Production of Honeydew by Scale Insects Associated with Bracatinga (Mimosa scabrella Benth) in Serra Catarinense, Southern Brazil

ABSTRACT Scale insects Stigmacoccus paranaensis (Foldi, 2006) associated with bracatinga trees (Mimosa scabrella) in Santa Catarina, Brazil, can play an important economic role and guarantee the production of "bracatinga honeydew honey". This scale insect has the ability to excrete large amounts of honeydew, of economic importance for beekeepers, especially due to the natural occurrence of host plants at high density, known as "bracatingais". In this sense, the objective of this study was to evaluate the honeydew produced by scale insects associated with M. scabrella in the Bom Retiro, Santa Catarina, Brazil. We determined the density of the host plant in the studied area, the intensity of infestation by scale insects, and the volume and sugar concentration of excreted honeydew. The average density of bracatinga was 437.5 individuals ha-1, and the average density of scale insects per plant was 8,287. During 10 minutes, the average rate of honeydew excretion by scale insects was 0.45 µl and 0.34 µl, respectively, in 2002 and 2004. The estimated volume of honeydew production was 0.54 L in 2002 and 0.41 L in 2004 tree-1 day-1. The highest sugar concentration was observed in 2004 (28.13%). The excretion rate was affected by climatological factors and the size of the insects. This is the first study presenting a systematic evaluation of honeydew production by scale insects in Southern Brazil. The results of the present study support production of honeydew honey in the Serra Catarinense region as an important sustainable economic and traditional activity.

Changes in hypopharyngeal glands of nurse bees (Apis mellifera) induced by pollen-containing sublethal doses of the herbicide Roundup®.

Decreasing pollinator populations worldwide has generated great concern and stimulated countless studies to understand the origin of colony losses. One main cause is the indiscriminate use of different pesticides, producing subtle negative effects on bee physiology and behavior. Royal jelly synthesized in the hypopharyngeal glands is an essential protein for feeding all individuals of the hive, especially the queen. Therefore, the present study aimed to determine the effect of sublethal concentrations of Roundup® on the hypopharyngeal glands of nursing workers, including its interference with the production of royal jelly. The herbicide was found to promote changes in the cellular ultrastructure of these glands, causing early degeneration of the rough endoplasmic reticulum and morphological and structural changes in the mitochondria. No changes were noted in the amount of royal jelly produced, but additional long-term studies are necessary to determine possible qualitative changes. This is the first study to evaluate the effect of Roundup® on the royal jelly-producing glands, showing that resultant alterations in these structures can trigger damage to the development and survival of bee colonies.

Reproductive Biology of Varronia curassavica Jacq. (Boraginaceae)

ABSTRACT Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.

Reproductive Biology of Varronia curassavica Jacq. (Boraginaceae).

Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.

Chronic Responses of Daphnia magna Under Dietary Exposure to Leaves of a Transgenic (Event MON810) Bt-Maize Hybrid and its Conventional Near-Isoline.

Insect resistance is the second most common trait globally in cultivated genetically modified (GM) plants. Resistance is usually obtained by introducing into the plant's genome genes from the bacterium Bacillus thuringiensis (Bt) coding for insecticidal proteins (Cry proteins or toxins) that target insect pests. The aim of this study was to examine the hypothesis that a chronic, high-dose dietary exposure to leaves of a Bt-maize hybrid (GM event MON810, expressing a transgenic or recombinant Cry1Ab toxin), exerted no adverse effects on fitness parameters of the aquatic nontarget organism Daphnia magna (water flea) when compared to an identical control diet based on leaves of the non-GM near-isoline. Cry1Ab was immunologically detected and quantified in GM maize leaf material used for Daphnia feed. A 69-kD protein near Bt's active core-toxin size and a 34-kD protein were identified. The D. magna bioassay showed a resource allocation to production of resting eggs and early fecundity in D. magna fed GM maize, with adverse effects for body size and fecundity later in life. This is the first study to examine GM-plant leaf material in the D. magna model, and provides of negative fitness effects of a MON810 maize hybrid in a nontarget model organism under chronic, high dietary exposure. Based upon these results, it is postulated that the observed transgenic proteins exert a nontarget effect in D. magna and/or unintended changes were produced in the maize genome/metabolome by the transformation process, producing a nutritional difference between GM-maize and non-GM near-isoline.