No abstract

Bermudagrass (Cynodon sp.) and paspalum (Paspalum vaginatum) genotypes were evaluated in laboratory, greenhouse, and field experiments for potential resistance to the common turfgrass pests, tawny mole cricket (Scapteriscus vicinus Scudder) and southern mole cricket (Scapteriscus borellii Giglio-tos). Potential resistance among 21 seashore paspalums to both insects in an environmental chamber at 27 °C, 85% relative humidity, and 15 hours light/9 hours dark) revealed that Glenn Oaks `Adalayd' was least tolerant of cricket injury, while 561-79, HI-1, and `Excalibur' were most tolerant. Nymphal survival was not influenced by turfgrass type. Plant selections that maintained the highest percentage of their normal growth after 4 weeks of feeding by tawny mole crickets over three separate greenhouse trials were 561-79, HI-1, HI-2, PI-509018, `Excalibur', SIPV-1 paspalums, and `Tifeagle' and `Tifsport' bermudagrasses. Although none of the tested genotypes was highly resistant to tawny mole cricket injury, `TifSport' bermudagrass and 561-79 (Argentine) seashore paspalum were most tolerant.

The first successful inoculative releases of an entomopathogenic nematode, Steinernema scapterisci Nguyen and Smart, for the control of exotic pests, Scapteriscus spp. mole crickets, were made at three pasture sites in Alachua County, Florida in 1985. Based on the evaluation of field-collected crickets, the nematode was established at all sites and persisted for over 5 years. Mean yearly percentage of infected crickets ranged from 0 to 21.4% for individual release sites. Mean adult infection level for all years combined, 10.9%, was significantly greater than that for nymphs (2.5%) and infection levels for Scapteriscus borellii Giglio-Tos, 12.7%, was significantly greater than that for Scapteriscus vicinus Scudder (4.5%) for all years combined. Although 24 h trap catch results indicate mole cricket populations were significantly reduced, the nematode's effect on pest abundance could not be adequately assessed because of the variation in trap catch results and inadequate knowledge about the relationship between trap catch and the mole cricket field populations being sampled. Despite inadequacies in estimating pest abundance, the results indicate S. scapterisci has potential as a biological control agent for pest mole crickets in the genus Scapteriscus.

The muscid shoot-fly Atherigona reversura Villeneuve (Diptera: Muscidae), recently introduced to North America, is reported for the first time from the Neotropical Region: Mexico, Chiapas, Chiapa de Corzo. Information about distribution throughout the continent is summarized. Morphology of the second and third instar larva and puparium is described using light microscopy techniques, including photographs of posterior spiracles and cephaloskeleton as well as line drawings of the latter. Detailed scanning electron microscopy documentation is provided for the following morphological structures of the third instar larva: pseudocephalon; antennal complex; maxillary palpus; facial mask; ventral organ; thoracic and abdominal spinulation; bubble membrane; anal division; and anal plate. Previous descriptions of immature stages of Atherigona Rondani, particularly details of the cephaloskeleton, are revised.