The use of traps baited with live females as a tool for improving control programs of the spiny bollworm,Earias insulana Boisd., in cotton fields

Phytoparasitica - An investigation was undertaken to determine whether traps baited with virgin females could provide a reliable tool for early detection of theEarias insulana adult population, and...     

Development of an artificial diet for mass rearing of the spiny bollworm,Earias insulana

An artificial diet for rearing the spiny bollworm,Earias insulana (Boisd.), was developed in experiments with three successive generations. The present recommended diet is based on kidney beans, alfalfa meal, whole powdered milk and yeast; methyl-P-hydroxy benzoate, chloramphenicol and formaldehyde were included as preservatives. The effect of the diets on the insect quality is discussed.     

Inheritance of two body color mutations of the spiny bollworm (Earias insulana)

Reciprocal crosses in all possible combinations between the yellow-green (YG) wild line and two body color mutations — viridian-green (VG) and grayish-white (GW) — of the spiny bollworm,Earias insulana (Boisd.), indicated that these mutations were not sex-linked or controlled cytoplasmically. The YG phenotype was dominant over both body color mutations. A genetic model involving two genes with recessive epistasis is proposed for the inheritance of body color.

     

The use of traps baited with live females or synthetic pheromone as a tool for improving control programs of the cotton leaf-worm,Spodoptera littoralis (Boisd.), in cotton fields in israel

The aim of this investigation was to clarify whether pheromone traps could provide a reliable tool for early detection of aS. littoralis adult population and for indicating infestation by its larvae in the field. The aggregated pattern of distribution of adults is indicated by the fit of data to Taylor’s Power Law or to the negative binomial distribution. However, the relatively high k values obtained indicate thatS. littoralis adults are only slightly aggregated and sometimes almost randomly distributed. Trap position in the field and number of traps per area unit affected size of catches in both female-baited and synthetic-pheromone-baited traps. No relationship between size of catches and temperature, wind velocity or moon phase was detected. Variations in size of catches among traps was not affected much by the baited females. Pheromone traps proved to be a reliable tool for estimating fluctuations in population density and for indicating adult peaks. However, no correlation between male catches and infestation by larvae in the experimental plots was found. Pheromone traps may serve only as a warning device indicating the possibility of potential attack due to an increase in adult population level. Mercury vapor light traps were inferior to pheromone traps in detecting changes inS. littoralis population densities. Synthetic pheromone (“Litlure”) was somewhat less efficient in attracting males than virgin females; however, it is suitable for detecting fluctuations in theS. littoralis adult population.     

Studies of the response of the spiny bollworm,earias insulana,to rearing on leaves,flower buds and bolls of high-terpenoid-aldehyde cotton genotypes in the laboratory

Survival rates of neonate larvae of the spiny bollworm,Earias insulana Boisd., on leaves, flower buds and bolls of ten high-gossypol (HG) [terpenoid-aldehyde] and Acala SJ^b2 cotton lines were 40-74%, 66-92% and 54-76%, respectively. Partial resistance of leaves of three cotton lines, no resistance of flower buds, and resistance of bolls of one line (HG-BR-8) to larval infestation were observed. Bolls which had their bases and bracts removed were heavily penetrated by larvae and more adults were obtained on them, as compared with intact ones. Complete development on cotton bolls, from hatching to the adult, took 25.6-32.6 days, with significant differences among some of the cotton lines. Growth on bolls of HG lines in the larval stage had no effect on oviposition by the corresponding adults. Fertility of these eggs was not affected.     

Sex pheromone traps for detecting and monitoring the raisin moth,cadra figulilella,in date palm plantations

Field tests were carried out to determine whether pheromone traps, baited with (Z,E)-9,12-tetradecadienyl acetate (Z9,E12-14:Ac) impregnated in rubber septa (Maavit, Israel), could provide a reliable tool for monitoring the raisin moth,Cadra figulilella (Gregson), in date palm plantations. No significant differences were detected between captures of males in traps baited with 1 or 10 mg pheromone/dispenser. However, traps baited with 1 mg pheromone captured significantly more males than those baited with 0.1 mg pheromone/dispenser. No differences were found between captures of males in traps hung at a height of 8 m (near the bunches) or 2–3 m (on palm trunks). Two peaks of male capture were detected, one in May-June and the other during September-October (ripening period). Results indicate a positive relationship between captures in traps and infestation levels by larvae. Pheromone traps baited with 1 mg Z9,E12–14:Ac impregnated in rubber septa and hung on palm trunks (at a height of 2–3 m), were very useful for monitoringC. figulilella populations and for determining the accurate timing of insecticide applications.     

Field evaluation of (E,E)-10,12-hexadecadienal,a component of the Female Sex Pheromone of the Spiny Bollworm,Earias insulana (Boisd.) (Lepidoptera,Noctuidae)

Field tests demonstrated that (E,E)-10,12-hexadecadienal is an effective attractant for maleEarias insulana (Boisd.).     

Sex pheromone traps for monitoring the honeydew moth,Cryptoblabes gnidiella: Effect of pheromone components,pheromone dose,field aging of dispenser,and type of trap on male captures

The effects of pheromone components, pheromone dose in the dispenser, aging of dispenser in the field, and trap type on trapping efficiency of males of the honeydew moth,Cryptoblabes gnidiella (Mill.) (Lepidoptera: Pyralidae), were investigated. At dosages of 2 or 0.2 mg, a binary blend containing (Z)-11-hexadecenal (Z11–16: Aid) and (Z)-13-octadecenal (Z13–18:Ald) (1:1) was as effective in attracting males as a quaternary blend containing Zll-16:Ald, (E)-11-hexadecenal (Ell-16:Ald), Z13–18:Ald and (E)-13-octadecenal (E13–18:Ald), (10:1:10:1). Within the range of 20 to 2000 μg pheromone/dispenser, response of males increased positively with the pheromone dose; however, a load of 10 or 20 mg/dispenser was significantly less attractive to males than 2 mg/dispenser. The effect of aging of the dispenser in the field on trapping efficiency was significant. Captures in traps baited with 3- and 4-week-old septa were lower than those in traps baited with 1- or 2-week-old septa. The gradual loss of attractancy exhibited by rubber septa indicates that septa should be renewed within 2-3 weeks. The release rate of the pheromone was measured in a flow system and monitored with Zl1– 16:Ald only. The emission was almost constant for 18 days and then decreased gradually until the 34th day. The nonsticky IPS trap was as effective in capturing honeydew moth males as the sticky Pherocon 1C trap. The possibility of using the nonsticky, non-saturating and easy-to-handle IPS traps may lead to better and easier monitoring of honeydew moth populations.     

Evaluation of a pheromone trap for the cotton pink bollworm Pectinophora gossypiella Saunders

This 4-year study examined the susceptibility of nine cultivars of apple, Malus domestica Borkhausen to attack by woolly apple aphid (WAA), Eriosoma lanigerum in Jordan. The cultivars under investigation were: Prima Rouge, Delberd Steval, Early Gold, Starking Delicious, Harmony, Golden Smoothee, Fuji, Melrose, and Golden Delicious. Estimation of susceptibility was based upon a numeric scale of 0–4 for both root and shoot, but each with different specifications. A tree infestation rating was obtained by calculating the average rating of both edaphic and arboreal ratings of each tree. Fuji was significantly the most infested cultivar during the period of study and it ranked as a highly susceptible cultivar. Prima Rouge, Early Gold, Starking Delicious, Golden Smoothee, and Golden Delicious showed lower susceptibility. Harmony was an immune cultivar as it sustained neither edaphic (root inhabiting) nor arboreal colonies of woolly apple aphid. We propose the development of rootstocks from Harmony cultivar. The latter offers a new gene for resistance to WAA that will open the door for plant breeders to produce different resistant rootstocks.     

Identification of the sex pheromone of the cotton bollworm,Heliothis armigera,in Israel

The composition of the female sex pheromone ofHeliothis armigera in Israel has been identified, with four main compounds detected: Z-9-hexadecenal (3%), Z-11-hexadecenal (87%), hexadecanal (4%), and hexadecanol (6%). The first two aldehydes are the essential components of the sex pheromone ofH. armigera.     

Bait additives as a means of improving acceptance by rodents1

There is a general desire by those formulating rodent baits to improve them to achieve better rodent control. Various bait additives are currently in use while others have been evaluated without significant benefit. Some food or taste preferences are innate while other specific food preferences of rodents are learned during early experiences in life. Sugar (sweet items) and vegetable oils and animal fats are the most universally effective additives for cereal baits to improve acceptance and palatability for the three major species of commensal rodents. Salt, monosodium glutamate, and a wide array of natural, semi-natural, and synthetic flavors/aromas as bait enhancers have been explored as gustatory (taste) and olfactory (odor) additives. Their influence on rodents seeking out the bait and on bait acceptance are varied and inconsistent. Flavor additives to baits have often decreased rather than increased consumption.     

Carbon dioxide as a potential fumigant for termite control

Formosan subterranean termites, Coptotermes formosanus Shiraki, were exposed to ? 95% or 50% carbon dioxide atmospheres for intervals of 24-120 h at 26(±3)°C. A 24-h exposure to ? 95% carbon dioxide caused significant termite mortality, but 60 h were required for complete mortality. Exposure to 50% carbon dioxide for 60 h resulted in approximately 70% termite mortality, while complete mortality was recorded after 120 h. When termites were sealed in wooden blocks (90 × 90 × 152 mm), 72-96 h exposure to ? 95% carbon dioxide was necessary for complete control. A limited study with Cryptotermes brevis (Walker) suggested that this drywood termite is also susceptible to carbon dioxide fumigation, although slightly longer exposures may be required than with C. formosanus. Carbon dioxide-modified atmospheres are a viable alternative to conventional fumigants for vault fumigation of termite-infested materials, and may also be applicable to larger-scale fumigations to control structural pests.     

Use of pheromone traps for the proper timing of fumigation in the storage environment1

We have broadly divided the methods of storage insect manipulation into curative and preventive measures. Sex and aggregation pheromoncs combined with additional sensory stimuli in adhesive bait traps can be utilized as a preventive measure which may lead to insectistasis (a state wherein the insect population density is diminished to the extent of allowing storage without significant impairment). Insectistasis can be readily achieved by continual supervision of store rooms, use of adhesive bait traps in combination with a limited number of curative measures (e.g. gaseous or contact insecticides) timed according to the extent of trap catches. The sensory stimuli causing male storage moths (Phycitinae) to fly towards these bait traps involve, in sequence, a circadian rhythm, increasing or decreasing light (intensity approximately 1–10 Lux), an air current, a vertical rectangular figure and the main pheromone component. The antennae of male Anagasta kuehniella, Ephestia elutella and Plodia interpunctella comprise two types of receptor cells, of which one is selectively responsive to (Z,E)-9,12-tetradecadienyl acetate (TDA) and (Z)-9-tetradecenyl acetate (TA), while the other responds to (Z,E)-9,12-tetradecadien-l-ol (TDO).     

Night observations on the cotton leafworm,Spodoptera littoralis: Reliability of pheromone traps for population assessment and efficacy of widely separated pheromone dispensers for mating disruption

Night observations on the cotton leafworm,Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), were conducted in pheromone-treated and untreated plots in which males, females, mating pairs on plants, and males caught in traps were collected. Results indicated that emergence of a new population was rapid (8-9 days) and that the number of virgin females and of mating pairs on plants reached a peak 5–6 days prior to that of males captured in pheromone traps. Males responded to pheromone traps most actively when the actual virgin female popution had already declined considerably. Dispensers adsorbed with(Z,E)-9,11-tetradecadienyl acetate and located 25 m apart, effectively reduced male captures in traps. However, the number of native mating pairs observed in the treated field during the night was not reduced. Few releasers at wide spacing, even with high amounts of the major pheromonal component, were ineffective in causing mating disruption ofSpodoptera littoralis.     

Alarm pheromones and allelochemics as a means of aphid control

The relevance of studies on aphid-plant relationships for plant virus epidemiology is highlighted. Many behavior-modulating chemicals (semiochemicals) play a major role in intraspecific (pheromones) or interspecific (allelochemics) interrelations and therefore offer opportunities to interfere with virus transmission. Present knowledge on the role of semiochemicals in different behavioral events is emphasized using examples (alarm and sex pheromones, allelochemics involved in host selection, antifeedants) and their potential for controlling virus transmission and spread is discussed.     

Alarm pheromones and allelochemics as a means of aphid control

The relevance of studies on aphid-plant relationships for plant virus epidemiology is highlighted. Many behavior-modulating chemicals (semiochemicals) play a major role in intraspecific (pheromones) or interspecific (allelochemics) interrelations and therefore offer opportunities to interfere with virus transmission. Present knowledge on the role of semiochemicals in different behavioral events is emphasized using examples (alarm and sex pheromones, allelochemics involved in host selection, antifeedants) and their potential for controlling virus transmission and spread is discussed.     

二化螟诱捕器在有机稻生产上的应用效果

水稻二化螟是灌阳县水稻的主要害虫,一年发生4代,在水稻分蘖期为害,造成枯鞘、枯心,在大胎、破口抽穗期为害,造成"白穗"或"虫伤株".历年来都是采取化学防治方法,于二化螟孵化至低龄幼虫发生期施用农药进行防治.