Diversity of Arthropods and Population Dynamics of Diamondback Moth Visiting Organically Cultivated Cabbage

The biodiversity of insects visiting cabbage and population dynamics of diamondback moth was studies on Golden acre variety of cabbage. The experiment was conducted at experimental plot of Ramakrishna Mission Vivekananda Educational and Research Institute, Morabadi, Ranchi, during October to January, 2018-19. During the experiment, Bihar hairy caterpillar, Diamondback moth, Cabbage aphid, Cabbage maggot, Cabbage butterfly, Tobacco caterpillar, Ladybird beetle, Rice bug, Cricket and Spider were noticed. The population of diamondback moth was positively correlated with maximum, minimum, average temperature and maximum relative humidity and negatively correlated with minimum RH, wind speed; rainfall. The highest larval population of was recorded during 1st week of January (1st Standard Meteorological Week, SMW).

Population variability of three Delia species (Diptera: Anthomyiidae) from the same agricultural habitat in Québec, Canada

Long-term trap catches of seedcorn maggot, Delia platura (Meigen), onion maggot, Delia antiqua (Meigen), and cabbage maggot, Delia radicum (Linnaeus) (Diptera: Anthomyiidae), were used to test the hypothesis that related species have more similar population variability than unrelated ones. Annual abundance was estimated from trap catches for 32 years (two species) or 17 years (one species). Population variability was quantified as PV, a proportion between 0 and 1. The three Delia Robineau-Desvoidy species had PV values of 0.51–0.55 that did not differ significantly. These PV values were found to differ significantly from two unrelated species studied over the same time period in the same habitat, which had PV values of 0.39 and 0.67. The hypothesis that related species have more similar population variabilities than unrelated species in the same habitat was supported. These data strengthen the view that PV is a species-specific trait reflecting the adaptation of life histories to their habitat, with related species showing more similar adaptations than unrelated species. The polyphagous and saprophagous seedcorn maggot had PV similar to the two oligophagous herbivores, casting doubt on the hypothesis that more generalist feeders have less variable populations than more specialised feeders.