Behavior Of Moths Research Articles

Sublethal effects of neuroactive compounds on pheromone response thresholds in male oriental fruit moths

AbstractThe pheromone‐mediated flight behavior of male Oriental fruit moths in a sustained‐flight tunnel was observed after males were treated topically with sublethal concentrations of permethrin, carbaryl, chlordimeform, dieldrin, octopamine, serotonin, yohimbine, and cyproheptadine. With the exception of serotonin all compounds were found to disrupt one or more specific elements of the male precopulatory flight sequence. Among the insecticides, dieldrin was least active, whereas permethrin, carbaryl, and chlordimeform induced unique effects at specific phases of the sequence. Octopamine induced a hypersensitivity to the olfactory signal and mimicked one of the effects observed with chlordimeform. Yohimbine and cyproheptadine significantly decreased moth activation to the chemical signal but did not alter flight performance in responding moths. Yohimbine and cyproheptadine also reversed the effects induced by octopamine. The results of our study show that the complex precopulatory sequence of behaviors exhibited by males is very sensitive to sublethal concentrations of a range of neuroactive compounds.

Appetitive Flight Behavior of Male Gypsy Moths 1 (Lepidoptera: Lymantridae)

The flight direction of male gypsy moths across an observation area (10 by 10 m) at three sites representing high, intermediate, and low population densities was not preferentially crosswind, upwind, or downwind, nor was it correlated with any cardinal direction. Horizontal flight and tree-oriented vertical flight were the predominant behaviors observed at both low- and high-density sites. Males spent more time in tree-oriented vertical flight in the high-density site, although even at low density it was a predominant behavior in the virtual absence of females and, presumably, pheromone. Similarly, more males were captured at sticky traps unbaited with pheromone stapled to tree trunks than at traps hung in the air >2 m from large trees. Most males flew at heights 2 m from large trees, most males were captured at 0 m at the low-density site, but trap catch was evenly distributed at all heights in the high-density site.

Observations of the flight behaviour of the army worm moth, Spodoptera exempta, at an emergence site using radar and infra‐red optical techniques

ABSTRACT. Studies were made in Kenya of the flight behaviour of African armyworm moths which had emerged from areas previously infested with‘gregarious’caterpillars. The use of radar and an infra‐red optical detector permitted quantitative, direct observations of the flying moths, over all of their flight altitudes, without disturbing their behaviour. Almost all of the successfully emergent moths climbed to altitudes of several hundred metres above ground level and migrated from the emergence sites. Their migratory flights sometimes started on the night of emergence, but on other occasions the moths remained roosting in trees until dawn, then engaged in short dispersal flights, concealed themselves during the day. and commenced migration in mass flights at dusk the following night. The onset of these‘dusk flights’occurred when the irradiance level fell on average to 2.7 × 10−5Wm−2 nm−1 in the 450–800 nm range (in the photometric units appropriate for human vision this corresponds approximately to 2 lux). The‘dawn flights’began with the first sustained increase in irradiance at dawn, and terminated at the end of dawn twilight. Migratory flight in the strong, easterly winds which usually occurred during the first half of the night resulted in rapid, down‐wind displacement to the west. Observations of groups of flying moths passing successively over two radars demonstrated that these migrations could cover at least 20 km. In the second half of the night, winds were usually weak and variable, and up‐wind or cross‐wind directions of displacement were sometimes observed. Moths were observed to disperse rapidly during their migration, so that the mass influxes which lead to outbreaks must be a consequence of subsequent reconcentration. The importance of meso‐scale wind convergence zones in reconcentrating flying moths, and the role of rainfall in inducing descent, and possibly landing, are discussed.

Wind tunnel studies on the effects of secondary sex pheromone components on the behaviour of male Egyptian cotton leafworm moths, Spodoptera littoralis

ABSTRACT. The responses of adult male Spodoptera littoralis (Boisd.) (Noctuidae) to components of the female sex pheromone were examined in a wind tunnel. The responses of male moths from both Egyptian and Cretan stocks to the primary ‘attractant’ (Z, E)‐9,11 tetradecadienyl acetate (III), were compared with the responses to III combined with various percentages of the secondary components tetradecyl acetate (I), (Z)‐9‐tetradecenyl acetate (IIA), (E)‐11‐tetradecenyl acetate (IIB), IIA and IIB combined, and(Z, E)‐9,12‐tetradecadienyl acetate (IV). Analysis of the flight behaviour recorded on videotape showed that with one exception (IV), the secondary components increased the males' success in reaching the source and increased the length of time they spent at the source. In most cases, increasing the relative percentage of the secondary component caused a reduction in the number of males responding. The results are compared with those obtained in field trials with S.littoralis.

Re-evaluation of the role of corpora cardiaca in calling and oviposition behaviour of giant silk moths

Re-investigation of the role of the corpora cardiaca in the reproductive behaviour of the giant silkmoths, Hyalophora cecropia and Antheraea polyphemus, showed that this pair of glands plays no essential role, either in “calling” behaviour by virgin females or in increased oviposition due to mating. Removal of corpora cardiaca-corpora allata complexes, either from diapausing pupae or from freshly eclosed adult females, had no effect on the calling behaviour or on its timing in either species. Moreover after mating, these operated females laid eggs in the typical mated oviposition pattern. Furthermore, females in which there was only a nervous connection between the brain and the abdomen but no haemolymph circulation called normally and oviposited after mating. Although the corpora cardiaca were not essential for calling behaviour, hormogenates of corpora cardiaca-corpora allata complexes and blood from calling or ovipositing females induced a typical “calling” response in 30–60% of the isolated virgin H. cecropia abdomens tested. This activity was not species-specific as it was also found in Manduca sexta, but the restriction of major activity to corpora cardiaca extracts and haemolymph suggested that a neurosecretory factor may modulate the normal neural control of calling behaviour.

Modification of sex pheromone blend discrimination in male Oriental fruit moths by pre‐exposure to (E)‐8‐dodecenyl acetate

ABSTRACT. A pre‐exposure regime was developed to test the hypothesis that arrestment of in‐flight behaviour in Oriental fruit moths, Grapholitha molesta (Busck), to high dosage and/or high %(E)‐8‐dodecenyl acetate blends was due to a high proportion of E8‐12: Ac in the pheromone blend. When tested in a sustained‐flight tunnel to various ratios of (Z)‐ and (E)‐8‐dodecenyl acetate plus a constant % of Z8‐12: OH at two dosages (3 and 100μg), males displayed an optimum number of completed flights to the source to the natural 6%E blend at 3 μg, with significant decreases in response levels occurring to high %E blends at both dosages. Pre‐exposure of males to E8‐12: Ac alone enhanced their response at each dosage to selected higher %E blends that normally elicited low numbers of completed flights. Pre‐exposure enhanced all aspects of the flight response, but this was dependent on both dosage and duration of pre‐exposure, with later behaviours in the sequence (landing and hairpencil display) requiring greater amounts of pre‐exposure than early behaviour (taking flight). Pre‐exposure did not affect high response levels to optimal blends or low response levels to the highest or lowest blends tested at each dosage. The selective nature of the pre‐exposure effect implied alteration of central processes in discrimination of blend rather than disturbance of olfactory receptor function.

Influence of Pheromone Trap Color on Capture of Lilac Borer Males 123

Color is important in optimizing capture rate of male lilac borers, Podosesia syringae (Harris), in pheromone traps. Significantly more moths were captured with black, brown, or red traps than with other trap colors tested. White traps were consistently poorest. Painting dark-colored traps with a contrasting band did not increase their effectiveness. Although dark-colored Pherocon® 1C traps were up to five times more effective than standard white traps, traps painted on the exterior only failed to catch significantly more borers than did solid white traps. These findings appear to result from attraction and orientation of pheromone-stimulated males to dark shapes, rather than male hesitancy to enter a white trap. The role of visual stiumli in the searching behavior of male clearwing moths is discussed.

Responses of male Mediterranean fruit flies, Ceratitis capitata, to trimediure in a wind tunnel of novel design

ABSTRACT. The responses of male Ceratitis capitata (Wiedemann) (Diptera; Tephritidae) to trimediure were investigated in a wind tunnel of novel design with disposable plastic walls. Trimediure was presented to the flies either in the form of a discrete ‘plume’ or uniformly dispersed in the air passing through the tunnel. The flies showed an increase in flight activity in response to the two forms of stimulation and performed a zig‐zag anemotactic flight in response to the plume, reminiscent of the behaviour of moths responding to a sex pheromone. They performed a straight, upwind, anemotactic response to the uniformly dispersed odour. The design of wind tunnel used in these tests was found to have several advantages: air flow and turbulence can be easily varied and the plastic walls can be changed to eliminate contamination problems.

Surveillance of storage moth species (Pyralidae, Gelechiidae) in a flour mill by adhesive traps with notes on the pheromone — mediated flight behaviour of male moths

Surveillance of storage moth species (Pyralidae, Gelechiidae) in a flour mill by adhesive traps with notes on the pheromone — mediated flight behaviour of male moths

Mating Behavior of Jute Hairy Caterpillar, Diacrisia obliqua WALKER (Lepidoptera : Arctiidae) I : Precopulatory Behavior Patterns in Adults

Experiments were carried out in the laboratory to determine the patterns of adult emergence and mating behavior of jute hairy caterpillar moths. Moths were used from larval rearing on leaves of ground nuts, cowpea, field pea, brinjal, cabbage and artificial diet. The emergence of male moths usually began late in the afternoon and that of female ones began at dusk. Moths after emergence were paired in screen cages before dusk. The female moths more than 12 hr old used to release a brownish fluid from the adbominal tip and assumed typical calling position while clinging to the side walls of the screen cages, 1 or 2 hr before sunset by frequent movement of antennae and wing raising. The assumption of calling position was followed by rhythmical protraction and retraction of the apical abdominal segments 7, 8 and 9. The male moths that emerged in the evening or before midnight most frequently responded to this calling posture of the female moths by stop-gap movement and wing vibrations. The calling behavior ceased at mignight and again commenced 2 or 3 hours before sunrise. The time of mating coincided very closely with that of their emergence. Two peakes of mating were recorded at 1830 and 0400 hr respectively. More than 80% of the pairs copulated before midnight. Maximum mating was observed in the 1st-day-adults. Mating activity ceased after the 2nd-day of emergence and sunrise in both sexes.

Moth Behaviour and Dispersal of the Pine Looper, Bupalus Piniarius (L.) (Lepidoptera, Geometridae)

In studies of the dynamics of insect populations, migration and dispersion are seldom quantified separately but are included in a mortality rate, which refers mostly to the adults. Other studies describing the migration and dispersion of insects seldom explain the consequences they have for the dynamics of the population studied. The aim of this study is to connect these two aspects by describing the behaviour and dispersion of the pine looper moth, Bupalus piniarius L., and by discussing the consequences they have for the dynamics and genetics of a pine looper population. Various aspects of moth behaviour have been studied in the field and in laboratory experiments in which an aktograph has been used to record the flight activity of the moths. In two field experiments marked moths were released at one point in a pine plantation and were recaptured in sex-traps and light-traps at different distances from this point inside and outside the plantation. First a survey of the life of the moths is given, followed by its implications for the population. Males.-From the end of May till July the males emerge between 06.00-09.00 h. After 2.5 hours they fly from the ground to the crowns of the pine trees and during the following hours until about 14.00 h they sometimes fly off taking long periods of rest in between these sorties. In this time their behaviour is strongly affected by sex pheromone released by virgin females. When the male perceives pheromone, it is stimulated to fly against the wind in search for the source of the sex pheromone. If the male finds a virgin female during this period of flight activity it mates with her and after the copulation, which takes on average 2.5 hours, it settles down in the tree-crowns. In the evening, just after sunset, during about 30 min, it has a second period of flight activity, alternating the flights with rests. Apart from the process of emerging, this behaviour is repeated the following days until the male dies at about six days old. During its lifetime the male moves randomly directed through the forest. When it perceives sex pheromone does it fly against the wind. The daily displacement of a male is about 25 m and is the result of the short flights in the morning and evening. During its lifetime the maximum distance it will cover is 150 m. The males tend to stay inside the plantation. Females.-On average females emerge four days later than the males and on the day of emergence they arrive on the ground surface half an hour later than the males. They fly up to the tree crowns one hour later than the males, and settle down directly in the crowns where they start to release sex pheromone, a process they sometimes interrupt briefly by flying. When the female is found by a male they mate and she stops releasing sex pheromone. Half an hour after copulation the female deposits her first eggs on the pine needles in the crown of a tree. Once she has laid a row of eggs she rests a while near the eggs, flies away and then alights to

Hormonal Release of Programmed Behavior in Silk Moths: Probable Mediation by Cyclic AMP

The eclosion hormone triggers a stereotyped preprogrammed pattern of behavior in silk moths. The effects of the hormone were duplicated by the injection of dibutyryl adenosine 3', 5'-monophosphate, adenosine 3', 5'-monophosphate (cyclic AMP), or guanosine 3', 5'-monophosphate (cyclic GMP) into theophylline-treated pharate moths. Treatment with theophylline reduced the latency of the response to a low dose of hormone, presumably by blocking phosphodiesterase. Endogenous levels of cyclic AMP, but not cyclic GMP, increased significantly in the central nervous system within 10 minutes after hormone injection. We conclude that an early step leading to the release of the eclosion motor program is an increase in cyclic AMP in target neurons of the central nervous system.

PRE-MATING SEXUAL ACTIVITY OF GYPSY MOTH MALES IN SMALL PLOT FIELD TESTS (LYMANTRIA (= PORTHETRIA) DISPAR (L.): LYMANTRIIDAE)

AbstractPre-mating behavior of male gypsy moths was investigated in 0.2 ha circular plots containing from 0 to 72 virgin females/plot in untreated areas and in areas treated with an aerial application of 20 g/ha microencapsulated disparlure. Male moths in both treated and untreated plots oriented initially to trees, not directly to females. Mating was disrupted in treated plots but males continued search behavior. No anemotactic behavior was evident in either treated plots or untreated plots with females. In untreated plots, male moths were not caught on sticky panels (panels suspended at 2, 4, and 6 m) higher than pheromone baited traps set at 2 m. In treated plots, equal number of males were caught at all panel heights and in baited traps at 2 m. Previous mating and pheromone exposure histories of males did not affect the response of these males to traps baited with 4–5 mg of disparlure in untreated plots. In a test of the relative attractiveness of a cotton wick and a new laminated bait dispenser in Johnson traps, traps baited with the laminated dispenser had a greater male moth catch/male contact to trap than the traps baited with the cotton wick. Not all males contacting the Johnson trap were caught. A mode of action for disparlure as a disruptive agent in the long range sexual communication system of gypsy moth is proposed.

Sex Pheromones of Lepidoptera. The Influence of Prolonged Exposure to Pheromone on the Behavior of Males of Trichoplusia ni12

When males of Trichoplusia ni were continuously exposed to female sex pheromone, their pheromone-induced activity diminished more rapidly than it did for males exposed to repetitive pulses of pheromone. The males remained partially habituated for at least 15 min following many hours of pre-exposure to either the continuous supply or repetitive pulses of pheromone. When the males were continuously exposed and presumably habituated to pheromone throughout the night, there was no apparent effect on the timing of their flight or feeding behavior. An understanding of the behavior of male moths during and following prolonged exposure to sex pheromones may enhance man's utilization of the pheromones for pest control.

Courtship behavior of phycitid moths. I. Comparison of Plodia interpunctella and Cadra cautella and role of male scent glands

Courtships of the Indian meal moth, Plodia interpunctella, and the almond moth, Cadra cautella, were observed in the laboratory in petri dish arenas. The sequence of behavioral responses which alternate between male and female are released by tactile, visual, and pheromonal stimuli arising from both sexes. The courtship sequences are species specific if males approach females from the rear, but are quite similar if males approach from the front facing the females. For both species the most important feature of courtship is the female's acceptance posture (female stationary with abdomen elevated between wings), which releases male copulatory behavior and facilitates copulation.During courtship, male Indian meal moths release a sex pheromone from wing glands located at the base of each forewing. By completely amputating the female's antennae or the male's forewings including glands, it could be shown that the male pheromone induces the female to remain stationary and adopt the acceptance posture. In the absence of male pheromone, the female actively rejects the courting male and does not mate. These observations are supported by quantitative data. A male pheromone could not be demonstrated for male almond moths but it is argued that a pheromone is probably involved in the courtship of this species as well.

Courtship behavior of phycitid moths. II. Behavioral and pheromonal isolation of Plodia interpunctella and Cadra cautella in the laboratory

Interspecific courtship was observed between the Indian meal moth, Plodia interpunctella, and the almond moth, Cadra cautella. Successful cross-mating did not occur, however, because of the following isolation mechanisms: (1) incompatible courtship behavior, (2) male sex pheromone as a species recognition signal, (3) inhibition of males to female sex pheromone stimulation, and (4) mechanical or physiological barriers to insemination.Male Indian meal moths were strongly excited by calling almond moth females and courted them vigorously. However, because the courtship behavior of this combination was incompatible, copulation did not occur. Occasionally courtship continued to a later stage in the sequence but then the female rejected the male apparently because he releases an inappropriate aphrodisiac from his scent scales.In the reciprocal cross, fully two-thirds of the almond moth males failed to be sufficiently excited by Indian meal moth females to court them. Most of these males were inhibited, as indicated by their subsequent lack of response to pheromone extracts from their own female. Those males which were excited by Indian meal moth females courted them successfully and copulated, but insemination apparently did not occur. In a few cases the females rejected the males, as in the reverse cross.

Physiology of insect ecdysis: neural and hormonal factors involved in wing-spreading behaviour of moths.

ABSTRACT In the tobacco hornworm, wing spreading involves a stereotyped series of movements which take 74 min to complete and which include two components, wing folding and wing inflation. Moths decapitated at the moment of eclosion show neither wing inflation nor wing folding. If decapitation is delayed until 5 sec after emergence, then the full wing-spreading behaviour is displayed. Newly emerged moths which are confined show intense digging-behaviour and delay the onset of wing spreading until after their release. Decapitated moths attempt to spread their wings immediately, regardless of whether or not they are confined. Surgical experiments showed that the brain was not required in a neural capacity in order for wing spreading to occur; it was needed only as a source of the eclosion hormone. The neural influence of the suboesophageal ganglion was required until immediately after eclosion. Newly emerged moths whose abdomens had been removed showed wing-folding behaviour. No inflation occurred and the duration of wing folding was much longer than normal. It was concluded that wing-folding behaviour was centrally programmed but that the abdomen could modify the length of the programme. Injections of bursicon into abdomenless moths reduced the duration of wing-folding behaviour to almost normal levels. Therefore, in some manner, bursicon has an important role in determining when wing-folding behaviour will come to an end.

Circadian Rhythmicity of Sex Pheromone Release by Dioryctria abietella (Lepidoptera: Pyralidae (Phycitinae)) and the Effect of a Diel Light Cycle on Its Precopulatory Behavior1

The extent to which male moths of Dioryctria abietella (Denis and Schiffermuller) passed through successive stages of precopulatory behavior was dependent on the concentration of sex pheronione. Pheronione responsiveness of males and female production of the sex pheromone were influenced by diel cycles of 12 hours of light: 12 hours of darkness (12L: 12D). The quantity of pheronione present on abdominal tips of females decreased during photophase and was maximum 9 hours after onset of scotophase during periods of peak calling activity. The duration of male responsiveness to the pheromone was about twice as long as the period of female release during the 12L:12D photoperiods. Female production and release of the sex pheromone, as well as male responsiveness to the pheromone, were inhibited by light. Periods of locomotor activity and calling behavior of female moths followed a circadian rhythm that appeared to be endogenously timed but strongly entrained to imposed photoperiods.

Role of the corpora cardiaca in the behavior of saturniid moths. II. Oviposition.

1. In females of the Cecropia silkmoth, mating stimulates the rate of egg deposition. 2. When virgin Cecropia are mated to castrated males, they receive an apparently normal spermatophore except that it lacks sperm. Such females show an oviposition pattern corresponding to that of unmated females. Thus, the normal increase in oviposition rate is triggered by the reception of sperm by the female. 3. The corpora cardiaca are shown to be involved in this change in oviposition rate. After the corpora allata are removed from female pupae, the resulting moths respond normally to insemination. After removal of the corpora allata-corpora cardiaca complexes, the ovipositional response to mating is effectively abolished. Reimplantation of up to 5 pairs of corpora allata-corpora cardiaca complexes into pupae lacking their own complexes does not restore the normal oviposition pattern. 4. It is concluded that the increase in oviposition rate is due to a hormone which is produced by the intrinsic cells of the corpora cardiaca. By an apparent reflex mechanism, the presence of sperm in the female's spermatheca causes the brain to trigger the release of the hormone in question from the corpora cardiaca.

MATING FLIGHT BEHAVIOUR IN THREE SPECIES OF ONCOPERA MOTHS (LEPIDOPTERA: HEPIALIDAE)

AbstractField observations were made on the mating and oviposition behaviour of the hepialid moths, Oncopera alboguttata, O. rufobrunnea and O. tindalei. The three species, which are pasture pests in the New England district of New South Wales, have superficially similar behaviour patterns but a number of differences were observed. In particular, the behaviour of O. alboguttata differs from that of the other two species in several respects. The behaviour patterns of the three species are compared with those of O. intricata and O. fasciculata which have been studied by other workers.