The cottonwood leaf beetle, Chrysomela scripta F., is the most serious defoliator of young plantation-grown Populus in the eastern United States, yet there is a paucity of data on larval feedingperformance acrossPopulus clones used in treebreeding. Field experimentswere conducted in 1998 and 1999 to determine the overall feeding performance of larval C. scripta on 8 Populus selections from a pe...

For many marine fish, intense larval mortality may provide considerable opportunity for selection, yet much less is known about the evolutionary potential of larval traits. We combined field demographic studies and manipulative experiments to estimate quantitative genetic parameters for both larval size and swimming performance for a natural population of a common coral-reef fish, the bicolor d...

1. Hosts experiencing frequent variation in density are thought to benefit from allocating more resources to parasite defence when density is high (‘densitydependent prophylaxis’). However, high density conditions can increase intra-specific competition and induce physiological stress, hence increasing host susceptibility to infection (‘crowding-stress hypothesis’). 2. We studied monarch butter...

Sparidentex hasta is superior over Acanthopagrus latus in market price and growth rate while A. latus is superior over S. hasta in number of eggs produced, hatching rate, larval survival and eventually number of fry produced. Thus, the possibility of obtaining a hybrid with close resemblance in appearance and growth rate to S. hasta and being superior in fry production resembling A. latus would...

Spodoptera frugiperda J.E. Smith (fall armyworm) is considered one of the most destructive pests of corn throughout the Americas. Although this pest has been extensively studied, little is known about its larval movement and feeding behavior on reproductive compared to vegetative corn stages. Thus, we conducted studies with two corn stages (R1 and R3) and four corn plant zones (tassel, above ea...

Insects use chemosensory cues to feed and mate. In Drosophila, the effect of pheromones has been extensively investigated in adults, but rarely in larvae. The colonization of natural food sources by Drosophila buzzatii and Drosophila simulans species may depend on species-specific chemical cues left in the food by larvae and adults. We identified such chemicals in both species and measured thei...

As a ubiquitous, persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has the potential to cause lethal deformities in larval fishes. Few studies have examined its impacts on larval growth and craniofacial development in conjunction with feeding capability. The authors used morphological and behavioral assessments to demonstrate that feeding capability of larvae is i...

Ocean acidification, characterized by elevated pCO₂ and the associated decreases in seawater pH and calcium carbonate saturation state (Ω), has a variable impact on the growth and survival of marine invertebrates. Larval stages are thought to be particularly vulnerable to environmental stressors, and negative impacts of ocean acidification have been seen on fertilization as well as on embryonic...

Ground covers were tested for 3 consecutive yr for their effect on Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), abundance and behavior in a blueberry planting. Alsike clover (Trifolium hybridum L.), buckwheat (Fagopyrum esculentum Moench), perennial ryegrass (Lolium perenne L.), and bare ground were compared within row-middles for their effect on abundance of adult fema...

The dispersal potential of crown-of-thorns starfish (CoTS) larvae is important in understanding both the initiation and spread of population outbreaks, and is fundamentally dependent upon how long larvae can persist while still retaining the capacity to settle. This study quantified variation in larval survivorship and settlement rates for CoTS maintained at three different chlorophyll concentr...