Seasonal diversity of soil microarthropods in two different vegetable plots of Aligarh-India

Soil microarthropods are intimately linked with health and fertility of soil as well as plant productivity. In India, despite their rich faunal diversity, information on soil microarthropods diversity and interactions with variety of edaphic factors is extremely limited. The present study has been carried out to observe seasonal diversity of soil microarthropods in two different vegetable plots at Aligarh. The two vegetable plots chosen in this study where predominantly Tomato (Lycopersicom esculentum) and Brinjal (Solanum melongena, family-Solaneceae) have been grown and sapling has been sown in the month of April when plants attained a height of approximately 6″. The samples were collected randomly from a depth of 5cm. @ of four samples per month for a period of one year. All microarthropods extracted with the help of Tullgren funnel apparatus. Among soil microarthropods collected, Collembolans have highest average monthly density (15.20 inds./sample) in brinjal plot and greatest abundance (18.7inds./sample) in tomato plot. A highly significant negative correlation was recorded between Collembolans population with reference to soil temperature (r = −0.867, P<0.05), whereas available nitrogen showed a positive correlation (r = 0.847, P>0.05). Interestingly, at neutral pH level, the highest population of Collembolans as well as Acari(mites) were recorded. During spring and winter months, there was a peak population buildup of Collembola and Acarina, whereas a sharp decline was recorded in summer months. So, this study clearly establishes that habitat difference as well as edaphic factors plays an important role along with seasonal parameters on their diversity.

Annual juvenile recruitment of spiny lobsters, Panulirus argus (Decapoda, Palinuridae), in a shallow seagrass bed and a deeper hard bottom off western Puerto Rico

We found 158 juvenile Caribbean spiny lobsters (Panulirus argus) recruiting over a year into 10 artificial shelters in shallow (2-3 m) seagrass beds, but none recruiting into 10 shelters on deeper (approximately 10 m) hard bottom. Spiny lobster juveniles were observed at 10 m or greater depth in submerged fish cages. They may have been strained out by currents rather than naturally recruiting. A large number of these cages inshore could impede natural lobster recruitment. One of the shallow shelters recruited most (85/158) of the juveniles and two shelters recruited most of all (118/158). With no discernable natural habitat difference, we assume that early recruitment into those shelters and the “guide effect” may have been responsible for these preferences. Previous Caribbean studies found the maximum settling periods of juveniles in August to December. Our results were similar with the exception of having more recruits one month later (August to January). Shelters with covers had more juveniles than those without covers; however, this result was largely due to the preponderance of juveniles in one shelter.

Habitat difference in food abundance possibly causes within-population variation in the timing of breeding in the Madagascar paradise flycatcher (Terpsiphone mutata)

Within-population variation in the timing of breeding in the insectivorous Madagascar paradise flycatcher, Terpsiphone mutata (L., 1766), was investigated in a dry forest of northwestern Madagascar. The study area was divided into two sites (namely, A and B) based on the distance from the waterside. An examination was conducted to determine whether the date of egg laying varies between the two sites, and if it does vary, what are the environmental factors that affect the variation. The females started egg laying significantly earlier at site B than at site A. The two sites are located in a continuous forest; hence, photoperiod and precipitation would not differ between them. The number of insects was higher at site B than at site A. The difference in the temperature was not considered to be the cause of the variation in the date of egg laying. Age structure of the females was not likely to differ between the sites. Therefore, the variation in the date of egg laying is considered to be caused by the difference in food abundance that is associated with the relative distance from the waterside.

Etudes sur les Acanthodactyles de Tunisie: VII - Les Acanthodactyles de l'Extrême-Sud tunisien

A multidimensional analysis of 34 characters of the colouring and scale pattern, providing 101 mathematical variables, applied to 77 Acanthodactylus collected in ten field stations in the Saharien Far-South of Tunisia, reveals a gradual and continuous morphological variation from populations of Acanthodactylus inornatus (with the back and sides of their body blackly reticulated and short legs) to populations with a A. longipes habitus (orange light body with small dorsal white spots, faint or nul black marks on their flanks and longer legs). Variation axis, approximately directed from North to South, also express an habitat difference between the populations dwelling on the reg nebkhas and sandy knolls in the beds and edges of the rivers (oueds) and those restricted to the high sand dunes of the Great Eastern Erg. The taxonomic status of the Acanthodactylus populations living in the Southern Tunisia should obviously be revised in relation with a high and mostly uncorrelated variability of the morphological characters of diagnostic use.

An Investigation of the Distribution and Field Habits of the Varied Carpet Beetle, Anthrenus verbasci (L.) (Col., Dermestidae) in Britain, with comparative Notes on A. fuscus Ol. and A. museorum (L.)

Conclusions concerning the distribution and field habits of Anthrenus verbasci (L.), A. fuscus Ol. and A. museorum (L.), are based upon the results of three surveys.The first survey comprised the collection of adults of Anthrenus from attractive flowers, e.g., hogweed, Heracleum sphondylium, in various localities furing June and July. This showed that:—A. Verbasci occurred in large numbers only in the suburban areas of south-east England, extending also to the west along the south coast.A. fuscus was generally distributed in all types of locality in the south reaching a peak abundance in the vicinity of farms. Its members diminished rapidly towards the north.A. museorum occurred in small numbers only, often accompanying A. fuscus.The second survey comprised the collection of larvae from natural habitats and included results from an earlier survey of certain birds' nests. This showed that:—A. verbasci was characteristically an inhabitant of dry birds' nests.A. fuscus was usually found feeding on dead insects around spiders' webs, under the bark of trees, etc.A. museorum occurred in small numbers in company with A. fuscus.The habitat difference between A. verbasci and A. fuscus was sharply defined. Only very rarely was one sspecies found in the habitat typical of the other.