objective: taro (colocasia esculenta l. schott) is a perennial root crop that belongs to araceace family.  it is widely cultivated as a staple food in africa, asia and pacific islands. despite its importance, there is limited information on many aspects of the crop. in order to obtain data that can support improved and sustainable taro production, a field trial was conducted to study the effect...

To understand the efficacy of emamectin benzoate, avermectin, milbemectin, and thiacloprid on the reproduction and development of Bursaphelenchus xylophilus, seven parameters, namely population growth, fecundity, egg hatchability, larval lethality, percent larval development, body size, and sexual ratio, were investigated using sublethal (LC20) doses of these compounds in the laboratory. Emamec...

Defining the scale of connectivity, or exchange, among marine populations and determining the factors driving this exchange are pivotal to our understanding of the population dynamics, genetic structure, and biogeography of many coastal species. Using a high-resolution biophysical model for the Caribbean region, we report that typical larval dispersal distances of ecologically relevant magnitud...

bionomics of aphis gossypii glover and its predators coccinella septempunctata l. and hippodamia variegata goeze were studied in varamin (tehran province) during 11th may to 5th october 2006 on eggplant crop, with the interaction (density dependence) between the aphid and either of the predators determined. the reliable sample size (number of leaves) with a maximum variation of 6.73% was about ...

Between September 1996 and May 1998, the influence of habitat complexity and larval supply on the establishment of early post-settlement populations of red king crab (Paralithodes camtschaticus) was studied in situ in Auke Bay, southeast Alaska. Dive transects and suction dredge surveys conducted during fall 1996 and spring 1998 indicated that late age 0 to 1 1 red king crabs were located only ...

As a result of numerous successful invasions by bothAedes albopictus (Skuse) andAdes aegypti (L.), the current worldwide distributions of these mosquito species overlap. Shared larval habitats and shifts in the distribution and abundance of resident A. albopictus or A. aegypti after the establishment of the other species suggest that competitive displacement occurs. Experiments on larval compet...

Management and conservation can be greatly informed by considering explicitly how environmental factors influence population genetic structure. Using simulated larval dispersal estimates based on ocean current observations, we demonstrate how explicit consideration of frequency of exchange of larvae among sites via ocean advection can fundamentally change the interpretation of empirical populat...

Defence from parasites and pathogens involves a cost. Thus, it is expected that organisms use this only at high population densities, where the risk of pathogen transmission may be high, as proposed by the "density-dependent prophylaxis" (DDP) hypothesis. These predictions have been tested in a wide range of insects, both in comparative and experimental studies. We think it pertinent to conside...