bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrids OfNephotettix impicticepsIshihara andN. apicalis(Motsch.) and their ability to transmit the tungro virus Of rice
Authors: Ling K. C.
Published: July 2009

Rice tungo virus is tranmitted byNephotettix impicticepsIshihara but not by the closely relatedN. apicalis(Motsch.). Hybrids have been obtained from crosses between these two species. The morphological characteristics of the hybrids were not identical with either parent in respect to the marking on the abdomen of the nymphs, the submarginal black band on the vertex of the adults, or the number of teeth on the ventral surface of the aedeagus of the male genitalia. However, more than 10 per cent. of them, regardless of stage of development or sex, were able to transmit the tungo virus, indicating that the transmissive ability is inherited even in an interspecific cross. The virus seems to be nonpersistent in the hybrids as it is inN. impicticeps.
Contribution towards our Knowledge of the Aleyrodidae of Ceylon
Authors: Corbett G. H.
Published: July 2009

In this paper the species of Aleyrodidae occurring in Ceylon are listed, and the descriptions of two genera and nineteen species new to science are included.
Observations on the ecology of Glossina morsitans submorsitans Newst. in the Northern Guinea Savannah of Northern Nigeria
Authors: Jordan A. M.
Published: July 2009

Observations, largely based on regular catches along a fly-round, were made over the five years 1959–64 on a population of Glossina morsitans submorsitans Newst. in the Northern Guinea Savannah of Nigeria. The results showed that the largest numbers of flies were caught in the early dry season (November–January) and that, as the climate became progressively drier and more severe, fly numbers declined to reach their annual minimum at the end of the dry season or in the early rains (March–May). These results are tentatively interpreted in terms of the true density of the flies and their activity. Differences occurred between the various years, some of which could be explained by climatic differences.

Of the 7,412 flies caught over the five years, 1,128 (15·2%) were females; the percentage of females was highest in the dry season, rising to a peak of 24·1 per cent, in February, and was below 10 per cent. during the wet season. Many more females were caught on the bodies of the catching team than on vegetation or the ground near the team.

The flies rarely fed on civet cat (Civettictis civetta) or duiker (Cephalophus rufilatus, Sylvicapra grimmia), which were the potential hosts most frequently observed in the experimental area, but fed mainly on wart-hog (Phacochoerus aethiopicus) and man, the next most commonly observed potential hosts.

During the heavy rains, males of G. m. submorsitans were evenly distributed over the fly-round, but at all other seasons they were concentrated to some extent in areas of thicker vegetation. During the dry season, pupae were found in the dry soil of forest islands and riverine vegetation in the savannah; the wet season breeding sites were not discovered. Previously published data on the resting sites and trypanosome infection rate of G. m. submorsitans in the area are summarised.

The results are discussed and compared with the conclusions reached by other workers from earlier more extensive studies on G. m. morsitans Westw. in Tanganyika and on G. m. submorsitans in the Sudan Savannah vegetation zone of Northern Nigeria.
The flight activity of some East African mosquitos (Diptera, Culicidae). I.—Studies on a high steel tower in Zika Forest, Uganda
Authors: Goma L. K. H.
Published: July 2009

A series of forty 24-hour catches was carried out at seven levels (20-ft. intervals from 0 to 120 ft.) on a steel tower in Zika Forest by means of unbaited and unlighted suction traps that acted simply as air samplers. The object was to study the general flight activity of mosquitos in a tropical forest environment from samples that would not be subject to the selective effects exercised by bait-traps and light-traps.

Altogether, 4,151 mosquitos belonging to thirty-four species or species-groups were taken. Eight species, Aedes (Stegomyia) apicoargenteus (Theo.), Mansonia (Coquillettidia) aurites (Theo.), M. (C.) fuscopennata (Theo.), M. (C.) maculipennis (Theo.), M. (C.) metallica (Theo.), M. (C.) pseudoconopas (Theo.), M. (Mansonioides) africana (Theo.) and M. (M.) uniformis (Theo.), were taken in numbers sufficient for detailed analysis. By far the most abundant of these was M. aurites, comprising 55·7 per cent, of the total sample. The remaining twenty-six species together constituted only 7·6 per cent.

Only 144 or 3·5 per cent, of the mosquitos taken were males; and of the females, only 19 or 0.5 per cent. were blood-fed and only 11 or 0·3 per cent, were gravid. Thus, catches in the suction traps consisted almost entirely of unfed non-gravid females. It is tentatively concluded that male mosquitos in the forest are generally very inactive in the absence of stimuli such as lights or baits. The paucity of engorged and gravid females was expected; few of these would come within range of the unlighted unbaited suction traps.

Dissection of 3,072 females belonging to the eight most numerous species showed all to be inseminated. Age-composition was determined in species of Mansonia only; the majority of females in the subgenus Coquillettidia were nulliparous, whereas in the Mansonioides, nulliparous and parous females occurred in roughly equal proportions.

The unlighted, unbaited suction traps caught far fewer mosquitos than did light- and bait-traps under similar conditions.

In general, the vertical distributions and flight-activity cycles of the various species as indicated by the suction-trap catches differed distinctly from those indicated by bait- and light-trap catches reported by other workers. Very little activity was recorded above the forest. Although, in general, activity was irregular, three main patterns could be distinguished: largely nocturnal activity continuing up to about midday but almost completely suppressed in the afternoon, as in M. aurites, M. fuscopennata, M. maculipennis, M. metallica and M. pseudoconopas; activity spread throughout the entire 24-hour period, as in M. africana and M. uniformis; and mainly diurnal activity, as in A. apicoargenteus.
The ovarian cycle and egg stage in Leptoconops (Holoconops) becquaerti (Kieff.) (Diptera, Ceratopogonidae)
Authors: Linley J. R.
Published: July 2009

Leptoconops becquaerti (Kieff.) is one of the most troublesome species of biting midge in Jamaica. The gonotrophic cycle in this insect was studied and is described. In this species a single blood-meal is sufficient for the development of the ovaries and the maturation of eggs.

The stages in follicle development and digestion of the blood-meal adopted for other blood-sucking Diptera have been applied to L. becquaerti with slight modifications. A high degree of gonotrophic harmony is present in this insect.

Fully fed females were kept at five temperatures, 68, 77, 85, 91 and 98°F., to determine the time taken for the ovarian follicles to reach Stage V of development (egg mature, chorion present). The times were approximately 98, 64, 36, 30 and 27 hours, respectively.

It was demonstrated that the number of ovarioles in L. becquaerti was proportional to the size of the individual (as measured by wing length). The average number of ovarioles in an insect of wing length 0.83 mm. (the mean wing length of the population sampled) was about 103.

The number of eggs matured was also proportional to wing length, and was also dependent upon the temperature at which the flies were kept. Thus at the standard wing length of 0·83 mm., the average numbers of eggs matured at the five chosen temperatures (68 to 98°F.) were 78, 85, 65, 61 and 60, respectively. Females that had matured eggs were induced to oviposit by the decapitation technique.

Females provided with a source of carbohydrate (honey) during egg maturation produced slightly more eggs on the average than those fed on blood alone. The comparable figures at 91°F. in the standard individual were 65 and 61, respectively. The probable rôle of supplementary carbohydrate feeding in nature is discussed.

At the five experimental temperatures the greatest number of eggs hatched on days 11, 7, 5, 4 and 4, respectively, after laying. Egg-batches used in these experiments were deposited by decapitated females, and may therefore have been laid somewhat before the usual time in nature. The percentage fertility varied between individual batches at all temperatures, but the over-all fertility was consistently high (70–75%) at the lower four temperatures, and very low (4%) at 98°F. This difference almost certainly resulted from high temperature in the latter instance. Fertility in egg-batches deposited naturally (without decapitation) was of the same order as that in batches deposited by headless females.
A high proportion of early deaths among uninseminated females of Glossina austeni Newst.
Authors: Nash T. A. M. , Kernaghan E. J.
Published: July 2009

Three-day-old virgin females of Glossina austeni Newst. that had emerged in the laboratory in Britain from wild puparia collected in Africa or from subsequent laboratory cultures were caged with males over nine days old for 24 hours and dissected after death. Of the 5,474 flies so treated, 38 per cent. died within 14 days after mating day, whereas of the 593 found to be uninseminated, 73 per cent. died during that period, mostly within the first six days. A possible explanation of the discrepancy is that females with a poor expectation of life are unattractive to males, and this could account for the very small proportion of uninseminated flies in field collections, since such flies would tend to die before they could be captured.
Biology of some ground beetles (Col., Carabidae) injurious to strawberries
Authors: Briggs J. B.
Published: July 2009

Work at East Malling, Kent, between 1952 and 1963 on the biology of Harpalus rufipes (Deg.) (Carabidae), the strawberry seed beetle, is described in detail, and briefer notes are given on the life-histories of H. aeneus (F.), Feronia melanaria (Ill.) and F. madida (F.), which are less abundant but may also damage strawberries. Soil samples for larvae were washed over suitable sieves, those for pupae and adults were carefully searched in the field. Soil sampling showed that adults of H. rufipes colonised strawberry fields only during the fruiting period, weedy arable land and grassy situations being preferred at other times. By soil sampling, it was found that larvae of H. rufipes hatched from eggs laid in weedy soil in late summer, and evidence from pitfall trapping showed that the first two instars were sometimes active on the soil surface from August to December, before penetrating to a depth of 6–18 in. to overwinter. Development was resumed in April, but the larvae remained and the pupae were subsequently found at the overwinter depth in the soil, the larvae presumably feeding on the seed of fat hen (Chenopodium album) lodged in worm burrows. Third-instar larvae occurred from April to July, and adults emerged soon after. In the laboratory, adults lived for a further two years, hibernating in winter, and becoming active and breeding each summer. Laboratory observations on oviposition periods, fecundity and feeding were also made. Larvae, which in the field were mostly found associated with plants of fat hen, fed on germinating seeds of several plants in the laboratory but growth was most rapid when they were reared on the germinating seed of fat hen.

The life-cycles and habits of the three other species are briefly described and compared with those of H. rufipes, the seasonal occurrence of the different stages in the life-cycles of all species being shown in a table.
Virus disease of the African armyworm,Spodoptera exempta(Wlk.)
Authors: Brown E. S. , Swaine G.
Published: July 2009

Field and laboratory studies of virus disease in the armywormSpodoptera exempta(Wlk.) were carried out in East Africa in 1962–64. A nuclear polyhedrosis virus was detected microscopically in pupae, prepupae and all larval instars except the first, and was found to be widely distributed in most areas subject to outbreaks of armyworm in East Africa. The signs and course of the disease in larvae ofS. exemptaare described. Attempts made in the laboratory to infectS. triturataand other species ofSpodopterawith virus fromS. exemptafailed. In unsterile conditions of maintenance, almost all laboratory cultures from wild-caught female moths sustained heavy infections. The appearance of the symptoms of polyhedrosis was accelerated at higher temperatures, and the incidence was higher in more crowded cultures. Transmission took place from contaminated leaves to larvae and probably from one larva to another. There was evidence also of generation-to-generation transmission through the egg.

The effect on polyhedra of immersion in alkali solutions was investigated; it. was found that immersion for 15 minutes in 0·2 per cent. caustic potash effectively dissolved the matrix and inactivated the virus. When all equipment was sterilised in this way (or, later, with 0·4% caustic potash) apparently virus-free cultures were obtained by rearing the larvae from wild-caught females in isolation and breeding from those that survived to become adults.

The possible use of the virus for control of outbreaks of armyworm in the field is discussed; it is concluded that there is at present insufficient evidence to show whether such a measure would be effective.
Heliothis armigera (Hb.) (Noctuidae) in Western Tanganyika. II.—Ecology and natural and chemical control
Authors: Reed W.
Published: July 2009

In Western Tanganyika, Heliothis armigera (Hb.) occurs as a major pest of cotton from February to April, but also feeds on many other host plants. The dry season (August–October) is spanned usually by diapause pupae, the moths emerging from which oviposit on a species of Gleome, on which the first generation develops, giving rise to adults in November–December. Larvae of the second generation feed mainly on early-sown maize, and it is usually those of the third and fourth generations that attack cotton. Two subsequent generations occur on a variety of host plants, including late cotton, maize and legumes. The increasing severity of the attacks of Heliothis on cotton has accompanied the replacement of sorghum by maize in recent years. Maize is not only an intermediate host on which Heliothis builds up before it attacks cotton but also a source of diapause pupae later in the season.

In studies of the natural control of H. armigera, based on regular sampling of eggs and larvae on host plants in the field, the most important parasites were the Tachinids Drino imberbis (Wied.) and Goniophthalmus halli Mesnil, and field observations suggested that a species of Chrysopa (Neuroptera) was the main predator. Increasing use of insecticides may be reducing the effectiveness of natural control. A polyhedral virus was common, mainly found in larvae of Heliothis feeding on maize. The control of Heliothis on cotton by cultural methods was attempted by banning early sowing of maize and by sowing strips of maize in cotton fields as trap crops. Neither method is practicable on a large scale. Early sowing of cotton appears to be the best means of withstanding attack by Heliothis, for the local strains of cotton are able to compensate by later growth even for a very heavy Heliothis attack, provided they are sown early enough to utilise the late rains.

In cotton that was subject to a heavy attack by H. armigera, five applications at 2-week intervals of DDT at 1 lb. per acre gave good control of the larvae and increased the yield from about 200 lb. seed cotton per acre to about 500 lb., the difference being mainly in the early pickings. The addition of toxaphene increased the yield, probably by controlling Earias spp., but neither toxaphene alone nor carbaryl appeared to control Heliothis. The numbers of eggs laid were higher on cotton treated with DDT than on untreated cotton.
A verandah-trap hut for studying the house-frequenting habits of mosquitos and for assessing insecticides. I.—A description of the verandah-trap hut and of studies on the egress of Anopheles gambiae Giles and Mansonia uniformis (Theo.) from an untreated Hut
Authors: Smith Alec
Published: July 2009

A description is given of a verandah-trap hut designed to assess the egress and survival of mosquitos escaping through the eaves of the type of window-trap hut used in insecticide testing in East Africa.

Fifty-one per cent. of females of Anopheles gambiae Giles in all gonotrophic stages and 19 per cent. of those recently fed left the hut each night, with 15 and 30 per cent., respectively, of the egress occurring through the eaves.

Ninety per cent of females of Mansonia uniformis (Theo.) in all gonotrophic stages and 91 per cent. of those recently fed left the hut each night, with 69 and 66 per cent., respectively, of the egress occurring through the eaves.

It was concluded that, owing to the high proportion of individuals of M. uniformis that leaves by the eaves, the verandah-trap hut was of a more suitable design for studying the house-frequenting habits of this species, and of other species with similar habits, than the simple window-trap hut.
The biology and phenology of Arenipses sabella Hmps. and Cadra figulilella (Gregson) (Lepidoptera, Pyralidae) on dates in israel
Authors: Kehat M. , Greenberg S.
Published: July 2009

Larvae of Arenipses sabella Hmps., a serious pest of date palm trees in Israel, developed normally on inflorescences, immature or ripe rates and on green fruits of Phoenix canariensis, and their development at 30°C. took 34–45 days. Survival of males and fertilised famales was 10.8–12.0 days at 25°C. and 7.0–8.2 days at 27°C. No difference was found between survival of males and females, but unfertilised females lived rather longer than fertilised famales. The total production of eggs per female was 285 eggs at 25°C. and 328 at 27°C. At 25°C. 825 per cent. of the eggs were laid during the sixth and seventh nights of the female’s life, at 27°C. 74 per cent. were laid during the third and fourth nights. The total number of eggs laid by unfertilised females was lower than that of fertilised ones. The number of females fertilised was dependent on the number of males present in the rearing cage.

In Israel, only two generations of A. sabella— those in the spring and in the late autumn—become sufficiently large to be of economic importance. Damage occurs during only a short period in spring, when inflorescences, toung fruits and fruit stalks are attacked. In autumn and winter most larvae enter diapause. In the laboratory, the moth passes through four generations a year and even at the relatively high temperatures maintained during the winter the larvae entered a diapause.

Cadra figulilella (Gregson) is a serious pest of ripening dates in Israel and damages fruit still on the tree and also after it has been picked, if it is not then fumigated.

The time taken for development at 30°C. was 54–65 days. At this temperature adults lived for 4–6 days and the average number of eggs laid per fertilised female was 160. Unfertilised females laid fewer eggs. Most of the eggs were laid during the second and third nights after emergence of the female. The number of fertilised females depended on the number of males present in the rearing cage.

A few larvae were observed in the plantation in dropped, decaying dates throughout the year, but attack on the bunches started only when the fruit began to ripen.

Azinophos-methyl (E.C.20%) 0.5 per cent. and diazinon (E.C.25%) 0.5 per cent. were the most effective of the compounds tested. Application when the colour of the fruit began to change and again three or four weeks later resulted in excellent control of the pset.
Aircraft applications of insecticides in East Africa. Xvii. Airspray experiment with fenthion against Glossina morsitans Westw., G. swynnertoni Aust. And G. pallidipes Aust
Authors: Irving N. S. , Beesley J. S. S.
Published: July 2009

In an attempt made in 1966 to reduce the tsetse fly population in an experiment area of eight square miles in northern Tanganyika to a density low enough to permit safe settlement, undiluted technical fenthion (95% active ingredient) was applied three times at three-week intervals at 0.0041 gal. per acre from a Cassna 185 aircraft fitted with rotary atomisers. The total cost was £95 per sq. mile. Catches in the four weeks immediately following treatment on a flyround of 23,500 yd. sampling the area showed a reduction of over 90 per cent. when compared with those in the four weeks preceding treatment in the case of Glossina swynnertoni Aust. and G. pallidipes Aust. Five months after spraying, the reduction of the former species still exceeded 80 per cent, and that of the latter, 90 per cent. The reduction was smaller in G. morsitans Westw., the most numerous species; a fourth application would probably have improved the kill. The results are compared with those of an earlier experiment in the same area using endosulfan. Some settlement took place in the part of the area where G. swynnertoni predominated.
Laboratory culture of the rice gall midge Pachydiplosis oryzae (Wood-Mason)
Authors: Perera Nalini , Fernando Henry E.
Published: July 2009

No method has so far been available for the laboratory culture of Pachydiplosis oryzae Wood-Mason or for the controlled infestation of rice plants with this pest. Suitable techniques for the above have been developed and are described.

For the laboratory culture of P. oryzae, exposure of rice seedlings to gravid females for oviposition and the subsequent maintenance of the plants at a very high humidity in a mist chamber gave high infestation rates but results were not consistent. But this method is suitable for the maintenance of a laboratory culture of this insect.

A special oviposition tube was developed for inducing oviposition on limited areas of muslin, and this permitted easy observation, collection and handling of eggs.

It was found that oviposition tended to occur most frequently between 1900 and 2200 hr. and that the midges most commonly laid 200–285 eggs.

Eggs developed normally and hatched after seventy-two hours when the muslin carrying them was kept on barely moist filter paper in petri dishes.

Sixty-hour-old eggs could be stored for up to five days at 80 ± 2°C. with the percentage hatch decreasing gradually from the first to the fifth day. Low temperature affected development and hatching of thirty-six-hour-old eggs more severely, and hatching was completely inhibited if eggs of this age were exposed to this low temperature for more than two days. Hatching was normal when eggs were maintained at relative humidities of and above 88.8 per cent., but below this level some eggs collapsed as a result of desiccation. At relative humidities below 94.8 per cent., larval movement was initially limited and thereafter inhibited and the larvae were contracted. Such larvae resumed normal activity on immersion in water. These immobilised larvae, obtained by exposure of fully developed eggs to a relative humidity in the range 92.9–94.8 per cent., could be revived by immersion in water and used for infesting paddy plants.

Fully developed eggs, freshly hatched larvae and larvae subjected to relative humidities in the range 92.9–94.8 per cent. and subsequently revived, were transferred to rica plants bt spraying, or by pipetting on the leaf at the ligules or by pipetting on to the soil at the bases of plants. All these mathods proved successful but pipetting on to the soil between rows of plants was the simplest and is to be preferred for controlled infestation of plants.

A very high relative humidity and wet plant surfaces as obtained in the mist chamber used in these studies were essential for successful infestation of rice plants by the gall midge larvae.
The effects of crowding on the survival, rate of development, size, colour and fecundity ofDysdercus fasciatusSign. (Hem., Pyrrhocoridae) in the laboratory
Authors: Hodjat S. Hossein
Published: July 2009

Experiments were conducted to ascertain whether the rearing density ofDysdercus fasciatusSign. affected its rate of development, colour, size, reproduction and general activity. The length of the nymphal and adult life decreased when more than 12 insects were reared per 200-cc. cage. Isolated virgin females and females that eopulated once lived longer than females each kept constantly with one male. Nymphal crowding in adults that were smaller than those reared in isolation and in an excess of males. Nympha derived from crowded parents became red at an earlier age than the progeny of one male and one female per cage. Crowding reduced feeundity when the density of nymphs or adults, either male or female, was increased.

The pre-oviposition period and the time interval between successive egg-batches were greater for virgin than for mated females. Infertile eggs were the longest; females allowed to copulate once laid eggs intermediate in size between infertile ones and those laid by females each kept with a male. The number of eggs laid by females isolated throughout life with one male was found to be higher than the number laid by those that were crowded either in the nymphal stages or were crowded with males in the adult stage. When Dysdercu8 was crowded with one or two locusts the number of eggs laid and the number of egg-batches were considerably reduced; amputation or painting the antennae, which caused the Dysdercus to be less active, also reduced egg production but disturbance by mechanical shaking of the container had little effect. These findings are discussed in relation to the ' phases ' of locusts and other insects, and it is concluded that the effects of crowding on D. fasciatus do not completely parallel phase differences in locusts.
The biology of Earias biplaga Wlk. (Lep., Noctuidae) on Theobroma cacao in Western Nigeria
Authors: Entwistle P. F.
Published: July 2009

Earias biplaga Wlk. has been recorded to attack Theobroma cacao from the Ivory Coast to the Congo (Léopoldville) and also in San Thomé and is the only species of the genus to do so in Africa. Attack is most serious on seedlings in the field as the apical buds are destroyed.

Eggs are laid on the stem mainly, especially on leaf bracts. The first half of the larval period is passed within the apical bud and the last half in feeding on unhardened flush leaves, or, in their absence, in burrowing down the stem below the apex or in devouring the epidermis of the upper stem.

The length of the larval and pupal periods is inversely related to the mean maximum temperature; they are shortest in the dry season and longest in the wet season.

Differences between the sexes exist in the wing coloration, and in the shape of the labial palps, the last segment of which is much longer in the female than in the male. The dry-season form, which has the forewings suffused with golden brown in the female and with yellow-green in the male, instead of the wet-season green, occurs from January to March in the region of Ibadan, Western Nigeria.

The adults are largely nocturnal and they are attracted to ultra-violet light.

Adults lived longer in the laboratory on a diet of sucrose in water (males, on average, 17 days and females, 28 days) than on water alone or without either. A mean of 95 eggs per female was recorded from sucrose-fed adults in the laboratory and the greatest number of eggs laid by a single female was 461. The peak period of oviposition was the fourth to fifth day after mating (fifth to sixth after emergence). A method of rearing E. biplaga in the laboratory is described.

Six alternative host-plants in Nigeria, all in the Malvales, are listed, and one, Hibiscus esculentus, is a locally important food crop. Nine Hymenopterous parasites were found to attack E. biplaga in Western Nigeria, the most important being Trichogramma luteum (Gir.) which attacks the eggs, destroying over 90 per cent, of them at certain times of the year. All the other parasites, with one possible exception, appeared to attack only the larval stage of the host.
Scarab damage to grass and clover as influenced by depth of feeding
Authors: Davison R. L. , Roberts R. J.
Published: July 2009

Third-instar larvae of Rhopaea morbillosa Blkb. (Melolonthinae) were maintained at fixed depths between wire-mesh screens in earthenware pots during a 12-week factorial experiment designed to study the relationship between depths of feeding and damage to roots and foliage yield of Lolium perenne and Trifolium repens under two soil-moisture treatments (10% and 20%), with and without fertilisers.

Depth of feeding had a highly significant effect on relative root damage and foliage yield, and at all depths (18, 14, 12, 1, 2, and 4 in.) significantly greater root damage occurred under conditions more favourable for pasture growth.

Ryegrass was deeper rooted and suffered more damage than clover. The degree of non-linearity of root distribution with depth affected damage to roots at all depths so that species in mixed swards should suffer damage in proportion to their deep-rootedness.

It is clear that depth of feeding can confound experimental studies of damage by scarab larvae, and in the field it will influence the damage caused to pastures.
A survey of the Arthropod fauna of plum trees at East Malling in 1966
Authors: Ward Lena K.
Published: July 2009

In an investigation of the fauna of plum at East Mailing Research Station in 1966, over 70 species of the commoner arthropods were listed.

Different species of mite were found to prefer different parts of the tree, different parts of the leaf, and leaves of different ages on a shoot. Aculus fockeui (Nal. & Trt.) (Eriophyidae) was found to spread up the shoots during the early summer and to attain a density of over 100 per sq. cm. of leaf surface. Panonychus ulmi (Koch) was found to be commoner to the east of the tree, and leaf damage that it caused graded in severity across the plot. The species composition of populations of the Phytoseiid mites could differ markedly between trees in the same plot.

A study of the population trends of the commoner species based on numbers per shoot revealed that the populations of aphids and their predators developed two peaks during the season. There was a relatively high incidence of Entomophthora infection on the aphids, and overwintering fungal spores were produced when the aphids died in crevices on the bark, but only short-lived cornidia when they died on the leaves. The population density of member species of the fauna varied considerably, the smallest phytophagous mites reaching levels of 200 per shoot, predacious mites 10.0 per shoot and predatory bugs such as Blepharidopterus angulatus (Fall.) only about 0.01 per shoot.
Prediction of outbreaks of coffee leaf-miners on Kilimanjaro
Authors: Bigger M. , Tapley R. G.
Published: July 2009

Analysis of the results obtained from suction-trap catches of the coffee leaf-miners, Leucoptera meyricki Ghesq. and L. caffeina Wshbn. on an unsprayed block of coffee at the Coffee Eesearch Station, Lyamungu, on the slopes of Kilimanjaro, are given.

By thermal summation methods it was possible to delimit successive generations of moths with some degree of accuracy and the generation catches were used for regression analysis with various meteorological factors. With L. meyricki, a negative correlation was shown between the rate of increase from one generation to the next and with both maximum and mean daily temperature, solar radiation and duration of sunshine taken as means over the period of each generation. In each case, the highest degree of correlation was found between the meteorological data in one generation and the rate of increase in the next.

When the generation catches were plotted on a logarithmic scale it was found that linear regression lines could be fitted to the periods of both rise and fall of the annual outbreak. With L. meyricki, the rate of increase of the rise was negatively correlated with, and the rate of decrease of the fall positively correlated with, the size of the generation present at the beginning of the outbreak. It is therefore possible, knowing the size of the minimum generation, to predict the size of the coming outbreak. No such relationship could be proved with L. caffeina, probably because the catches of the key generations were very small, but when the catches of the two species were pooled the same relationship held. It is probable that parasites are the main factor governing the annual fluctuations.
Effect of blood intake of Glossina austeni Newst. on pupal weights in successive reproductive cycles
Authors: Boyle J. A.
Published: July 2009

Ten fertilised female Glossina austeni Newst. reared from pupae with a weight range of 17–33 mg were maintained singly in small cages, and were offered food six days per week. The mean data for the flies were 151 days life span, 14–5 pupae per female and 25–4 mg pupal weight. One fly showed an abnormal digestive condition, and several failed to larviposit at the end of a cycle. The weight of pupae produced was related to the total amount of blood ingested in each normal cycle. A comparison between fertilised and virgin flies indicated that 50% of the blood ingested by the former was for pupal production. Large flies took larger blood-meals and fed less frequently than small flies.
Redescriptions of some known species of Trichogramma (Hym., Trichogrammatidae), showing the importance of the male genitalia as a diagnostic character
Authors: Nagarkatti Sudha , Nagaraja H.
Published: July 2009

Twelve Trichogramma spp. are redescribed. These are: T. australicum Girault, T. dendrolimi Matsumura, T. euproctidis (Girault), T. evanescens Westwood, T. fasciatum(Perkins), T. japonicum Ashmead, T. minutum Riley, T. perkinsi Girault, T. pretiosum Riley, T. retorridum (Girault), T. semblidis (Aurivillius) and T. semifumatum(Perkins). Differences in male genitalia are emphasised, being most stable and reliable, and pigmentation as well as wing and antennal trichiation are described, being characters of supplementary importance for species diagnosis. Host and distribution records are also given. In the male genitalia, the shape of the dorsal expansion of the gonobase differs considerably in some species and the position of the chelate structures with respect to the tips of the gonoforceps also varies; the median ventral projection
is large in some species, reduced in some and almost absent in others. A comparative account of the most distinguishing characters of the different species is included and a key to 15 species is provided
Laboratory studies on the biology of Lepidosaphes conchiformis (Gmel.) (Hem., Diaspididae) and of its parasite Aphytis maculicornis (Masi) (Hym., Aphelinidae)
Authors: Ahmad Rafiq , Ghani M. A.
Published: July 2009

During 1963–69 the United States Department of Agriculture sponsored investigations on scale insects and their natural enemies in West Pakistan.* In the course of the survey Lepidosaphes conchiformis (Gmel.)† was collected from several localities. It occurred sporadically, but infestations were heavy on most of the plants on which it was found. In the hills it was commonly parasitised by Aphytis maculicornis (Masi). The potential importance of the scale and its parasite merited laboratory studies at Rawalpindi.
A new genus of Euscelinae from the Lower Himalayas, and a new species of Balclutha Kirkaldy (Homoptera, Cicadelloidea)
Authors: Ghauri M. S. K.
Published: July 2009

The genus Subhimalus is erected for the new species S. melanus on potato and S. fuscus on clover; Balclutha versicoloroides from clover is described as new.
Group effects on feeding in adult males of the desert locust,Schistocerca gregaria(Forsk.), in relation to sexual maturation.
Authors: Norris Maud J.
Published: July 2009

It has previously been shown that the sexual maturation of males ofScliistocerca grcgaria(Forsk.) is accelerated by crowding with other individuals of similar or greater age, and that the maturation of males kept in single pairs with older mature males is accelerated as compared with that of isolated males or males kept in single pairs with other young males or females of their own age. The effects of these groupings on the levels of feeding and excretion are investigated in the present work.

Crowded males ate and excreted more than isolated ones during the first ten days of adult life. Five males in a 9-litre cage are sufficient to induce almost the full effect of crowding, and marked effects are shown when only two males are present in such a cage.

After the second or third week, the level of feeding declines. This occurs earlier in early-maturing individuals, so that for a short period the crowded males eat little more or even less than the isolated ones. When the isolated males in their turn become mature their feeding again falls slightly below that of the crowded ones. When all males are isolated, there is a significant tendency for those males which eat least from the beginning of adult life and which increase their weight least to become mature earliest.

The proportion of the food utilised was not affected by density. It was higher during the early period of maximum consumption than it was after the level of feeding declined.
Studies on the bionomics of the jute stem girdler, Nupserha bicolor postbrunnea Dutt (COL., LAMIIDAE).
Authors: Dutt N.
Published: July 2009

Nupserha bicolor postbrunnea Dutt has become established on olitorius jute (Corchorus olitorius), possibly from its wild food-plant, Sesbania aegyptiaca, and from jute it has spread to other agricultural crops. Incidence on the green-manure crop, Sesbania bispinosa, has increased so much in recent years that it has surpassed that on olitorius jute. The stem diameter most favourable for girdling and oviposition in S. bispinosa ranges from 3·1 to 5 mm., whilst in C. olitorius it is from 2·6 to 3 mm. In spite of this wide difference in preferred stem diameter, the ratio of mandibular length to depth of extra-medullary tissue of such stems in the two plants agrees well.

All the varieties of capsularis jute (C.capsularis) are unacceptable to the adults though they are acceptable to the larvae. Adults obtained from larvae reared on varieties of capsularis jute also show aversion to capsularis types. The pest selects the susceptible olitorius from amongst capsularis jute when these are grown as a mixed crop. Amongst the olitorius varieties, C.G. is the most susceptible. Plants coming within the height range of 100 to 200 cm. are attacked more than others. Girdling causes suspension of unidirectional vertical growth, and this is followed by the appearance of a number of side branches, which are of little value from the point of view of fibre.
The variability of fly-round catches in field studies of Glossina.
Authors: Glasgow J. P.
Published: July 2009

In an attempt at some assessment of the errors to which fly-round data obtained for the study of populations of Glossina are subject, three fly-rounds at Shinyanga, Tanganyika, were worked every weekday for four weeks. The species studied was G. swynnertoni Aust. One of the rounds was a ‘transect fly-round ’, the others, the older type, divided into a few long sections according to the vegetation. The catches showed no obvious trend during the experiment, suggesting that the true population had not altered in the period, but in all three rounds there were considerable day-to-day variations in catch and, in this respect, the transect fly-round did not differ from the older method. An analysis of variance of the transect fly-round data showed that the variance between days was greater than could be accounted for by random errors

By considering separately the data collected on certain days of the week, it is concluded that a 7,500-yd. fly-round done once a week could not detect less than a five-fold change in the mean catch. To detect a two-fold change, a 15,000-yd. fly-round done twice a week would be necessary.

The relation between fly-round catch and true density is discussed. This relation is usually termed ‘ availability ’. Earlier workers have shown that its mean value, over periods of about one month, is not necessarily constant; the present work shows that it varies in one place from day to day.
Insecticidal operations against Chironomid midges along the Blue Nile.
Authors: Brown A. W. A. , Mckinley D. J. , Bedford H. W. , Qutubuddin M.
Published: July 2009

In 1956 and 1957, tests were made in the Sudan Eepublic of four methods of applying insecticides for the control of heavy infestations of midges, particularlyTanytarsus lewisiFreeman, which breed in the Blue Nile. During the winter season the adults occur in myriads in areas adjacent to the river in Khartoum and similar localities, resting in trees and shrubs by day and being attracted to artificial lights after dusk

An emulsion containing 0·4 per cent. DDT applied from the ground to shadetrees in Khartoum at the rate of 0·5·1·0 lb. DDT per tree achieved local control of the midges for three days and detectable reduction for 10 days. An emulsion containing 12·5 per cent. DDT applied from an aircraft to the wooded riverfrontage at Khartoum at 2·1 lb. per acre reduced the numbers of adult midges for the next 15 days, but subsequent applications under conditions of greater air turbulence were ineffective.

The application of DDT as a larvicide in oil solution from aircraft to the river 10 miles above Khartoum, at a concentration approximately equivalent to 0·1 p.p.m. in 2 hours' riverflow, did not appear to reduce the numbers of adults or immature stages at Khartoum, and was followed by some mortality of fish.
Large-scale field testing of a granulosis virus for the control of the potato Moth (Phthorimaea Operculella (Zell.) (Lep., Gelechiidae))
Authors: Reed E. M. , Springett B. P.
Published: July 2009

A granulosis virus was tested on a field scale at Manjimup and Pemberton in Western Australia for control of its host, the potato moth Phthorimaea operculella (Zell.). The virus was produced on laboratory-reared larvae, and applied as a suspension of pulverised larvae (6 275 in 111 gal/ha) to second-crop (December-planted) potatoes. There were untreated and insecticide-treated (DDT, dieldrin, methyl-demeton) fields for comparison. The effectiveness of the treatments was assessed on numbers of larval mines and tuber damage. Virus infection rates of 100% were achieved, with a residual effect of 12 weeks. Variation in larval body weight indicated that initial dosages and those due to recycled virus were excessive, but were optimum after two months. Virus applications were as effective in preventing damage as insecticide treatments. Virus spread to untreated crops some miles distant was attributed to movements of personnel, farm materials or birds.
Control of Spodoptera littoralis (Boisd.), Myzus persicae (Sulz.) and Tetranychus urticae (Koch) by cold storage and fumigation
Authors: Powell D. F. , Gostick K. G.
Published: July 2009

In laboratory experiments, all stages of the Egyptian cotton-leaf worm (Spodoptera littoralis (Boisd.)) were killed by exposure at 1–2%C for ten days, but the peach-potato aphid (Myzus persicae (Sulz.)) and the red spider mite (Tetranychus urticae (Koch)) were not controlled by this treatment. When exposed to methyl bromide, all the S. littoralis eggs tested were killed by a concentration × time product (CTP) of 44 mg h/litre at 18%C, but control of all stages of M. persicae and T. urticae required a CTP of at least 88 mg h/litre.
The effects of smoke from mosquito coils on Anopheles gambiae Giles and Mansonia uniformis (Theo.) in verandah-trap huts at Magugu, Tanzania
Authors: Hudson J. E. , Esozed S.
Published: July 2009

The effects of smoke from mosquito coils containing pyrethrins or DDT on Anopheles gambiae Giles and Mansonia uniformis (Theo.) were investigated by burning coils for five nights per week in three man-baited verandah-trap huts. Three other verandah-trap huts served as controls. Smoke from 004–0–3% pyrethrins coils deterred 24–84% of A. gambiae and 71–93% of M. uniformis from entering treated huts, and that from 7–3–130% DDT coils deterred 91 % of A. gambiae and 92% of M. uniformis.In pyrethrum-treated huts 62–76% A. gambiae were unfed (33–67% in the controls) and 80–99% were in the exit traps (43–79% in the controls). In DDT-treated huts 85% A.gambiae were unfed (48% in the controls) and 100% were in the exit traps (55% in the controls). With M. uniformis, 61–84% in the pyrethrum-treated huts were unfed (38–54% in the controls) and in the DDT-treated huts 71 % (69% in the controls). The effects of the smokes on the egress of M. uniformis could not be assessed since 82–100% were in the exit traps in the treated and in the control huts. Overall mortalities never exceeded 22% of A. gambiae and 12% of M. uniformis, but some dead mosquitoes may have been removed by ants. With pyrethrum coils, feeder-survivor indices were 15–84% for A. gambiae and 90–98% for M. uniformis, and with the DDT coils, 94% and 96%, respectively. When caged A. gambiae females were exposed all night in the huts, 24-h delayed mortalities caused by 019–0–30% pyrethrins coils were 38–56%, by 009% pyrethrins coils 12–27%, and by 004% pyrethrins coils 3–5%. DDT coils produced 99–100% mortality in 24 h, but this may have been due to contact with contaminated mosquito netting.
The biting flies of the Kano Plains, Kenya: Part II. Larval habitats of common mosquito species (Dipt., Culicidae)
Authors: Khamala Canute P. M.
Published: July 2009

Six natural terrestrial mosquito breeding habitats were recognised in the Kano Plains of Kenya by their condition, i.e. temporary or permanent, presence or absence of emergent plants, and by the chemical and physical characteristics of their water. Between September 1968 and March 1970, 13 mosquito species were found breeding in these habitats. Most species were restricted to a few habitats; only four showed a wide occurrence, being found in at least four. Anopheles gambiae Giles and Culex annulioris Theo. exploited all six habitats, suggesting that the characteristics studied were probably not critical to their selection of a breeding site. Mansonia and Coquillettidia spp. were restricted to habitats with some plants, indicating their dependence on such vegetation for respiration and protection. The indiscriminate selection of breeding sites by disease vectors, e.g. A. gambiae, A. pharoensis Theo. and Culex pipiens fatigans Wied., is worth noting in irrigation schemes.
Motor responses ofRhodnius prolixusStål (Hem., Reduviidae) to volatile drugs
Authors: McLure Ian
Published: July 2009

Fifth-instar nymphs ofRhodnius prolixusStålwere exposed to the vapours of 11 volatile drugs: acetone, bromobenzene, bromoform, carbon tetrachloride, chloral hydrate, chloroform, dioxane, ethanol, ethyl ether, isopropanol and paraldehyde. Bromobenzene, bromoform, carbon tetrachloride, chloroform and ether induced reversible anaesthesia. For each of these five, the insects exhibited a different andspecific pattern of motor responses before becoming totally immobile; these responses are described. The responses to carbon tetrachloride are similar to the normal feeding responses of this insect. The other six drugs did not induce anaesthesia, but instead, a commonand stereotyped pattern of cleaning responses, suggesting irritation of the sensory organs. It is proposed that the agent-specific responses to the anaesthesiainducing drugs are due to their differential action upon specific portions of the insect central nervous system.
Chemosterilisation of the red bollworm Diparopsis castanea Hmps. (Lep., Noctuidae): effects of certain s-triazines and a carbamate insecticide
Authors: Campion D. G.
Published: July 2009

Sublethal topically applied doses of the carbamate insecticide carbaryl and injection of certain s-triazine chemosterilants to female Diparopsis castanea Hmps. enhanced the rate of oviposition without reducing fertility. Treatment of male moths with carbaryl and certain s-triazines often caused an increase in mating disfunction expressed as an absence of sperm from the spermatheca after an apparently normal mating, permanent copulation or spontaneous extrusion of a spermatophore. No evidencewas found for a direct sterilising action of the chemosterilants against the insect sperm.