| ultrastructure of the antennal sensilla of aphids. i. coeloconic and placoid sensilla. | an electron microscopical study was made of the coeloconic and placoid sensilla on the antennae of the aphids aphis pomi, macrosiphum euphorbiae, nasonovia ribis-nigri, and pemphigus bursarius. scanning electron microscopy revealed some variation in morphology which may be functionally important but is more likely to reflect the evolution of these species. the placoid sensilla were shown by tranwo or three neurons is surrounded by two ensheathing cells. the ciliary regions of the dendrites pass ... | 1979 | 519733 |
| low-drift nozzles vs. standard nozzles for pesticide application in the biological efficacy trials of pesticides in apple pest and disease control. | the coarse spray air-induction nozzles have documented pesticide drift reducing potential and hence pose lower risk of environmental pollution than the standard fine spray hollow cone nozzles. however, it is questioned that use of the low-drift nozzles might not provide as effective crop protection as the standard nozzles. the objective of work was to assess the pest and disease control efficacy as affected by spray volume rate and nozzle type. the experiment was carried out in apple orchard, cv ... | 2017 | 27720255 |
| functional response of four syrphid predators associated with green apple aphid (hemiptera: aphididae) in laboratory. | aphis pomi de geer, the green apple aphid, is an economic pest of apple and other rosaceae throughout the world. in the present study, functional responses of the syrphids episyrphus balteatus de geer, eristalis tenax(l.), eristalis interruptus (poda), and sphaerophoria scripta (l.), to a. pomi were studied under laboratory conditions to determine their relative predatory potential. the second- and third-instar larvae of the predators were exposed to increasing densities of similar-sized a. pomi ... | 2016 | 26578626 |
| qualitative and quantitative prey requirements of two aphidophagous coccinellids, adalia tetraspilota and hippodamia variegata. | the suitability of two prey species, aphis pomi de geer (hemiptera: aphididae) and brevicoryne brassicae (l.), for two generalist aphidophagous coccinellids, adalia tetraspilota (hope) (coleoptera: coccinellidae) and hippodamia variegata (goeze), at various abundance levels was investigated under laboratory conditions. while both a. pomi and b. brassicae were found to be suitable, the predators performed better when feeding upon b. brassicae. the prey densities affected the developmental paramet ... | 2014 | 25373219 |
| first record of the adventive oriental aphid schizaphis piricola (matsumura, 1917) (hemiptera, aphididae) in europe. | the oriental aphid schizaphis piricola (matsumura) is recorded for the first time in europe, on the ornamental pear tree pyrus calleryana in landscaped areas in madrid (spain). data on the morphology of the forms on primary host (apterous and alate fundatrigeniae and fundatrices), and their biology and distribution are given. the keys for identifying species of schizaphis (schizaphis) in the iberian peninsula are updated. two species of aphids are also recorded for the first time on pyrus caller ... | 2011 | 21594084 |
| plant cues for aphid navigation in vascular tissues. | the ability of aphids to detect and find sieve tubes suggests that aphids receive cues for sieve-tube recognition by taking samples. specific natural conditions such as ph value, sugar species and concentration, viscosity, and oxygen pressure may enable sieve-tube detection. we tested the preference of megoura viciae and myzus persicae for potential plant-borne orientation parameters in artificial choice-chamber systems. both species preferred sucrose (in comparison with fructose, glucose, raffi ... | 2010 | 21075945 |
| relationship of insecticide tolerance to esterase enzyme activity in aphis pomi and aphis spiraecola (hemiptera: aphididae). | green apple aphid, aphis pomi de geer, and aphis spiraecola patch (both hemiptera: aphididae), are sympatric aphid species that are pests of apples (malus spp.) and other crops. a. spiraecola has been shown to be significantly more tolerant to several insecticides compared with a. pomi. to establish the mechanisms contributing to this difference in insecticide response, clones of both species were collected from british columbia, canada, and washington state. dose-response bioassays were conduct ... | 2010 | 20429451 |
| aphis pomi (hemiptera: aphididae) population development, shoot characteristics, and antibiosis resistance in different apple genotypes. | in high-value crops such as apple, malus x domestica (borkh.), insecticidal pest control is of high relevance. the use of resistant apple cultivars can increase the sustainability of pest management in apple orchards. besides variation in plant chemistry that may influence plant resistance by antibiosis or antixenosis, plant growth characteristics also can affect plant susceptibility to pests such as aphids. variable susceptibility to the apple aphid, aphis pomi de geer (hemiptera: aphididae), h ... | 2008 | 18767746 |
| estimating development of aphis pomi (de geer) (homoptera: aphididae) using linear and nonlinear models. | the development period of immature stages of the green apple aphid, aphis pomi (de geer) (homoptera: aphididae), at 6 constant temperature regimes (20, 24, 28, 30, 32, and 34 degrees c) were modelled to determine mathematical functions for simulating aphid development. 10 models (one linear and nine nonlinear), were used to describe the relationships between temperature and development rate of the different instars and stages of aphis pomi (degeer) at constant temperatures. all models (except lo ... | 2006 | 17385529 |
| susceptibilities of apple aphid and spirea aphid collected from apple in the pacific northwest to selected insecticides. | laboratory bioassays using leaf disks of apple dipped in test solutions of insecticides demonstrated that the apple aphid, aphis pomi de geer, and the spirea aphid, aphis spiraecola patch, differed significantly in susceptibility to a number of insecticides registered for control of aphids on apple (malus spp.). compared with a. pomi, a. spiraecola was approximately four- and three-fold less susceptible to pirimicarb and lambda-cyhalothrin, respectively, whereas there was little difference in re ... | 2006 | 16937694 |
| x-linked heterochromatin distribution in the holocentric chromosomes of the green apple aphid aphis pomi. | chromatin organization in the holocentric chromosomes of the green apple aphid aphis pomi has been investigated at a cytological level after c-banding, nor, giemsa, fluorochrome staining and fluorescent in situ hybridization (fish). c-banding technique showed that heterochromatic bands are exclusively located on x chromosomes. this data represents a peculiar feature that clearly contradicts the equilocal distribution of heterochromatin typical of monocentric chromosomes. moreover, silver stainin ... | 2005 | 16011007 |
| baseline susceptibilities to imidacloprid for green apple aphid and spirea aphid (homoptera: aphididae) collected from apple in the pacific northwest. | susceptibilities to the neonicotinyl insecticide imidacloprid were determined for clones of apple aphid, aphis pomi de geer, and spirea aphid, aphis spiraecola patch, collected from conventional and organic apple orchards and from crab apple and wild apple in washington state and british columbia over a period of 6 yr. for aphids collected during 1996--1998, adults were dipped in test solutions by using the food and agriculture organization protocol, and third instars and adults were reared on t ... | 2005 | 15765682 |
| comparison of bioassay techniques for determining baseline susceptibilities to imidacloprid for green apple aphid (homoptera: aphididae). | the susceptibility of a clone of green apple aphid, aphis pomi (de geer), to the neonicotinyl insecticide imidacloprid was determined by direct and indirect bioassay techniques. aphid numbers were assessed on potted apple seedlings treated with various concentrations of imidacloprid, adults were dipped in test solutions as per the food and agriculture organization protocol, or nymphs and adults were reared on treated apple leaf disks. effective concentrations required to kill half of the test po ... | 2003 | 14977128 |