Contribuição para o controle biológico da broca da cana de açúcar

GC-EAD and GC-MS analysis of pheromone gland extracts of sugarcane borer, Diatraea saccharalis, revealed two antennally active compounds, (9Z,11E)-hexadeca-9,1-dienal and (11Z)-hexadec-11-enal, in approximately 10 : 1 ratio. Various doses of identified compounds were investigated in wind tunnel experiments individually and in a 10 : 1 ratio. At all tested doses (9Z,11E)-hexadeca-9,1-dienal alone elicited upwind orientation and source location only in a minority of tested males. An admixture of (11Z)-hex-11-enal enhanced the attractiveness of (9Z,11E)-hexadeca-9,11-dienal significantly. This two-component blend (100 pg) was as attractive as natural pheromone extracted from three female pheromone glands. The data suggest that (11Z)-hexadec-11-enal is a part of the D. saccharalis sex pheromone.

Section: Introductionmentioning

confidence: 99%

(11Z)‐hexadec‐11‐enal enhances the attractiveness of Diatraea saccharalis main pheromone component in wind tunnel experiments

Kalinová

Kindl

Hovorka

et al. 2005

“…Another tachinid fly, Paratheresia claripalpis Wulp., native to South America, was first studied in 1942, and in 1950, a third tachinid species, Lyxophaga diatraea Towns. was introduced from Cuba ( Gallo , 1980). These three tachinids were reared in sugarcane mill laboratories and intensively released into sugarcane fields.…”

Section: Introductionmentioning

confidence: 99%

Evidences of non‐additive effects of multiple parasitoids on Diatraea saccharalis Fabr. (Lep., Crambidae) populations in sugarcane fields in Brazil

Rossi

2004

Biological control is a relatively benign method of pest control. However, considerable debate exists over whether multiple natural enemies often interact to produce additive or non‐additive effects on their prey or host populations. Based on the large data set stored in the São João and Barra sugarcane mills (state of São Paulo, Brazil) regarding the programme of biological control of Diatraea saccharalis using the parasitoids Cotesia flavipes and tachinid flies, in the present study the author investigated whether the parasitoids released into sugarcane fields interfered significantly with the rate of parasitized D. saccharalis hosts. The author also observed whether there was an additive effect of releasing C. flavipes and tachinids on the rate of parasitized hosts, and looked for evidence of possible negative effects of the use of multiple parasitoid species in this biological control programme. Results showed that C. flavipes and the tachinids were concomitantly released in the Barra Mill, but not in the São Jão Mill. Furthermore, in the Barra Mill there was evidence that the parasitoids interacted because the percentage of parasitism did not increase after the release of either C. flavipes or tachinids. In the São João Mill, when both parasitoid species were released out of synchrony, both the percentage of parasitism by C. flavipes as well as that of the tachinids increased. When large numbers of tachinids were released in the Barra Mill, they caused a significant lower percentage of parasitism imposed by C. flavipes. The implications of the results as evidence of non‐additive effects of C. flavipes plus tachinids on D. saccharalis populations are discussed.

“…(Dip., Tachinidae) was reared and released into the sugarcane fields. Another tachinid, Paratheresia claripalpis Wulp., also native to South America, began to be studied in 1942, and in 1950, a third tachinid, Lyxophaga diatraea , Towns., was introduced from Cuba ( Gallo , 1980). These three tachinids were reared in sugarcane mill laboratories and intensively released into sugarcane fields.…”

Section: Introductionmentioning

confidence: 99%

Spatial and temporal population interactions between the parasitoids Cotesia flavipes and Tachinidae flies: considerations on the adverse effects of biological control practice

Rossi

Fowler

2004

Biological control of Diatraea saccharalis is regarded as one of the best examples of successful classical biological control in Brazil. Since the introduction of the exotic parasitoid Cotesia flavipes, the decrease of D. saccharalis infestation in sugarcane fields has been attributed to the effectiveness of this agent. Recently, the native tachinid fly parasitoids (Lydella minense and Paratheresia claripalpis) have also been implicated in the success. Here, we investigated the spatial and temporal population interactions between C. flavipes and the tachinid flies, and provide a critical analysis of the biological control practice, focusing on the undesirable effects of introductions of exotic natural enemies. To investigate these questions, a large data set comprising information from two sugarcane mills located in the state of Sa˜o Paulo, Brazil (Barra and Sa˜o Joa˜o Mills), was analysed. Analysis of the correlation between C. flavipes and tachinid fly population densities through time revealed that such populations were inversely correlated in the Sa˜o Joa˜o Mill and not correlated in the Barra Mill. Logistic regressions were computed to investigate the proportion of sites occupied by the parasitoid species at both mills as a function of time. An increasing trend in the proportion of sites occupied by C. flavipes was observed, with a concomitant decrease of the sites occupied by tachinid flies. This effect was more intense in the Sa˜o Joa˜o Mill. Thus, there is a convincing possibility that constant releases of C. flavipes decreased the tachinid fly populations, resulting in an undesirable effect of biological control practice.