We studied Spodoptera frugiperda development using different food sources in the laboratory and field. Newly hatched larvae were fed soybean, cotton, maize, wheat, and oat leaves. An artificial diet was used as the control. Duration of pre-pupal, pupal, and larva-adult period, pupal weight, sex ratio, survival, larva feeding preferences, oviposition preferences, and nutritional quality of different hosts were evaluated. Insects fed on wheat showed the shortest larva-adult period. The insects fed on cotton and soybean had longer larval development cycles and pupae of lower weight. Feeding preference was evident for third instar larvae and did not differ between wheat, oat, maize, and soybean, which were the preferred hosts. Moths oviposited to a greater extent on the upper canopy of wheat than that of other plants in both the no-choice and free-choice tests. Treatments influenced insect growth, food consumption, and digestion when nutritional variables were analyzed. Thus, grasses were better hosts for S. frugiperda development. Cotton was the least preferred food, followed by soybean. The present study can improve our understanding of S. frugiperda in these different crops and help in developing management strategies. Even though S. frugiperda is considered to be polyphagous, this pest is closely associated with grasses (maize, wheat, oat) and has lower potential as a soybean or cotton feeder. Howerver, S. frugiperda food intake regulation appears to be triggered by a complex of different mechanisms. Thus, S. frugiperda can also damage soybean and cotton and adapt to them in the absence of preferred hosts.
-Spodoptera eridania (Cramer) is a pest under expansion in cotton and soybean fields in the cerrado, and biology studies are needed on different hosts. In order to gain knowledge about the biology and leaf intake of S. eridania on cotton, soybean and morning glory (Ipomoea grandifolia), newly-hatched caterpillars were individualized and reared in the laboratory (27 ± 2 o C, R.H. 60 ± 10%, photophase of 14h). Parameters related to biology, leaf intake and reproduction were observed. The larval development period of caterpillars was shorter when fed on cotton and morning glory leaves than on soybean leaves, even though, the survival on soybean had been satisfactory (80%). Caterpillars fed on cotton and morning glory leaves had similar mean pupal weights, however 1.3 and 1.4 times higher than those obtained for male and female pupae, respectively, on soybean leaves. The soybean also influenced prepupal (37.5%) and pupal survival (68.3%) negatively, in contrast with the values obtained on the two other hosts, which were above 91.8%. In general, the soybean leaves were the least suitable for the development of S. eridania, causing 6.3% of pupal deformities. Variables like the pre-oviposition and oviposition periods, number of egg clutches/female and total number of eggs/female were not affected by the diets. Even though cotton leaves were less consumed, they provided good development to the insect. The morning glory weed was shown a suitable alternate host for the species, allowing its development and reproduction in the absence of cultivated hosts.KEY WORDS: Insecta, nutritional ecology, alternative host RESUMO -Spodoptera eridania (Cramer) é uma praga em expansão nas culturas de algodão e de soja no cerrado, necessitando de estudos de biologia em diferentes hospedeiros. Com o objetivo de conhecer a biologia e o consumo foliar de S. eridania em algodoeiro, soja e corda-de-viola (Ipomoea grandifolia), este inseto foi criado em laboratório (27± 2 o C, UR 60± 10%, fotofase de 14h), a partir de lagartas recém-eclodidas e individualizadas. Foram observados parâmetros relacionados à biologia, ao consumo foliar e à reprodução quando alimentadas nos três hospedeiros. O período de desenvolvimento larval foi menor nos insetos alimentados com algodoeiro e corda-de-viola do que em soja, embora a sobrevivência em soja tenha sido satisfatória (80%). Lagartas alimentadas com folhas de algodoeiro e corda-de-viola tiveram peso médio de pupas semelhante, porém 1,3 e 1,4 vezes maior do que o obtido por pupa macho e fêmea, respectivamente, em folhas de soja. A soja, também influenciou negativamente a sobrevivência de pré-pupa e pupa, contrastando com os valores, acima de 91,8%, nos outros dois hospedeiros. Em geral, a folha de soja foi a menos adequada para S. eridania, causando 6,3% de deformidade em pupas. Variáveis como períodos de pré-oviposição, oviposição, número de posturas/fêmea e o total de ovos/fêmea, não foram afetados pelas dietas. Embora as folhas de algodoeiro tenham sido as menos consumidas, elas proporcionaram ...
Selection ofconidia/ml). Vegetative growth on culture media and sporulation on culture media, cooked rice and lesser mealworm cadavers were also evaluated. Isolates of B. bassiana were more effective than the M. anisopliae isolates and larvae were more susceptible than adults. The isolates UNIOESTE 04 and UNIOESTE 02 were originally obtained from adults of the lesser mealworm and were the most efficient isolates. In addition, UNIOESTE 04 showed high level of sporulation on different culture media and is considered a potential useful tool to lesser mealworm control.KEY WORDS: Biological control, poultry house, lesser mealworm RESUMO -Este trabalho teve por objetivo selecionar isolados de fungos entomopatogênicos, visando sua utilização no controle do cascudinho, Alphitobius diaperinus (Panzer). Larvas e adultos foram inoculados com suspensões de conídios de 99 isolados de Beauveria bassiana (Bals.) Vuill. e Metarhizium anisopliae (Metsch.) Sorok. em concentrações variáveis de 10 5 a 10 9
Knowledge about interactions among biological control agents, used in sequence or simultaneously, may help to increase their efficiency, or in the case of conservation biological control, to avoid the impairment of efficiency. The aim of this study was to evaluate the interaction between two isolates of Beauveria bassiana (Bals.) Vuill. (Hypocreales) (Unioeste 47 and Unioeste 57) and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae), varying the timing of sprays of the fungus. Isolates were sprayed at 109 conidia ml−1 upon cards (1 × 5 cm; i.e., 2 × 105 conidia mm−2) with eggs of Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) and the control group was sprayed with sterile distilled water with Tween® 80 (0.01%). First, the percentage of parasitized eggs was assessed in a choice test: females of T. pretiosum were confined with two cards, one of them treated with either of the fungus isolates, the other a water‐treated control. Second, parasitism was compared on cards sprayed at various time intervals pre‐ vs. post‐parasitism: the number of parasitized eggs was assessed, as well as the parasitoid's emergence percentage, egg‐adult period, offspring sex ratio, and the longevity of parasitizing females. Trichogramma pretiosum preferred to parasitize control eggs (65 and 72%) and parasitization of the treated eggs did not differ between fungus isolates: 35% (Unioeste 47) vs. 28% (Unioeste 57). Spraying before or after parasitizing did not affect the number of parasitized eggs, nor offspring sex ratio; however, both treatments affected the percentage of emerged adults, egg‐adult period, and longevity. These findings suggested that isolates did not interfere in the longevity of parasitizing females. When the fungus was sprayed on the various development stages of the parasitoid within the host egg, or when it was offered to the parasitoid at different times after spraying, differences in adults' longevity, parasitism, emergency period from egg to adult, and sex ratio were observed. Beauveria bassiana may be used in conjunction with this parasitoid in a program of pest control.
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