The dual origin of the nurse chamber in the ovarioles of the gall midge,Heteropeza pygmaea

1973 ◽  
Vol 173 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Mekkara M. Madhavan
Keyword(s):  
Gall Midge ◽  
Heteropeza Pygmaea ◽  
Dual Origin ◽  
Nurse Chamber

Composite eggs and Siamese twins in paedogenetic gall midges

Development ◽  
1972 ◽  
Vol 28 (3) ◽  
pp. 647-657
Author(s):  
Dirk F. Went ◽  
René Camenzind
Keyword(s):  
Gall Midge ◽  
Follicular Epithelium ◽  
Oocyte Nucleus ◽  
Gall Midges ◽  
Cell Complexes ◽  
Siamese Twins ◽  
Egg Chambers ◽  
Oocyte Stage ◽  
Nurse Chamber

Several types of composite eggs were found in two species of paedogenetic gall midges. One composite egg, consisting of two blastoderms, was cultured in vitro, and its development was recorded on film. Two other composite eggs were fixed in the oocyte stage; each contained two nurse chambers, two egg chambers and one oocyte nucleus. Some other ‘eggs’ are described, which consisted merely of a nurse chamber or of one or two oocytes and of the follicular epithelium. It is argued that the formation of composite eggs and incomplete eggs must be due to errors in the formation of the oocyte-nurse cell complexes. The article also describes three Siamese twins in larval stage which were found in two paedogenetic gall-midge species. In two twins the larvae were linked posterior–posterior, while in the third they were connected anterior–anterior. It is assumed that the Siamese twin-larvae evolved from composite eggs.

Efficacy of some insecticide modules against major insect pests and spider population of rice, Oryza sativa L.

ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 257-262
Author(s):  
Atanu Seni ◽  
Bhimasen Naik
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Untreated Control ◽  
Insect Pests ◽  
Oryza Sativa L ◽  
Gall Midge ◽  
Stem Borer ◽  
The Other ◽  
The Third ◽  
Treated Plot

Experiments were carried out to assess some insecticide modules against major insect pests of rice. Each module consists of a basal application of carbofuran 3G @ 1 kg a.i ha-1 at 20 DAT and Rynaxypyr 20 SC @ 30 g a.i ha-1 at 45 DAT except untreated control. All modules differ with each other only in third treatment which was applied in 65 DAT. The third treatment includes: Imidacloprid 17.8 SL @ 27 g a.i ha-1, Pymetrozine 50 WG @ 150 g a.i ha-1, Triflumezopyrim 106 SC @ 27 g a.i ha-1, Buprofezin 25 SC @ 250 g a.i ha-1; Glamore (Imidacloprid 40+Ethiprole 40% w/w) 80 WG @ 100 g a.i. ha-1, Thiacloprid 24 SC @ 60 g a.i ha-1, Azadirachtin 0.03 EC @ 8 g a.i ha-1, Dinotefuran 20 SG@ 40 g a.i ha-1 and untreated control. All the treated plots recorded significantly lower percent of dead heart, white ear- head caused by stem borer and silver shoot caused by gall midge. Module with Pymetrozine 50 WG @ 150 g a.i ha-1 treated plot recorded significantly higher per cent reduction of plant hoppers (>80% over untreated control) and produced higher grain yield (50.75 qha-1) than the other modules. Among the different treated modules the maximum number of spiders was found in Azadirachtin 0.03 EC @ 8 g a.i ha-1 treated module plot followed by other treatments.

Further Problems in the Interpretation and Homology of the Insect Ovipositor

1964 ◽  
Vol 96 (1-2) ◽  
pp. 405-417 ◽  
Author(s):  
G. G. E. Scudder
Keyword(s):  
Experimental Study ◽  
Normal Development ◽  
Organ Formation ◽  
Larval Stages ◽  
Insect Phylogeny ◽  
Correct Form ◽  
Developmental Capacity ◽  
Mode Of Development ◽  
Dual Origin

AbstractAn attempt is made to re-evaluate the data on the origin of the ovipositor in insects and to explain its mode of development in living forms. Comparative developmental data from other groups of animals is cited to substantiate the claim that part of the insect ectodermal genitalia is appendicular rather than sternal in origin. It is suggested that the primary abdominal segmental appendages have provided a source of competent tissue which through subtle changes in selection, has evolved along many pathways, to form the gonocoxae, the pleuropodia, the pseudoplacenta and perhaps the prolegs in many different taxa.It is shown, by aid of sections through the insect embryo and larval stages, that the primary embryonic segmental appendages on the abdomen, do not differentiate; there is no loss of tissue and it cannot be proven that such appendages have been lost in insect phylogeny. The fact that they are represented still in the modern embryo, indicates that they have been retained. To explain the observable developmental details, it is suggested that abdominal limb histogenesis is arrested or suppressed in normal development, but this limb tissue retains its competence to differentiate. Thus development may be initiated again at a later time in postembryonic life. In this manner, the original limb tissue is available for organ formation in the maturing insect.The study has suggested that the appendages on the eighth and ninth segments of the abdomen initiate but do not complete their development in the polypod embryo. Possibly the potential limb tissue is arrested in development because it has not undergone some vital change as regards its capacity to respond (competence) to an inductor, perhaps the inductor is not available or perhaps it is not available in the correct form.There is evidence to suggest that the developmental capacity of the limb anlagen are reduced with time, so that full limb formation is not possible in postembryonic life: this can explain the development of abdominal coxae in the Thysanura and hence gonocoxae in higher insects. It is noted that should Gustafson's suggestion that the eversible sacs and gonapophyses are homologous with primary segmental genitalic ampullae prove acceptable, then the female ectodermal genitalia in insects would appear to have a dual origin.It is emphasized that the speculation expressed are being subjected to experimental study in an attempt to verify the suggested ontogeny and phylogeny.

Sign in / Sign up

Export Citation Format

Share Document