Prepupal Period Research Articles

Calcium Storage in Face Fly (Diptera: Muscidae) Larvae for Puparium Formation1

The Malpighian tubules are shown to be the main storage site for Ca and other elements for puparium formation by the face fly, Musca autumnalis De Geer. Calcium in the anterior Malpighian tubules is stored in the form of amorphous, layered spheres 0.4 μm to >10.0 μm in diameter. Major elements in the composition of these spheres were Ca, P, and Mg, with traces of K. The weight of the tubules' content increased during the prepupal period. A major decrease then occurred and continued through the pupal period. The decrease results from movement of mineralized elements from the spheres and corresponds with the first significant amount of Ca and P found in the cuticle of the puparium. Mineralized spheres undergo dissolution in the proximal portion of the anterior Malpighian tubules, as indicated by external shrinkage and dissolution of internal layers, probably by changes in pH or enzymatic action.

Ecdysteroid production during caste differentiation in larvae of the ant, Plagiolepis pygmaea

ABSTRACT. Variations in ecdysteroids were measured by radio‐immunoassay in worker‐biased and queen‐biased larvae of the ant Plagiolepis pygmaea Latr. (Hymenoptera, Formicidae) during late larval development, i.e. from the end of winter diapause up to the prepupal period. At the end of diapause, larvae are bipotential and, depending on culture conditions, can become either queens or workers. Ecdysteroid profiles revealed that there are striking differences between the two castes: worker larvae showed high titres during their development, queen larvae had low titres over the same period.

Serological Determination of Carabid (Coleoptera: Adephaga) Predation of Corn Earworm (Lepidoptera: Noctuidae) in Field Corn 1

Carabids were collected alive with pitfall traps in cornfields during the second-generation corn earworm prepupal period. Double immunodiffusion assays showed 10 of 17 potential predators to have consumed earworm protein. Within species tested, positive responses ranged from 2.8 to 75% of the individuals.

Juvenile hormone synthesis in vitro by larval and pupal corpora allata of Manduca sexta

The synthesis of juvenile hormone I (JH I) and juvenile hormone III (JH III) in vitro by isolated corpora allata (CA) and brain-corpora cardiaca-corpora allata complexes (BR-CC-CA) from fourth and fifth instar larvae and pupae of Manduca sexta was assessed by JH I and JH III radioimmunoassays of incubation medium. Fluctuations in synthesis occurred at specific stages during larval-pupal development. These fluctuations temporally approximated those of previously determined hemolymph titers of JH I and III for this developmental period, except for the synthesis of JH III during the prepupal period, when the JH III hemolymph titer was negligible but JH HI synthesis in vitro increased to the highest rate observed. The overall agreement between CA activity and the JH hemolymph titers suggests that the in vitro system supports physiological gland activity and that changes in biosynthesis contribute significantly to changes in the titers. A comparison of JH I and JH III synthesis by isolated CA with that by BR-CC-CA suggests that the BR-CC can differentially modulate the synthesis of these two homologs. The significance of these findings with regard to the possible endocrine function of JH III and the proposed neuroendocrine control of the CA is discussed.

A rearing method forHeliothis armiger confertus, and its use for production of the parasitoidApanteles kazakand two insect viruses

Abstract Heliothis armiger confertus (Walker) (Lepidoptera: Noctuidae) was reared on an artificial diet in the laboratory. Larvae and pupae were reared at 25±1°C and 18:6 (L/D) photoperiod, and adults were mated at an average of 20°C under natural light conditions. The average generation time was 38 days, with larval period 17.3 days, prepupal period 3.6 days, and pupal period 14.5 days. Other data are: average pupal weight - 9 401.5 mg, d 392.0 mg; average survival to pupa 84.9%; average survival to adult 65.4%; pre-oviposition period 2.7 days; fecundity 973 ± 121 eggs per female; adult lifespan approximately 12 days. The parasitoid Apanteles kazak (Telenga) (Hymenoptera: Braconidae) was reared for several generations using H. a. confertus larvae as hosts. It took, on average, 19.3 days from oviposition to cocoon formation, and 26.8 and 29.0 days for adult male and female emergence respectively. Only 25.9% of the host larvae produced parasite cocoons, and 74.1% of these produced adult parasitoids. Two He...

Monoclonal antibodies against a specific nonhistone chromosomal protein of Drosophila associated with active genes.

Hybridomas secreting monoclonal antibodies have been produced by fusion of NS-1 mouse myeloma cells with the spleen cells of mice inoculated with a 60-65,000-mol wt fraction of proteins released from Drosophila embryo nuclei treated with DNase I. The antibodies secreted by the hybridomas were examined with polytene chromosomes of formaldehyde-fixed salivary gland squashes by an immunofluorescence assay. Most of the clonal antibodies obtained resulted in specific staining of the chromosomes relative to the cytoplasmic debris. In the case of clone 28, the antibodies showed a preferential association with sites of gene activity, both puffs and loci identified as puffing at some time during the third instar and prepupal period. In larvae that were heat shocked (exposed to 35 degrees C for 15 min before removal and fixation of the glands), the antibodies of clone 28 stained preferentially the induced heat-shock loci while continuing to stain most of the normal set of loci. The antigen for clone 28 was identified as a single protein of approximately 62,000 mol wt by using the antibodies followed by 125I-rabbit anti-mouse Ig to stain nitrocellulose replicas of SDS polyacrylamide gels of total chromosomal proteins. This study demonstrates that monoclonal antibodies can be used successfully in immunofluorescence staining of formaldehyde-fixed polytene chromosomes. The results verify the hypothesis that a specific nonhistone chromosomal protein is preferentially associated with the set of loci that includes both active sites and those scheduled to be active at some time in this developmental program. Such proteins may play a general role in the mechanisms of cell determination and gene activation.

Changing muscle patterns in a segmental epidermal field

ABSTRACT The spatial rearrangements that take place during metamorphosis in the abdominal sternites and associated retractor muscles of the beetle Tenebrio molitor are described. This paper provides the descriptive background needed to consider whether a morphogenetic gradient is involved in specifying the position at which adult muscle attachments develop. (Experimental work in support of this gradient hypothesis is published in a companion paper.) The ventral abdominal retractor muscles are extensively remodelled at metamorphosis so that the adult muscles differ considerably in appearance from the larval muscles from which they are derived. In particular, there is a change in both the absolute and relative positions of the sites of muscle attachment. Rearrangement of muscles takes place during both the pre- pupal period and the pupal stage. It is achieved by means of two separate and temporally distinct mechanisms. Epidermal remodelling in the pre-pupal period results in the movement of attached retractor muscles (epidermokinetic muscle movement). In the pupal stage, however, the muscles move over the basal surface of the epidermis (myokinetic muscle movement). Myokinetic movements may be brought about by extension of myoblast processes from the metamorphosing muscles. These findings are considered in terms of Poyarkoff’s theory that the pupa serves as an integumental mould, approximating the shape of the adult, within which certain adult muscles develop.

Timing of the Action of Photoperiod and Temperature On Events Leading to Diapause and Development in Pupae of Heliothis Punctigera (Lepidoptera: Noctuidae)

ABSTRACT Diapause in H. punctigera occurs in the pupa at some stage between pupation and the pupal-adult apolysis. Its occurrence is induced by 12 L: 12 D photoperiod, which is specifically effective during the last half of larval life, and by low temperature (19 °C). Irrespective of the conditions during larval life, the insects do not diapause if subjected to high temperature (28 °C) after feeding ceases and before the pupal ecdysis. The insects are most sensitive to high temperature during the short perioid between the larval-pupal apolysis and pupal ecdysis. At both 28° and 19 °C the brain and thoracic glands secrete almost simultaneously to trigger the larval-pupal apolysis, which occurs almost immediately after the release of the hormones. High temperature during the prepupal period results in an increased rate of development from pupal ecdysis to emergence of the adult.

Biology and Life History of Amynothrips andersoni, a Thrip for the Biological Control of Alligatorweed 1

Amynothrips andersoni O'Neill, a natural enemy of alligatorweed, was studied in its indigenous environment in South America and under laboratory conditions in California. Five stages occur, including a prepupal period and a pupa characterized by early and late changes. Development required 28 days (egg to egg) in the laboratory. Amynothrips andersoni is multivoltine, producing an estimated 4—5 generations annually in Argentina. Production of males only by unfertilized females indicates that this thrip reproduces by arrhenotoky (facultative parthenogenesis). The geographic distribution, life history, seasonal occurrence, population dynamics, developmental behavior, and ecological relationships of A. andersoni are discussed.

Biological and systematic studies of developmental stages inAphytis(Hymenoptera: Aphelinidae): I. Developmental history ofAphytis chilensisHoward

Species of Aphytis Howard (Hymenoptera: Aphelinidae) are the most effective natural enemies of armored scale insects (Homoptera: Diaspididae). Their classification, based on the morphology of adult wasps, is difficult. The studies herein were intended to explore the possibility of using morphological characteristics of developmental stages in the systematics of this genus. The developmental stages of A. chilensis Howard, the generotype of Aphytis, are described. The ovarian egg is double-bodied, whereas the deposited egg is stalked. The larva passes through three instars, each of which differs markedly in shape and size of the mandibles. First-instar larvae have four pairs of spiracles; the second and third instars have eight pairs, viz., one pair in the mesothoracic segment and one in each of the first seven abdominal segments. The cephalic skeleton, respiratory system, and various integumentary structures of the third-instar larva are described. The morphology of the pupa was studied with light and scanning electron microscopy. At 28 ± 1° C, egg development takes 2 to 3 days, larval development (including the prepupal period) 10 to 12 days, and pupal development 6 to 7 days. Rearings under various constant temperatures gave the theoretical threshold of development as 14.1° C and a thermal constant of 270.2 day-degrees for the completion of development.

Biology of Microlarinus lypriformis (Col.: Curculionidae) on Puncturevine in Southern California

Eggs of Microlarinus lareynii (Jacquilin du Val) hatched 2–3 days after their deposition in pits chewed in the tender pericarps of immature fruit and, occasionally, in floral buds and flowers. Of 50 egg niches examined, 60% penetrated a seed chamber. Thus, most larvae immediately contacted a seed upon hatching, while some fed on the pericarp and interlocular tissues, sometimes quite extensively, before attacking a seed. All seeds were destroyed in 11, 35, and 20 of 100 infested, mature fruit sampled from low desert, inland valley, and coastal locations, respectively. The incidence of aborted carpels (those lacking seed) in those fruit in which all seed were destroyed was considerably higher (85%, 1.7/fruit) than in the remaining fruit in these samples (48%, 0.5/fruit) in which seed destruction averaged 68, 73, and 64%, respectively. External scarification of young fruit and other plant parts by ovipositing adults, as well as stem weevil ( M. lypriformis (Wollaston)) attack, apparently caused carpel abortion, and thus additional, indirect, reduced seed production, estimated at 24% of seed/fruit at one location. Larval development lasted 13–16 days. Pupation occurred in an open cell in an excavated fruit. The prepupal period lasted 1 day; the pupal stadium, 4–5 days. Egg-to-egg development for 20 individuals averaged 29 (range: 24–34) days. One, or sometimes 2 weevils emerged from a single fruit. Males and females mated repeatedly, and the latter lived an avg of 96±11 (SE) days. Mating was preceded by a brief series of antennal contacts. Oviposition began 4-9 days after pupal ecdysis. The oviposition periods averaged 78±7 days, during which 193±24 (max: 324) eggs were laid at a rate of 2.6±0.5 (max: 11) per day. Females favored the carpel junctures just below a lateral spine as ovipositional sites. Eggs in niches were capped with a dried, whitish, anal secretion often stained dark with feces.

A role of juvenile hormone in pupal development of the tobacco hornworm, Manduca sexta

In the tobacco hornworm, Manduca sexta, as in other Lepidoptera, allatectomy of the penultimate instar larva causes precocious pupation. When allatectomized immediately after the initiation of the moult to the fifth instar, the resultant black larvae begin metamorphosis one day sooner than controls. They form pupae which show precocious adult differentiation of the eye and at the base of the forewings, nonextension and nonfusion of the pupal proboscis, and shortened pupal wings. Such adultoid characters appear if the larvae are allatectomized any time in the fifth instar up to the end of the wandering phase. Application of juvenile hormone (either JH I or a mimic, epoxygeranylsesamole) just before the onset of ocellar retraction at the beginning of the prepupal period prevents this precocious adult differentiation (the 50% effective dose of JH I is 3.3 ng/animal).

Bionomics and Life History of a Filbert Leafroller, Archips rosanus (Lepidoptera: Tortricidae)1,2

Field studies conducted in the Willamette Valley of Oregon 1973-1976 showed that overwintering eggs of Archips rosanus hatch in the last wk of March or the 1st wk of April. Egg hatch is spread over a 2 wk period. The median egg hatch was noticed at the accumulation of about 40 thermal units over a base of 8°C starting Jan. 1st. The young larvae move to the opening buds soon after hatching, and feed on leaves they have webbed together. Head capsule widths of the field-collected larvae indicate that there are 5 instars. Under field conditions, the 1st and 2nd instar larval periods vary from 2-3 wk. The first 2 instars make inconspicuous webbings and leaf rolls, but those of the 3rd, 4th and 5th instars are more noticeable. Their larval periods vary from 7-15 days each. Before pupation, the larvae go through a short pre-pupal period of 1-3 days. The pupae are formed within rolled leaves and are light brown at first changing to dark brown with age. The adults emerge within 1-2 wk after pupation, and are active only at night. Eggs are laid in masses, mostly on the trunks and major scaffold branches of the trees. The number of eggs in each mass ranges from 16-137, with an avg of about 50. Eggs of A. rosanus have an obligatory diapause which normally is broken by winter weather. Egg masses collected in March, 1976 and held in the laboratory at 26.7°C hatched within 6 days. Under laboratory conditions, the larvae went through 5 larval instars, but 7% went through 6, and the larval period varied from 10-20 days. The pupal period was about 1 wk. Adults lived for 10-12 days, and deposited an average of 147 eggs/female. The preoviposition period was about 2 days, the oviposition period 8 days, and the post oviposition period 5 days. Under field conditions, approximately ⅔ of the life cycle of A. rosanus was spent in the egg stage. The diapausing eggs were laid during June and July, and hatched in the following spring. Larvae were found in April and May, and pupae during the latter part of May and early June. Adults emerged during the 2nd half of June and early part of July, and were active until the 2nd wk of August. Reduced egg hatch (about 50%), and a high incidence of larval-pupal parasites were the 2 major mortality factors in untreated orchards. The major natural enemies of A. rosanus in the Willamette Valley include 2 tachinids, 1 pteromalid, 1 chalcid, 3 braconid, and 2 ichneumonid species.

Sequential gene activation by ecdysone in polytene chromosomes of Drosophila melanogaster, : IV. The mid prepupal period

In the mid prepupal period of development of Drosophila melanogaster two major changes in gene activity occur in the salivary glands: (a) The mid prepupal puffs (e.g., 63E, 75CD) are induced and (b) the late prepupal puffs (e.g., 62E, 74EF, 75B, and 93F) acquire the competence to respond to ecdysone. These events can be studied in vitro. Both require that the ecdysone titre be very low (<5 × 10 −9, M) and both events depend upon protein synthesis.

Anatomy and Histology of Selected Systems in Larval and Adult Elasmopalpus lignosellus (Lepidoptera: Pyralidae)1,2

The anatomy and histology of the digestive, nervous, and reproductive systems of mature larval and adult Elasmopalpus lignosellus (Zeller) are described. There are considerable differences in structure of the alimentary canal of larvae and adults. Adults possess a large, sac-like crop and a rectal sac; neither occurs in larvae. Little fusion of ganglia occurs in the larval nervous system. In adults the mesothoracic and metathoracic ganglia are fused with abdominal ganglia 1 and 2 to form the pterothoracic ganglion. Primordial gonadal tissues are located in abdominal segment 5 of mature larvae. Fusion of the testes to form a single organ occurs during the prepupal period.

Prepupal larval mosaics in Drosophila melanogaster.

THE metamorphosis of insects provides a model system for the study of hormone action. In Drosophila, metamorphosis is initiated by the formation of a puparium with a rigid cuticle that becomes tanned early in the prepupal period. Subsequently many larval tissues degenerate and the imaginal tissues develop to produce the adult insect. These processes are initiated in Drosophila by the steroid moulting hormone, β-ecdysone1. We are interested in the mechanisms by which β-ecdysone elicits adult development. The recovery of mutants which cannot respond to the hormone would facilitate investigation into the nature of the action of β-ecdysone. We have isolated systematically a series of late larval and prepupal X-linked lethals (ref. 2 and unpublished results of I.K. et al.), about 15% of which are non-pupariating (npr) lethals in which metamorphosis is not initiated. We have investigated whether the npr condition is a result of the autonomous inability of the mutant target tissues to respond normally to β-ecdysone or rather is a stage-specific failure in the production of the hormone. Our results indicate that in most npr lethals the tissue cannot respond to the hormone. Futhermore, we estimate that there are 100–200 such lethals in the genome of D. melanogaster.

Biology of and rearing technique for Sturmiopsis parasitica (Curr.) (Diptera, Tachinidae), a parasite of graminaceous borers in Africa

AbstractSturmiopsis parasitica (Curr.), an important larval pupal parasite of graminaceous borers in Africa south of the Sahara, was collected from Sesamia spp. and Eldana saccharina Wlk. in Ghana. Puparia were shipped to the CIBC station at Bangalore, where a rearing technique, using field-collected borers as hosts, was devised. At 26°C the larval period was 12–14 days, prepupal period 12 h, and the pupal period 12–19 days. In its 3–4 week life span a male could successfully inseminate 4–5 females, which each produced 500–900 maggots after a gestation period of 18–19 days. In the laboratory Sturmiopsis parasitica successfully parasitised Chilo auricilius Dudgn., C. partellus (Swinh.), C. infuscatellus Sn., C. sacchariphagus indicus (Kapur) and Sesamia inferens (Wlk.); it did not parasitise Tryporyza nivella (F.) or Corcyra cephalonica (Stnt.) and was only once recovered from Galleria mellonella (L.). Its potential as a biocontrol agent against graminaceous borers in the tropics is considered high.

Protein synthesis in salivary glands of Drosophila melanogaster: Relation to chromosome puffs

The salivary glands and other tissues from Drosophila melanogaster were dissected at various times throughout the prepupal period, as well as after heat shocks and ecdysterone treatments, and the proteins labelled by incubating the isolated tissues with [ 35S]methionine were separated by electrophoresis on sodium dodecyl sulphate-polyacrylamide gel. The labelled band patterns from salivary gland, as seen on the autoradiograph of the gel, showed striking variations, in a manner remarkably similar to variations in puff patterns during the same prepupal period. In proteins from Malpighian tubes, the pattern of bands varied to a lesser extent and in brain only a few components were modified. Heat shock brought about the appearance of a number of new bands, while others were reduced in intensity. This effect was observed with all the tissues examined, salivary glands, brain and Malpighian tubes, as well as wing imaginal discs, tissue lacking polytene chromosomes. The six most heavily labelled bands induced by heat shock represent about 30%, and one component alone represents over 15%, of the total label in the sample, as seen in salivary glands, brain and Malpighian tubes. The synthesis of RNA at puff sites was investigated after heat shock by [ 3H]uridine labelling. By correlating the amount of [ 3H]uridine in some puffs with the level of [ 35S]methionine in some bands a tentative relation is suggested in a few instances. The effect of ecdysterone treatment was also studied in the salivary glands. Changes in a number of protein bands were noticed, though they were much less pronounced than those following heat shock.

Studies on Mass Culturing of Heliothis armigera (Hbn.) (Noctuidae: Lepidoptera) on Semi - Synthetic Diets. II. Effect on the Development of Pre-imaginal Instars

Two semi-synthetic diets were studied with reference to their effect on the develo pment of the pro-imaginal stages of gram pod borer, Heliothis armigera. Incubation period was not at all influenced while the larval period was found to be reduced by 50 to 60 per cent from that on lab-lab. The number of instars in the larval stage was reduced to five in the second generation on diet-A, while in the others it was only six in both the generations. Increase in length and weight of larvae was evidenced conso- quent to intake of semi-synthetic diet. While the prepupal period was shorter on natural hosts, the total period was markedly shorter and pupal weight distinctly greater on arti- ficial diets. The total life-cycle as such was also found to be shortened, especially in the second generation in all the diets.

The influence of ecdysterone on gene amplification, DNA synthesis, and puff formation in the salivary gland chromosomes of Rhynchosciara hollaenderi.

Many of the DNA and RNA puffing changes observed in Rhynchosciara during the prepupal period have been induced in younger larvae by injection of ecdysterone. However, the dose of hormone necessary for this induction is high, especially in the large cells of the proximal region of the gland. There are differences in the amplification and puffing response from that observed during normal development. Particular similarities and differences with possible explanations for the differences are discussed. Preceding and during the amplification which occurs at certain chromosomal regions, ecdysterone induces DNA synthesis along the entire chromosome. This induction of general DNA synthesis can occur independently of the amplification process. It appears to be similar in pattern to that occurring normally toward the end of larval life. — The normal prepupal behavior of Rhynchosciara was not induced by injection of ecdysterone into larvae of any age thus far examined.