Williams (1960) suggested the use of insect hormones as possible pest control agents. Hormones are internal secretions that regulate a wide variety of physiological processes especially those concerned with growth, development and egg maturation (Novék, 1966). Similar activity has been reported for a series of compounds related to insect hormones and known as juvenile hormone mimics or analogues (see reviews by Berkoff, 1969; El-Ibrashy, 1970; Ellis et al., 1970; Wigglesworth, 1970). This paper presents the results of a laboratory investigation using one such hormone analogue, methyl farnesoate dihydrochioride (DMF) prepared according to methods described by Law et al. (1966) and Romaňuk et al. (1967) when applied to the cotton stainer bug Dysdercus fasciatus Say.

The genus Matutinus Distant is characterised and differentiated from Chlorionidea Loew, with which it was at one time synonymised. Descriptions are given of 26 species, 15 of which are described as new; three are transferred from other genera and a new subgenus is erected to accommodate one of them. Notes are given on their geographical distribution and host-plants.

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.

Each spherical spermatheca of Glossina austeni Newst. is composed of a cuticular lining of the lumen which is surrounded by a layer of secretory cells. When the spermatheca is immersed in Amann's lactophenol the cells of the cellular layer lift away from the cuticular intima revealing numerous clubbed processes projecting outwards from the surface of the intima. Sections of spermathecae examined by transmission electron microscopy show that one clubbed process is associated with each cell of the cellular layer. The “porous” head of the process is within a fluidfilled cavity in the cell, lined with microvilli. The stalk of each process is an extracellular duct down which secretions from the cellular layer pass into the lumen of the spermatheca. It is considered that these secretions are the medium, probably containing nutrients, in which spermatozoa are held while in the spermatheca.

An account is given of the biology and different life stages of Lioadalia flavomaculata (Deg.), an important predator of the wheat aphid, Schizaphis graminum (Rond.), in the Orange Free State, South Africa. Eggs are laid in batches of 6–23 eggs, generally on the soil, and incubation takes 2.1–2.8 days at 32°C and 8.6–9.1 days at 16°C. There are four larval instars, the last of which has the longest duration; total development of the immature stages averaged 11.5, 161, 220, 30.2, 35.5 and 54.0 days at 32, 27, 24, 21, 18.5 and 16°C, respectively. Beetles mate within a few days of emergence and oviposition commences 3–10 days later, depending on temperature. Maximum fecundity averaged 858.5 eggs at 24°C. From 20.7 to 24.6 eggs per day were laid at the higher range of temperatures studied (24–32°C). Oviposition took place mainly during the day. Adult life span was 24–74.3 days.

Physcus seminotus Silv. (properly P. sp. nr. seminotus Silv.) and P. subflavus Annecke & Insley (Aphelinidae) are parasites of the sugar-cane scale insect Aulacaspis tegalensis (Zhnt.) (Diaspididae) in East Africa and they have been purposely introduced into Mauritius where A. tegalensis is an important pest. P. seminotus has brachypterous, flightless females and P. subflavus winged females but their biology is essentially similar. The parasites are arrhenotokous and fertilised and unfertilised eggs are deposited in different sites concomitant with development of female and male larvae on different primary hosts. Female larvae develop endoparasitically in A. tegalensis from fertilised eggs deposited in the host's body cavity. Male larvae develop ectoparasitically on immature Hymenoptera in A. tegalensis from unfertilised eggs deposited in the air-filled cavity of the latter's integumentary remnant. The males of the two Physcus spp. are therefore hyperparasitic and they frequently develop on the immature stages, both male and female, of their own kind (autoparasitism). Unfertilised eggs are laid by virgin females and also by mated females, the latter being able to deposit fertilised and unfertilised eggs at will, depending on the egg site encountered. Sexual dimorphism occurs at all stages, including the deposited egg. The preovipositional adult is the preferred stage of A. tegalensis for deposition of fertilised eggs and development of females is most rapid in such hosts. Development in young hosts is arrested until the hosts have grown to virtually their full size. The host of a male is apparently a matter of chance in so far as evelopment will occur on larval and pupal Hymenoptera of various species found in the empty, inflated, brittle integument of parasitised A. tegalensis. Only one individual, whether male or female, develops per host. Oviposition behaviour of mated females is such that superparasitism is largely avoided but it is liable to occur frequently when virgin females oviposit. Adult females will feed on the body fluids of A. tegalensis that are released by insertion of the ovipositor and also on sugary fluids. They live a month or more, ovipositing continually at a gradually decreasing rate, and laying usually 50–100 eggs.

Two carbamate insecticides, Mobam (4-benzothienyl methylcarbamate) and carbaryl, were tested at dosages of 2 g/m2 active ingredient in grass-roofed verandah-trap huts at Taveta, Kenya, in 1967 and 1968, respectively. In Mobamtreated huts, overall mortalities were over 70% for 20 weeks in Anopheles gambiae Giles and A. funestus Giles, and for 12 weeks in Culex pipiens fatigans Wied. In the carboryl-treated huts overall mortalities were over 70% for 12 weeks in A. funestus, but in A. gambiae and C.p. fatigans never exceeded 64% and 33%, respectively. Neither compound had a deterrent effect on A. gambiae, which entered the treated huts in more than the expected numbers. Mobam did not appear to be repellent; and carbaryl was only slightly so. Egress of blood-fed A. gambiae increased after treatment but most of the mosquitoes died after reaching the verandah traps. There were slightly more unfed A. gambiae in the treated huts than in the control hut but there were never more than 35% unfed.

In Leptohylemyia coarctata (Fall.) the germarium cuts off oocytes which develop through the stages 00 and 0 and I-V, recognised in other Cyclorraphous flies, in 4–5 weeks. All eggs of one batch of the gonadotrophic cycle ripen at the same time. After oviposition, the split intima, the remains of the follicular epithelium, and the nurse cells slowly contract to form the follicular relic. Flies swept from winter wheat during June and July and caught in water traps in July and August showed all stages of egg development. In 1970, 24·7% of the females swept from the crop had completed the first, 4–7% the second and 0–4% the third gonadotrophic cycle. All the eggs were not laid at the same time. During later gonadotrophic cycles, some ovarioles were non-functional. Flies laid one or two batches of eggs, rarely three. In 1970, many flies were attacked and killed by E. muscae. Only one out of 115 newly emerged female wheat bulb flies presented with foods usually found in the crop or citrated blood contained mature eggs after 24–27 days in small cages. Those fed only on 0·1 M glucose survived but did not deposit yolk in the ovum; those provided only with yeast paste died. Honey dew from cereal aphids was the main source of sugar. Water in droplet form and space to move seem necessary for the maturation of the eggs.

The distribution of the almond wasp, Eurytoma amygdali End., as a major pest of almonds in areas of the eastern Mediterranean, a general outline of its seasonal history, and studies on the biology of the adult in Israel, have been reported previously (Plaut, 1971a). This paper presents data obtained in 1964–71 on the biology of the immature stages.

Field and laboratory observations on the adults of Eurytoma amygdali End. at Newe Ya'ar, Israel, were made as a basis for improving control measures against this pest of almond fruits. After hatching from the pupa, the adults took 3–9 days to bore through the pericarp. Emergence usually began in March, but was delayed by cold weather in February and March. Males emerged earlier than females, and oviposition began the first or second day after emergence. Drilling and deposition of the egg into the nucellar tissue of the young fruits took 9–34 min, up to five eggs per fruit being laid under natural conditions. As oviposition sites, larger fruits were preferred to small, and uninfested fruits to infested. At 23 °C indoors fecundity and life span were 128·9 and 7–18 days, respectively, but outdoors under unsettled weather conditions were 23·0 and 4–25 days, respectively. When fed on honey dew or water instead of 10% honey, fewer eggs were laid. The lack of an oviposition site reduced the life span of the female.

The use of standardised artificial substratum units (SASUs) for sampling preimaginal populations of Simulium is reviewed and the results then given of experiments with SASUs in rivers and artificial streams in West Cameroon in 1968–70. The increase of downstream drift of larvae by night is attributed to the increased activity of associated fauna at night. The numbers of larvae settling on SASUs is partly afunction of how long the latter have been set and partly due to the pattern of fluctuation in river depth. Any particular SASU appears to be selective in relation to the different species of Simulium available for settlement. A new index of uniformity is proposed for comparing the diversity of Simulium faunas occurring on different substrata.

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.

Techniques and apparatus developed for pheromone bioassay studies of ants are described. They include a ventilated cage, with a blacked-out nest area and a two-compartment arena, in which colonies are maintained in the laboratory, and in which group experiments are carried out; a prey treatment apparatus, in which a stinging ant is clamped at the junction of head and thorax, with its body supported on a length of black nylon tubing which is used as artificial prey after it has been stung for a specified period; an applicator for introducing into the cage artificial prey which have been treated with ant secretions, either by the latter method, or by the direct application of dissected gland material; and a closed-system, pheromone-testing apparatus, in which an ant is held in a perspex observation chamber with controlled lighting, supplied with air at constant temperature, relative humidity and flow rate, and treated with gland odours introduced into the conditioned air.

An improved technique for small-scale rearing of Rhodnius prolixus Stal on rabbits is described. For feeding, the bugs are presented in tubes closed with silk to the shaved stomachs of rabbits; between feeds the bugs are held in 1-lb glass jars at 28°C. Large-scale rearing by this method was precluded by the amount of handling required. Feeding on defibrinated blood resulted in a survival rate to the adult stage of less than 10%, but sheep on which up to 6 600 fourth instar could be fed weekly proved satisfactory hosts, although they had to be replaced after 1–9 weeks as they developed a resistance which prevented the bugs feeding. A large-scale rearing technique is described in which instars 2–5 are presented to sheep in wire cages covered with nylon netting while instar 1 and adults are fed on rabbits; between feeds the bugs are housed in 3½–7-lb glass jars or in net-covered cages. A production of 4 000 fed fourth instar or larger bugs per week for 18 months was achieved, sometimes reaching 7 000 per week.

Laboratory investigations of olfactory perception in the tsetse fly Glossina morsitans orientalis Vanderplank, were carried out by measuring the modulation of the spontaneous rate of activity by sudden olfactory stimulation. Marked responses were obtained to emanations from guinea-pig, chick, crocodile and the human hand and forearm. Emanations from human skin despite the absence of expired carbon dioxide induced a strong response compared to the other host types. The stimulus was removed by rinsing the skin with acetone solvent. Air passed over material impregnated with human sweat and odour was ineffective. Responses to guinea-pig odour and guinea-pig expired air were approximately equal. Carbon dioxide was the important factor in expired air. The quantitative relationship between stimulus and response was non-linear, responses increasing with approximately exponential increases in stimulus intensity. The existence of an airborne sexual stimulus could not be demonstrated.

Exitianus curvipenis (representing a new sixth species-group) from rice-field grasses in Nigeria, and E. upenis (okahandia-group) from open grassland in Abyssinia are described as new.

Descriptions are given of the immature and adult stages of Tenuipalpus ghanii sp. n., and the characters distinguishing this species from T. punicae Pritchard & Baker and T. granati Sayed are listed. In West Pakistan the preferred host-plant is Pyrus communis. T. ghanii overwinters in the adult stage; it reproduces parthenogenetically and populations of all stages reach their peak in June or July. Of the four predators recorded, Exothorhis sp. (Eupalopsellidae) was the most abundant but was restricted to Pyrus communis.

The result of treating Tenebrio molitor L. pupae with synthetic juvenile hormone (JH) or a juvenile hormone analogue, methyl farnesoate dihydrochloride (DMF), is to arrest pupal development, producing pupal/adult intermediates. Both substances induced approximately 50% pupal/adult intermediates at a topically applied dose of 1 μg. The activity was greatly affected by the age of the pupa at the time of treatment, one- and two-day-old pupae being the most sensitive. Applied to four-day-old and older pupae complete metamorphosis to the adult was possible at a dose of 8 μg of synthetic JH and up to 200 μg for DMF. Doses above these levels merely increased toxicity without juvenilising activity.

Adults of Aphis fabae Scop. can weigh from as little as 200 μg to as much as 1 800 μg (Way & Banks, 1967), a remarkable range in size for a single species. An extensive range in size also occurs among the adults in other species of aphid (Murdie, 1969a, b; Dixon, 1970). Small individuals result when aphids develop either under crowded conditions or on a mature host-plant; large aphids result when the nymphs are reared in isolation or on young or senescent host-plants (Way & Banks, 1967; Murdie, 1969a, b; Dixon, 1970). A small adult produces fewer nymphs and also smaller nymphs than average (Murdie, 1969b; Dixon, 1970). When aphids are overcrowded or feed on host-plants of poor quality, many aphids reach maturity that might otherwise fail to mature because of the ability of the species to produce viable adults of a great variety of size, including very small adults (Way & Banks, 1967).

The main purpose of the investigation was to determine when larviposition occurs in these laboratories, under conditions of constant temperature, relative humidity and light cycle.