Pupae storage effect of Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) in low temperature.

The study was developed in the 'Laboratorio de Biologia e Criacao de Insetos' (LBCI), 'Faculdade de Ciencias Agrarias e Veterinarias (FCAV), 'Universidade Estadual Paulista' (Unesp), Jaboticabal, SP, with objective of evaluating the pupae storage effect of Cotesia flavipes in low temperature (medium temperature = 2,75[degree]C). The experiment was made up of 13 treatments: fi, 1, 2, 3, 4, 5, 6, 7, 8, 9.10 and 11 masses storage days of pupae in refrigerator temperature and the check was man maintained on 25[plus or minus]2[degree]C and relative humidity of 70[plus or minus]10%. The next generation of parasitoid also was analyzed, maintained to 25[plus or minus]2[degree]C during all development. It was evaluated: period and pupae viability; average number, longevity and adults' sex ratio of the stored generation and period egg-larvae; period and pupae viability: average number, longevity and adults' sex ratio of the next generation. It verified that the pupae storage of C. flavipes in refrigerator temperature for until 5 days does not affect its development and the stored generation, suggesting the utilization possibility of this resource in mass rearing of this insect.

Knowledge gaps and bibliographical revision about descriptions of free-swimming anuran larvae from Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento pós-embrionário de Ceraeochrysa cincta (Schneider, 1851) (Neuroptera: Chrysopidae) alimentada com ovos de Diatraea saccharallis (Fabricius, 1794) (Lepidoptera: Crambidae)

The lacewings (Ceraeochrysa cincta) are important predators found associated to many pests in several agroecosystems. Eggs of Sitotroga cerealella and Anagasta kuehniella are used traditionally for massal rearing of these predators. Other foods can be used in substitution to the traditional ones, but little is known about the biology of lacewings and other alternative foods. So, this work was carried out to evaluate the effect of different diets on the post-embryonic development of C. cincta in laboratory. After been individualized in glass tubes, each larva was fed with S. cereallella and Diatraea saccharallis. It was evaluated the larvae duration, weight and viability in each instar, the duration, weight and viability of the pupa and pre-pupa stages and the duration of the post-embryonic period. It was adopted a completely randomized design with ten replications per treatment, each consisting of five eggs or larvae of C. cincta. Larvae were weighed 48 hours after hatching and 48 hours after each molt, and pre-pupae and pupae, 48 hours after starting these stages. There was no effect of the kind of food provided on the parameters evaluated. Therefore, D. saccharallis eggs can be used to feed C. cincta.

Preferência alimentar de adultos de Metriona elatior Klug (Coleoptera: Chrysomelidae, Cassidinae) por diferentes híbridos de Solanum melogena Linnaeus (Solanaceae)

Feeding preference of adults of Metriona elatior Klug (Coleoptera: Chrysomelidae, Cassidinae) for different hybrids of Solanum melogena Linnaeus (Solanaceae). Metriona elatior Klug is a potential biocontrol agent for Solanum viarum Dunal (tropical soda apple), because larvae and adults feed on its leaves and this species shows a low dispersion rate. Specificity plays a major role in the feasibility of an organism as a biological control agent, especially in the inundative strategy. The feeding preference of M. elatior adults was evaluated to 14 eggplant (Solanum melogena Linnaeus) hybrids. Mass rearing was carried out under lab conditions, with the insect feeding directly on S. viarum leaves. The study started with dual and multiple choice tests in 24 and 48 hour feeding times, by offering leaf disks in Petri dish conditions. Survival and leaf consumption analysis were performed in newly adults in tropical soda apple and eggplant leaves kept turgid by immersing the petioles in water. The leaf area was measured before and after four days of insect exposure. M. elatior showed higher feeding preference, survival and consumption of the weed species, especially in comparison with the hybrid Ryoma. The highest feeding preference among the eggplant hybrids was observed in 'Minikuro Kowishiki'.

Induced ovulation and rearing of the pacu (Colossoma mitrei)

A method is described for spawning the economically important Brazilian characin species Colossoma mitrei. Ovulation was induced using a priming injection of 0.2 mg/kg partially purified gonadotropin SG-G100 followed at 8 h by injecting an extract of 20 mg/kg acetone-dried chum salmon pituitary powder. Spermiation was induced in the male using a similar primer followed by 14 mg/kg acetone-dried chum salmon pituitary powder. Eggs were successfully fertilized and incubated at 25-26°C. Hatching occurred at 20.5 h and a survival of 10% to fingerling size was achieved. © 1981.

Protein requirements in larvae and adults of Scaptotrigona postica (Hymenoptera: Apidia, Meliponinae): Midgut proteolytic activity and pollen digestion

The number and degree of digestion of pollen grains in the midgut and rectum, the midgut proteolytic activity and the time of pollen grain passage through the digestive tract in the stingless bee Scaptotrigona postica (Latreille) have been analyzed. The results show similar protein requirements among larvae, nurse bees and queens, as well as between forager bees and old males, but these requirements are higher in individuals from the former groups than in those from the latter. Although protein requirements have been demonstrated to vary according to a bee's activity in the colony, they are similar among bees from different castes or sexes. These changes in feeding behavior are related to the bee's function and to less competition for nourishment among individuals of the colony. It is also noted that pollen grains took between 6 and 28 h to pass through the digestive tract. Pollen grains are irregularly accumulated in the various regions of the midgut, which may reflect functional differentiation throughout the midgut. © 2001 Elsevier B.V.

Effects of food quality on growth and biochemical composition of a calanoid copepod, Argyrodiaptomus furcatus, and its importance as a natural food source for larvae of two tropical fishes

Growth, reproduction and biochemical composition were analyzed for the copepod Argyrodiaptomus furcatus fed on the alga Ankistrodesmus gracilis grown in different media. The ingestion of this copepod by larvae of two species of tropical fishes was also evaluated. The mean peak density of the copepod population was 1369 individuals 1-1 for all four diets used, and the highest was 1387 individuals 1-1 on diet ARV (algae + ration + vitamins). A small copepod, A. furcatus tends to have a short life span. The smallest females did not attain maturity in the shortest time on all diets used. Food quality may play a major role in the dynamics of the biochemical composition of this copepod. Argyrodiaptomus furcatus was a more important food item for larvae of tambaqui (Colossoma macropomum) than of pacu (Piaractus mesopotamicus). However, it made up a large part of the gut contents of larvae of both species.

Alterations induced by juvenile hormone in glandular cells of the Apis mellifera venom gland I - Application on the larvae (Hymenoptera: Apidae)

Histological analyses were made in order to evaluate the effects of the topic application of a synthetic juvenile hormone (JH-III Sigma) on the development of the venom glands in workers of Apis mellifera. Three experimental groups were used: the first received 1 μl of a dilution of the juvenile hormone in hexane (2μg/μl); the second group received 1 μl of hexane; and the third group, the control, did not receive any kind of treatment. The application was made on larvae at the beginning of the fifth instar and the glands were collected at different developmental stages. The results showed that the application of the diluted hormone, as well as the hexane alone, accelerated gland development in relation to the control group at all developmental stages studied. These data suggest that the juvenile hormone acts on the development of the venom gland; nevertheless, this action could be amplified by the effect of the solvent used in the present work, as well as in other studies concerning this matter.

Influence of the application of juvenile hormone on the haemolymph total proteins and electrophoretic pattern of worker larvae of Apis mellifera

The aim of the present work was to verify the influence of the juvenile hormone (JH) applied on worker larvae of Apis mellifera 2 to 5 days old over the haemolymph total protein and electrophoretic pattern. Each larvae received topical applications of 1 ml of a solution of JH in hexane (1 μg/ml) on their 2 nd, 3 rd 4 th and 5 th day after hatching and had the amount and electrophoretic pattern of proteins from the haemolymph analyzed during the remaining days of their life. As a control, haemolymph of larvae of the same age that did not receive any kind of treatment was analyzed. The results show that the application of JH on larvae 3 or more days old affect the amount and electrophoretic pattern of the proteins, with this effect lasting through the subsequent days.

Utilization of fish protein hydrolysate in prepared diets for pacu, Piaractus mesopotamicus, larvae

Growth and survival rates of pacu, Piaractus mesopotamicus, larvae fed prepared diets containing different animal protein sources were evaluated. Four diets with the same level of crude protein (CP) (36%) and calories (4.02 kcal gross energy/g of diet) were fed to the larvae. Diets were formulated to contain one of four protein sources: (1) fish meal (FM), (2) tilapia residue silage (TS), (3) protein hydrolysate from tilapia residue (HT), and (4) eviscerated tilapia residue (HET). Larvae were fed Artemia nauplii for six days, prior to the start of the study, and the prepared diet was supplied from day 7 until the study concluded. Variance analysis showed no significant differences (P > 0.05) for survival rates and larval final lengths among treatments. However, final average weights were significantly different (P < 0.05 for larvae fed FM and HT. Average survival rates were relatively high and ranged from 68.1% to 73.9%. After the live food was replaced by prepared diets, no larval growth was observed for any treatment. Fish protein hydrolysate (HT and HET) and fish silage showed potential to be used as ingredients in the diet of pacu larvae. However, hydrolysate inclusion levels, processing methods to minimize nutrient lixiviation, and the best moment to replace live food with an inert diet (weaning) need further investigation. © 2003 by The Haworth Press, Inc. All rights reserved.

Dynamics of handling time and functional response by larvae of Chrysomya albiceps (Dipt., Calliphoridae) on different prey species

One way to understand the behavioural patterns exhibited by a predator in response to prey density is to evaluate its functional response. Such evaluation yields information about basic mechanisms of prey-predator dynamics, and is an essential component of prey-predator models. In this paper we analysed experimentally the functional response and the handling time spent by Chrysomya albiceps on different prey species and larval instars of blowflies. The type II functional response was observed when second instar larvae of Chrysomya megacephala and Chrysomya macellaria were consumed. The handling time spent by the predator was significantly different between instars and species. The implications of the functional response and handling time for the interaction dynamics of Brazilian Chrysomyinae species are discussed.

Macromolecular array patterns of silk gland secretion in social Hymenoptera larvae

The cocoon, produced by most holometabolous insects, is built with silk that is usually produced by the larval salivary gland. Although this silk has been widely studied in the Lepidoptera, its composition and macromolecular arrangement remains unknown in the Hymenoptera. The macromolecular array patterns of the silk in the larval salivary gland of some meliponids, wasps, and ants were analyzed with polarized-light microscopy, and they were compared with those of Bombyx mori (Lepidoptera). There is a birefringent secretion in the glandular lumen of all larvae, due to filamentous structural proteins that display anisotropy. The silk in the distal, middle and proximal regions of the secretory portion of Formicidae and Vespidae glands presented a lattice optical pattern. We found a different pattern in the middle secretory portion of the Meliponini, with a zigzag rather than a lattice pattern. This indicates that the biopolymer fibers begin their macromolecular reorganization at this glandular region, different from the Formicidae and the Vespidae, in which the zigzag optical pattern was only found at the lateral duct. Probably, the mechanism of silk production in the Hymenoptera is a characteristic inherited from a common ancestor of Vespoidea and Sphecoidea; the alterations in the pattern observed in the Meliponini could be a derived characteristic in the Hymenoptera. We found no similarity in the macromolecular reorganization patterns of the silk between the Hymenoptera species and the silkworm.

Co-feeding of pacu, Piaractus mesopotamicus Holmberg (1887), larvae with Artemia naupili and a microencapsulated diet

Aiming at a precocious substitution of live prey by artificial diet, a 20-day experiment with pacu, Piaractus mesopotamicus, larvae using co-feeding and abrupt weaning strategies was set up. At the end of the experiment, larvae fed Artemia showed the best results (P < 0.05) in weight, total length and biomass, compared with other treatments. Larvae fed exclusively a microencapsulated diet never ingested the diet. Diet ingestion in co-fed and abrupt-weaned larvae was low, but did increase during the experiment; however, Artemia influenced diet ingestion on co-fed larvae. Careful considerations should be given to diet processing and formulation to ensure survival and growth of larvae fed exclusively on prepared diets. © 2005 by The Haworth Press, Inc. All rights reserved.

Crescimento e sobrevivência do camarão-rosa (Farfantepenaeus paulensis) na fase de berçário em meio heterotrófico

The objective of the present study was to evaluate the potential of a heterotrophic rearing media (microbial flocs) on the growth and survival of Farfantepenaeus paulensis reared in the nursery phase. For 30 days, F. paulensis post-larvae (0.019 ± 0.01g) were reared in nine 40-liter plastic tanks at the density of 500 post-larvae m -2. Three treatments with three replicates each were used: rearing in the presence of microbial flocs with ration supply (FLOC + R); rearing in the sole presence of flocs - no ration supplied (FLOC); and rearing in clear water plus with ration supply (AC + R). The presence of microbial flocs had no significant effect on growth and survival in the nursery rearing of F. paulensis.

Susceptibility/resistance of Anticarsia gemmatalis larvae to its nucleopolyhedrovirus (AgMNPV): Structural study of the peritrophic membrane

This investigation compares the peritrophic membrane (PM) morphology along the midgut of susceptible (SL) and resistant (RL) Anticarsia gemmatalis larvae to the AgMNPV. The PM increased the thickness from the anterior to the posterior midgut region in both insects strain; however, the intensity of FITC-WGA reaction of the PM in the RL were greater than in SL. The PM in RL was ultrastructurally constituted by several layers of fibrous/vesicular materials in comparison with the few ones in SL. Our results showed that the structure of PM in the RL could be one of the resistance barriers to AgMNPV. © 2007.