scholarly journals Larval feeding behaviour and toxicity of Bacillus thuringiensis against Ctenopseustis obliquana on avocados

2001 ◽  
Vol 54 ◽  
pp. 21-26
Author(s):  
P. Stevens ◽  
P. Jamieson ◽  
L.E. Jamieson ◽  
M. Knights
Keyword(s):  
Bacillus Thuringiensis ◽  
Feeding Behaviour ◽  
Tree Canopy ◽  
Short Exposure ◽  
Larval Feeding ◽  
Leaf Discs ◽  
First Instar ◽  
Outer Perimeter ◽  
Ctenopseustis Obliquana ◽  
Third Instar Larvae

Ctenopseustis obliquana is a serious pest of avocado in New Zealand Laboratory experiments to gain a greater understanding of the interaction between larval feeding behaviour and environmental degradation of Bacillus thuringiensis (Bt) residues were carried out Larval C obliquana were found to feed equally during light and dark periods and the application of Bt sprays in the evening did not consistently result in higher mortality than sprays applied in the morning First instar larvae were more susceptible to Bt sprays than third instar larvae However when first instar larvae were provided with leaf discs that had been sprayed with Bt seven days previously mortality was equivalent to that of larvae feeding on unsprayed leaves Mortality of first and third instar larvae provided with Bttreated leaf discs collected from within the shade of the avocado tree canopy (zero and one day after spraying) was significantly greater than that of larvae provided with Bttreated leaf discs collected from the outer perimeter of the canopy Results indicated that even very short exposure to sunlight (ie 3060 minutes) was sufficient to cause a significant reduction in the toxicity of Btsprayed leaves to C obliquana larvae

The Hydraenidae of Cuba (Insecta: Coleoptera) II: Morphology of preimaginal stages of six species and notes on their biology

Zootaxa ◽  
2017 ◽  
Vol 4238 (4) ◽  
pp. 451 ◽  
Author(s):  
ALBERT DELER-HERNÁNDEZ ◽  
JUAN A. DELGADO
Keyword(s):  
Instar Larva ◽  
Morphological Characters ◽  
Larval Instars ◽  
First Instar ◽  
Preimaginal Stages ◽  
First Time ◽  
Third Instar Larvae

Preimaginal stages of the six species of Hydraenidae presently known from Cuba were obtained by rearing adults in the laboratory. Eggs of Hydraena perkinsi Spangler, 1980, H. decui Spangler, 1980 and H. franklyni Deler-Hernández & Delgado, 2012 are described and illustrated for the first time. The first instar larva of Gymnochthebius fossatus (LeConte, 1855) is redescribed, adding some new remarkable morphological characters including what could be the first abdominal egg-burster reported for this family. All larval instars of H. perkinsi, H. guadelupensis Orchymont, 1923 and Ochthebius attritus LeConte, 1878 are described and illustrated for the first time, with a special emphasis on their chaetotaxy. The second instar larva of G. fossatus along with first and third instar larvae of H. decui and H. franklyni are also studied for the first time. The pupal morphology and vestiture of a species belonging to the genus Hydraena are described for the first time, based on the pupa of H. perkinsi. Biological notes for several preimaginal stages of the studied species are also given. 

A STANDARDIZED BIOASSAY FOR LARVICIDAL ACTIVITY OF BACILLUS THURINGIENSIS IN SUNFLOWER MOTH HOMOEOSOMA ELECTELLUM (LEPIDOPTERA: PHYCITIDAE)

1985 ◽  
Vol 117 (1) ◽  
pp. 15-22 ◽  
Author(s):  
R. G. Lidstone ◽  
D. W. Goerzen ◽  
G. G. Khachatourians
Keyword(s):  
Bacillus Thuringiensis ◽  
Larvicidal Activity ◽  
Standard Test ◽  
Mortality Curve ◽  
Bioassay Technique ◽  
Sunflower Moth ◽  
Homoeosoma Electellum ◽  
Third Instar Larvae

AbstractA standard test for the larvicidal activity of Bacillus thuringiensis (B.t.) against the larvae of the sunflower moth Homoeosoma electellum (Hulst) has been developed. Bioassay parameters investigated include diet preparation, concentration of B.t., effect of formaldehyde, and method of pathogen incorporation in diet. The LC50 for seconded third-instar larvae is 1.24 μg of Dipel® WP ml−1 or 19.8 IU B.t. ml−1 pathogen-incorporated diet. Layering of a pathogen-suspension upon the surface of the diet was not a reliable bioassay technique for H. electellum. The addition of formaldehyde in the diet reduced the slope of the dose–mortality curve but did not change the LC50.

scholarly journals Development and functional morphology of the larval foregut of two brachyuran species from Northern Brazil

2011 ◽  
Vol 83 (4) ◽  
pp. 1269-1278 ◽  
Author(s):  
Fernando A. Abrunhosa ◽  
Darlan J.B. Simith ◽  
Joely R.C. Monteiro ◽  
Antonio N. de Souza Junior ◽  
Pedro A.C. Oliva
Keyword(s):  
Larval Development ◽  
Feeding Behaviour ◽  
Food Source ◽  
Morphological Structure ◽  
Filter Press ◽  
Larval Feeding ◽  
Structural Development ◽  
Gastric Mill ◽  
Larval Stages ◽  
Northern Brazil

Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both . vocator and P occidentalis need an external food source before completing the larval development in a planktonic environment.

scholarly journals Efficacy of Bacillus thuringiensis (Berliner) isolates on fig moth, Ephestia cautella (Walker) Larvae

2014 ◽  
Vol 11 (2) ◽  
pp. 943-951
Author(s):  
Baghdad Science Journal
Keyword(s):  
Bacillus Thuringiensis ◽  
Larval Stage ◽  
Filter Paper ◽  
Larval Instar ◽  
Ephestia Cautella ◽  
Larval Stages ◽  
The Third ◽  
Total Percentage ◽  
First Instar ◽  
Paper Method

The following dilution 5×10-1, 10-1, 10?2 , 10-3 gm/L for the indigenous isolate of Bacillus thuringiensis bacteria and the commercially isalate were used for experiments against the different stages of fig moth of E.cautella which exposed by filter paper method. The results showed that mortality of larval stages was increased with the increasing concentration of the biocide, in addition to increase in the mortality of the larval stages reached to the highest percentage in the third days of treatment of the larval stage in comparison with the first and second days of exposure. The results also showed that the sensitivity of larval stages was increased in first and second instars while reduced in the last instars .The high percentage of first instar mortality for the indigenous isolate in the concentration of 5×10-1 was 72.8% , while the low percentage of mortality showed in the concentration of 5×10-1 for the fifth instar larvae which was 13.3% in third days of treatment while a high percentage of mortality was showed for the first instar larvae for the commercially isulate in the concentration of 5×10-1 was 59.4% Furthermore, low percentage of mortality was shown in the concentration of 5×10-1 in fifth instar larval which was 8.3% in the third days of treatment. The results also showed that the indigenous isolated was more effective than the commercially produced bacteria for killing larval instars of fig moth E.cautella .The total percentage of larval instar mortality reached to 44.5 % after the third days of treatment in concentration 5×10-1 in the indigenous isolate , and it was 33.8 % in the commercially produced bacteria .

scholarly journals Pre-imaginal stages of the blowfly Protocalliphora falcozi in nests of the tree sparrow (Passer montanus)

2019 ◽  
Vol 21 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Viera Jánošková ◽  
Ivan Országh ◽  
Ján Jamriška ◽  
Martin Kopáni
Keyword(s):  
Nature Reserve ◽  
Instar Larva ◽  
Tree Sparrow ◽  
Passer Montanus ◽  
National Nature Reserve ◽  
First Instar ◽  
Initial Description ◽  
Third Instar Larvae

This paper offers the initial description ofthe first instar larva of Protocalliphora falcozi Séguy, 1928 (Diptera: Calliphoridae) and redescription of the second and third instar larvae and puparium, as well as distinction between P. falcozi and its relative P. azurea Fallén (Diptera: Calliphoridae). The material was sampled in the National Nature Reserve Šúr (SW Slovakia) from nests of the tree sparrow (Passer montanus), which has not previously been classified as a host of P. falcozi. Knowledge of diagnostically relevant characterics to determine bird blowfly larvae and puparia will undoubtedly contribute to the current accepted phylogeny and classification of the genus Protocalliphora.

scholarly journals Morphology of immature stages of Paraegidium costalimai (Coleoptera: Scarabaeidae: Orphninae) and remarks on egg-busters in Scarabaeidae first‑instar larvae

2020 ◽  
Author(s):  
Rafael Clayton De Jesus e Sousa ◽  
Juares Fuhrmann
Keyword(s):  
Comparative Study ◽  
New World ◽  
Immature Stages ◽  
Old World ◽  
The Third ◽  
First Instar ◽  
Third Instar Larvae

Studies about the immature stages of Orphninae (Coleoptera: Scarabaeidae) species are scarce. The subfamily includes 214 species, but only 5 have the immature stages described: Chaetonyx robustus liguricus Mariani, 1946, Hybalus benoiti Tournier, 1864, H. rotroui Petrovitz, 1964 and Triodontus nitidulus (Guérin, 1844) from Old World; and Aegidium cribratum Bates, 1887 from the New World. The Neotropical genus Paraegidium Vulcano, Pereira & Martinez, 1966 encompass five species, mainly recorded from Brazil. Herein, the immature stages of P. costalimai Vulcano, Pereira & Martinez, 1966 are described and illustrated, along with remarks on the presence of egg-buster in Scarabaeidae first-instar larvae. A key to the third-instar larvae of known Orphninae and a comparative study of chaetotaxy are also provided.

Larval morphology of the Neotropical genus Epispasta (Coleoptera, Meloidae)

2005 ◽  
Vol 137 (6) ◽  
pp. 657-671 ◽  
Author(s):  
Andrea Di Giulio ◽  
John D. Pinto ◽  
Marco A. Bologna
Keyword(s):  
South American ◽  
Monotypic Genus ◽  
Larval Morphology ◽  
The South ◽  
Morphological Convergence ◽  
First Instar ◽  
Third Instar Larvae

AbstractThe first-instar (triungulin), second-instar, and third-instar larvae of the South American monotypic genus Epispasta Selander, 1960 are described and figured. The triungulin of E. abbreviata (Klug, 1825) is highly adapted for phoresy on bees and resembles the triungulins of several other phoretic genera in the subfamily Meloinae. The second- and third-instar larvae of Epispasta are unique in that they retain the campodeiform phenotype of the first instar. These instars in other meloid genera are scarabaeiform. A discussion is provided on the similarity of the triungulin of Epispasta to that of other phoretic meloines. We argue that this similarity is a result of morphological convergence correlated with phoretic behavior and is not evidence of a relationship. The position of Epispasta in Meloinae remains questionable, as none of its larval or adult features ally it to any other genus.

Field Evaluation of Transgenic Corn Containing a Bacillus thuringiensis Berliner Insecticidal Protein Gene Against Helicoverpa zea (Lepidoptera: Noctuidae)

1996 ◽  
Vol 31 (3) ◽  
pp. 340-346 ◽  
Author(s):  
Steven R. Sims ◽  
Jay C. Pershing ◽  
Barbara J. Reich
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Zea ◽  
Negative Relationship ◽  
Field Evaluation ◽  
Corn Earworm ◽  
Insecticidal Protein ◽  
Transgenic Corn ◽  
First Instar ◽  
Transgenic Lines ◽  
Lepidoptera Noctuidae

Twelve independently transformed lines of transgenic corn (Zea mays L.) expressing the CryIA(b) insecticidal protein from Bacillus thuringiensis var. kurstaki were field tested to evaluate their resistance to the corn earworm, Helicoverpa zea (Boddie). Silks of the primary (=top) ears of transgenic [CryIA(b) positive] and isoline control plants [no CryIA(b) protein] were artificially infested with first-instar H. zea larvae and the length of ear penetration was measured after 19 d. Eight of the 12 lines had significantly less ear damage than their respective isoline controls; 3 transgenic lines reduced H. zea feeding damage by > 75% and stunted surviving H. zea larvae. Concentration of the CryIA(b) protein (μg/g fresh weight) in silks of the transgenic lines, determined using ELISA, ranged from 0.0 to 1.28 μg/g. Within transgenic lines, there was a weak (P < 0.06) negative relationship between the concentration of CryIA(b) protein in fresh silks and the length of H. zea ear penetration.

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