Effects Of Insect Growth Regulators Research Articles

Effects of insect growth regulators on honey bees and non-Apis bees. A review

The insect growth regulators (IGRs) are ecdysone or juvenile hormone mimics, or chitin synthesis inhibitors. They are more likely to be hazardous to larval insects than to adults. Application of JH mimics to adult honey bees may affect foraging behaviour and some physiological traits. Top- ical and feeding revealed that application of IGRs to may result in death and larval ejec- tion by workers, malformed and pupae with typical rimmed eyes, or malformed adults. Sev- eral laboratory larvae tests using artificially contaminated diets have been described for honey bees and bumble bees. Field and cage methods have also been published for honey bees and bumble bees respectively. Diflubenzuron was generally safe for honey bee brood in fields treated at 35 to 400 g.ha -1 a.i. and harmful to bumble bees at 300 g .ha -1 a.i. Fenoxycarb was safe for bumble bees at 1 200 g.ha -1 a.i. and hazardous to honey bees causing damage to honey bee brood at 140 g .ha -1 . insect growth regulator / honey bee / non-Apis bee / toxicity / risk assessment

The use of insect growth regulators for the control of insect pests of cotton

Studies were conducted to evaluate the effectiveness of insect growth regulators for the control of cotton insect pests. Three field trials were carried out and the insect growth regulators including lufenuron (A 7814) and lufenuron plus profenofos (A 9441) were compared with lambda-cyhalothrin. The lufenuron plus profenofos (275 g.a.i./ha) provided yields similar to lambda-cyhalothrin (19.5 g.a.i./ha) in all trials. In one trial the yield was also similar to polytrin-C (660 g.a.i./ha). However, lufenuron alone at 300 g.a.i./ha gave a lower yield than lambda-cyhalothrin in the first two trials. A higher dosage level of400 g.a.i./ha, yielded similar to lambda-cyhalothrin in the third trial. The lufenuron treatment was generally more effective against outbreaks of Spodoptera littoralis than the commonly used pyrethroid (lambda-cyhalothrin) and was also comparatively less harmful to predators. Insect growth regulators could be included in the spray programmes for the management of cotton pests rather than continuous use of pyrethroids on a routine basis and their use integrated with other pest management practices might play an important role in the management of insect pests of cotton on small-scale farms in Africa and other cotton-growing countries.

Comparative Effects of Insect Growth Regulators on Longevity and Mortality of Beet Armyworm (Lepidoptera: Noctuidae) Larvae2

Laboratory bioassays demonstrated the toxic effects of three distinct types of insect growth regulators, diflubenzuron, fenoxycarb, and RH-5992, against 1- and 6-d-old larvae of the beet armyworm, Spodoptera exigua (Hübner). Diflubenzuron and RH-5992 were somewhat more active and provided faster knockdown of beet armyworm larvae than did fenoxycarb. RH-5992 and diflubenzuron were 12–21 and 3–5 times more effective, respectively, against beet armyworm larvae than fenoxycarb. Larvae exposed to fenoxycarb lived up to 34 d following treatment and continued to feed. Therefore, fenoxycarb in field settings may not be as acceptable for controlling larvae of the beet armyworm as are diflubenzuron and RH-5992.

Effect of insect growth regulators on hatching of eggs of three vector mosquito species

Hatchability of eggs ofCulex quinquefasciatus, Aedes aegypti andAnopheles stephensi was studied by exposing freshly laid (0–1 h) and older (12–18 h) eggs to varying concentrations (0–0001–l-0mg/l) of 6 insect growth regulators viz. OMS 3019, OMS 3007, OMS 2015, OMS 3031, OMS 3013 and OMS 3009. In all the 3 species, dosage dependent response was observed. The response was also dependent on the age of eggs. Among the 6 IGR compounds OMS 3031 was found highly active resulting in maximum reduction in hatching of freshly laid eggs ofAnopheles stephensi (99-95%) followed byAedes aegypti (89–9%) whereas 50% inhibition in hatching occurred in older eggs ofCulex quinquefasciatus exposed to OMS 3009 at the same dosage. Dose, age and dose and age dependent hatching was evident in eggs of the 3 test species exposed to insect growth regulators OMS 3019, OMS 3013 and OMS 2015. Higher proportion of unhatched eggs with varying abnormalities was noticed in test species. Percentage mortality observed was higher in first instar larvae hatched from treated eggs reared in untreated water. Therefore, insect growth regulators have great potency in suppressing the population by affecting hatching of mosquito eggs in addition to inhibition of adult emergence, thus providing a useful tool for integrated vector management.

ニカメイガ幼虫表皮の組織培養系を用いたこん虫成育抑制物質の作用機構の研究

ニカメイガ幼虫表皮の組織培養系を用いたこん虫成育抑制物質の作用機構の研究

The Effects of Insect Growth Regulators and Their Potential as Control Agents for Imported Fire Ants (Hymenoptera: Formicidae)

The Effects of Insect Growth Regulators and Their Potential as Control Agents for Imported Fire Ants (Hymenoptera: Formicidae)

Effects of Insect Growth Regulators on Subterranean Termites: Induction of Differentiation, Defaunation, and Starvation

Exposing groups of Reticulitermesflavipes, R. virginicus, and Coptotermes formosanus to methoprene and hydroprene had concentration-dependent morphogenetic and lethal effects on the Reticulitermes species but no effect on Coptotermes. Methoprene was not directly toxic to R. flavipes. Instead, most lethal effects probably result from starvation induced by elimination of termites' symbiotic protozoa and from trophic demands placed on them by the many presoldiers present. A small proportion of the mortality resulted from ecdysis failures.

Sublethal effects of insect growth regulators upon crab larval behavior

Both swimming speeds and phototaxis by the four larval stages of the crab Rhithropanopeus harrisii were monitored upon chronic exposure to sublethal concentrations of the insect growth regulators methroprene (AltosidR: ZR-515), hydroprene (AltozarR: ZR-512) and dimiline (TH-6040). Larvae were reared under conditions of salinity (20orbo) and temperature (25°C) which produce the greatest developmental success. Sublethal concentrations of methroprene had no effect on swimming rates or phototaxis as compared to the acetone control larvae. For hydroprene, swimming rates by stage I, II and III zoeae were unaffected while a significant increase in swimming speeds occurred in Stage IV zoeae exposed to concentrations of 0.05 and 0.1 ppm. Only Stage III zoeae exposed to 0.l ppm showed a significant decrease in the level of positive phototaxis. Dimilin was much more potent, as significant increases in swimming speeds occurred in Stage I, II and III zoeae, with 0.3 ppb being the lowest effective concentration. Although swimming by Stage IV zoeae was unaffected, phototaxis was altered at concentrations as low as 0.1 ppb. Concentrations, which alter behavior, are related to levels which are reported to control mosquitoe larvae.

Red Imported Fire Ants: Effects of Insect Growth Regulators on Caste Formation and Colony Growth and Survival1

Fourteen of 26 insect growth regulators (IGRs) administered in peanut butter bait to large laboratory colonies of Solenopsis invicta Buren caused a shift in caste differentiation with the result that worker brood production ceased and production of alate forms, most deformed wings, increased. Also, 8 of the compounds caused one or more colonies to die: AI3-36206 (1-(S-methoxy-4,8-dimethylnonyl)-4-(I-ethylethyl) benzene) caused 15 of 20 treated colonies to die; and A13-36093 (1-(8-ethoxy-4,8-dimethylnonyl)-4-(1-methylethyl) benzene) and AI3-35477 (JH-25) (E) -1-[(7-ethoxy-3,7-dimethyl-2-octenyl) oxy]-4-ethylbenzene or (E) -1-[ (7-eth-oxy-3,7-dimethyl-2-octenyl)oxy]-4-ethylbenzene) caused 3 of 4 and 6 of 9 colonies, respectively, to die.

Effect of insect growth regulators and fertilizers applied as foliar sprays during the egg stage of the sawfly Neodiprionsertifer

Two insect growth regulators, a mixture containing about 25% Cecropia juvenile hormone with its geometrical isomers (AY-22342-3: Ayerst Research Laboratories, Saint-Laurent, Quebec) and a preparation containing 75% of the aromatic terpenoid ether, 4-ethylphenyl-6,7-epoxygeranyl ether (R-20458-B: Stauffer Chemical Co., Mountain View, California), were tested under field conditions for ovicidal activity against eggs of Neodiprionsertifer (Geoff.). Single egg clusters on Scots pine (Pinussylvestris L.) and whole red pine (P. resinosa Ait.) trees were sprayed to the drip point with formulations containing 0.1, 1, or 10 g/litre of insect growth regulator. AY-22342-3 reduced egg hatch at 10 g/litre on both tree species but was more effective in the red pine trial. R-20458-B did not reduce egg hatch significantly. Results with AY-22342-3 in the laboratory were about twice as effective as field trials. The application of fertilizers (urea, KNO3, or NH4NO3) accompanying a spray of AY-22342-3 on whole red pine trees does not enhance larval mortality. For trees receiving relatively intensive care, notably ornamentals and Christmas trees, the ovicidal activity of insect growth regulators might be useful as a means of preventing sawfly defoliation.

Effect of insect growth regulators on growth and differentiation of the tobacco caterpillarSpodoptera litura FB. (Noctuidae: Lepidoptera)

Topical application of insect growth regulators to freshly moulted sixth-instar larvae ofSpodoptera litura prevented their differentiation into pupae and resulted in the formation of a larval-pupal mosaic and of supernumerary larvae. The degree of the juvenilizing effect was dose-dependent; the doses above 20 μg produced the greatest effect, with 13.3 — 23.3% short-term mortality of treated caterpillars.

Effects of insect growth regulators on the tobacco cutworm, Spodoptera litura: Rectal prolapse

Prolapse of the rectum was observed when ZR-515 (isopropyl 11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate) was applied to the 6th instar larva of the tobacco cutworm, Spodoptera litura. It was induced by an administration of ZR-515 in the middle of the 6th instar larval stage, and either by a dose higher than required for the induction of larval-pupal intermediates or by a dose lower than the dose that produces extra larvae. Larvae with a rectal prolapse appeared only on the 3rd day after treatment. These larvae did not survive for more than 1 to 2 days because the prolapsed rectum ruptured, leading to haemorrhage. Rectal prolapse was also induced by other two IGRs, ZR-512 (ethyl 3,7,11-trimethyl-2,4-dodecadienoate) and ZR-619 (ethyl 11-methoxy-3,7,11-trimethyl-2,4-dodecadienethiolate).

Effects of Insect Growth Regulators with Juvenile Hormone Activity on Metamorphosis, Reproduction, and Egg Fertility ofAdoxophyes orana1

Topical application of insect growth regulators (IGRs) on older L3 last stage larvae of Adoxophyes orana (Fischler von Rosenstamm) eventually inhibited adult ecdysis. Applications on young L3 larvae only gave this effect when pupae retained juvenile characters scored 4 or higher on a 7-point scale. Reproductive activities of moths emerging from pupae scored 0 (no effect) to 3, correlated negatively with the pupal score. IGR effects on both sexes were analyzed by allowing matings only between a treated and an untreated sex partner. Males showed a strongly reduced mating activity when they emerged from score-2 or -3 pupae. Also, ovarian development and egg production were reduced in females from score-2 pupae; higher scores coincided with defects in the ovaries. Whenever both sex partners resulted from pupae scored 1 or higher, a dramatic decrease in the number of offspring followed. Both IGRs showed only low ovicidal potentials at high concentrations and with young eggs. Delayed effects on the metamorphosis of 2nd-generation larvae were not observed.

Effects of Insect Growth Regulators with Juvenile Hormone Activity on the Development of the California Red Scale12

Five insect growth regulators with juvenile hormone activity (IGRs) were tested against the 1st instar of Aonidiella aurantii (Maskell). All concentrations tested evoked response in varying degrees, resulting in growth being arrested at certain stages of development. Cessation of growth in the 1st and early 2nd instar stages obscured sex differentiations. Most of the tested IGRs, and in particular, methoprene (isopropyl (EE-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate), were more effective in inhibiting the metamorphosis of the males than that of the females, particularly at lower concentrations. Substantial response to the compounds was elicited at higher concentrations; at the highest concentration levels, 100% inhibition of male and female development was achieved with all the IGRs.

Effectiveness of insect growth regulators in the control of populations of the German cockroach.

The effectiveness of 10 insect growth regulators (IGR) on small populations of Blattella germanica (L.) was assayed by treating the bedding material with an IGR-corn-starch mixture. Ethyl-3,7,11-trimethyl-2,4-dodecadienoate (ZR-512) was the most effective, with 5 ppm preventing normal metamorphosis in 97% of the population. But even with 100 ppm ZR-512, a mixed population of 100 adults and nymphs was not totally exterminated in 7 months, as some adultoids survived although no reproduction occurred. Besides interference with metamorphosis, these juvenile hormone mimics produced an increased melanization of both adultoids and supernumerary nymphs.

Control of the Pear Psylla with Insect Growth Regulators and Preliminary Effects on Some Non-target Species1

Two insect growth regulators (IGR) ZR-512 (Ethyl 3,7,1l-trimethyldodeca-2,4-dienoate) and ZR-515 (Isopropyl 11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate) were evaluated for their control of the pear psylla, Psylla pyricola Forster, and for their effect on nontarget pear pests and predators. Under laboratory conditions, adult psylla exposed to residues of IGR's failed to lay viable eggs, though the number laid and the general appearance of eggs seemed normal. Adult psylla from late-instar nymphs which were exposed to ZR-515 failed to lay viable eggs. In field tests no direct reduction in adult psylla levels was observed following application with IGR's, but 3 weeks post treatment the ratio of psylla eggs per nymphs was much greater in these plots. The effect of IGR's was minimal on other pest species, and no significant decrease in predator species was noted.

Effects of insect growth regulators on the oleander scale (Aspidiotus nerii) and the european fruit lecanium (Parthenolecanium corni)

AbstractTwo insect growth regulators (IGRS) were tested against the armoured scale Aspidiotus nerii and the soft scale Parthenolecanium corni in the greenhouse. The most sensitive stages appeared to be the second instar in the females and nymphal stages in males. CGA 34300 and CGA 34301 applied at a rate of 0.05 % a.i. with appropriate timing gave encouraging results and merit further evaluation as control agents under field conditions.ZusammenfassungWirkungen von Insekten‐Wachstumsregulatoren auf die Oleander‐Schildlaus (Aspidiotus nerii) und die Europäische Napfschildlaus (Parthenolecanium corni)Zwei Insektenwachstumsregulatoren wurden gegen die Deckelschildlaus Aspidiotus nerii und gegen die Napfschildlaus Parthenolecanium corni im Gewächshaus geprüft. Die weib‐lichen Schildläuse sind im 2. Larvalstadium sensibel, die Männchen in den Nymphenstadien. Unter der Voraussetzung, daß die Behandlung im richtigen Zeitpunkt erfolgt, werden mit CGA 34300 und CGA 34301 mit 0,05 % Wirkstoff gute Ergebnisse erzielt. Die Versuche werden im Freiland weitergeführt.