Progress 10/01/02 to 10/01/03
Outputs
The following areas were emphasized: 1) Catollacus hunteri, a parasite of the pepper weevil, was released in cooperation with a commercial scouting firm on the perimeter of former pepper fields at three conventional farms during the summer and fall off-season and pepper weevil populations were compared to those on three other former pepper fields at the same farms the following spring. The number of pepper weevils observed were low during the following spring season in both release fields and in non-release fields, with the result that no differences were detected; however, when the fields were destroyed at the end of the season, more adults were captured on pheromone/attractant-baited sticky traps in non-release fields than traps in release fields. 2) Four plots of nightshade were established at the University of Florida Gulf Coast Research and Education Center research farm in mid to late summer. The plots were artificially infested with lab reared pepper weevil
adults. C. hunteri was released weekly during the fall on the nightshade on two of the plots. The following spring, three-row plots of bell pepper were established adjacent to the nightshade in all four of the plots. C. hunteri was released weekly at a rate of 1600 adults/plot in the two plots where the parasite had been released during the fall. No parasites were release in the other two plots. The subsequent yield of non-infested fruit determined in all plots. In general, more non-infested fruit were harvested from plots receiving weekly parasite releases compared to plots where no parasites were released; however, the differences were not significant. 3) Jalapeno fruit infested in the lab with pepper weevil larvae were placed on the soil surface or loosely buried 5, 10, 20 or 30 cm and covered with plastic pot traps. Emerging weevil adults were recovered mostly from the peppers on the soil surface and from those buried no more than 5 cm; however, a few were recovered from peppers
buried 10 cm.
Impacts
Releasing Catolaccus hunteri on field perimeters in the summer and fall off-season and in the pepper crop followed with selective insecticides could result in maximizing biological control of the pepper weevil while minimizing the environmental impact of conventional insecticides. Deep discing infested fields immediately after harvest and destroying over-summering alternative host plants would reduce weevil populations in subsequent pepper crops.
Publications
- Seal, D. R., P. A. Stansly and D. J. Schuster. 2002. Influence of temperature and host on life history parameters of Catolaccus hunteri (Homoptera: Pteromalidae). Environ. Entomol. 31:354-360.
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Progress 09/15/00 to 09/14/03
Outputs
The following areas were emphasized: 1) A density and sex ratio of 50 females to 50 males of Catolaccus hunteri, a parasite of the pepper weevil, was found to result in maximum parasitism when rearing the parasite on larvae of the factitious host, Callosobruchus maculatus, in garbanzo beans in the laboratory. 2) C. hunteri was released weekly in pepper on an organic farm at densities of 400, 800 and 1600 per acre in 0.5 acre plots. Early in the season there were more damaged fruit in plots where no parasites were released compared to those where 1600 were released. 3) C. hunteri was released in cooperation with a commercial scouting firm on the perimeters of former pepper fields at two farms in 2001-02 and three farms in 2002-03 during the summer off-season and pepper weevil populations were compared to those on two (2001-02) or three (2002-03) former pepper fields at the same farms the following spring. In 2002, there were about 30 percent fewer dropped fruit in
release fields compared to the non-release fields. In 2003, more weevil adults were captured on pheromone/attractant-baited sticky traps in non-release fields than on traps in release fields. 4) Weekly releases of C. hunteri in nightshade plots followed by weekly releases in adjacent pepper resulted in fewer fruit infested with pepper weevil larvae compared to pepper grown adjacent to nightshade where the parasite was not released. 5) Pepper weevil infested serrano or jalapeno fruit placed on the soil surface or loosely buried 5, 10, 20 or 30 cm and covered with plastic pot emergence traps. No emergent weevil adults were recovered from peppers buried 20 or 30 cm while most were recovered from pepper on the soil surface and from those buried no more than 5 cm. 6) Pepper weevil adults were released in late June into field cages with and without alternative host plants and were observed until late November. In the cages with only natural vegetation, weevil adults were observed up to 90
days after release while, in cages with either nightshade or pepper plants present, adults were observed for at least 150 days. 7) Using a residue vial method, methomyl and chlorpyrifos were found to be highly toxic to female adults of C. hunteri; spinosad, oxamyl and indoxacarb were moderately toxic; and tebufenozide, azadirachtin and cryolite were found to be non-toxic. Using a topical misting method, chlorpyrifos and tebufenozide were highly toxic to adults; methomyl, oxamyl and spinosad were moderately toxic; and indoxacarb was non-toxic. 8) Pepper weevil adults and pepper weevils females with both eggs and fat bodies present were captured year round, indicating the presence of alternative host plants and the lack of diapause or estivation
Impacts
Releasing Catolaccus hunteri on field perimeters in the summer and fall off-season and in the pepper crop followed with selective insecticides could result in maximizing biological control of the pepper weevil while minimizing the environmental impact of conventional insecticides. Deep discing infested fields immediately after harvest and destroying over-summering alternative host plants would reduce weevil populations in subsequent pepper crops.
Publications
- Seal, D. R., P. A. Stansly and D. J. Schuster. 2002. Influence of temperature and host on life history parameters of Catolaccus hunteri (Homoptera: Pteromalidae). Environ. Entomol. 31:354-360.
- Vasquez, E., D. Dean, D. Schuster and P. van Etten. 2005. A laboratory method for rearing Catolaccus hunteri (Hymenoptera: Pteromalidae), a parasitoid of the pepper weevil (Coleoptera: Curculionidae). Fla. Entomol. (accepted for publication).
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Progress 10/01/01 to 10/01/02
Outputs
The following research areas were emphasized: 1) The pepper weevil parasite, Catolaccus hunteri, was released in pepper on an organic farm at densities of 400, 800 and 1600 per acre in 0.5 acre plots. Early in the season, there generally were more damaged fruit in the plots where no parasites were released compared to those where 1600 were released; however, later in the season there tended to be more damaged fruit in the release plot. 2) C. hunteri was released on the perimeter of former pepper fields at three conventional farms during the summer off-season and pepper weevil populations were compared to those on three other former pepper fields at the same farms the following spring. No differences in pepper weevil populations were detected the following spring between release and non-release fields because the growers sprayed all fields with a new nicotinoid insecticide, thiamethoxam. 3) C. hunteri was released in cooperation with a commercial scouting firm on the
perimeter of former pepper fields at two additional conventional farms during the summer off-season and pepper weevil populations were compared to those on two other former pepper fields at the same farms the following spring. There were about 30 percent fewer dropped fruit in the release fields the following spring compared to the non-release fields. 4) Pepper weevil infested jalapeno fruit were placed on the soil surface or loosely buried 5, 10, 20 and 30 cm and covered with conical screen or plastic pot traps. Emerging weevil adults were recovered mostly from the peppers on the soil surface and from those buried no more than 5 cm; however, a few were recovered from peppers buried 10 cm.
Impacts
Releasing Catolaccus hunteri on field perimeters in the summer off-season and in the pepper crop followed with selective insecticides could result in maximizing control of the pepper weevil while minimizing the environmental impact of conventional insecticides. Deep discing infested fields immediately after harvest and destroying over-summering host plants would reduce weevil populations in subsequent crops.
Publications
- Seal, D. R., P. A. Stansly and D. J. Schuster. 2002. Influence of temperature and host on life history parameters of Catolaccus hunteri (Homoptera: Pteromalidae). Environ. Entomol. 31: 354-360.
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Progress 10/01/00 to 10/01/01
Outputs
The following research areas were emphasized: 1) The pepper weevil parasite, C. hunteri, was released in pepper at densities of 400, 800 and 1600 per acre in 0.5 acre plots. Early in the season, there generally were more damaged fruit in the plots where no parasites were released compared to those where 1600 were released; however, later in the season there tended to be more damaged fruit in the release plot. 2) C. hunteri was released on the perimeter of former pepper fields at two organic farms during the summer off-season. Pepper weevil populations generally were lower in the release areas than they had been in previous years. 3) Pepper weevil adults were released in late June into field cages with and without alternative hot plants and were observed until late November. Weevil adults were observed in the cages with only natural vegetation for up to 90 dayys from the beginning of the experiment while adults were observed for at least 150 days in the cages into
which either pepper or nightshade plants had been introduced. 4) Pepper weevil infested serrano and jalapeno fruit were placed on the soil surface or loosely buried 5, 10 ,20 and 30 cm and covered with conical screen traps. No emerging weevil adults were captured. When the experiment was repeated using a trap constructed from a large, plastic pot, weevils were recovered only from the peppers on the soil surface and from those buried no more than 5 cm. 5) Using a residue vial method, methomyl and chlorpyrifos were found to be highly toxic to adults of C. hunteri; spinosad, oxamyl and indoxacarb were moderately toxic; and tebufenozide, azadirachtin and cryolite were found to be non-toxic. 6) A density and sex ratio of 50 females to 50 males of C. hunteri was found to result in maximum parasitism when rearing the parasite on Callosobruchus maculata larvae in garbanzo beans in the laboratory.
Impacts
Releasing C. hunteri on field perimeters in the summer off-season and in the pepper crop followed with selective insecticides could result in maximizing control of the pepper weevil while minimizing the environmental impact of conventional insecticides. Deep discing infested fields immediately after harvest and destroying over-summering host plants would reduce weevil populations in subsequent crops.
Publications
- D. R. Seal, Stansly, P. A. and Schuster, D. J. 2001. Population parameters for Catolaccus hunteri (Hymenoptera: Pteromalidae): influence of temperature and host. Environ. Entomol. 30(accepted for publication).
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