New tropical pumpkin (Cucurbita moschata Duchesne) genotypes were evaluated for yield, flesh (mesocarp) color, pest resistance and seed production as compared with the standard cultivar Soler in six field trials at three Puerto Rico locations during a two-year period (2003-2005). Genotypes included an open-pollinated population (PRShortvine-1) and four lines (E0305-1, E0305-2, E0305-3 and E0305-4) with a semi-bush growth habit, as well as a new long-vine open-pollinated population (PRLongvineSLR). Various within-row (0.9- and 1.9-m) and between-row (1.9- and 3.8-m) planting distances were tested. Not all genotypes nor planting distances were included in each trial. PRLongvineSLR was partially resistant to the melonworm (Diaphania hyalinata), whereas lines E0305-1 and E0305-2 were very susceptible. These same lines, as well as PRShortvine-1, were also susceptible to downy mildew, Pseudoperonospora cubensis. All genotypes produced similar yields. Within-row planting distance generally had no effect on fruit weight, fruit number and yield. All new genotypes had good flesh thickness (>4 cm) and small fruit cavities. Flesh color of PRShortvine-1 and PRLongvineSLR tended to be more orange than that of Soler. Lines E0305-3 and E0305-4 had poor seed production, whereas seed production in fruits of PRShortvine-1 and PRLongvineSLR was similar to that of Soler. Despite some shortcomings, PRShortvine-1 and PRLongvineSLR are two advanced open-pollinated populations that should be considered for formal release on the basis of their field performance, good fruit quality and ability to produce profitable amounts of seed in a seed production program.

The arrival of the invasive Asian lime swallowtail, Papilio demoleus L., in Puerto Rico has prompted the need for a better understanding of its life cycle, and its control options under local citrus-producing conditions. Our results show that P. demoleus has a life cycle of approximately 30 days. From oviposition, eggs hatch in three days. Larval instar durations are 3, 2, 3, 3, and 5 d for larval stages 1 to 5, respectively. Pupal stage lasts approximately 12 days. Head capsule measurements for instars 1 to 4 are similar in males and females. Last instar females tend to be larger than males. Our data suggest that 12 or more generations are possible under local conditions. Acute stomach toxicity tests on third instar larvae indicate that spinosad and Bacillus thuringiensis subs, kurstaki cause 100% mortality in most concentrations tested. Other insecticides were not effective. Possible advantages of using these products are discussed in light of initiatives to use reduced risk pesticides and biologically-based pesticides.

NEW REPORT OF A LEAF BEETLE PEST FROM NORTH AMERICA IN PUERTO RICO: DIABROTICA BALTEATA LE CONTE (COLEOPTERA: CHRYSOMELIDAE) AND ITS CHEMICAL CONTROL

HIGHER PLANTING DENSITY INCREASES YIELD OF SEMI-BUSH TROPICAL PUMPKIN

Velvet bean [Mucuna deeringiana (Bort.) Meer.], pigeon pea [Cajanus cajan (L.) Huth], sorghum [Sorghum bicolor (L.) Moench.] and tropical pumpkin or calabaza [Cucurbita moschata (Duchesne) Poir.] were evaluated as cover crops for the control of nutsedges in rotation with onion (Allium cepa L.) at the Lajas Agricultural Experiment Station during the years 1998-99 and 1999-2000. In each year of study, the four cover crops were grown until mature stage, and plant residue was disked or removed from soil surface before onion planting. Cover crop species had no significant influence (P < 0.05) on nutsedge density, mainly represented by Cyperus rotundus L. and C. esculentus L., neither six weeks before onion planting nor after nine weeks of cropping during 1998-99. Disc incorporation of all cover crops suppressed nutsedge density more than removal of plant residues from soil surface. Onion produced greater yield (30,030 kg/ha) after calabaza rotation than after pigeon pea (21,090 kg/ha) or sorghum (18,940 kg/ha) in 1998-99. In 1999-2000, plots grown with velvet bean, pigeon pea and calabaza had less nutsedge than the untreated controls two weeks before incorporation of plant residues. Plots with these three cover crops also had lower density of nutsedges than plots with sorghum. Nutsedge density was not significant at three, six, and 10 weeks after onion planting. In 1999-2000, onion yields among cover crop rotations were not significantly different, with an average of 5,837 kg/ha. Cover crop allelopathy, as well as nutsedge interference, may have reduced onion production during the second year of planting.