Role of oviposition preference in an invasive crambid impacting two graminaceous host crops.

Department of Entomology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA.
Environmental Entomology (Impact Factor: 1.31). 09/2007; 36(4):938-51. DOI:10.1603/0046-225X(2007)36[938:ROOPIA]2.0.CO;2
Source: PubMed

ABSTRACT Oviposition preference studies of the Mexican rice borer, Eoreuma loftini (Dyar), on sugarcane, Saccharum spp., and rice, Oryza sativa L., showed that drought stressed sugarcane was 1.8-fold more attractive based on egg masses/plant than well watered sugarcane. The E. loftini susceptible sugarcane cultivar LCP 85-384 was 1.6-fold more attractive than HoCP 85-845 based on numbers of eggs per egg mass. Egg masses were 9.2-fold more abundant and 2.3-fold larger on sugarcane than on rice. Rice, however, was preferred to sugarcane on a plant biomass basis. Oviposition on sugarcane occurred exclusively on dry leaf material, which increased under drought stress. Egg masses per plant increased on drought stressed sugarcane and were correlated with several foliar free amino acids essential for insect growth and development. The more resistant (based on injury) but more attractive (based on oviposition) rice cultivar XL8 had higher levels of several free amino acids than the susceptible cultivar Cocodrie. The association of host plant characteristics to oviposition preference is discussed. Projected oviposition patterns relative to sugarcane and rice production areas were estimated for Texas and Louisiana based on the availability of each host in different regions of each state. These results suggest that, where sugarcane and rice co-occur, the majority of eggs would be found on sugarcane early in the season, because of this crop's substantially greater biomass compared with rice. Abundance later in the season would also favor sugarcane; however, the abundance on rice would be greater than expected solely based on host availability, largely because of the greater preference per gram of rice plant dry weight.

0 0
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), a key pest of sugarcane (Saccharum spp.) and rice, Oryza sativa L., in Texas, has not been controlled with chemical insecticides or biological agents, but some sugarcane varieties have shown degrees of resistance. Assessment of selected sugarcane leaf characteristics indicate that preference for oviposition sites is mostly determined by the presence of a leaf fold and secondarily by the availability of dry leaf tissue, both of which are antixenotic nonchemical stimuli. We suggest that breeding sugarcane lines bearing leaves that do not fold on drying could provide substantial antixenotic resistance against the Mexican rice borer. Previously identified antixenotic chemical stimuli, i.e., low quantities or absence of important nutrients in green leaf tissue, only become apparent when resistant and susceptible sugarcane varieties are compared. Varietal differences in oviposition preference, however, were not observed on excised dry leaf tissue, indicating that expression of resistance in terms of chemical stimuli requires detection of biochemicals in nearby living leaf tissue. Excised dry sugarcane leaves retain the two dominant nonchemical oviposition preference stimuli for Mexican rice borers, and the leaves effectively trapped eggs away from intact plants when dry leaves were used as "mulch" at the bottom of greenhouse cages. Under commercial sugarcane field conditions, bundled dry leaves also collected Mexican rice borer eggs. Possible applications of dry sugarcane leaf substrate for egg scouting and for trapping eggs are discussed.
    Journal of Economic Entomology 08/2010; 103(4):1180-6. · 1.60 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: The sugarcane borer, Diatraea saccharalis (F.), is a pest of a variety of graminaceous crops in the southern United States, including sugarcane, maize, and rice in Louisiana. This study examined several aspects of D. saccharalis oviposition behavior on rice (Oryza sativa). The vertical distribution of egg masses on four phenological stages of rice in the field showed that D. saccharalis prefers to oviposit on the uppermost portions of rice plants, regardless of plant stage. In greenhouse choice experiments, females strongly preferred plants at the boot and panicle differentiation stages over plants at the tillering stage for oviposition. Greenhouse studies were also conducted to quantify the oviposition preference of D. saccharalis for different cultivars of. When plants were at the tillering stage, cultivars Cocodrie, Priscilla, Bengal, Cheniere, and CL161 were more preferred than cultivars Jupiter, XL723, and XP744. When plants reached the panicle initiation stage, cultivars Cocodrie, CL161, and Priscilla were more preferred than Bengal, Cheniere, Jupiter, XL723, and XP744. Females also oviposited significantly more egg masses on the adaxial surfaces of rice leaves than on the abaxial surfaces. These results will facilitate scouting and management of sugarcane borer and can be used as a foundation for the development of sugarcane borer resistant cultivars.
    Environmental Entomology 06/2012; 41(3):571-7. · 1.31 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is the key pest of sugarcane (Saccharum spp.) in Texas; it can attack several grassy crop and noncrop host plants and has spread into Louisiana. Through small-plot, commercial field, and pheromone trap experiments, this study demonstrates that the pest uses corn, Zea mays L., more than sugarcane and sorghum, Sorghum bicolor (L.) Moench, but when corn is harvested in late summer, injury to nearby sugarcane strongly increases during the next approximately equal to 2 mo to harvest. Corn was more infested than sugarcane and sorghum in commercial fields regardless of whether sampling occurred on field edges or farther into field interiors. Differences in numbers of infested stalks and in numbers of larval entry holes between field edges and interiors were not detected. We found that Mexican rice borer infestation of corn can cause loss of ears, and lodging, shattering, and complete destruction of maturing stalks. The larger quantities of adult Mexican rice borers captured in pheromone-based traps placed at corn field edges compared with sorghum and sugarcane field edges further indicates that corn is preferred to sugarcane and sorghum. The basis for the pest's attraction to corn and implications to potential range expansion to other U.S. sugarcane-growing regions are discussed.
    Journal of Economic Entomology 10/2012; 105(5):1597-602. · 1.60 Impact Factor


Available from

F P F Reay-Jones