scholarly journals OBSERVATIONS ON SOME INSECTS ASSOCIATED WITH SUGARCANE IN PUERTO RICO

1969 ◽  
Vol 21 (2) ◽  
pp. 103-114
Author(s):  
F. M. Wadley

Survey work in 1935-36 on sugarcane insects of Puerto Rico, especially those which may transmit mosaic disease, is described. Previous work is cited; climate, geography, and methods are outlined briefly. Aphis maidis was found to be rather abundant on tasseled corn, sparingly present on several grasses, and scarce on cane. Hysteroneura setariae was moderately abundant on some grasses, occasional on cane along the south coast, and rare on cane elsewhere. Sipha flava was widespread on cane, sometimes injurious, and small numbers occurred on grasses. Carolinaia cyperi was found in moderate numbers on a sedge. A. maidis was most numerous in the rainy season, the other three in the dry season. Mealybugs were numerous, especially on mature cane. Saccharosydne saccharivora was widespread but seldom numerous on cane. Some minor insect notes are recorded. Aphis maidis seems likely to be important in mosaic dissemination, because more abundant in areas of rapid than of slow spread. Hysteronera and Carolinaia seem less likely to be important, and the other insects named seem unlikely to be implicated at all. Some aphids not breeding on grasses may be important.

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
N. Mbahin ◽  
S. K. Raina ◽  
E. N. Kioko ◽  
J. M. Mueke

A study on the life cycle of the silkmothAnaphe panda(Boisduval) was conducted in two different habitats of the Kakamega Forest in western Kenya: Ikuywa, an indigenous forest, and Isecheno, a mixed indigenous forest. Eggs were laid in clusters, and the incubation period ranged from 40 to 45 days. Larvae fed onBridelia micrantha(Hochst) and passed through seven instars. The developmental period took between 83 to 86 days in the dry season and 112 to118 days in the rainy season. The pupal period ranged between 158 and 178 days in the rainy season and, on the other hand, between 107 and 138 days in the dry season. But the later caught up in development with those that formed earlier. Moths emerged from mid-October until mid-May. Longevity of adultAnaphe pandamoths took between 4 and 6 days, but generally females seemed to live longer than males. The moth also seems to have higher lifespan in the indigenous forest compared to the mixed indigenous forest.


The chief circumstance that induced Capt. Flinders to think his observations Upon the marine barometer were worthy of attention, was the coincidence that took place between the rising and falling of the mercury, and the setting in of winds that blew from the sea and from off the land, to which there seemed to be at least as much reference as to the strength of the wind or the state of the atmosphere. Our author’s examination of the coasts of New Holland and the other parts of the Terra Australis, began at Cape Leuwen, and con­tinued eastward along the south coast. His observations, which, on account of their length, we must pass over, show, that a change of wind from the northern half of the compass to any point in the southern half, caused the mercury to rise; and that a contrary change caused it to fall. Also, that the mercury stood considerably higher When the wind came from the south side of east and west, than when, in similar weather, it came from the north side.


1998 ◽  
Vol 14 (2) ◽  
pp. 191-200 ◽  
Author(s):  
J. W. Hansen ◽  
F. H. Beinroth ◽  
J. W. Jones
Keyword(s):  
Land Use ◽  

1917 ◽  
Vol 4 (4) ◽  
pp. 150-157 ◽  
Author(s):  
Arthur Holmes ◽  
H. F. Harwood

Almost due west of Mozambique Island, at a distance of about forty-two miles from the sea, the military road from Mosuril to Nampula crosses the Ampwihi River, an important tributary of the Monapo. During the dry season the stream is reduced to a string of stagnant pools, separated by long reaches of sand and gravel that here and there are interrupted by outcrops of the underlying formations. Throughout the greater part of its course the Ampwihi flows through a region in which gneisses persist with monotonous regularity, the only variation being that due to occasional intrusions of granite and of still later pegmatite dykes. At the point where the military road crosses the narrow channel a welcome diversion is introduced by the presence of a dark compact dyke about 10 feet in thickness. The dyke appears on the right-hand bank and crosses obliquely to the other side, taking a N.N.W.–S.S.E. course across the strike of the older rocks. Upstream, about seventy yards to the south-east, the Ampwihi bends to the south-west, so that it returns towards the dyke, which is again exposed across its sandy floor. The dyke was traced by Mr. E. J. Wayland in July, 1911, for a distance of altogether 200 yards, and was examined by Mr. D. Alex. Wray and later by myself during the same year. It is clearly the latest rock of the district, and is intruded along a line of fault, for in two cases pegmatite dykes seen on the eastern side are broken across and reappear on the western side with a well-marked northerly displacement.


1969 ◽  
Vol 72 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Megh R. Goyal

The Hargreaves and Samani model was used to estimate monthly potential evapotranspiration (PET) for Central Aguirre, Fortuna and Lajas substations and Magueyes Island located on the south coast of Puerto Rico. The model uses maximum, minimum and average temperatures. Daily PET varies from 3.68 to 5.37 mm/day in the region with minimum in December and maximum in July. Annual PET was 1613.3 mm/year for Central Aguirre, 1653.5 for Fortuna, 1846.9 for Lajas, 1857.9 for Magueyes Island, with a regional average of 1704.6. These PET values can be used to estimate crop water requirements for vegetables and fruits, to plan irrigation and water management projects, and to schedule irrigation in the semiarid region of Puerto Rico.


1969 ◽  
Vol 92 (3-4) ◽  
pp. 207-214
Author(s):  
Lymari M. Calero-Toledo ◽  
Raúl Macchiavelli ◽  
Ángel L. González

The corn earworm, Helicoverpa zea (Boddie), is the major insect pest of corn, Zea mays L., in Puerto Rico. The objective of this study was to design a sequential sampling plan with fixed precision levels for H. zea (Boddie) in corn fields on the south coast of Puerto Rico. For determining the presence (= 1) or absence (= 0) of H. zea eggs, 25 corn plants were randomly sampled from December 2003 to March 2004. Data were analyzed by using the beta binomial distribution. Critical density levels of 0.10 and 0.08 infested plants, before and after the emergence of ear silks, were used for Iwao's and converging lines formulae. A converging line sampling plan is recommended because it selected a smaller average sample size. This plan can be used to make cost effective control decisions on field corn in Puerto Rico.


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