Relationships between juvenile hormone levels and synthesis of major haemolymph proteins in Bombyx mori larvae

Effects of ultralow doses of fenoxycarb on juvenile hormone-regulated physiological parameters in the silkworm,Bombyx mori L.

“…In B. mori, JH seems to be present at the beginning of the last larval instar, and then its hemolymph titer rapidly drops to undetectable levels (Sakurai, 1983;Plantevin et al, 1987;Akai and Rembold, 1989). Artificial maintenance of this titer at high levels by JH treatment leads to the prolongation of the instar or the induction of permanent larvae, depending on the doses applied and duration of the treatment (Akai and Kobayashi, 1971).…”

“…Numerous authors have reported the inhibitory effect of JH and JHA on the occurrence of specific hemolymph proteins, such as storage proteins (Tojo et al, 1981;Mine et al, 1983), and a group of ''30 K proteins'' named major hemolymph proteins (MHP) (Izumi et al, 1984;Bosquet and Fourche, 1987;Plantevin et al, 1987;Bosquet et al, 1989a,b). MHP and storage proteins constitute the two major protein components in the hemolymph of fifth instar silkworms (Tomino, 1985).…”

“…During this period, JH induces a total inhibition of prothoracic gland activity (Sakurai, 1984;Okuda et al, 1985;Sakurai et al, 1989). From the fourth day, when JH becomes undetectable in the hemolymph (Plantevin et al, 1987), the prothoracic glands (PGs) recover their activity (Okuda et al, 1985), silk gland growth is accelerated (Garel, 1983), and major hemolymph protein synthesis is enhanced (Izumi et al, 1984;Tomino, 1985;Plantevin et al, 1987). Akai and Kobayashi (1971) were the first to show that JH treatment of early last instar larvae prolongs the instar or produces permanent larvae, depending on the doses applied.…”

“…In holometabolous insects, JH Abbreviations used: CA = corpora allata; EIA = enzymeimmuno-assay; IGR = insect growth regulator; JH = juvenile hormone; JHA = juvenile hormone analog; MHP = major hemolymph proteins; PGs = prothoracic glands; PTTH = prothoracicotropic hormone; SD = standard deviation; 20E = 20-hydroxyecdysone titer drops to undetectable levels during the last larval instar, and the ensuing absence of this hormone is known to trigger several physiological changes that prepare the insect for metamorphosis. In the silkworm, B. mori, JH titer decreases in the first 3 days of the last larval instar (Sakurai, 1983;Plantevin et al, 1987). During this period, JH induces a total inhibition of prothoracic gland activity (Sakurai, 1984;Okuda et al, 1985;Sakurai et al, 1989).…”

Effect of the age of the pupal holotissue on the nutritional quality of artificial diets for Trichogramma spp. (Hymenoptera: Trichogrammatidae)

“…The concentration of these proteins is higher in the hemolymph of the pupae than in the hemolymph of the larvae, making also part of the cuticle of the insects. They are also taken from the hemolymph by the ovaries and are found in a high concentration in the egg of insects, representing 30% to 35% of all of its soluble proteins (Kunkel & Nordin 1985, Plantevin et al 1987, Kanost et al 1990). Yet, the newly molted pupae are basically composed of a very high amount of less complex proteins and peptides since all the tissues from the larval stage are being broken down by histolysis.…”