bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations on the life-history and bionomics ofAnjeerodiplosis peshawarensisMani (Diptera: Cecidomyiidae)
Authors: Srivastava U. S. , Agarwal S. B. 
Published: July 2009

Anjeerodiplosis peshawarensisMani is a serious pest in North India of the fruit of the country fig (Ficus carica), which is its only known host. The midges are abundant, hovering under the host tree in the mornings and at dusk, and breed throughout the year, except in the summer from April until the July rains. In this period newly formed fruits are not infested, but in other months scarcely 30 per cent, of the fruits remain free from attack.Eggs are laid in fruits when they one week old, succulent, and of the size of a pea. The eggs are minute, hyaline, unsculptured, oval and pedicellate and occur in bundles of 16. Incubation takes three days in September and March and five days in December and January. In laboratory tests, average viability in January was found to be about 83 per cent.The entire larval period is passed inside the figs, each of which may contain 200–300 larvae. There are four larval instars, which differ in size according to Dyar's law and in morphology. The first-instar larva is devoid of cuticular outgrowths and does not show spiracles; the second and third instars have nine pairs of spiracles and possess characteristic spines, warts and tubercles; the fourth instar develops the sternal spatula. The entire larval period lasts three weeks from the middle of August to October and four weeks in January and February. From the middle of April until the July rains, fourth-instar larvae remain inside the figs. When the larval period is three weeks, the first and second instars together and the third and fourth instars separately last about a week.Full-grown fourth-instar larvae bore out of the fruit and drop to the ground, where they jump for some time with the aid of their sternal spatula. They finally pupate in the soil without forming a cocoon but become covered in a protective case composed of soil particles that adhere to the larval skin. Early fourth-instar larvae, which do not have a sternal spatula, if taken from the fruits, may also successfully pupate, and the pupal period is normal. This period is 10–15 days between July and November and 25–26 days in January and February. It is shortest (10 days) in the rainy season, when both temperature and humidity are high.The pupa is obtect, creamy white and bears poorly developed cephalic horns and bristles, well developed thoracic horns and many spines and cuticular outgrowths. Mortality in the pupal stage is between 15 and 30 per cent.Emergence of the adults invariably occurs in the early hours of the day. Two or three days before emergence, the protective case becomes detached piecemeal. Males emerge before females. The ratio of males to females on the day of emergence is 1:2 between March and December and 2:3 in January and February. Copulation starts soon after emergence and lasts from 60 to 90 seconds.There is considerable overlapping of generations. On the basis of the time required for completion of the life-cycle in different months, it is calculated that seven generations are completed in a year.
On the bionomics and ecology ofHeteronychus licas(Klug) (Coleoptera, Dynastinae), a new pest of sugar-cane in Nigeria
Authors: Taylor T. Ajibola 
Published: July 2009

Late in 1962,Heteronychus licas(Klug) was recorded causing damage to sugar-cane for the first time in Nigeria. It had previously been known there only as an inhabitant of grassland and a negligible pest of yams (Dioscoreaspp.). The damage to sugar-cane, which was first noted at an early stage in the development of a large commercial sugar-growing estate (the first in the country) in Nothern Nigeria, resmbles that caused by Lepidopterous stem borers; the young shoots and tillers are eaten away around soil level by the larvae and adults and are eventually killed (‘deadhearts’). The adults sometimes tunnel in the pith of older canes, but seldom kill them. Surveys on the estate in 1963–64 showed that damage by the beetle was becoming increasingly important. In anticipation that this might happen, field and laboratory investigations into the habits and life-historv ofH. licaswere carried out in the same two years, and the initial results are reported.There is one generation a year. Oviposition took place in moist soil near the bases of cane plants from late October to December. In the laboratory, the average female laid 60–75 eggs over a period of 1–3 weeks, hatching occurred after 9–16 days and the three instars lasted successively 14–19, 15–24 and 20–25 days. Larvae were found in the field from November to March, but occured in large numbers only during January and early February, mostly within a depth of 1 ft. in the soil; only those in the second and third instars fed on the canes. Puation took place in a cell 112–3 ft. below the surface; the prepupal and pupal stages together lasted 23–31 days in the laboratory. In the field, pupae were most numerous in February and March and adults, which began to emerge early in March, reached their greatest numbers between then and May.Evening catches at a light-source showed thatH. licashad two flight seasons each year, a subsidiary (post-teneral) one in April-June and a main (pre-reproductive) one in October-November, separated by a period of inactivity. Egg laying follows the second, and the adults die. Factors influencing the behaviour of the adults are discussed.There were marked seasonal fluctuations in the incidence of ‘deadhearts’ caused byH. licas;it was highest in March-June each year, lowest during the period of adult inactivity, and again high during October-November.Larvae kept together in the laboratory inflicted mutual injuries, mostly ending in death, but the extent to which this occured in nature could not be determined. Five Carabid species were found preying on the larvae in the field, and one on the adults as well. The importance of these and other possible predators and of parasites for the control ofH. licasis discussed.Measures that could be adopted for control are reviewed the literature.
The Effect of Climate and Weather on the Numbers of the Red Locust, Nomadacris septemfasciata (Serv.), in the Rukwa Valley Outbreak Area
Authors: Symmons P. 
Published: July 2009

An examination of the records from 1930 onwards shows that a very high level of Lake Rukwa is correlated with small numbers of the red locust, Nomadacris septemfasciata (Serv.), in the Rukwa Valley outbreak area in Tanganyika. When the lake level is not very high, the size of the adult locust population (taken as that present in the middle of the dry season) is correlated negatively with the total rainfall of the last but one wet season (broadly, November–May), positively with the size of the preceding parental population (taken as that present at the time of oviposition) and possibly also with the rainfall of the preceding October–December, but not significantly with the date of the drop in temperature that is thought to be associated with the start of ovarian development.Three tentative explanations of the correlation between adult population and rainfall are offered. First, if the water-table is high because of heavy rain in the previous season, the early rains may make the soil unsuitable for successful egg-laying and incubation; second, after a season of heavy rainfall the grass cover may be particularly dense at the end of the following dry season and the consequent reduction of the oviposition sites may make breeding unsuccessful; third, parental mortality may be high during a dry season following heavy rains. These possibilities are being further investigated.It is suggested that by using a multiple regression equation incorporating the correlations that have been established, the size of the adult locust population can be forecast in time for the scale of hopper control measures to be appropriately modified and economies thereby achieved.
Some Observations on the fusca Group of Tsetse Flies (Glossina) in the South of Nigeria
Authors: Page W. A. 
Published: July 2009

Observations were made on Glossina tabaniformis Westw., G. fusca (Wlk.), G. nigrofusca Newst. and G. medicorum Aust., which all occur near the field station of the West African Institute for Trypanosomiasis Research at Ugbobigha in southern Nigeria. Identification of these species by the use of external characters has not been found possible between the females of G. tabaniformis and G. fusca, but is fairly simple between males of these two species and between both sexes of G. nigrofusca and G. medicorum. A simple key, based on external characters, is given. When necessary, females of G. tabaniformis and G. fusca were separated by dissection. G. tabaniformis, G. fusca and G. nigrofusca usually rest in a vertical position, with the head downwards, at a height of 4–6 ft. above ground (possibly lower for G. nigrofusca), on tree trunks, climber stems, etc., having a diameter of 5 in. or less.A fly-round was started using a Zebu bull as bait. G. tabaniformis and G. fusca were caught in good numbers, G. tabaniformis forming 83 per cent. of the catch. There appears to be a decrease in population in the late dry season (January and February) in both these species. Females comprised 56 per cent. of the total catch of G. tabaniformis and 47 per cent. of that of G. fusca.The vegetation of the fly-round, which is typical secondary rain-forest as found in southern Nigeria, was analysed; both G. tabaniformis and G. fusca prefer old forest with an absence of a lower stratum, beneath a continuous middle stratum and good upper stratum, that is to say, where visibility beneath the trees is good. G. nigrofusca comprised only 1·1 per cent. of the catch on the fly-round, although at first it was believed to be common in the area. G. medicorum does not inhabit the main forest belt, but is confined to riverine vegetation and forest islands in savannah.G. tabaniformis is unlikely to be of economic importance, since the rate of infection with trypanosomes is low (3·7%) and this fly is confined to the forest. G. fusca and G. medicorum are both of economic importance, since their infection rates are high (14·9 and 15·4%, respectively) and they travel out into the savannah grassland. G. nigrofusca has a yet higher infection rate (26·7%), but it is confined to the forest at Ugbobigha; where, as in Ghana, it frequents the savannah, it is potentially dangerous. Females of G. tabaniformis and G. fusca are more heavily infected than males.Females of G. tabaniformis were examined (by dissection) for pregnancy; 82 per cent. of the females were pregnant and 4·3 per cent. unfertilised. No seasonal fluctuations in the rate were apparent.
Mycophagy as a factor limiting predation of aphids (Hemiptera: Aphididae) by staphylinid beetles (Coleoptera: Staphylinidae) in cereals
Authors: Dennis P. , Wratten S. D. , Sotherton N. W. 
Published: July 2009

AbstractPrevious work demonstrated the potential of the staphylinidsTachyporus hypnorum(Fabricius),T. chrysomelinus(Linnaeus),T. obtusus(Linnaeus) andPhilonthus cognatus(Stephens) to feed on the grain aphid,Sitobion avenae(Fabricius). However, gut dissection and observations of foraging behaviour showed that mycophagy could be a factor influencing the potential ofTachyporusspp. to control aphids. The main fungal material detected in the guts ofTachyporusspp. was spores (conidia) ofErysiphespp. (powdery mildews). In the present study, numbers of conidia (pustules of mildew on leaf-sections) were offered with aphids in food-choice experiments to test how fungal food affected feeding on aphids by these staphylinids. An index of food preference was calculated for each species, sex and for two age classes of larvae, based on the number of conidia and aphids remaining after feeding. Results showed a preference for mildew conidia byT. hypnorum, no preference byT. chrysomelinusandTachyporusspp. larvae and a preference for aphids byT. obtususandP. cognatus(adults and larvae). Food-preferences compared well with dietary composition in recent studies of field collected staphylinids. Futhermore, a functional response was detected to increasing numbers of mildew conidia presented (in mildew only consumption-rate experiments) and to the increase in total food density in food-choice experiments. Mycophagy limited aphid predation and explained the numerical response of staphylinid beetles to areas of cereals with high aphid densities, whilst, in other studies, the proportion of aphids eaten by those beetles did not increase.
Biology of Chrysomya megacephala (Diptera: Calliphoridae) and reduction of losses caused to the salted-dried fish industry in south-east Asia
Authors: Esser J.R. 
Published: July 2009

AbstractChrysomya megacephala (Fabricius) is shown to be a principal cause of loss of salted-dried fish in south-east Asia. Field and laboratory work conducted in 1982–1989 was aimed at reducing these losses. Field work at a small–scale fish processing site in Cirebon, West Java, showed that fully gravid C. megacephala females were highly differentially attracted to fish at the salting stage, which means that the salting tanks must have properly designed fly-tight lids to prevent infestation. C. megacephala counts and ovary examinations showed that females with various stages of immature ovaries (stages I–IV) were predominent during the drying stage after the fish had been removed from the salting tanks, with numbers usually greater on the first day of drying than the second. C. megacephala counts were high during the dry season, although numbers fluctuated enormously depending on weather, among other factors. Physically screening fish during the initial drying period effectively controlled infestation, although problems associated with the screen design were identified. In laboratory cultures adult sex ratio was approximately 1:1 and longevity in both sexes, over three generations, ranged from 47 to 55 days (maximum induced longevity, 98 days) at c. 29°C, 30–60% r.h.; under similar conditions, 10% of females had mature (stage V/VI) oocytes after one week, 40% after two weeks and 90% after three weeks. Mean number of ripe oocytes in gravid flies was 221 (range 151–228).
Ovarian ages of tsetse flies (Diptera: Glossinidae) caught from mobile and stationary baits in the presence and absence of humans
Authors: Hargrove J.W. 
Published: July 2009

AbstractOvarian ages were obtained for tsetse flies Glossina morsitans morsitans Westwood and G. pallidipes Austen caught in Zimbabwe using a stationary bait ox, an odour-baited trap in the presence or absence of humans, a mobile ox fly-round and a vehicle-mounted electric net. The biggest daily catches were obtained from the electric net and the unacccompanied trap, but while for G. m. morsitans the ratio of the catches from these two methods was 7:1, for G. pallidipes it was 0.7:1. Evening catches were 1.3–5.5 and 2.9–18.8 times higher than morning catches for the two species, respectively; the differences were greater for stationary than for mobile baits. The sample age structures differed significantly (P < 0.05: x2) between methods in six of the ten possible contrasts between pairs of methods in G. m. morsitans and for all ten in G. pallidipes. The differences in age distribution and mean catch levels are attributed to increases in flight activity with age; at each age G. pallidipes is more active than G. m. morsitans. Man's presence in the trapping system reduced catches significantly (P < 0.05: t test) but this effect was small in the youngest and oldest flies. Odour-baited traps are biased in favour of G. pallidipes and, for both species, in favour of older flies; mortalities calculated from age distributions of trap samples therefore underestimate the true value.
Factors determining the peak abundance of Metopolophium dirhodum (Homoptera: Aphididae) on cereals
Authors: Honěk A. 
Published: July 2009

AbstractFrom 1986 to 1989, the factors that determined the abundance of Metopolophium dirhodum (Walker) on cereals were studied in western Czechoslovakia. Forty seven sites were selected within cereal fields, mainly of winter wheat. Host plant size and leaf area varied between sites. The maximum abundance of M. dirhodum per tiller varied annually and with host plant stature. The main factor determining maximum abundance was the length of time for which the aphid population grew. M. dirhodum populations differed both in the time of the onset and termination of their growth. On stunted plants population growth started, with little variation, 200 day degrees later than on well developed plants. Within years, nearly all populations ceased growing simultaneously. In years of low or medium aphid abundance it was 40 to 90 day degrees earlier than in aphid outbreak years, and this extension of the population growth was the principal cause of the outbreak. Population growth rates varied slightly with plant quality and differed little between years. They were not important factors determining maximum abundances. 55–75% of the aphids occupied the flag leaves. The lower leaves of well developed plants were more heavily populated than nutritionally and water stressed smaller plants. The population growth rates on particular leaves were related to leaf nitrogen content, but not water content. A relationship for calculating the maximum abundances from a census made during the middle phase of population growth was proposed.
Populations of African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae) in a Mediterranean climate region of Australia
Authors: Matthiessen J.N. , Ridsdill-Smith T.J. 
Published: July 2009

AbstractPopulations of African black beetle, Heteronychus arator (Fabricius), a subterranean pasture-dwelling pest of potatoes, were examined in pastures in geographically separated potato-growing areas covering 3½° of latitude in southwestern Australia. Abundance of all life stages was estimated by taking soil cores and the reproductive state of females was assessed from the stage of their ovarian development. H. arator adults emerged in late summer-early autumn (January–March), ovaries matured slowly during winter and oviposition occurred in spring (September–November). The interval between equivalent population events was about six weeks from the northernmost to the southernmost regions. Fecundity was estimated to be around 12 eggs/female and greatest natural mortality occurred late in the pre-adult development phase.
The absolute efficiency of gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), milk-carton pheromone traps
Authors: Taylor R. A. J. , McManus M. L. , Pitts C. W. 
Published: July 2009

AbstractCatches by gypsy moth (Lymantria dispar (Linnaeus)) ‘milk-carton’ pheromone traps with (+)-disparlure were compared with estimates of the absolute aerial density of gypsy moths obtained using a suction trap of known absolute sampling efficiency. The mean number of male L. dispar caught per pheromone trap per day was found to be proportional to the 2/3 power of the suction trap's estimate of aerial density. We infer that the efficiency of the gypsy moth milk-carton pheromone trap is density-dependent, declining as aerial density increases. The significance of the density-dependent efficiency and the mode of action of attractant traps are discussed, and the problems of designing and building suction traps to standardize pheromone traps for other species are also considered. It is concluded that standardization is only possible when some basic biology is known because pheromone trap parameters are specific to the field behaviour of the species.
A Quantitative Study of a Population of Wheat Bulb Fly, Leptohylemyia coarctata (Fall.), in the Field
Authors: Dobson Ronald M. , Stephenson J. W. , Lofty J. R. 
Published: July 2009

During the summer of 1956, a quantitative study of a field population of Wheat Bulb Fly, Leptohylemyia coarctata (Fall.), was carried out at Rothamsted.The work consisted principally of a study of the development and decline of a population of adult flies. This was supplemented by observations on the populations of the immature stages.Emergence was investigated by the use of a cage of fine terylene netting, 24 ft. long, 12 ft. wide, and 6 ft. high. This was erected in an infested wheat field shortly before flies were expected to appear, and was searched twice daily, at 10 a.m. and shortly before sunset.A total of 293 male flies was caught during the 26 days from 24th June to 19th July. Of these, 186 appeared between 1st and 6th July. The highest day's catch was 40 flies on 6th July, by which date (inclusive) about 84 per cent, of the final total had emerged.A total of 258 female flies was caught during the 35 days from 21st June to 25th July. Of these, about half emerged between 6th and 10th July. The highest day's catch was 37 flies on 8th, by which date (inclusive) 66 per cent, of the final total had emerged.Population decrease was investigated by the method of marking and recapture. The newly emerged flies caught in the cage were marked with Artist's oil colours and released in the cage. The colour of the mark was changed daily so that the age of marked flies could be ascertained. A search was made for marked flies every three days and their numbers, marks and sex were recorded. From the recapture figures, estimates of the numbers of flies surviving at different times after marking were obtained. Mortality during the first day was very high, but after this numbers decreased at a steady rate. This initial high mortality was believed to be due to marking. The length of life of marked flies which survived this immediate effect was, however, not impaired, therefore the rate of population decrease was estimated from the recapture figures alone, that is, without reference to the numbers originally marked. The half-life of male and female populations was estimated as 7·3 and 11·1 days, respectively.Application of the estimated rate of population decrease to the observed emergence figures enabled a general picture of the size and structure of the population to be obtained. The predominance of males over females during the early part of the season and the later predominance of females over males were explained.Observations on the populations of the various stages showed that the mortality between pupation and maturation of adults was high, and that the egg populations inside the cage during the autumn of 1956 was only about 1/7th of that of the previous year. This reduction was not observed outside the cage and may have been due to the survival rate and fecundity of the flies being affected by the experiment. Further work will be necessary before this can be elucidated.