Sioux Falls, FL, United States
Sioux Falls, FL, United States

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Chen X.,University of Florida | Rohrig E.,Methods Development and Biological Control | Stansly P.A.,University of Florida
Florida Entomologist | Year: 2013

Carbon dioxide anesthesia is a convenient tool for manipulating insects, but can cause deleterious side effects. In this case, a 5 min exposure of Tamarixia radiata adults to 100% CO2 concentration caused a knockdown of about 4 min, significantly reduced survivorship and fecundity, but did not affect the sex ratio of progeny from treated adults. Future research will focus on using less concentrated doses or shorter exposure times to inactivate the wasps in order to improve survival and fecundity.


Paraiso O.,Methods Development and Biological Control | Hight S.D.,U.S. Department of Agriculture | Kairo M.T.K.,University of Maryland Eastern Shore | Bloem S.,U.S. Department of Agriculture
Florida Entomologist | Year: 2013

Our study characterized host searching and oviposition ability of T. fuentesi. In general, female wasps walked to a C. cactorum egg, drummed over the surface, drilled into the chorion, and deposited an egg. Grooming and resting behaviors were observed infrequently and host feeding was never recorded. In a typical observation period of 60 min with eggs of the exotic C. cactorum, female parasitoids spent 16% of their time drumming, 4% drilling, and 8% egg laying into the selected host. Most of the oviposition behaviors happened in the first hour.


Paraiso O.,Methods Development and Biological Control | Hight S.D.,U.S. Department of Agriculture | Kairo M.T.K.,University of Maryland Eastern Shore | Bloem S.,U.S. Department of Agriculture
Florida Entomologist | Year: 2013

Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) is a non-native moth attacking prickly pear cactus, Opuntia spp., in southeastern U.S. The insect is also an important threat to ecological systems and to native and endangered Opuntia spp. in southwestern USA. The egg parasitoid Trichogramma fuentesi Torre (Hymenoptera: Trichogrammatidae) was discovered attacking wild C. cactorum in Florida. To evaluate the potential effect of inundative releases of T. fuentesi against C. cactorum, the host searching behavior of T. fuentesi on C. cactorum eggs and host suitability of selected lepidopteran eggs were studied in the laboratory. Host suitability was studied on the native blue cactus moth, Melitara prodenialis Walker, and 6 selected species of butterfly eggs [Danaus plexippus (L.), Dryas iulia (Hübner), Junonia coenia (Hübner), Papilio glaucus (L.), Papilio polyxenes (F.), and Vanessa cardui (L.)] to assess the potential for non-target effects from T. fuentesi. The proportion of parasitism of the native cactus moth (M. prodenialis) was 98%; significantly higher than the non-native cactus moth, C. cactorum (11% average parasitism rate). The high proportion of parasitism for all native non-target species tested and the lowest proportion of parasitism for the exotic target species suggested that T. fuentesi not be considered for inundative releases in a biological control approach against C. cactorum.


Rayamajhi M.B.,U.S. Department of Agriculture | Pratt P.D.,U.S. Department of Agriculture | Tipping P.W.,U.S. Department of Agriculture | Lake E.,U.S. Department of Agriculture | And 4 more authors.
Invasive Plant Science and Management | Year: 2016

Dioscorea bulbifera is a serious invader of various ecosystems in Florida, where plants generated by its two morphotypes climb aggressively and smother supporting vegetation. There is a dearth of published research on its invasive biological attributes including vine growth and biomass production by plants generated from bulbils. Herein, we assessed these parameters in common garden studies by planting bulbils from four biomass categories (PBBCs I-IV) of both morphotypes. Vine lengths, longevity-based growth rates (VLGR), biomass, and quantities of leaves and daughter bulbils in both morphotypes showed positive correlation with the biomass of planted parental bulbils. This indicated similarity between corresponding attributes in two morphotypes. Total vine length showed strong positive correlation with VLGR, biomass, and quantities of leaves and bulbils. Overall vine longevity among plants from PBBCs I-IV did not significantly differ whereas the total vine lengths, VLGRs, number of branches, and quantities of leaves and bulbils increased with the biomass of the parental bulbils. Plants recruited by smaller bulbils allocated more biomass to leaves and tubers compared to stems and bulbils, whereas the plants recruited by larger bulbils allocated more biomass to leaves and bulbils compared to tubers and stems. Higher proportion of biomass allocation to leaves and bulbils presumably ensures immediate faster growth, longer vines, and a greater number of daughter bulbils for future recruitment of new plants. Vine length (associated with faster growth rate, capable of blanketing supporting structures and producing large quantities of bulbils) has been noted as the primary invasive biological attribute that facilitates D. bulbifera's status as a noxious exotic weed in Florida. Control measure that can reduce vine length should reduce or eliminate the invasive behavior of D. bulbifera in Florida. Nomenclature: Air-potato, Dioscorea bulbifera L. Management Implications: The exotic invasive air potato vine D. bulbifera has become a serious problem for public and private land managers across Florida and beyond by blanketing and smothering native vegetation. Despite its common occurrence in Florida, there are no published research data related to the role of propagule biomass on the resulting vines' growth rate, biomass, and invasive biological traits. We conducted common garden studies using vegetative propagules (parent bulbils) ranging from small to large biomass and examined the growth and biomass of the plants generated from these bulbils. Biomass of the parent bulbils of both morphotypes was positively correlated with total vine lengths, growth rates, and the number of branches, leaves, and bulbils. The vine longevity of plants generated by bulbils of all sizes was not significantly different. However, the total vine length, vine growth rates, and the number of branches, leaves, and bulbils increased with the biomass of the parent bulbils. Plants recruited by smaller bulbils allocated a major proportion of total biomass to leaves and tubers compared to the stems and bulbils, whereas the larger bulbils allocated a greater proportion of total biomass to bulbils and leaves compared to tubers and stems. Total vine length was positively correlated with the total plant biomass. Reduced vine length should have concomitant negative impacts on leaf and bulbil production. These reductions should, in turn, negatively affect (1) plant biomass and the number of branches and leaves that are responsible for causing smothering effects on invaded plant communities and (2) bulbil production that will have direct negative impact on plant recruitment and invasion of the new areas. Therefore, control measures that reduce seasonal vine length should reduce the quantity of bulbils and hence invasiveness of D. bulbifera vines in Florida.


Paraiso O.,Methods Development and Biological Control | Smith T.R.,Methods Development and Biological Control | Hight S.D.,U.S. Department of Agriculture | Davis B.J.,Methods Development and Biological Control
Florida Entomologist | Year: 2014

This study compared several biological parameters of native cactus moth, Melitara prodenialis, reared on an artificial versus the natural diet of Opuntia spp. cladodes. Results suggest that the current artificial diet developed for mass rearing C. cactorum can provide nutritional value for the rearing of Melitara spp. native cactus moths. Overall, rearing M. prodenialis on the artificial diet was more successful than on Opuntia cladodes and required less time and labor. Mass rearing of M. prodenialis using artificial diet should improve once subsequent generations become adapted to laboratory rearing conditions.

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