Diaspis echinocacti (Hemiptera: Diaspididae) on cactus pear cladodes: biological aspects at different temperatures

The scale mealybug, Diaspis echinocacti (Bouché, 1833) (Hemiptera: Diaspididae), is one of the main pests of the cactus pear in Brazil. The objective was to study biological aspects of D. echinocacti at the constant temperatures of 25, 28, 30, 33 and 35 °C with relative humidity of 60 ± 10% and photoperiod of 12 hours in the laboratory on the cactus pear cultivar, "Orelha de Elefante Mexicana", Opuntia stricta [Haw.] Haw. The development period (22 to 35 days) and survival in the egg (92 to 100%) and nymph (21.8 to 100%) stages and of the egg-adult cycle (20 to 100%), longevity (34.1 to 59.6 days) and fecundity (33 to 112 eggs) of D. echinocacti females with the different temperature and absence of males at the highest temperatures (> 30°C), indicated that the range between 25 °C and 30°C is the most favorable for this scale mealybug. This information may help to improve integrated management programs for D. echinocacti, in areas subject to seasonal temperature changes in the Brazilian regions where cactus pear is cultivated.

Mortality of the cotton boll weevil in drip and sprinkler irrigated cotton crops

The cotton boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a key cotton crop pest in Brazil. Adverse climatic factors, such as high temperatures and low soil moisture, dehydrate oviposited cotton squares (bud flowers) on the ground and cause high mortality of its offspring within these plant structures. The objective of this research was to evaluate the mortality of the cotton boll weevil in drip and sprinkler irrigated cotton crops. The experimental design was in randomized blocks with two treatments: drip (T1) and sprinkler (T2, control) irrigated cotton crops with sixteen replications. Each parcel had one emergence cage, installed between two cotton rows per irrigation system, with 37 cotton squares with opened oviposition punctures and yellowish bracts, to capture adult cotton boll weevils. The average number of boll weevils that emerged from the cotton squares and the causes of mortality at different development stages were determined per treatment. Third-generation life tables of the boll weevil were prepared using the natural mortality data in drip and sprinkler irrigation treatments and plus actual, apparent and indispensable mortality rates and the lethality of each mortality cause. We conclude that the application of water directly to the root zone of the plants in a targeted manner, using the drip irrigation system, can cause high mortality of the cotton boll weevil immature stages inside cotton squares fallen on the ground. This is because the cotton squares fallen on the drier and hotter soil between the rows of drip-irrigated cotton dehydrates causing the boll weevils to die. This is important because it can reduce its population density of the pest and, consequently, the number of applications of chemical insecticides for its control. Thus, contributing to increase the viability of cotton production, mainly in areas of the Brazilian semiarid region where the cotton is cultivated in organic system.

Human adipose-derived mesenchymal stromal cells from face and abdomen undergo replicative senescence and loss of genetic integrity after long-term culture

Body fat depots are heterogeneous concerning their embryonic origin, structure, exposure to environmental stressors, and availability. Thus, investigating adipose-derived mesenchymal stromal cells (ASCs) from different sources is essential to standardization for future therapies. In vitro amplification is also critical because it may predispose cell senescence and mutations, reducing regenerative properties and safety. Here, we evaluated long-term culture of human facial ASCs (fASCs) and abdominal ASCs (aASCs) and showed that both met the criteria for MSCs characterization but presented differences in their immunophenotypic profile, and differentiation and clonogenic potentials. The abdominal tissue yielded more ASCs, and these had higher proliferative potential, but facial cells displayed fewer mitotic errors at higher passages. However, both cell types reduced clonal efficiency over time and entered replicative senescence around P12, as evaluated by progressive morphological alterations, reduced proliferative capacity, and SA-β-galactosidase expression. Loss of genetic integrity was detected by a higher proportion of cells showing nuclear alterations and γ-H2AX expression. Our findings indicate that the source of ASCs can substantially influence their phenotype and therefore should be carefully considered in future cell therapies, avoiding, however, long-term culture to ensure genetic stability.

Courtship, Mating Behavior, and Ovary Histology of the Nymph Parasitoid Psyllaephagus bliteus (Hymenoptera: Encyrtidae)

The potential of the parasitoid Psyllaephagus bliteus Riek for the biological control of the eucalyptus pest Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) nymphs is high. This research sought to analyze the courtship, male competition, and mating behavior of P. bliteus at the proportions of 1:1 and 2:1 males to female in a Petri dish (5 cm diameter), and to describe the ovary histology of virgin and mated females of this parasitoid. At 1:1, males touch the antennae and thorax-abdomen of females during courtship, but females avoid mate attempts before they are 48 h old. At 2:1, the competition between male parasitoids inhibits mating. The histology of ovaries of virgin and mated P. bliteus females is similar, with two well-defined germarium and vitellarium regions, with oocytes at different developmental stages, including mature ones rich in yolk and with eggshell. A clearer understanding of the reproductive behavior and histology of P. bliteus aids in the use of this parasitoid for the biological control of G. brimblecombei.

Susceptibility of Alabama argillacea and Chrysodeixis includens (Lepidoptera: Noctuidae) larvae to Beauveria bassiana associated with kaolin

The mortality of the Alabama argillacea and Chrysodeixis includens (Lepidoptera: Noctuidae) larvae caused by the kaolin inert powder and the entomopathogenic fungus Beauveria bassiana were determined under laboratory conditions. Using the caterpillar submersion method, the CG 138 B. bassiana isolate was more pathogenic to A. argillacea than the CG 70, GC 82, ESALQ 634, and ESALQ 645. All five tested isolates caused similar mortality of C. includens. The mortality of first-instar larvae of A. argillacea and C. includens by feeding on leaf-disc impregnated with B. bassiana (CG 138) and kaolin was also determined. Higher A. argillacea mortalities were observed in the B. bassiana (CG 138) treatments, regardless of the presence of kaolin. However, the activity of kaolin + B. bassiana (CG 138) against C. includens was higher than each ingredient alone, indicating an additive action against C. includes larvae. The mortality of A. argillacea and C. includens larvae treated with kaolin + B. bassiana (CG 138) was similar, and the A. argillacea mortality was higher than that of C. includens with kaolin and B. bassiana (GC 138) separated. The treatment kaolin + B. bassiana (CG 138) is promising for the simultaneous management of these two defoliator pests, mainly A. includes. In addition, the monophagous A. argillacea is more susceptible to both kaolin and B. bassiana (GC 138) than the polyphagous C. includens, suggesting that the nutritional ecology plays an important role in the susceptibility of these defoliator species to alternative insecticides.

Proctolaelaps bickleyi (Acari: Mesostigmata: Melicharidae): First Record of Its Association with Cotton Boll Weevil

The objective was to register the occurrence of Proctolaelaps bickleyi (Bram) (Acari: Mesostigmata: Melicharidae) in association with adults of the Anthonomus grandis Boheman (Coleoptera: Curculionidae) and to describe aspects of its behavior. This is the first record of a mesostigmatid mite associated with the cotton boll weevil in the Americas. Beetles carrying the mites had lower mobility than usual. The stress caused by this mite attached to the A. grandis body can reduce mating and oviposition of this beetle.

Survival, development and reproduction of Phenacoccus solenopsis (Hemiptera: Pseudococcidae) on kaolin-treated cotton

The mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is a cotton pest widespread in several cotton growing regions of Brazil, particularly in the semi-arid region of southwestern Bahia. The impact of kaolin on survival, development and reproduction of P. solenopsis was evaluated in the laboratory. The experiment was developed in a completely randomized design with two treatments: immature or newly emerged adults of P. solenopsis sprayed with kaolin and fed with cotton leaf discs treated with kaolin suspension (with kaolin) (T1) and immature or newly emerged adults of P. solenopsis sprayed with distilled water and fed with cotton leaf discs treated with distilled water (without kaolin) (T2). The kaolin suspension shortens the life cycle, increases the reproductive potential and population growth of the cotton mealybug, P. solenopsis and, therefore, it should be used with caution on cotton plants in regions with a history of occurrence of this pest.

Biology of Corythucha gossypii Fabricius, 1794 (Hemiptera: Tingidae) in Ricinus communis at different temperatures and thermal requirements

We studied the biology of Corythucha gossypii in Ricinus communis under different temperatures in climatic chambers adjusted at 20, 23, 25, and 28 °C, 60 ± 10% relative humidity, and a 12-h photoperiod. The development period and viability of eggs, the development period and survival rate of nymphs, and egg-adult cycle of C. gossypii as well as the adult longevity and fecundity were estimated. The thermal requirements (K) and temperature-base (Tb) were estimated for each of the immature stages and for the eggs-adults period. The duration of the eggs and nymphs phases and the egg-adult cycle of the C. gossypii on castor bean leaves at 20-28 °C were 7.6-17 days, 10.2-27.5 days, and 16.9-44.5 days, respectively. The lower temperature inhibited the oviposition of C. gossypii, whereas the higher temperatures were most favorable for its development. The municipalities of the Bahia state of Brumado, Irecê, Itaberaba, Jacobina, and Senhor do Bonfim were estimated to have a high potential for the population growth of C. gossypii. However, a greater number of generations per year of C. gossypii were observed in the municipalities of Brumado and Itaberaba.

Assessment of fennel aphids (Hemiptera: Aphididae) and their predators in fennel intercropped with cotton with colored fibers

The fennel aphid, Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a major pest of fennel, Foeniculum vulgare Miller in northeast region of Brazil. We hypothesize that intercropping can be used as an alternative pest management strategy to reduce aphid yield loss in fennel. Thus, we investigated the severity of fennel plant damage in relation to infestation by the fennel aphid and predation by Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) (spotless lady beetle), green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and Scymnus spp. (Coleoptera: Coccinellidae) in sole fennel plots and plots of fennel intercropped with cotton with colored fibers. The fennel aphid populations in nontreated plots were significantly larger in sole fennel plots than in intercropped plots. The highest densities of C. sanguinea, green lacewings and Scymnus spp., associated with the suppression of fennel aphid populations was found in fennel in the intercropping systems. Fennel aphids reduced the fennel seed yield by 80% in the sole fennel plots compared with approximately 30% for all intercropping systems. The results obtained in this research are of practical significance for designing appropriate strategies for fennel aphid control in fennel-cotton intercropping systems. In summary, intercropping fennel with cotton with colored fibers apparently promoted biocontrol of fennel aphid in fennel.

Within-plant distribution of cotton aphids, Aphis gossypii Glover (Hemiptera: Aphididae), in Bt and non-Bt cotton fields

Knowledge of the vertical and horizontal distribution of Aphis gossypii Glover (Hemiptera: Aphididae) on genetically modified cotton plants over time could help optimize decision-making in integrated cotton aphid management programs. Therefore, the aim of the present study was to determine the vertical and horizontal distribution of A. gossypii in non-transgenic Bt cotton and transgenic Bt-cotton over time during two cotton seasons by examining plants throughout the seasons. There was no significant interaction between years and cotton cultivar treatments for apterous or alate aphids. Considering year-to-year data, analyses on season-long averages of apterous or alate aphids showed that aphid densities per plant did not differ among years. The number of apterous aphids found per plant for the Bt transgenic cultivar (2427 apterous aphids per plant) was lower than for its isoline (3335 apterous aphids per plant). The number of alate aphids found per plant on the Bt transgenic cultivar (12.28 alate aphids per plant) was lower than for the isoline (140.56 alate aphids per plant). With regard to the vertical distribution of apterous aphids or alate aphids, there were interactions between cotton cultivar, plant age and plant region. We conclude that in comparison to non-Bt cotton (DP 4049), Bt cotton (DP 404 BG (Bollgard)) has significant effects on the vertical, horizontal, spatial and temporal distribution patterns of A. gossypii, showing changes in its distribution behaviour inside the plant as the cotton crop develops. The results of our study are relevant for understanding the vertical and horizontal distribution of A. gossypii on Bt cotton cultivar (DP 404 BG (Bollgard)) and on its isoline (DP 4049), and could be useful in decision-making, implementing controls and determining the timing of population peaks of this insect.