, a new species of goniine Tachinidae, is described (both sexes) from north-eastern Natal, South Africa, where it is parasitic on larvae of the sugarcane borer, Eldana saccharina Walker, in Cyperus papyrus umbels. The genus Schembria Rondani was previously known only from two females of S. meridionalis Rondani from Malta and Israel.
The concentration of lamdacyhalothrin and its effect on the cutworm Agrotis segetum (Lepidoptera: Noctuidae)
Authors: Blair B.W.
Published: July 2009

During initial screening of the synthetic pyrethroid lamdacyhalothrin (PP 321) at a concentration of 44 and 22 mg/l and applied as a 30 ml drench over each plant against third to fourth instar cutworms, Agrotis segetum (Denis & Schiffermüller) in microplots, few died but they did not damage the plants. Reducing the concentrations to 11 and 5.5 mg/l increased mortality and plant damage. When A. segetum were confined on soil treated with the insecticide at concentrations of 22, 11 and 5.5 mg/l and sprayed at an equivalent rate of 500 l/ha, they all died within one day. The higher concentrations appeared to have a repellent and/or antifeedant effect, and it has been possible to reduce the concentration of lamdacyhalothrin to 12.5 mg/l (≡5.6g a.i./ha) for the drench treatment without risking economic plant damage. For insecticides that have repellent and/or antifeedant properties, it should be possible to balance lower concentrations with adequate protection of plants from pest damage.
A new genus and species of coccinellid (Coleoptera: Coccinellidae) predator on Rastrococcus spp. (Homiptera: Pseudococcidae) from India
Authors: Booth R.G.
Published: July 2009

Aponephus lentiformis, a new genus and species of Coccinellidae, is described from southern India and placed in the tribe Scymnini. It was found during searches for natural enemies of Rastrococcus spp.
Egg mortality of the brown planthopper,Nilaparvata lugens(Homoptera: Delphacidae) and green leafhoppers,Nephotettixspp. (Homoptera: Cicadellidae), on rice in Sri Lanka
Authors: Fowler S.V. , Claridge M.F. , Morgan J.C. , Peries I.D.R. , Nugaliyadde L.
Published: July 2009

Rice plants, infested with eggs ofNilaparvata lugens(Stål) orNephotettixspp. in laboratory cultures, were used to trap egg parasitoids in rice fields at two sites over a period of four days in Sri Lanka. Levels of egg parasitism per plant varied from 0 to 54% inN. lugensand 45 to 100% inNephotettixspp. Egg predation was a minor cause of mortality, but attack by a species ofPanstenon(Hymenoptera: Pteromalidae) killed up to 18%Nilaparvata lugenseggs.N. lugenseggs were parasitized byAnagrussp. nrflaveolusWaterhouse,A. optabilis(Perkins) (Hymenoptera: Mymaridae) andOligositasp. (Hymenoptera: Trichogrammatidae).Nephotettixspp. eggs were parasitized by two species ofGonatocerus(Hymenoptera: Mymaridae) and one ofParacentrobia(Hymenoptera: Trichogrammatidae). There was no overlap in field host range between the two parasitoid assemblages.Gonatocerusspp. andParacentrobiaspp. seldom attacked the sameNephotettixsp. egg batch, suggesting the possibility that these species compete in the field. Overall egg parasitism ofNilaparvata lugenswas positively related to host egg density at the spatial scale of the rice plant, but unrelated at the tiller or batch scale.Nephotettixspp. egg parasitism showed a negative density dependent relationship at the spatial scales of the tiller and plant and no relationship at the batch level. The potential role of these egg parasitoids in preventing outbreaks of hopper pests in Sri Lanka is discussed.