Sodium: a male moth's gift to its offspring.

Males of the moth Gluphisia septentrionis acquire sodium by drinking from mud puddles. Analyses of male and female bodies indicate that such "puddling" behavior enables the male to provide his mate with a nuptial gift of sodium, presumably via the spermatophore. This gift (about 10 microg), amounting to more than half of a puddler male's total body sodium, is in large measure apportioned by the female to her eggs. Puddler-sired eggs contain 2 to 4 times more sodium than those control-sired; this difference is already apparent in eggs laid the night after mating. Paternal endowment of offspring with sodium had not previously been demonstrated for an insect to our knowledge. The potential adaptive significance of such chemical bestowal is evident, given that the foliar diet of G. septentrionis larvae is extremely low in sodium content.

The loss of female sex pheromone after mating in the corn earworm moth Helicoverpa zea: identification of a male pheromonostatic peptide.

Female moths often become depleted of sex pheromone after mating as the various components of virgin behavior are switched off. In examining a potential male contribution to these events in the corn earworm moth Helicoverpa zea, we have characterized a basic polypeptide from the tissues producing (accessory glands) and storing (duplex) the seminal fluids. The peptide evokes the depletion of sex pheromone when injected into virgin females. This pheromonostatic peptide (PSP) is 57 amino acids long and contains a single disulfide bridge. It is blocked at the N terminus with pyroglutamate and at the C terminus by amidation. As little as 23 ng of peptide evokes the near-complete depletion of pheromone in decapitated (neck-ligated) females that had been injected with pheromone biosynthesis-activating neuropeptide. Activity is approximately 15-fold less in intact virgins, showing that the head limits the expression of activity in these injected females. Females mated to surgically impaired males, capable of producing a spermatophore but not transferring spermatozoa or seminal fluids, are depleted of pheromone by injected peptide. Females whose abdominal nerve cords have been severed are not depleted of pheromone after mating. Thus, neural signals either descending or ascending via the nerve cord are required for the depletion of pheromone after mating. PSP, from the seminal fluids, may participate in this process by direct or indirect action on the glandular tissue; if so, it represents an unusual mechanism in insects for the regulation by seminal fluids of postmating reproductive behavior.

Ablação ocular no camarão Macrobrachium rosenbergii (De Man) (Crustacea, Decapoda, Palaemonidae): efeitos sobre a reprodução, pigmentação epidérmica e atividade alimentar

This study analyze the consequences of unilateral and bilateral ablation based on ovigerous percentage, consecutive spawns, and secondary effects of the surgical process in the females of Macrobrachium rosenbergii (De Man, 1879). Two experiments were carried out with four and seven months old females in intermolt stage. Each experiment was comprised of control, unilateral and bilateral ablation. Eyestalk ablation was done with a bistoury with a topic hot cauterization followed by application of antibiotic pomades. The animals were maintained at constant temperature (28 ± 1,05ºC) and photoperiod of 12L: 12D within fibercement boxes with sandy bottom and biological filter. Females were observed once a day during fourteen weeks, registering gonadal condition, ecdysis and presence of spermatophore (mating) and spawning. Unilateral ablation technique is more efficient due to the anticipation of the first spawn, repeatability between spawns, expressive rate of ovigerous females and survival, that favored its applicability. Bilateral eyestalk ablation produced the mortality of ali the females with change in coloration and food activity patterns. These results corroborate other observations on penaeid shrimps. though bilateral ablation on some lobsters was a success. These results showing an interespecific variation and can be used in aquaculture projects.

Estratégias de acasalamento e qualidade do espermatóforo em heliconius (Lepidoptera, Nymphalidae)

Butterflies are insects known, in a variety of environments and for easy visual identification. The adult form may be frequently found in flowers looking for nectar. However, for many species of Heliconius (Lepidoptera, Nymphalidae) to visit the flower also represents the collecting of pollen, an important source of protein for adults. The protein obtained from the pollen allows the maintenance of physiological processes that increase the performance of the individual, promoting greater longevity and egg production. For males, proteins can also be part in your investment in reproductive success and fitness of offspring through a nutritional contribution that is transferred to the female in the act of mating as a nuptial present. It is known that this protein contains essential to the performance of the female oviposition, however the proportion of content and specific importance to the monogamous and polygamous species is not known yet. Whereas the species studied in this work have different patterns of mating in the strategy was to verify a significant difference in the quality of the spermatophore, and H. erato and H. melpomene, on the amount of protein present in this structure, indicating a difference in investment between the male reproductive strategies