scholarly journals Occurrence, development and natural enemies of cecidogenous generations of Pemphigus gairi Stroyan (Sternorrhyncha, Pemphigidae)

2012 ◽  
Vol 50 (No. 9) ◽  
pp. 415-438 ◽  
Author(s):  
J. Urban

The paper deals with the occurrence, development and natural enemies of the cecidogenous aphid Pemphigus gairi Stroyan (Pemphigidae). The aphid abundantly occurred on leaves of Populus nigra and P. nigra var. italica in Brno in 2003. It was described from England and no information on its occurrence is available in literature from continental Europe. It refers to a holocyclic and heteroecious species. In localities under study, larvae of fundatrices hatched mainly in the last decade of April. Through their sucking on the abaxial face of freshly unfolded leaves of poplars, species-unspecific lengthwise tile-like galls originate on the adaxial face of leaves (near the central leaf vein). During 12 to 14 days, fundatrices mature in galls of an average length and width 11.2 and <br />3.9 mm, respectively. Adults live about 1.5 months, namely max. until mid-July. They produce on average 75.6 fundatrigeniae which mature to winged migrantes alatae in the course of 16 days. In the period of hatching the first migrants (at the end of May), galls grow up to the final length of about 11.8 mm and width 4.7 mm. In primary slit-shaped caps on the abaxial face of leaves, migrants leave the galls through emergence holes. In a secondary host (Aethusa cynapium, Daucaceae), they produce on average about <br />17.5 larvae of exules. Owing to natural enemies (above all true bugs of the species Anthocoris minki), aphids die in 90% of galls.

1981 ◽  
Vol 113 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Susan H. Claflin ◽  
Douglas C. Allen

AbstractAncylis discigerana (Walker) is a univoltine leaf folder of yellow birch. Final instar larvae overwinter in litter and pupate from mid-April through mid-May. Adults emerge in early June and deposit single eggs on the upper surface of a leaf, usually on a major leaf vein or other small depression in the epidermis. The first two instars skeletonize the lower surface of a leaf, beneath a sheet of silk that is constructed between two lateral veins. Third-instar larvae move to the upper surface of a different leaf and fold it lengthwise. Larvae feed on the upper epidermis within the fold until leaf-fall. Life stages are described.An egg parasitoid, Trichogramma minutum Riley, and a larval parasitoid, Apanteles polychrosidis Viereck, were the major natural enemies in the population studied.A key is presented for three species of Ancylis found on yellow birch.


2019 ◽  
Vol 48 (No. 6) ◽  
pp. 248-270 ◽  
Author(s):  
J. Urban

In 2001, galls were analysed of Pemphigus spyrothecae Pass. taken in one- to three-week intervals from Populus nigra and P. nigra var. italica at 4 localities in Brno. Fundatrices matured in the first half of June and during the first half of summer produced about 50 offsprings. Virgines produced about 10 offsprings which grew up in winged sexuparae. The winged individuals started to occur in galls from the beginning of August. In galls with intact development, on average 500 aphids developed. Galls with intact development on P. nigra var. italica reached larger average dimensions and contained at least by 4% more aphids than galls on P. nigra. About 5% of fundatrices died already in the 1st instar and other 3 to 6% in higher instars by the beginning of reproduction. At localities under investigation, 7.5 to 39.0% of galls on P. nigra and 3.9 to 13.7% of galls on P. nigra var. italica were occupied by the fly Leucopis puncticornis Meig. (Chamaemyiidae). About 24.3 to 32.2% of galls on P. nigra and 23.3 to 49.3% of galls on P. nigra var. italica were occupied by the bug Anthocoris minki Dohrn (Anthocoridae). Hover flies Heringia heringi (Zett.) and Pipiza festiva Meig. (Syrphidae) killing aphids in 3.8 to 30.4% of galls on P. nigra and 6.5 to 6.8% of galls on P. nigra var. italica were an important regulator. In August (i.e. at the beginning of the formation of winged sexuparae), the majority of galls opened through primary slit-shaped or oval emergence holes. A part (7.8 to 19.5%) of galls with so far intact development, however, remained closed and all aphids contained in them died. Diseases (particularly mycoses) often participated in the accelerated dying of aphids. The effect of mortality factors on the gall size differentiation was evaluated in details. The galls do not cause any leaf area reduction. In the case of mass outbreak, they decrease decorativeness of poplars in street alleys. In August and September, liquid excrements fall out from the galls (honeydew) polluting the environment in villages and housing estates.


2012 ◽  
Vol 49 (No. 8) ◽  
pp. 359-379 ◽  
Author(s):  
J. Urban

The paper deals with the occurrence, development, natural enemies and harmfulness of a heteroecious aphid Eriosoma (= Schizoneura) ulmi (L.) which showed outbreaks in elm Ulmus glabra Huds. in Moravia in 2002. At main localities under study in B&iacute;lovice nad Svitavou and Brno-Jundrov, the aphid damaged about 63% leaves. Larvae of fundatrices hatched from mid-April and their development from hatching to maturity took about 14 days. Mature fundatrices occurred in May and reproduced for a period of 14 days. Their average physiological fecundity amounted to 311 larvae and ecological fecundity 291 larvae. Migrantes alatae occurred in galls from 18 May to 15 June and their physiological fecundity was about 22 larvae. Leaves were damaged even by 3 galls of an average length of 41 and width 11 mm. Sucking affected on average 11 cm<sup>2</sup>, i.e. 27% (in case of the occurrence of 2 or 3 even 100%) leaf area. Natural enemies killed 90% aphids. A bug Anthocoris confusus Reut. killing aphids in 80% galls was the most effective control agent. Its eggs occurred from 25 April to 25 May and nymphs from 3 May to 25 June. Larvae of Syrphidae [mainly Syrphus ribesii (L.)] killed the aphids in 4 and birds in 6% galls. E. ulmi should be considered to be an important occasional pest of orchards and forests.


Swiss Surgery ◽  
2002 ◽  
Vol 8 (6) ◽  
pp. 255-258 ◽  
Author(s):  
Perruchoud ◽  
Vuilleumier ◽  
Givel

Aims: The purpose of this study was to evaluate excision and open granulation versus excision and primary closure as treatments for pilonidal sinus. Subjects and methods: We evaluated a group of 141 patients operated on for a pilonidal sinus between 1991 and 1995. Ninety patients were treated by excision and open granulation, 34 patients by excision and primary closure and 17 patients by incision and drainage, as a unique treatment of an infected pilonidal sinus. Results: The first group, receiving treatment of excision and open granulation, experienced the following outcomes: average length of hospital stay, four days; average healing time; 72 days; average number of post-operative ambulatory visits, 40; average off-work delay, 38 days; and average follow-up time, 43 months. There were five recurrences (6%) in this group during the follow-up period. For the second group treated by excision and primary closure, the corresponding outcome measurements were as follows: average length of hospital stay, four days; average healing time, 23 days; primary healing failure rate, 9%; average number of post-operative ambulatory visits, 6; average off-work delay, 21 days. The average follow-up time was 34 months, and two recurrences (6%) were observed during the follow-up period. In the third group, seventeen patients benefited from an incision and drainage as unique treatment. The mean follow-up was 37 months. Five recurrences (29%) were noticed, requiring a new operation in all the cases. Discussion and conclusion: This series of 141 patients is too limited to permit final conclusions to be drawn concerning significant advantages of one form of treatment compared to the other. Nevertheless, primary closure offers the advantages of quicker healing time, fewer post-operative visits and shorter time off work. When a primary closure can be carried out, it should be routinely considered for socio-economical and comfort reasons.


EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
James P. Cuda ◽  
Patricia Prade ◽  
Carey R. Minteer-Killian

In the late 1970s, Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), was targeted for classical biological control in Florida because its invasive properties (see Host Plants) are consistent with escape from natural enemies (Williams 1954), and there are no native Schinus spp. in North America. The lack of native close relatives should minimize the risk of damage to non-target plants from introduced biological control agents (Pemberton 2000). [...]


2013 ◽  
Vol 38 (1) ◽  
pp. 61-70 ◽  
Author(s):  
SMA Hossain ◽  
MA Baque ◽  
MR Amin

The Imidacloprid insecticide, Gaucho 70 WS at 1.5, 2.5, 3.5, 4.5 and 5.5 g/kg seed was used as seed treatment and monocrotophos 40 WSC at 1120 ml/ha was applied as foliar spray on CB9 cotton cultivar to suppress aphid, whitefly and thrips, and impact on their natural enemies during 2008-2011 at the Regional Cotton Research Station, Dinajpur, Bangladesh. The activity of natural enemies, such as ladybird beetle, lacewing, syrphid, and spider population on the sucking pests attacking cotton cultivar CB9 and yield of cotton were recorded. Imidacloprid significantly reduced aphid, whitefly, and thrips population on cotton crops compared to untreated control or foliar spray of monocrotophos 40 WSC at 1120 ml/ha. Ladybird beetles, lacewings, syrphids, and spiders were abundant in the field but their population decreased in the treated plots compared to untreated control. The CB9 cotton cultivar produced significantly higher yield (1.73 t/ha) with a benefit cost ratio 12.47 when seeds were treated with Imidacloprid at 5.5 g/kg fuzzy seed. This study indicated that Imidacloprid (Gaucho 70 WS) used as a seed treatment may be suggested to the cotton growers for controlling sucking pests. Bangladesh J. Agril. Res. 38(1): 61-70, March 2013 DOI: http://dx.doi.org/10.3329/bjar.v38i1.15190


2019 ◽  
Vol 25 (1) ◽  
Author(s):  
NARENDRA SINGH ◽  
N. S. BHADAURIA ◽  
PRADYUMN SINGH

The Bio-efficacy of eleven plant extracts namely viz.Neem Kernel; Rhizome of Ginger; Leaves of Datura, Gajarghas, Harsingar, Oak and Latjeera; Bulb of Garlic and Onion; Flowers of Chrysenthemum and Fruits of Chilli in the concentration of 5 percent and imidacloprid @ 40 g ai/ha was tested against mustard aphid, Lipaphiserysimi and their effect on D. rapae and Coccinellid beetle were tested in the Department of Entomology, College of Agriculture, Gwalior (M.P.). All the tested plant materials and imidacloprid @ 40 g ai/ha were effective significanty in reducing the aphid population over control.The aphid population in treated plots ranged from 7.2 to 40.0 as against 85.4 aphid/twig in untreated control. Among the plant material, three sprays of Neem Kernel were found most effective followed by three sprays of chilli fruits.All the plant extracts were found significantly safer to D. rapae and coccinellid bettle in comparision to insecticide (imidacloprid).


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