Crickets are convenient systems for studying life-cycle evolution. They show a considerable diversity in life-cycle types, being homodynamic in some parts of the tropics and heterodynamic with various kinds of diapause and other regulatory responses in the temperate region. Crickets are relatively free from constraints by food supply, because they are omnivorous. Therefore, their geographical variation may clearly reflect climatic selection as exemplified by latitudinal dines in adult size, egg size and ovipositor length. These morphometric dines are closely related to development time, egg diapause and photoperiodic responses, indicating that crickets are highly variable within the framework of their species-specific patterns of life cycle. More fundamental variation is divergence in life-cycle pattern that may be associated with speciation, because closely related species are often different in their life-cycle patterns (e.g., homodynamic versus heterodynamic, or egg overwintering versus larval overwintering). Evolutionary flexibility of life-cycle traits may be assessed by studying cricket populations under special natural or artificial conditions. In Japan, a population of the nemobiine cricket (Dianemobius mikado) introduced from a temperate to a subtropical island has almost lost egg diapause presumably in the last 130 years. At volcanic geothermal spots in the northern island (Hokkaido), presumptive relict populations of the nemobiine species Dianemobius nigrofasciatus occur and sing in mid-winter, but this cricket retains the photoperiodic response of a southern bivoltine type. In the subtropical nemobiine D. fascipes, artificial selection has been effective in changing the incidence and depth of diapause, and strains comparable to the tropical and temperate forms were established. The responsiveness to photoperiod in wing-form determination was also remarkably changed by selection, but this change was not associated with a change in critical photoperiod. Alternated selection in the opposite directions at photoperiods above and below the critical value to be selected was necessary to shift the critical photoperiod.

The rate of inbreeding is an important parameter in the population and evolutionary genetics of a species. Accurate measurement of the rate of close inbreeding can be gained through the use of DNA fingerprinting; however, this is both labour intensive and expensive. We here provide a more approximate measure of the rate of close inbreeding in Adalia bipunctata, utilising the unusual phenotypic effect of inbreeding, the production of eggs which develop but fail to hatch, which is seen in this species. Examination of the incidence of grey eggs in known outbred and inbred laboratory crosses and comparison to their incidence in wild-collected clutches produced an upper estimate of 2.7% of wild clutches being the product of close inbreeding. This result is discussed in the light of the ecology and evolutionary biology of Adalia bipunctata.

The present paper provides descriptions and diagnoses of three new taxa from Thailand: Satunia gen. n., with one species, S. tassirii sp. n., and Alloteratura kuehnelti sp. n. The hitherto unknown male of Xiphidiopsis cryprosticta Hebard, 1922 is described and diagnosed.

Adults collected in the Duars of the Himalayas of West Bengal (India) belong to five genera of the Harnischia complex. Four species, Cryptochironomus curryi Mason, C. ramus Mason, Demicryptochironomus vulneratus (Zetterstedt), and Harnischia curtilamellata (Malloch) are recorded for the first time from India, and four species, Cryptochironomus acuminatus, C. gracilis, Harnischia minuta and Paracladopelma diutinistyla are described as new. A key to the Indian species of Cryptochironomus Kieffer is presented. The female of Cryptochironomus subovatus Freeman, hitherto unknown, is described. One Japanese species, Demicryptochironomus chuzequartus Sasa, 1984 is proposed as a synonym of Demicryptochironomus vulneratus (Zetterstedt, 1838).

The effect of extracts from neuroendocrine complexes of brain-suboesophageal ganglion-corpora cardiaca-corpus allatum (NEC) on synthetic activity of corpora allata (CA) in vitro was investigated by a radiochemical assay in Pyrrhocoris apterus. NEC extracts from short-day (diapausing) females and long-day (active) females and males were compared. NEC extracts from both short-day and long-day insects stimulated synthetic activity of the CA from long-day females. The CA from shea-day females were refractory to stimulation. The stimulating activity of the NEC extract was retained after removal of proteins using 10,000-molecular weight limit centrifugal ultrafiltration, but was destroyed by treatment with proteinase K. Therefore, the stimulating factor appears to be a peptide. The culture medium containing a mixture of synthetic products of the CA was extracted by hexane and subjected to TLC analysis. It was revealed that the NEC extract stimulated synthesis of a product from radiolabelled methionine which elutes on TLC in the same position as the major product of the CA of four other heteropteran species.

It has often been stated that insects survive at low temperature by one of two main strategies, freeze tolerance and freeze avoidance by supercooling. Apart from the observation that the risk of freezing and its consequences is not the only injurious and possibly lethal effect of low temperature, it is interesting to consider a closely related question. If insects survive at low temperature by tolerating or avoiding freezing, under what circumstances do they die? A survey of the literature suggests there are five reasonably distinct situations representing decreasing levels of cold tolerance where death occurs (1) at some temperature below the freezing temperature or supercooling point (SCP), (2) when the organism freezes, (3) after prolonged chilling at moderate to low sub-zero temperatures, (4) after brief chilling at moderate to high sub-zero temperatures and (5) when temperatures are too low to maintain normal metabolism and the species is unable to enter any form of dormant state. This paper examines how the principles of freeze tolerance and freeze avoidance, derived primarily from studies on species from extreme environments, can be combined with observations on the cold tolerance of insects from less severe climatic zones, to produce a system of classification which allocates species to particular categories, using specific, ecologically-relevant criteria. The proposed new classes of cold hardy insects - freeze tolerant, freeze avoiding, chill tolerant, chill susceptible and opportunistic survival - thus form a continuum of distinct groups, from the most to least cold hardy, in a system of classifying insect cold hardiness that can be applied world-wide.

Thermal constants, Lower development threshold (LDT) and sum of effective temperatures (SET) were recalculated from literature data for 335 insect species. Included were only populations whose development rate was ascertained in at least 4 constant temperatures of <=28°C. Variation of thermal constants was investigated in relation to geographic origin of the populations to test the prediction that LDT will decrease and SET increase with increasing geographical latitude (Trudgill, 1995). In tropics (at <= 23°N or S), LDT was high with little geographic variation. In subtropical and temperate zones there was a significant trend for decreasing average LDT with increasing geographical latitude. SET increased with geographic latitude but the scatter of data was greater than in LDT. The geographic trends of variation in thermal constants conformed to the prediction but the scatter of data was large probably due to both ecophysiological differences between the species, and errors in estimating thermal constants of development.

This is the first report of the potential of the hyphomycete fungus, Paecilomyces fumosoroseus (Wize) Brown & Smith, for the microbial control of aphids. The LD₅₀ and LD₉₀ of a strain of P. fumosoroseus isolated from Bemisia tabaci (Gennadius) from Multan, Pakistan and bioassayed against third instar Diuraphis noxia (Mordvillco) were 1.78*10³ conidia/cm² and 1.43*10⁴ conidia/cm², respectively. Strong dosage-mortality and dosage-mycosis responses were evident with larger proportions of individuals dying within the first three days post-treatment at the higher conidial dosages (1.25-3.75*10⁴ conidia/cm²) than was observed for dosages equal to or lower than 3.75*10³ conidia/cm². The LT₅₀s for D. noxia treated with 3.75*10⁴ conidia/cm² and 3.75*10³ conidia/cm² were 2.06 and 7.50 days, respectively. The entomopathogenic activity of P. fumosoroseus against D. noxia compares favorably with other Hyphomycetes reported in the literature. Based on the results reported here, further investigation of the potential of P. fumosoroseus for the microbial control of D. noxia and other aphids is warranted.

In addition to data on the efficacy of P. fumosoroseus as a microbial control agent of D. noxia, a simple, but effective bioassay method for the evaluation of fungi against cereal aphids is described.

Two additional specimens of Canadaphis carpenteri Essig are described from amber in a primary site in Alberta, about 78 million years old. The rostrum is longer than previously supposed, and as siphuncular pores apparently are present, the family Canadaphididae is placed tentatively in the super-family Aphidoidea.

A workshop is an occasion to raise also ''nonproductive'' questions as stimuli for discussion between specialists from different fields: (1) What do we know about the processes leading to the end of diapause, and how can we discriminate this diapause end? (2) Is the diapause ''normally'' completed also when the ''natural'' diapause development is ''substituted'' by (re)activation?

It seems premature to search for criteria to directly monitor diapause end. We have to rely on the events of post-diapause development which can be recorded only after exposure to permissive environmental conditions. It should be defined clearly, in a study, whether the end of diapause is identified with the resumption of covert developmental potential or with the resumption of overt development. The crucial change to developmental potential should be recognized although it is not directly measurable.
The (re)activated adults can differ from adults that completed diapause development by decreased fecundity and/or persistence of photoperiodic response.

n contrast to northern polar areas, the dipteran fauna of Antarctica is depauperate, with only two naturally occurring species of Chironomidae. Surprisingly little is known of the biology of these species. One, Parochlus steinenii, reaches the southern limit of a distribution covering the high Andes, Tierra del Fuego, South Georgia and the South Shetland Islands in the maritime Antarctic. The other, Belgica antarctica, is endemic to the maritime Antarctic. What factors influence the distribution and past colonisation of these two species in the Antarctic?
Distributional data and evidence from an accidental introduction of a third chironomid (Eretmoptera murphyi) suggest that difficulty of colonisation is the major factor limiting the number of dipteran species present in the maritime Antarctic. Other sub-Antarctic species are likely to be preadapted to more rigorous conditions, should natural or man-induced colonisation opportunities occur.
Evidence from physiological and ecological studies identify adaptations which allow these two species to survive in the harsh terrestrial environment of Antarctica. Life history characteristics of all three species include flexibility in development rates and size achieved, and the ability to continue activity at low positive temperatures. The distribution of the endemic B. antarctica is probably limited by the availability of suitable moist, vegetated, habitats and its brachyptery, rather than biological constraints directly, whereas the southern distribution of P. steinenii may be temperature-limited. Competition does not appear to be an important factor in the biology and ecology of either species, or in Antarctic terrestrial ecosystems generally.

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A report is provided of a workshop at 4th International Symposium on Aphids, where the decision was reached to recommend a major simplification of the terms used in papers on aphid biology, in order to make aphid work more accessible. It was concluded that most of the specialist terms usually applied to aphid morphs anf life cycles could and should be avoided in papers that are intended to be of general interest to other biologists. Specific recommenadations are made for their replacement by terms that are simpler and more widely understood.

Freshly hatched Japanese quails of the strain Faraon were fed for 50 days by diets containing graded amounts of pulverized seeds of an Asiatic plant Leuzea carthamoides Iljin. The dry seeds of this plant contained 1.8%-2.1% of 20-hydroxyecdysone, together with some smaller amounts of other ecdysteroids. In additional experiments the quails were also offered the standard diet plus whole seeds of Leuzea ad libitum and the standard diet enriched with certain commercially available biostimulating preparations for birds, Biostrong and Ecovit.

The effects of the diets were evaluated first at the age of 37 days and then at the age of 50 days, which covered the reproduction period. Investigations related to the effects on growth, behaviour and overall developmental conditions were completed by RIA analysis of ecdysteroid concentrations circulating in the blood of the quails.
The basic experimental series involved testing of the following diets: 0) Standard diet (SD); 1) SD + 0.2% Leuzea seed; 2) SD + 1.0% Leuzea; 3) SD + 5.0% Leuzea; 4) SD + 5.0% Biostrong; 5) SD + 3.0% Ecovit, and; 6) SD + the whole seeds of Leuzea ad libitum. At the age of 37 days we found the following percentage increase of the living mass (Control group = 100%): 1) 102.8%; 2) 109.5%; 3) 120.4%; 4) 101.9%; 5) 104.9%:, and 6) 103.5%. These results confirm previous findings of strong anabolic effects of Leuzea in growth of the vertebrate animals. However, since the plant contains a number of other biologically active classes of the secondary plant substances, the true responsibility of ecdysteroids for the described effects cannot be guaranteed, without further studies with pure ecdysteroid. The results of RIA analyses revealed that the amount of 20-hydroxyecdysone circulating in the blood of Japanese quails was directly proportional to the amount of dietary ecdysteroid. The largest concentrations, around 80 ng/ml of blood were found in quails which consumed the whole seeds of Leuzea.

Reproductive biology, nesting and ontogenetic development of Onthophagus stylocerus Gräells, 1851 are studied under laboratory conditions. The species is univoltine. Egg-laying begins at the end of May and lasts until July. The development from oviposition to image takes 7-10 weeks. The aestivation of the offspring is combined with hibernation of emergent adults.

As with many other Onthophagini, sexual cooperation and food relocation for larval supply plays an important role in the nesting behaviour of O. stylocerus. Nest type may follow any of four patterns, involving: one or more entrance tunnels, branching and brood mass location. Pattern 1: simple, without branching; 1 to 5 brood-masses per nest; moderate depth: 60-160 mm. Pattern 2: simple, with branching but without brood masses in the stretch closest to the surface; 3-9 brood masses;depth: 100-315 mm. Pattern 3: simple, with branching, and brood masses in the stretch of tunnel closest to the surface; 6-7 brood masses; depth 130-220 mm, frequently 200-220 mm. Pattern 4: complex, with one or several entrance tunnels intersecting the main shaft at different levels or converging from the surface to the same brood mass; 10-14 brood masses; depth 280 mm.
Early spring emergence of O. stylocerus gives the larvae the time necessary to complete their development before the arrival of the Mediterranean mountain winter, and enables adults to avoid the severe competition which structures coprophagous communities in the late spring.

The influence of ovary and ecdysteroids on pheromone biosynthesis was investigated in D. melanogaster. Strains mutant for ovo produced enhanced amounts of cuticular hydrocarbons in both sexes. Female sex pheromone production was not affected by the mutation, except homozygous females for ovo^Dlrsl which exhibited a higher proportion of the pheromone, 7,11 heptacosadiene.

The amount of hydrocarbons in wild-type (CS) flies was stable at 21 and 25°C but dramatically increased at 29°C whereas the cuticular hydrocarbon pattern was unchanged. In contrast, ecdysone-less 1^ls (ecd-1) flies showed an increase in overall hydrocarbon production at both permissive and restrictive temperatures. At restrictive temperature they showed also a decrease in pheromonal dienes production for females with an increase in monoenes and an inversion of the 7 tricosene-7 pentacosene ratio for males. These effects were partially reversible since a switch from 29 to 21°C restored an intermediary hydrocarbon pattern.
It is suggested that the regulation of female sex pheromone might be under the control of the ecd-1 gene.

Insect moulting hormone, 20-hydroxyecdysone or ecdysterone (E), was tested in a series of bioassays that are commonly used for evaluation of the activity of phytohormones. The assays included: auxin coleoptile bioassay in wheat, gibberellin bioassays in dwarf maize and dwarf rice; cytokinin bioassay on tobacco callus; brassinolide related ethylene formation assay in dwarf maize, alfalfa and Chenopodium, flowering assay on Chenopodium and special assay on somatic embryogenesis in cell cultures of alfalfa.

The 20-hydroxyecdysone has no biological activity in tests used for detecting phytohormone activity, excepting for slight gibberellin-like activity in rice. Moreover, E does not have any synergistic or antagonistic activity. In tissue cultures of alfalfa, E affected differentiation of the embryos. It is concluded that, in spite of its widespread occurrence in plants, E has no direct action on growth and proliferation of plant tissues (which is the main action of E in arthropods). However, E and other ecdysteroids could provide a source of easily available, slightly polar, polyhydroxylated sterol, required for growth and cell proliferation in plants.

Experiments with the aphid Megoura viciae Buckton were directed toward quantitative analysis of the cumulative effects of different long- and short-day photoperiods, as dependent on the numbers of light-dark cycles. It has been shown that the accumulation of these effects is a nonlinear process since, as the number of the cycles experienced increases, this process gradually slows down and finally stops. From this observation a suggestion was derived that the kinetics of the cumulative effects depends on interaction of two opposite processes, viz. the increase of the effect due to summation of consecutive daily impulses (induction), and its spontaneous decrease due to degradation (deinduction). The dependence of the kinetics of the cumulative effect on the rates of induction and deinduction was analyzed in the framework of a model proposed earlier. Incorporation of these parameters into the model produced feasible explanations for (a) the compatibility of the quantitative perception of photoperiod with the evident ''all-or-nothing'' overt responses; (b) the dynamics of switches caused by photoperiod reversals, and (c) other aspects of insect photoperiodism. Since temperature coefficients of both parameters may be unequal, the outcome of interaction between induction and deinduction may be different at different temperatures. This provided novel explanations (1) of the well known variations in interaction between the photoperiodic and temperature reactions and (2) of the promotion of development in diapausing insects by chilling.

Pycnogonum litorale (Ström) is a primitive marine chelicerate. When mechanically irritated, it discharges a mixture of eight ecdysteroids (ES) that acts as a chemical defense against predatory decapod crustaceans. Injection of [³H]-20-hydroxyecdysone into the hemolymph or into the gut and subsequent autoradiography of frozen sections revealed that the majority of the ES in the pycnogonids is concentrated in epidermal glands. A novel autoradiographic technique for the localization of water soluble radioactive substances at uneven surfaces visualized the ES secretion through cuticular pores. Scanning electron microscopy shows that each pore is associated with a forked seta, which is suspected to have mechanoreceptory functions. The epidermal glands, numbering 10,000 to 20,000 in adults, are distributed on all parts of the body, except the arthrodial membranes. Thus, this system provides an effective allround defense against predators. Similar pores occur in many pycnogonid species, and it is suggested that chemical defense might be a common feature within the entire class of pycnogonids.

An ecdysteroid receptor protein has been identified and characterized from whole body extracts of Chironomus thummi larvae. The kinetic and physical characteristics of this binding are consistent with the criteria established for steroid hormone receptors and are similar to those exhibited by the Drosophila ecdysteroid receptor. The binding data of cytosols obtained from different developmental stages (third and fourth stage larvae, pupae and adults) indicate only a single type of binding site which exists throughout the life cycle of the insect with an average K_d value of 5 × 10^-9 mol/g of protein. Furthermore, single point determinations of the receptor concentration at these stages revealed that the receptor level fluctuates. This fluctuation in the receptor level corresponds well to the fluctuation in the ecdysteroid titer indicating that the number of receptors at any particular stage of development may be regulated by the presence of the moulting hormone.

The linyphiid spider Drapetisca socialis (Sundevall, 1832) attaches a specialized web vertically to tree trunks: A small sheet is surrounded by signal threads that inform the spider about passing arthropods. Field observations of prey composition revealed the importance of Collembola, especially Sminthuridae, as prey items. As can be seen from video recordings, D. socialis catches prey by a special technique, which is also employed outside the web. The spider moves carefully over its victim, which is grasped from above by means of modified chelicerae and pedipalps. They carry a setal trap, that is unique among linyphiid spiders (in spiders in general?). The tarsi of Drapetisca legs do not have adhesive hairs, thus not being specially adapted to seize prey. The development of triads (the spigots involved in the production of gluey capture threads) was examined in six linyphiid spiders: In three of them, including D. socialis, the triads ale reduced to some extent. which leads to the conclusion that gluey capture threads do not play an important role in the capture of prey in Linyphiidae.

Ecdysone monosulfates (at C-2, C-3 and C-22) and ecdysone 2,22-disulfate were synthesised using sulfur trioxide triethylamine complex as sulfation agent. Direct sulfation of ecdysone afforded a mixture of various sulfates. Regioselective sulfation of ecdysone was achieved by utilizing temporary protection of hydroxy groups. The chromatographic behaviour of synthetic sulfates was compared with that of various other polar conjugates of ecdysone and 20-hydroxyecdysone. General rules to characterise ecdysteroid conjugates are proposed.

Effects of diet meal containing 10, 20, 30 and 50% of Rhaponticum carthamoides hay meal on the increase of body weight, growth and development of selected internal organs and behaviour of animals were examined. The 10% diet, which is preferable from both health and economical viewpoints, stimulated the growth of testes, while the body growth curve was similar to that of animals fed on a conventional diet. The diet with 20% Rhaponticum resulted in high variability of the weight of testes. Effects of tested diets on the body weight and food consumption were different in males and females.

Four Alebra species, A. albostriella, A. coryli, A. viridis, A. wahlbergi and their colour morphs, have been investigated on the following host-plants: Corylus avellana, Castanea sativa, Quercus cerris, Q. robur, Q. petraea and Acer campestre.

Host-plant relationships of Alebra species showed an association between A. coryli and C. avellana, A. albostriella and Q. robur, A. wahlbergi and A. campestre. On the contrary on Q. cerris, Q. petraea and C. sativa two different species, A. albostriella and A. viridis, are coexisting.
Alebra species showed different phenology and life histories: A. coryli and A. wahlbergi appeared univoltine, A. viridis bivoltine, and A. albostriella both uni- and bivoltine.
The oviposition sites have been documented both for overwintering eggs, laid in the branches, and for summer eggs, laid in the main leaf nervation.
Associations between nymphal and adult morphs are reported. A new morph, A. albostriella m. atrata, has been found on Q. robur.

Apterygothrips jenseri sp. n. from Mongolia is described with illustrations. The new species is distinguished by its dark, chitinized subapical rings on antennal segment III and IV. Similar rings are not developed in other species of this genus.

The inducibility of antibacterial peptides in Calliphora is strongly reduced during pupal development. Similarly, a downregulation of the inducibility of a diptericin reporter transgene is observed in the pupae of transgenic Drosophila, indicating existence of a negative correlation between inducibility and ecdysteroid titre. In the present paper we show that the level of antibacterial activity induced by the injection of bacteria into the diapausing larvae of Calliphora is reduced if the insects simultaneously receive 20-hydroxyecdysone. The same effect is observed in ligated Calliphora larvae deprived of their brain-retrocerebral complex. The data suggest that at certain developmental stages ecdysteroids downregulate the induced antibacterial defense.

Effects of the synthetic ecdysone agonists RH-5849 and RH-5992 have been compared with the action of 20-hydroxyecdysone in several standard bioassays that are currently used for determination of the moulting hormone activity. In the assay on ligated larvae of Galleria, these synthetic hormone mimics, ecdysoids according to the endocrinological terminology, stimulated the extra-larval moult cycles with all developmental consequences similar to the action of 20-hydroxyecdysone. The ED-50 dosages were 1.3 µg for 20-hydroxyecdysone, 1.75 µg for RH-5849 and 0.9 µg/specimen for RH-5992. In the assays on diapausing pupae of Manduca and Pieris, RH-5849 also duplicated the developmental stimulation of 20-hydroxyecdysone at lower concentrations (in Manduca, ED-50 1.2 µg/spec. for RH-5849, 1.9 µg for 20-hydroxyecdysone; in Pieris, ED-50 0.013 µg for RH-5849, 0.1 µg for 20-hydroxyecdysone). When compared with 20-hydroxyecdysone, the ecdysoids caused pathophysiological symptoms of hyper-ecdysonismm or neurotoxic action at much lower concentrations, corresponding to the bottom of the dose-response curves. Both the ecdysoids were completely ineffective in the standard assays on ligated larvae of Sarcophaga and Calliphora and they were equally inactive in all methods of topical application that have been used.

In special assays on larvae of Galleria, the ecdysoid RH-5849 exhibited definite synergistic action with 20-hydroxyecdysone, there was no antagonism. The results confirm previous conclusions that these synthetic ecdysoids act directly at the peripheral tissue targets. The reasons in favour and against a hypothesis that they would act by inducing endogenous ecdysteroid synthesis in the target cells has been discussed.

The flight activity of C. septempunctata was examined in a mixed oak forest, North Hungary, in 1987-1988. Malaise traps were established at the shrub level (0-2 m), the canopy level (12.5-14.5 m) and above the forest (25-27 m). A fourth trap was placed in an open grassland 200 m from the forest edge at the ground level. Exact meteorological data were registered during the season.

The highest flight activity was observed in late July - early August in both years. This period fits to the migration period of C. septempunctata to hibernation sites. In this period a ''long distance flight behaviour'' was observed in the high strata of the forest. The meteorological conditions highly influenced the flight activity of beetles, especially in the canopy level. In 1987, long distance flight behaviour was almost completely absent due to the low temperature and high wind speed.

The head is traditionally considered to be the site of production and release of the egg development neurosecretory hormone (EDNH), involved in ovarian maturation in dipterans. We find, however, that the thorax and abdomen of the mosquito Aedes aegypti each possess factors which resemble EDNH in both physiological and biochemical properties. Extracts of thoraces or abdomens each stimulated the dose-dependent appearance of ecdysteroid in incubations of A. aegypti ovaries in vitro. In addition, each extract is capable of stimulating ovarian maturation in vivo in decapitated Aedes atropalpus. The head contains higher levels of activity, absolute and specific, than either the thorax or abdomen, but extracts of all three body portions yield similar chromatographic patterns of activity. Gonadotropic activity in all three extracts elutes in two molecular weight ranges, large (approx. 6,600-7,700 MW) and small (approx. 4,150-4,250 MW). In each tissue, the small molecular weight component is more active than the large component. The roles of these non-cerebral ecdysiotropins and gonadotropins are not clear, but their similarities to cerebral EDNH suggest a function in ovarian maturation.

Intermoult puffs constitute the first set of ecdysone-responsive puffs detected on salivary gland chromosomes of D. melanogaster third instar larave. In order to analyse the hormonal regulation of this puff set we have investigated the genetic regulatory hierarchy governing the expression of three genes mapping at the 3C polytene region, from which one of the most prominent intermoult puff originates. The results obtained reveal that the expression of the genes studied, named ng-1, ng-2 and ng-3, is coordinate and specifically restricted to the Puffing Stage 1 (PS 1). The repression of these genes appears to be related to the PS1/PS2 transition and is dependent on the activity of the ecdysone induced BR-C locus. While the ng-gene repression results to be a secondary response to ecdysone, the recent identification of functional EcREs within the ng-1,2 coding region suggests that the induction of ng-genes might be part of the early ecdysone primary response at the beginning of the third larval instar.