Evoneo Berti Filho

Marigold (Tagetes erecta L.) as an attractive crop to natural enemies in onion fields

4 UFLA - Depto. de Biologia. *Corresponding author ABSTRACT: Onion is the third most grown vegetable crop in Sao Paulo state, Brazil. Organic onion farming is expected to increase in the state due to the increasing demand. Pest management in organic onion farming is based on plant extracts with insecticide effects. However, the efficacy of such plant extracts has not been proved yet, and it was observed that they do negatively affect natural enemies. Plants surrounding onion fields, and that are attractive to natural enemies, may be a good option to farmers, since they may lead to increased diversity of arthropod species and, consequently, the natural control of pest populations. This study deals with the effect of marigold plants as a resource plant to natural enemies in onion fields. The experiment was set in a certified organic farm using marigold rows at a center of an onion field. Samples were taken from marigold and the onion plants 5 m (near) and 30 m (far) from the flowering strips. Higher numbers of arthropod pests were observed in onion plants 30 m from the marigold strip, while higher numbers of predators and parasitoids were found at 5 m distance. Species richness and Shannons diversity index were higher at 5 m from marigold. Therefore, marigold rows next to onion fields resulted in higher number of entomophagous species, potentially enhancing the natural control of onion pests. In the study field, marigold strips may be an alternative to crop sprays for organic control of onion pests.

Preferência de Palmistichus elaeisis por pupas de diferentes lepidópteros praga

Palmistichus elaeisis Delvare & LaSalle, 1993 (Hym.: Eulophidae) was found parasitizing pupae of Sabulodes sp. (Lep.: Geometridae) in an Eucalyptus plantation. To study the preference of this parasitoid for pupae of other lepidopteran pests, an experiment was conducted testing the following Lepidoptera species: Diatraea saccharalis (Fabricius, 1794) (Crambidae), Anticarsia gemmatalis Hubner, 1818, Heliothis virescens (Fabricius, 1781) and Spodoptera frugiperda (J.E. Smith, 1797) (Noctuidae). The percentage of parasitism ranged from 90% (H. virescens) to 100%. The highest value for the parasitoid sexual ratio was 0.98 for D. saccharalis, and the lowest was 0.69 for H. virescens. The host species significantly affected the size of P. elaeisis males (1.64 mm in S. frugiperda and 1.49 mm in H. virescens), and not that of females. The sex of the host had significant effect on the total number of parasitoids, whereas the host species had no statistical effect on the same variable.

First record of Sinoxylon conigerum Gerstäcker (Coleoptera: Bostrichidae) in Brazil

This is the first register of Sinoxylon conigerum attacking timber of teak (Tectona grandis L.f.), mango tree (Mangifera indica L.) and (Astronium fraxinifolium Schott) in the municipalities of Cuiabá and Várzea Grande, State of Mato Grosso, Brazil.

Desenvolvimento dos estágios imaturos de Palmistichus elaeisis Delvare & LaSalle (Hymenoptera, Eulophidae) em pupas de Lepidoptera

Palmistichus elaeisis Delvare & LaSalle, 1993 is an endoparasitoid collected from pupae of Sabulodes sp. (Lepidoptera, Geometridae). The immature stages of this parasitoid were studied in laboratory (25 ± 1oC; 70 ± 10% RH; 14-hour photoperiod) in the following Lepidoptera pupae: Diatraea saccharalis (Fabricius, 1794) (Crambidae), Anticarsia gemmatalis Hubner, 1818, Heliothis virescens (Fabricius, 1781), Spodoptera frugiperda (J. E. Smith, 1797) (Noctuidae) and Thyrinteina arnobia (Stoll, 1782) (Geometridae). It was observed that the eggs and the 1st instar larvae are hyaline and hymenopteriform; 2nd, 3rd and 4th instars larvae are whitish and 12-segmented. The host species did not influence the number of instars.

Exigências térmicas para o desenvolvimento de Palmistichus elaeisis (Hymenoptera, Eulophidae) em pupas de cinco espécies de lepidópteros

The thermal requirements of Palmistichus elaeisis Delvare & LaSalle, 1993 were determined by rearing this pupal parasitoid in the following lepidopteran hosts: Diatraea saccharalis (Fabricius, 1794) (Crambidae), Anticarsia gemmatalis (Hubner, 1818), Heliothis virescens (Fabricius, 1777), Spodoptera frugiperda (J.E. Smith, 1797) (Noctuidae) and Thyrinteina arnobia (Stoll, 1782) (Geometridae). The experiment was set in laboratory conditions (temperatures between 18oC and 30oC, RH=70 ± 10% and 14-hour photoperiod). The life cycle (egg-adult) ranged from 40.4 ± 0.63 days (18oC, H. virescens) to 18.1 ± 0.13 days (28oC, D. saccharalis). The thermal constant of the egg-adult period ranged from 353.1 (D. saccharalis) to 407.7 degree-days (S. frugiperda). The lowest thermal threshold ranged from 5.0oC (A. gemmatalis) to 7.5oC (D. saccharalis). At 30oC, all prepupae died. These results suggest that P. elaeisis can be reared in laboratory on all the hosts tested.

Influência da temperatura na freqüência de cópula de Anticarsia gemmatalis Hübner e Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

This paper deals with the influence of temperature on the mating frequency of two lepidopterans, Anticarsia gemmatalis Hubner and Spodoptera frugiperda (J.E. Smith), which use different strategies of allocation, and with the utilization of nutrients for their reproductive activities. The insects were reared on artificial diets at 25oC, and the adults were exposed to five temperatures (15, 20, 25, 30, and 35oC) to observe the influence of each temperature on their mating frequency, fecundity, fertility and longevity. The temperature affectedthe mating frequency of both species, being more evident at 15oC and 35oC, mainly for A. gemmatalis, which presented a drastic reduction on mating activities. The highest number of matings were observed from 20oC to 30oC, with S. frugiperda presenting mating activity (0-8) much higher than that of A. gemmatalis (0-2), but no correlation was observed among the number of matings and all other biological parameters evaluated (fecundity, fertility and longevity). However, S. frugiperda showed a positive correlation between fecundity and mating activity of females (r = 0.589; P = 0.003) at 25oC. The highest fecundities were observed at temperatures from 20oC to 30oC for S. frugiperda and at 25oC for A. gemmatalis. For both species, the longevity of males and females decreased as temperature increased.

First Record of Sinoxylon anale Lesne and Sinoxylon senegalensis (Karsch) (Coleoptera: Bostrichidae) in Brazil

Sinoxylon anale Lesne and Sinoxylon senegalensis (Karsch) are registered for the first time in Brazil in wood imported from India and China.

Biology of Bemisia tabaci (Genn.) B-biotype and parasitism by Encarsia formosa (Gahan) on collard, soybean and tomato plants

A mosca branca Bemisia tabaci (Genn.) biotipo B e uma praga polifaga que ataca muitas culturas de importância economica. O controle quimico pode causar problemas como o aparecimento de resistencia nesse inseto, residuos nos produtos das culturas, ou mesmo poluicao ambiental. Um metodo alternativo seria o controle biologico, com o parasitoide Encarsia formosa (Gahan), o mais usado contra moscas brancas a nivel mundial. Avaliaram-se o tempo de desenvolvimento de ovo a adulto e a porcentagem de ninfas eclodidas de B. tabaci (Genn.) biotipo B em couve (Brassica oleracea L. var. acephala D.C.), soja (Glycine max (L.) Merr.) e tomateiro (Lycopersicon esculentum Mill.), bem como o desenvolvimento de ovo a adulto de E. formosa em ninfas de 1o, 2o, 3o e 4o instares dessa mosca-branca nessas tres especies vegetais. Os experimentos foram desenvolvidos em laboratorio, a 25oC, 70 ± 10% UR e 14 h de fotofase. O tempo de duracao ovo-adulto de B. tabaci biotipo B foi mais curto em couve (19,8 dias) e mais longo em tomateiro (22,0 dias), ficando a soja (21,2 dias) em posicao intermediaria. A couve mostrou tambem a maior porcentagem de ninfas eclodidas comparativamente a soja e ao tomateiro. Com relacao a E. formosa, independentemente da planta, o periodo ovo-adulto foi menor em ninfas de 3o e 4o instares, demonstrando que esse parasitoide se desenvolve melhor em ninfas mais desenvolvidas.

Levantamento e identificação de cupins (Insecta: Isoptera) em área urbana de Piracicaba, SP.

This paper deals with the occurrence of termites in a urban area of Piracicaba City, State of Sao Paulo, Brazil. Samples of home and commercial buildings were surveyed and the termites collected were identified. The most frequent species were the drywood termite, Cryptotermes brevis , and the subterranean termite, Coptotermes havilandi . It was observed that the risk of termite attacks, as well as the number of attacks per building showed a tendency to increase with the age of the buildings.

Oviposition and predation of Pentilia egena mulsant (Coleoptera: Coccinellidae) in response to temperature

The species Pentilia egena Mulsant is an important predator of armored scales that occur in citrus orchards in Brazil. To intensify this biological control, knowing bioecological aspects in necessary for the improvement of massal insect rearing. This research investigated the influence of temperature (19oC, 24oC and 29oC) on the number of eggs laid by P. egena and the number of Aspidiotus nerii Bouche scales preyed by this coccinellid. The highest number of eggs laid and of scales preyed, 5.1 ± 0.59 and 11.3 ± 0.19, respectively, occurred at 29oC. However, egg viability (52.86%) was reduced at this temperature, and was lower than those at 19oC and 24oC (78.10% and 74.07%, respectively). Temperature did not affect the ladybeetle oviposition behavior as the eggs were laid under the scale of preyed A. nerii.