摘要:

AbstractThe individual esterase activity which is measured by filter paper test (FPT) method may determine the resistance of cotton aphidsAphis gossypii(Glover) against organophosphorus (OP) insecticides. For testing accurately resistant level caused by different insecticides, we applied FPT method for measuring inhibitory action of methyl‐parathion, monocrotophos and omethoate to α‐NA esterase of individual cotton aphids, and compared the inhibitory frequencies of these three insecticides to susceptible population (BCA) and resistant population (GCA). Results showed that their inhibitory frequencies of the susceptible population were evidently higher than that of the resistant population. The inhibitory rate of α‐NA esterase in F1 generation individual cotton aphids by monocrotophos was low when the cotton aphid population had been treated in advance with monocrotophos, but it got to 75%‐90% when the cotton aphid population had been untreated in advance with monocrotophos. Besides, the differences in esterase activity were not obvious between them. In same region when cotton aphids were treated with insecticides the inhibitory frequency of esterases in individual by the insecticides was lower than counterparts in individual cotton aphids which were not treated with insecticides. All these demonstrated that inhibitory frequency of α‐NA esterase in individual cotton aphids by OP insecticides could be used as a technique of forecasting pes

ISSN:1672-9609    

DOI:10.1111/j.1744-7917.1996.tb00404.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThe substrate specificity and developmental changes of acetylcholinesterase (AChE) of cotton bollworm,Helicoverpa armigeraHübner, were investigated during 1991 to 1994. The insects were collected from Handan suburbs of Hebei Province and Guan County of Shandong Province. The results show that the specific activity and Michaelis constants (km) of AChE toward acetylthiocholine (ATCH) and acetyl‐β‐methyl‐thiocholine (MeTCh) regularly varied with the developmental stage of cotton bollworm. The two peaks of the specific activity were observed respectively in the third instar and sixth instar of larvae. The specific activity of AChE in pupae was the lowest and that in heads of four‐days moth was the highest in various developmental stages of cotton bollworms. The tendency of Kmand maximum velocity (Vmax) was identical with the change of specific activity in the AChEs of cotton bollworm. The activation energy (Ea) of AChE toward MeTCh in pupae and adults was 3. 9–4. 3 times as much as that of, larvae in cotton bollworms from Handan of Hebei Province. It suggests that the spending energies of AChE for hydrolysing substrate are different in larva, pupa and adult. The optimum conditions of AChE reaction with ATCh in larvae were 50–100 mg of tissue weights for the amount of enzyme, 10–20 minutes for the reaction time, 35°C for the reaction temperature and 8. 0 for the r

ISSN:1672-9609    

DOI:10.1111/j.1744-7917.1996.tb00405.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThe result of a study on the internal structures during the development of sensilium and anal segment from first instar larva to adult ofLeptopsylla segnis(Schinherr 1811),Monopsyllus anisus(Rothschild 1907) andCtenocephalides felis felis(Bouche 1835) is reported and summarized as follows: (1) The development of the sensilium and anal segment of these fleas is essentially the same. (2) The first sensilium rudiment appears in the early third instar larva on the anterior one‐second part of the tergite of the tenth abdominal segment, and in prepupa the eleventh abdominal segment which is composed of the dorsal and ventral anal lobes is formed, and in the pupa the sensilium and its frame are fully developed. (3) The differenced of opinions on the terminal segments of the flea are discusse

ISSN:1672-9609    

DOI:10.1111/j.1744-7917.1996.tb00406.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY